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Planted woodland islets can provide seeds for restoring forest ecosystems in Mediterranean old fields lacking seed sources, but other factors than seed arrival can also hinder the establishment of woody species. We experimentally examined factors affecting the emergence, survival, growth and recruitment of holm oak (Quercus ilex) seedlings juveniles from 25-year-old 100-m2 oak woodland islets planted in a Mediterranean old field. Wet springs and summers increased seedling emergence and survival. Distance to the islets per se did not affect seedling performance. However, emergence and survival increased in microsites close to the islets in less sun-exposed orientations of the islets and far from the islets in more sun-exposed orientations. Damage by wild boar reduced emergence, and unsheltered seedlings had 26% lower survival than sheltered ones, reflecting herbivory. Herb community biomass and light reduction by herbs increased with distance from nearest islet; the sparse herb cover around islets was due to competition from woodland islets, not to herbivory. There was a mismatch between the pattern of seedling survival and how the abundance of naturally recruited oaks varied with distance from the nearest islet; this suggests that other drivers can counteract the spatial pattern of seedling survival. We conclude that natural regeneration of Q. ilex in old fields from planted woodland islets is slow (5.7 seedlings ha−1 yr−1) due to acorn and seedling predation, and drought during spring and summer. Despite their small size, planted islets affected survival of oak juveniles depending on the orientation and distance relative to the islets.

Biological invasions are one of the most important threats to Antarctic biodiversity. Springtails (Collembola) make up most of the diversity in soil arthropod communities in Antarctic terrestrial ecosystems. However, the potential range expansion of already established alien springtails and their consequent impacts on Antarctic ecosystems remains largely unknown. Species Distribution Models (SDMs) are a useful tool to identify areas potentially suitable for the geographical spread of alien species that are as yet unoccupied. In Antarctica, however, the application of SDMs is relatively less developed and initially received greater attention in marine rather than terrestrial environments. Here, we implement an ensemble forecasting approach and compute eight modelling algorithms to better understand the geographic distributions and potential range dynamics of four reportedly established alien springtail species (Hypogastrura viatica, Folsomia candida, Mesaphorura macrochaeta and Proisotoma minuta) on the Antarctic Peninsula. Our models identify several ice-free areas across the South Shetland Islands which offer highly suitable environmental conditions for establishment. Thus, biosecurity provisions ought to be reinforced in those sites more vulnerable to invasions. Model predictions of our ensemble SDM approach would benefit from additional field sampling effort across the introduced range and could be complemented with mechanistic models that critically need experimental physiological data to define the fundamental climatic niche of each species.

Members of the Cryptococcus gattii species complex are notorious causes of cryptococcosis as they often cause severe, life-threatening infections. Here we describe a case of a severe disseminated C. deuterogattii infection in a previously healthy patient who was initially treated with amphotericin B, 5-fluorocytosine and fluconazole, which led to a good neurological response, but the infection in the lungs remained unaltered and was not completely resolved until switching the antifungal therapy to isavuconazole. The infection was likely acquired during a one-month stay at the Azores Islands, Portugal. Environmental sampling did not yield any cryptococcal isolate; therefore, the source of this apparent autochthonous case could not be determined. Molecular typing showed that the cultured C. deuterogattii isolates were closely related to the Vancouver Island outbreak-genotype.

Forestry plantations have been established globally to meet timber demands, often leading to the conversion of natural to artificial forests. Forestry plantations may support natural elements of forest biodiversity, but understanding their role in the maintenance of biodiversity is a crucial question. We performed a meta-analysis of 48 studies to determine how forestry plantations relative to natural forests influence the species richness and abundance of three important coleopteran groups (i.e., ground beetles, rove beetles, and dung beetles), given their essential role in ecosystem functioning. We assessed whether beetle responses depended on taxonomic group, geographical location, native or exotic character of the planted tree species, and associated management characteristics (i.e., composition, size, age, and connectivity of the plantations). We found that forestry plantations negatively affected coleopteran species richness and abundance compared to natural forests. The negative impact was most severe in plantations with exotic tree species and located in tropical biomes. Species richness and abundance of beetles significantly increased with plantation age in native plantations but decreased in exotic ones. Also, small plantations close to native forest had higher beetle species richness and abundance than ones located far away from native forest. Stopping the conversion of natural forests to plantations, promoting the use of native tree species, and lengthening rotations are critical for allowing biodiversity recovery in forestry plantations, combined with a robust conservation strategy to protect threatened biodiversity and ecosystem functioning., Hungarian Basic Research Fund, Remedinal, Natural Environment Research Council, Ministerio de Ciencia e Innovación

Multiple myeloma is a genetically heterogeneous cancer of the bone marrow plasma cells (PC). Distinct myeloma transcriptome profiles are primarily driven by myeloma initiating events (MIE) and converge into a mutually exclusive overexpression of the CCND1 and CCND2 oncogenes. Here, with reference to their normal counterparts, we find that myeloma PC enhanced chromatin accessibility combined with paired transcriptome profiling can classify MIE-defined genetic subgroups. Across and within different MM genetic subgroups, we ascribe regulation of genes and pathways critical for myeloma biology to unique or shared, developmentally activated or de novo formed candidate enhancers. Such enhancers co-opt recruitment of existing transcription factors, which although not transcriptionally deregulated per se, organise aberrant gene regulatory networks that help identify myeloma cell dependencies with prognostic impact. Finally, we identify and validate the critical super-enhancer that regulates ectopic expression of CCND2 in a subset of patients with MM and in chronic lymphocytic leukemia., Despite extensive genetic heterogeneity, nearly half of all multiple myeloma (MM) cases are driven by cyclin D2 (CCND2) over-expression. Here the authors dissect the chromatin landscape of MM to provide insights into the transcriptional regulatory landscape driving MM and divergent transcriptomes corresponding to different MM genetic subtypes.

1. For plants with seeds dispersed by scatter-hoarders, decision-making by animals when caching determines the spatial pattern of seed dispersal and lays the initial template for recruitment, driving the regeneration of many species. However, the mechanism by which animal behaviour shapes seed distributions in spatially complex landscapes is not well understood. We investigated caching territoriality and site preferences to determine the spatial pattern of seed caching at different scales and whether scatter-hoarding behaviour drives the spatial distribution of seedling emergence. 2. We used radio-tracking and automatic wildlife cameras to monitor holm oak (Quercus ilex) acorn caching by Eurasian magpies (Pica pica), who are effective scatter-hoarders in agroforestry systems. We assessed the effect of caching territories, distance to seed source, habitat, subhabitat, microsites, and caching material in the spatial pattern of acorn dispersal by magpies. In addition, we analysed the relationship between the density of cached acorns and of emerged seedlings in different habitats. 3. Breeding magpies cached the acorns inside their caching territories, where they preferred tilled areas over oak plantations and mostly avoided old fields. These differences in habitat preference were maximized at relatively short to medium dispersal distances, where most acorns were cached, and decreased or disappeared at long-distances. Within tree plantations, magpies preferred high plant-productivity sites over low productivity ones. At the finest spatial scale, magpies preferred structures built by animals, such as rabbit grit mounds and latrines and ant litter mounds, to cache the acorns. In many sites, magpies selected uncommon materials such as stones and litter to cover caches. In the subsequent spring, seedling emergence was positively correlated with acorn cache density. 4. Synthesis. Scatter-hoarding is a hierarchical process in which caching sites are selected using different criteria at different spatial scales driven by territoriality and site preferences. Territoriality constrained dispersal distance and the habitats available for acorn caching. Magpie territoriality therefore indirectly drives oak seedling emergence and can determine oak recruitment and forest regeneration., CGL2014-459 53308-P (Ministerio Ciencia y Tecnología) PID2019-106806GB-I00 (Ministerio Ciencia e Innovación) S2013/MAE-2719 and S2018/EMT-4338 (Remedinal, CAM) CCG2014/BIO-02 & GP2019-6 (UAH) BES-2015-075276(FPI, MCT)

Recovery of Mediterranean forests after field abandonment is a slow process, even without propagule limitations. This is mainly due to stressful conditions for seedling establishment. In this context, shrubs play a critical role in facilitating tree recruitment, but how this process unfolds after field abandonment is not entirely known. We evaluated the long-term dynamics of facilitation by the nurse shrub Retama sphaerocarpa in the recruitment of two ecologically contrasting oaks, the evergreen Quercus ilex and the deciduous Quercus faginea. Thirty years after field abandonment, we dated shrubs and oak established in an old field to estimate the annual recruitment rates and investigate temporal recruitment patterns. For oaks, we differentiated recruitment at each microsite (i.e., open or under shrub). To assess how nurse shrubs modulated environmental stressors, we modelled oak recruitment as a function of climatic variables. For the evergreen oak, we assessed these effects within each microsite. Finally, we estimated the annual interaction index between shrubs and oak juveniles as a function of climatic conditions.

Biological invasions are one of the major threats to Antarctic native biodiversity and to ecosystems integrity. Regional environmental change and increasing human activity in Maritime Antarctica facilitates the introduction, establishment and colonisation of an increasing number of non-indigenous species. Systematic monitoring is an essential tool for the early detection of the arrival of non-indigenous arthropods. In this study, we compiled the results of a long-term monitoring effort from 2011 to 2017 to survey non-native collembolan species on Deception Island, a highly visited terrestrial site in South Shetland Islands (Maritime Antarctica). Results include the first record of Ceratophysella succinea (Gisin) (Hypogastruridae) in Antarctica. Moreover, the global dataset indicates that the total number and the list of cumulatively occurrence localities for non-native species observed on the island has increased over this monitoring period. This suggests that repeated monitoring is advisable to characterise the full extent of microarthropod introductions into a high biosecurity risk area and improve the effectiveness of surveillance efforts.

Rey Benayas, J.M., Fraile Real, L., de la Torre Ceijas, R., Fernandez, N. 2020. Habitat suitability for Brown bear (Ursus arctos) in the south-eastern Iberian Range. Ecosistemas 29(2):1072. https://doi.org/10.7818/ECOS.1972 The Brown bear (Ursus arctos) is the biggest mammalian carnivore living in Western Europe and an endangered species in Spain. After centuries of decline, all Iberian populations have become extinct except two of them which are currently being recovered. Today, it seems feasible to initiate new conservation strategies to allow the recovery of extinct bear populations and their ecological functions by means of reintroduction programs. The goal of this study was to assess habitat suitability for the species in the south-eastern part of the Iberian Range. Our starting hypothesis predicts that this geographical area has favourable ecological characteristics to harbour a viable population of brown bears. The results point out that land abandonment, forest regeneration, a large forest extension, high habitat heterogeneity, and large natural protected areas network all provide suitable habitat conditions. The assessment of habitat suitability allowed ranking the land of the study area for the establishment of a Brown bear population; ca. 16 000 km2 has high or medium-high habitat suitability values. The most suitable areas included abrupt relief, forests and other vegetation cover types that will provide both refuge and food to brown bears throughout all seasons. This study is a first step towards the evaluation of a future reintroduction of the species into the area, which in following steps would require addressing social acceptance and, ultimately, would depend on bold policy decisions.

Multiple myeloma is a genetically heterogeneous cancer of the bone marrow plasma cells (PC). Myeloma initiating genetic events define subgroups (MIE) and drive distinct oncogenic transcriptomes that converge into a mutually exclusive overexpression of CCND1 and CCND2 oncogenes. Here, with reference to normal PC, we dissect how MIE impact the chromatin regulatory landscape of MM. We find that chromatin accessibility combined with transcriptome profiling classifies myeloma genetic subgroups, while in a topologically constrained manner, distal rather than proximal regulatory elements influence myeloma transcriptomes. Across and within MIE-defined subgroups, genes and pathways critical for myeloma biology can be linked to developmentally activated or de novo formed enhancers. We show that existing transcription factors, co-opted to organise highly ordered, aberrant regulatory networks, generate known and novel myeloma cell dependencies and help identify prognostic markers. Finally, we discover and functionally validate the critical enhancer that regulates ectopic expression of CCND2 in MM.

Different members of the tetraspanin superfamily have been described to regulate different virus infectious cycles at several stages: viral entry, viral replication or virion exit or infectivity. In addition, tetraspanin CD81 regulates HIV reverse transcription through its association with the dNTP hydrolase SAMHD1. Here we aimed at analysing the role of CD81 in Herpes simplex virus 1 infectivity using a neuroblastoma cell model. For this purpose, we generated a CD81 KO cell line using the CRISPR/Cas9 technology. Despite being CD81 a plasma membrane protein, CD81 KO cells showed no defects in viral entry nor in the expression of early protein markers. In contrast, glycoprotein B and C, which require viral DNA replication for their expression, were significantly reduced in CD81 KO infected cells. Indeed, HSV-1 DNA replication and the formation of new infectious particles were severely compromised in CD81 KO cells. We could not detect significant changes in SAMHD1 total expression levels, but a relocalization into endosomal structures was observed in CD81 KO cells. In summary, CD81 KO cells showed impaired viral DNA replication and produced greatly diminished viral titers., BIO2017-86500-R from Ministerio Español de Economía y Competitividad (MINECO) to MY-M and SAF2017-85747-R to MJB as well as USA NIH R01 AI136581 and AI150451 to BK. The institutional grants of Fundación Ramón Areces and Banco de Santander to the Centro de Biología Molecular Severo Ochoa

Barrientos Island is a small islet in the South Shetland archipelago frequently visited by Antarctic tourists. Collembola were recently used in another study developed in this site to assess the environmental conditions of two paths used by visitors, showing the importance of this soil faunal community. This motivated the realization of the first comprehensive census of Collembola from Barrientos Island. Fifty-six samples were recorded over three seasons, 2011–2013, from eight different substrate types. During the last campaign, 39 soil samples were also taken to analyze different physical, chemical, biological, microbiological, and biochemical variables in order to put into relation all these environmental conditions with abundance and richness of Collembola species. A total of ten species were recorded, all of them previously cited from Antarctica. The native species Cryptopygus antarcticus antarcticus Willem (Collembola: Isotomidae) is the most abundant in the island. Two cosmopolitan species—Hypogastrura viatica (Tullberg) (Hypogastruridae) and Mesaphorura macrochaeta Rusek (Tullbergiidae)—were also identified. Many of the species on this island can be considered as eurytopic, appearing in most of the analyzed substrate types. Collembola distribution was found to be influenced by elevation and, to a lesser extent, by phosphorous content and slope. Other variables that are usually cited in the specialized literature did not significantly influence the Collembola distribution in this island. Our results show that the distribution and abundance of Collembola in Antarctic locations is not directly dependent on a single factor. The environmental characteristics of each studied site will determine what factors are driving the composition and structure of this soil community.

Scatter-hoarding animals such as corvids play a crucial role in the dispersal of nut-producing tree species. This interaction is well known for some corvids, but remains elusive for other species such as the magpie (Pica pica), an abundant corvid in agroecosystems and open landscapes of the Palearctic region. In addition, the establishment of the individual dispersed seeds—a prerequisite for determining seed-dispersal effectiveness—has never before been documented for the interaction between corvids and nut-producing trees. We analyzed walnut dispersal by magpies in an agroecosystem in southern Spain. We used several complementary approaches, including video recording nut removal from feeders, measuring dispersal distance using radio tracking (with radio transmitters placed inside nuts), and monitoring the fate of dispersed nuts to the time of seedling emergence. Magpies were shown to be highly active nut dispersers. The dispersal distance averaged 39.6 ± 4.5 m and ranged from 4.1 to 158.5 m. Some 90% of the removed walnuts were cached later, and most of these (98%) were buried in the soil or hidden under plant material. By the time of seedling emergence, ca. 33% of nuts remained at the caching location. Finally, 12% of the cached nuts germinated and 4% yielded an emerged seedling, facilitating the transition to the next regeneration stage. The results demonstrate for the first time that magpies can be an effective scatter-hoarding disperser of a nut-producing tree species, suggesting that this bird species may play a key role in the regeneration and expansion of broadleaf forests in Eurasia., Gobierno de España, Comunidad de Madrid, Ministerio de Economía y Competitividad

The on-going introduction of non-native species to Antarctica due to expanding human activity presents an increasing threat to biodiversity. Under the Protocol on Environmental Protection to the Antarctic Treaty, all introduced non-native species should be removed from the Antarctic Treaty area. The non-native grass Poa pratensis was first introduced to Cierva Point (Danco Coast, Antarctic Peninsula), along with substantial quantities of non-Antarctic soil, in the mid-1950s. Consistent with the Protocol, in January 2015 an internationally coordinated team undertook the eradication of the grass. Immediately prior to removal of P. pratensis, factors affecting its establishment, persistence and impacts upon local indigenous species was examined within the international management framework of the Antarctic Treaty System. The underlying soil had a high organic content of 15.5%, which may have contributed to the successful establishment of P. pratensis and restricted, at least initially, its vegetative growth to the enriched area. Examination of P. pratensis expansion from the original introduction sites showed that the plant colony intricate root system facilitated little or no coexistence of other native plants within its extent. The non-native plant colony also constituted a novel habitat for soil fauna within Antarctic terrestrial environments. The P. pratensis plant colony provided an unfavorable habitat for two of the locally endemic soil invertebrates, Cryptopygus antarcticus and Belgica antarctica. These observations led to the selection of an appropriate eradication approach, where the plants were targeted for physical extraction along with all underlying soil. During the eradication, c. 500 kg of soil and plant material from the P. pratensis colony was removed from the site. Monitoring one year later showed no evidence of re-establishment. Consistent with the Committee for Environmental Protection ‘Non-native Species Manual’, we recommend development and implementation of rapid response protocols following the discovery of a non-native plant colony to limit future impacts on indigenous species and local habitats.

Este trabajo ha sido financiado con fondos de los proyectos CICYT Ministerio de Educación y Ciencia (CGL2007−60533/BOS, CGL2010−18312/BOS) y del Ministerio de Economía y Competitividad (CGL2014−53308−P), de la red REMEDINAL (S−0505/AMB/ 0335, S2009 AMB−1783, S2013/MAE−2719 y TE-CM S2018/EMT- 4338), de la Universidad de Alcalá (CCG2014/BIO−002) y del MAGRAMA y la Fundación Biodiversidad a través de la Fundación Internacional para la Restauración de Ecosistemas. GGS fue financiado con una beca FPU (AP2006−00891) y SMH por una beca FPI (BES−2008−006630), ambas del Ministerio de Educación y Ciencia. LMB fue financiada por una beca FPI (BES-2015-075276) del Ministerio de Ciencia y Tecnología. NM fue financiada por una beca de la Universidad de Alcalá. ABL agradece ayudas postdoctorales Juan de la Cierva (FJCI-2015-23687) y de la Fundación Alexander von Humboldt. Agradecemos la colaboración de la Dirección Xeral de Conservación da Natureza de la Xunta de Galicia por las facilidades para desarrollar las investigaciones realizadas en esta Comunidad y de las bodegas de Abadía Retuerta y Martín Berdugo y de Haciendas Bio. Finalmente, agradecemos la contribución de un revisor anónimo que mejoró la versión original de este artículo., Los elementos que soportan las funciones y servicios de los ecosistemas son insuficientemente conocidos, mermando nuestra capacidad para planificar la conservación, restauración y manejo de los ecosistemas. Entre dichos elementos, el papel de la avifauna es especialmente relevante al ser especies de gran movilidad (high mobile link species) que conectan distintas unidades del paisaje. Este trabajo analiza servicios ecosistémicos importantes dependientes de interacciones biológicas mediadas por la avifauna en mosaicos agroforestales. Abordamos tres objetivos específicos: el papel de (1) los córvidos en la dispersión y reclutamiento de quercíneas, (2) la avifauna insectívora en la regulación de plagas en cultivos leñosos y (3) las aves rapaces en la regulación de avifauna-plaga en viñedos. Nuestros resultados evidencian que la avifauna realiza funciones y servicios claves para la regeneración forestal y la regulación de plagas en mosaicos agroforestales. Identificamos especies que se desconocía que realizaban una función relevante, en particular la urraca (Pica pica), cuya actividad resulta en una dispersión efectiva de nueces y bellotas, y el abejero europeo (Pernis apivorus), con un elevado consumo de avispa asiática (Vespa velutina). La instalación de cajas-nido en cultivos leñosos aumenta las poblaciones de aves insectívoras que regulan plagas; sin embargo, la capacidad de regulación de las plagas es moderada y depende del contexto ambiental o estudio de caso. Las rapaces diurnas existentes en los paisajes estudiados contribuyen al control de plagas agrícolas como la del estornino negro (Sturnus unicolor). Proponemos integrar los servicios que proporcionan las aves en la ordenación del territorio para alcanzar modelos de desarrollo más sostenibles., The elements that support functions and ecosystem services are not well known yet, and this gap reduces our capacity to plan the conservation, restoration, and management of ecosystems. Among these elements, the role of avifauna is especially relevant as birds are high-mobile link species that connect different landscape units. This article analyzes important ecosystem services driven by biological interactions that are mediated by birds in farmland and forest mosaics. We propose three specific goals: to assess the role of (1) corvids in the dispersal and recruitment of oak species, (2) insectivorous birds in pest regulation of woody crops, and (3) raptors in regulation of plague birds in vineyards. Our results show that the avifauna performs key functions and services for forest regeneration and pest regulation in agroforestry mosaics. We identified species that were not known to perform relevant functions, particularly the magpie (Pica pica) and its effective dispersion of nuts and acorns, and the honey buzzard (Pernis apivorus) and its high consumption of Asian black hornet (Vespa velutina). The installation of nest-boxes in woody crops increases the populations of insectivorous birds that regulate pests; however, the capacity of pest control is moderate and depends on the environmental context or case study. The diurnal raptors thriving in the studied landscapes contribute to the control of agricultural pests such as the spotless starling (Sturnus unicolor). We propose to integrate the services provided by birds in landscape planning to achieve more sustainable development systems., Financiado con fondos de los proyectos CICYT Ministerio de Educación y Ciencia (CGL2007−60533/BOS, CGL2010−18312/BOS) y del Ministerio de Economía y Competitividad (CGL2014−53308−P), de la red REMEDINAL (S−0505/AMB/ 0335, S2009 AMB−1783, S2013/MAE−2719 y TE-CM S2018/EMT- 4338), de la Universidad de Alcalá (CCG2014/BIO−002) y del MAGRAMA y la Fundación Biodiversidad a través de la Fundación Internacional para la Restauración de Ecosistemas. GGS fue financiado con una beca FPU (AP2006−00891) y SMH por una beca FPI (BES−2008−006630), ambas del Ministerio de Educación y Ciencia. LMB fue financiada por una beca FPI (BES-2015-075276) del Ministerio de Ciencia y Tecnología. NM fue financiada por una beca de la Universidad de Alcalá. ABL agradece ayudas postdoctorales Juan de la Cierva (FJCI-2015-23687) y de la Fundación Alexander von Humboldt

Source at https://doi.org/10.1002/ece3.2579. The PREDICTS project—Projecting Responses of Ecological Diversity In Changing Terrestrial Systems (www.predicts.org.uk)—has collated from published studies a large, reasonably representative database of comparable samples of biodiversity from multiple sites that differ in the nature or intensity of human impacts relating to land use. We have used this evidence base to develop global and regional statistical models of how local biodiversity responds to these measures. We describe and make freely available this 2016 release of the database, containing more than 3.2 million records sampled at over 26,000 locations and representing over 47,000 species. We outline how the database can help in answering a range of questions in ecology and conservation biology. To our knowledge, this is the largest and most geographically and taxonomically representative database of spatial comparisons of biodiversity that has been collated to date; it will be useful to researchers and international efforts wishing to model and understand the global status of biodiversity.

Forest loss and degradation in the Brazilian Amazon due to mining activities has been intense for many years. To reverse this situation, a range of restoration programs for deforested and degraded areas have been created and implemented. The aim of this study was to analyze the tree composition, successional stage, dispersal and pollination syndromes, conservation status of tree species, and proximity to seed sources under different forest restoration techniques (seedling planting, natural regeneration, and assisted natural regeneration or nucleation) implemented in post-mining sites in the Paragominas municipality (Par&aacute, Brazil). Sixty permanent plots with a restoration age of three years were selected for tree sampling. A total of 119 species, 83 genera and 27 botanical families were identified. Sites restored with different techniques significantly differed in tree composition. Seedling planting sites exhibited the highest abundance, species richness, and diversity values. These were dominated less by pioneer species when compared to the natural regeneration and nucleation sites. Entomophilic pollination and zoochory dispersal were highly represented in the three types of restored sites. Abundance and species richness were negatively correlated with distance from plots to seed sources, and they sharply declined in natural regeneration and nucleation plots at &gt, 250 m from seed sources. Four threatened species were identified in the restored sites. We conclude that a combination of different restoration strategies at three-year-old post-mining restoration sites in the Brazilian Amazon results in the recovery of considerable levels of local tree diversity.

The Antarctic Treaty recognizes the outstanding scientific values of the Antarctic environment through the designation of Antarctic Specially Protected Areas (ASPAs) that have rigorous management plans specific to each site. Deception Island has the largest concentration of rare bryophyte species and communities in Antarctica, while also offering substantial opportunities for research in a range of scientific disciplines due to its volcanic nature. As a result, conflicts between research interests and conservation goals may arise. On the summit ridge of Caliente Hill severe trampling damage to the moss assemblages growing in association with localized geothermal activity was observed. The range of species affected included the entire known population of Schistidium deceptionense, an endemic moss known only from this site, as well as other very rare Antarctic mosses (Ditrichum ditrichoideum, Bryum orbiculatifolium, Bucklandiella subcrispipila, Pohlia wahlenbergii and Dicranella hookeri). A photomapping study was undertaken to characterize further the status of the site and monitor changes within it. Increased awareness, co-ordination of activities and a spatial zoning within the site could help mitigate damage from permitted activities. Nevertheless, prioritization of longer term conservation goals over short-term research interests may ultimately be necessary where local human impact cannot be managed by other means., This study was part of the MIDAH CTM2010-11013 project financed by the Spanish National Polar Programme. Our deepest gratitude goes to Olga LópezHilzinger for her photometric skills and continuous support on producing the photo-assemblages. Thanks also to all the Spanish researchers working in the area for sharing their valuable thoughts. In particular, special thanks to Dr Amos Gil. We are also indebted to Peter Convey for his valuable insight. We are very grateful to Ryszard Ochyra for critical review of the specimens. We also thank Graciela de Diego for field support. LRP was partially supported by a contract associated to the project NICHEAPPS (CGL2014-56416-P) from the Spanish Ministry of Economy and Competitiveness (MINECO)

La restauración ecológica se utiliza a menudo para recuperar los niveles de biodiversidad y de servicios ecosistémicos (SE) en ecosistemas degradados. En general, los resultados de la restauración ecológica se pueden estimar como el progreso o la compleción de la recuperación de indicadores de la integridad ecológica en el estado restaurado respecto al estado degradado o de referencia, respectivamente. Presentamos una síntesis de estos resultados según cuatro meta-análisis globales independientes, obtenidos en una amplia gama de ecosistemas, con énfasis en humedales, agroecosistemas y bosques. La restauración ecológica aumentó la biodiversidad y los SE en 58 y 99%, respectivamente. Sin embargo, estos niveles fueron inferiores a los de los ecosistemas de referencia (-10 y -8%, respectivamente). La recuperación varió entre tipos de ecosistema. Los humedales restaurados tuvieron niveles más altos de biodiversidad y de SE (19 y 43%, respectivamente) en relación a los degradados, aunque los niveles de los SE fueron inferiores (-13%) a los de referencia. La restauración aumentó los niveles de biodiversidad, SE de soporte y SE de regulación de los agroecosistemas en 68, 42 y 120%, respectivamente, y los agroecosistemas restaurados tuvieron niveles de biodiversidad y de estos SE similares a los ecosistemas de referencia. En el caso de los bosques, la recuperación fue completa para todos los SE, mientras que la biodiversidad, aunque aumentó 106% después de la restauración, fue 21% inferior a los niveles de referencia. Existe un hueco en la literatura científica sobre la evaluación cuantitativa de los SE culturales en ecosistemas restaurados. La recuperación de la biodiversidad y de los SE se correlacionaron de forma positiva en las comparaciones de ecosistemas degradados y restaurados en todos los meta-análisis. Concluimos que la restauración ecológica aumenta de forma notable la biodiversidad y los SE, aunque no se alcanzan los niveles de los ecosistemas de referencia, Comunidad de Madrid, Fondo para la Investigación Científica y Tecnológica (Argentina)

Aim: Forest recovery in Mediterranean environments is influenced by factors such as aridity, herbivory and facilitation by shrubs, as well as by seed limitation in the case of highly fragmented forests. How these various factors interact can determine the direction of secondary succession, yet these interactions are poorly understood. We assessed the relative importance of several factors in forest species recruitment in Retama sphaerocarpa (L.) Boiss (Retama) shrublands at different spatial scales. Location: Centre of the Iberian Peninsula. Methods: We surveyed mid- and late successional woody species common in Holm oak forests in 29 Retama shrublands that are distributed along an environmental gradient of increasing aridity and herbivory (regional scale) and are located at various distances from forest patches of different sizes (landscape and local scale). In each Retama shrubland, we analysed the effects of microhabitat (under Retama canopy vs open gaps), aridity, presence of nurse shrubs, herbivory, based on the density of pellet droppings, and propagule pressure, measured as the ratio between the size of forest patches acting as seed sources and their distance to Retama shrubs. Results: Quercus ilex, Asparagus acutifolius and Juniperus oxycedrus were the mid- and late successional woody species most recruited in Retama shrublands. Their frequency, which increased with precipitation, was higher under Retama canopy than in gaps. Differences in Q. ilex recruitment between Retama canopy or gaps increased with rainfall, suggesting a decrease in Retama facilitation effectiveness with increasing aridity. Frequency of recruited oaks increased with the total area of woodland remnants located at 0.5 km did not contribute to recruitment. Conclusions: Presence of the shrub R. sphaerocarpa and dispersal-related processes at local scale are main determinants of the colonization of shrublands by late successional woody species. Preserving Retama shrublands and Q. ilex woodland remnants is therefore crucial for extensive passive restoration of Mediterranean oak forests. However, facilitation by Retama is much weaker when both aridity and herbivory are high, regardless of seed source availability., This study was supported by project CGL2014-53308-P SERAVI of the MINECO and the network Remedinal-3 (S2013/MAE-2719) of the Community of Madrid.

Overexpression of the transcription factor MAF, as a result of its juxtaposition to the IgH enhancer [MAF-translocated t(14;16)], is a myeloma-initiating event in 3-5% of patients with multiple myeloma (MM) and confers a poor prognosis. MAF is also overexpressed in another 40% of cases, often in co-operation with the oncogene MMSET. The mechanisms by which MAF overexpression impacts on the regulatory genome to generate the MAF-driven oncogenic transcriptome and its direct targets are not known. To address this, we employed a multi-layer -omics approach using primary myeloma plasma cells (PC) as well as myeloma cell lines (MMCL). First, we determined the chromatin accessibility and transcriptome profiles of MAF-translocated myeloma by performing ATAC-seq and RNA-seq, respectively, in purified bone marrow CD138+ PC from two patients with t(14;16) and three healthy donors. We identified 6,640 differentially accessible regions, 87% of which displayed enhanced chromatin accessibility in MAF samples compared to normal PC. Secondary analysis comparing this with ATAC-seq data from a set of 28 other MM samples, including hyperdiploid, MMSET and CCND1-translocated MM, revealed 33% of those regions to be MAF subgroup specific (1,949 regions), with the rest shared between MAF and other cytogenetic groups. Gene annotation and pathway enrichment analysis using GREAT confirmed overrepresentation of the MF myeloma patient signature, as previously identified in microarray datasets. RNA-seq detected significant upregulation of approximately 900 genes in MAF samples compared to normal counterparts, including MAF itself (top 4th hit) as well as its presumed targets (CCND2, ITGB7 and NUAK1). Next, we obtained the MAF cistrome using ChIP-seq in the MAF-translocated MMCL MM1.S and integrated it with the primary PC ATAC-seq data. This revealed that 31% (618/1,949) of the differentially accessible regions in MAF-translocated MM PC are also MAF-bound. Additional overlay with ENCODE ChromHMM epigenome map showed that 47% of MAF binding sites are on active enhancers and 42% on active promoters signifying potential direct regulation of the corresponding genes. Next, we superimposed the accessible and MAF-bound loci on the epigenomic landscapes of normal PC and other B-cell types using their corresponding ChromHMM maps (Blueprint consortium data). Interestingly, 56% (345/618) of the MAF-specific regions were not active in any stage of B cell development. This suggests that aberrant MAF overexpression and chromatin binding in PC is associated with de novo activation of these chromatin regions, over half of which (200/345; 58%) are enhancers; we termed these 'neo-enhancers'. Upon de novo motif analysis of MAF ChIP-seq in MAF-translocated JJN3 and MM1.S MMCL, we confirmed MAF as the first and, interestingly, IRF4 as the second top hit, suggesting a possible MAF-IRF4 functional interaction in myelomagenesis. Indeed, overlay of the accessible MAF-bound loci with IRF4 ChIP-seq data in MM1.S revealed 63% co-occupancy (including 62% of "neo-enhancers"), proposing a novel and extensive co-operative chromatin-based network between the two transcription factors. Final integration of the accessible MAF-bound regions with the paired transcriptomes of primary myeloma PC revealed a set 206 candidate enhancer-gene pairs. Strikingly, we identified two IRF4-cobound "neo-enhancers" linked to overexpression of TLR4 and CCR1, two genes known for their roles in myeloma cell proliferation and migration. We confirmed significant downregulation of both genes upon shRNA-mediated knockdown of MAF in the two MAF-translocated MMCL, MM1.S and JJN3, as well as the lethality of MAF depletion. Further, MAF overexpression in MAF-negative myeloma backgrounds led to transcriptional upregulation of these genes, further validating them as MAF targets. While CRISPR/Cas9i experiments targeting TLR4 are ongoing, preliminary results validated the functional role of the "neo-enhancer" in CCR1 gene expression. In conclusion, we demonstrate for the first time an extensive re-organisation of the PC chromatin conferred by oncogenic MAF in MM; we reveal its extensive co-operation with IRF4 in this process; we validate the directly MAF-regulated genes and functionally characterise neo-enhancers of key MAF-dependent genes that in addition to MAF itself are also critical for myeloma biology. Disclosures Hatjiharissi: Janssen: Honoraria. Caputo:GSK: Research Funding. Karadimitris:GSK: Research Funding.

In multiple myeloma (MM), a malignancy of the bone marrow plasma cells (BMPC), hyperdiploidy (HY) and oncogene over-expression via chromosomal translocation [including CCND1- t(11;14), MAF- t(14;16), MMSET-t(4;14)] are the primary myeloma initiating events (MIE) that drive distinct transcriptional programs. These are further shaped by secondary SNV and CNV events. This genetic heterogeneity converges, in most cases, to a functionally dichotomous state of CCND1 or CCND2 overexpression. The molecular mechanisms underlying each of the distinct myelomagenic transcriptomes and the CCND1 vs CCND2 dichotomy have not been defined. To address these questions, we obtained highly purified BMPC from 3 healthy donors and 30 MM patients (HY: 15; CCND1: 4; MMSET: 5; MAF: 2; other: 4), either at diagnosis or relapse, and mapped their chromatin accessibility and transcriptome profiles by ATAC-seq and RNA-seq, respectively. In total, we obtained ~300K regions with accessible chromatin in either MM or normal PC. Overall chromatin accessibility increased in myeloma compared to normal PC, particularly in MAF- and MMSET-translocated subtypes. Analysis of combined ATAC-seq/RNA-seq by Multi-Omics Factor Analysis (MOFA) resulted in a clearer samples distinction than either ATAC-seq or RNA-seq alone, with altered chromatin accessibility accounting for more of the variance than expression. Of the top five identified factors, the top two (one transcriptome driven, one accessibility driven) distinguished normal from MM samples, whilst two more separated MMSET, MAF and CCND1 subgroups. Ninety seven, 157, 256 and 348 overexpressed genes in the CCND1, HY, MMSET and MAF subgroups, respectively, were predicted to be regulated by differentially accessible enhancers. Twenty percent (165/858) of these genes were overexpressed in >1 subgroup suggesting a process of chromatin accessibility-based convergence evolution. Enrichment analysis suggested direct or indirect involvement of Polycomb and chromatin remodellers; significant enrichment was also found for genes involved in neurogenesis. ATAC-seq footprinting predicted binding sites for 250 expressed transcription factors (TFs), 116 of which displayed higher binding frequency in myeloma than in normal PC and included both known (e.g., XBP1, RELA, IRF4, PRDM1) and potentially novel regulators of myeloma biology (e.g., CXXC1 and NFE2L1). The remaining 134 TF were predicted to be present in at least one MM subgroup, but absent in normal PC. Amongst them, as expected, MAF was active in the MMSET- and more so in the MAF-translocated subgroups. DepMap database analysis suggested myeloma cell dependency on 181/250 TF (CRISPR/Cas9 CERES score < -0.1 in >3/14 MMCL analysed). In dissecting the regulatory basis of CCND2 vs CCND1 dichotomy, one MOFA factor completely separated MAF from CCND1 samples, placing extreme opposite weights on the expression of CCND2 and CCND1 respectively. Interestingly, the same factor identified open-chromatin clusters upstream of CCND2 and linked them to its over-expression. These clusters were also open in the MMSET group and in CCND2-expressing HY samples. Conversely, no accessibility was detected in the CCND1 group, the CCND1-expressing HY samples or in normal PCs. Further, super-enhancer calling using the H3K27ac histone mark in MAF-translocated JJN3 cells identified the region of interest as a bona fide super-enhancer. Chromatin long range interactions, as assessed by Capture-HiC, demonstrated high frequency interactions of the CCND2 promoter with the constituent elements of the putative super-enhancer. Experimental validation using a CRISPR/Cas9i system confirmed the functional role of all 4 super-enhancer constituents tested in the regulation of CCND2 expression, while TF footprinting predicted MAF binding to the super-enhancer in MAF-translocated PC. In conclusion, we show that distinct oncogenic transcriptomes in MM are underpinned by extensive chromatin changes, accompanied by TF activity 're-wiring' that does not necessarily require transcriptional deregulation of the TF themselves. We identify novel, non-oncogene TF dependencies that suggest therapeutic opportunities in MM and we discover and characterise the critical super-enhancer that drives overexpression of the CCND2 oncogene in MM. Disclosures Auner: Amgen: Other: Consultancy and Research Funding; Takeda: Consultancy; Karyopharm: Consultancy. Hatjiharissi:Janssen: Honoraria. Caputo:GSK: Research Funding. Karadimitris:GSK: Research Funding.

A single colony of the non-native grass Poa pratensis L., which was introduced inadvertently to Cierva Point, Antarctic Peninsula, during the 1954–1955 season, was still present during a survey in February 2012, making it the longest surviving non-native vascular plant colony known in Antarctica. Since 1991, the grass cover has roughly tripled in size, with an annual increase in area of approximately 0.016 m2, and an estimated maximum radial growth rate of 1.43 cm y−1. However, it remains restricted to the original site of introduction and its immediate surroundings (c. 1 m2). Annual flowering of the plants occurred during the 2010/2011 and 2011/2012 seasons; however, there has been no seed production and only incomplete development of the sexual structures. Current environmental conditions, including low temperatures, may inhibit sexual reproduction. Lack of effective vegetative dispersal may be influenced by the low level of human activity at the site, which limits opportunities for human-mediated dispersal. Although P. pratensis has existed at Cierva Point for almost 60 years, it has not yet become invasive. Scenarios for the potential future development of the species in Antarctica and the associated negative impacts upon the native vegetation from competition are discussed in the context of regional climate change. Finally, we describe the environmental risk presented by P. pratensis and argue that this non-native species should be eradicated as soon as possible in accordance with the Protocol on Environmental Protection to the Antarctic Treaty.

This study explores the impact of human trampling on moss and lichen dominated communities of Maritime Antarctica. A simulation of trampling was performed on previously unaffected plots of different terricolous cryptogamic assemblages at Byers Peninsula, Livingston Island. The communities studied were: 1) a uniform moss carpet, 2) a heterogeneous moss assemblage composed of hummocks and turfs, and 3) a fellfield lichen community. All communities analysed were extremely sensitive but different denudation processes were observed. None of the plots maintained 50% of initial coverage after 200 pedestrian transits. Even very low trampling intensity resulted in disturbance at all plots. Sensitivities of the different communities were identified in order to formulate recommendations for minimizing the trampling impacts. In our study the lichen dominated community on dry exposed soils exhibited the lowest resistance to trampling. For moss communities, lower resistance was found in peat soils with higher water content and biomass. With the current trend of increasing human presence in Antarctica, we predict that the cumulative impacts of trampling over future decades will adversely affect all types of moss and lichen communities.

Seed dispersal effectiveness, which measures the number of adult plant individuals produced by seed dispersal, is the product of the number of seeds dispersed and the probability a seed produces an adult. Directed dispersal to certain habitat types may enhance some stages of recruitment but disfavor others, generating demographic conflicts in plant ontogeny. We asked whether temporal changes in habitat features may affect the distribution of seedlings recruited from dispersed acorns, and whether this could induce shifts in the life-stage conflicts experienced by successive cohorts of naturally recruited plants. As early successional habitats are characterized by rapid change, we used a burnt pine stand in southern Spain to monitor the recruitment and performance of a major tree species (Quercus ilex) across 7 yr in four types of post-fire habitats. These differed in structure and included patches of unburnt forest and three management alternatives of burnt trees: logging, partial cutting, and nonintervention. Young oaks that resprouted after the fire were mainly located near acorn sources, while new seedlings initially emerged mostly in habitats with standing snags due to habitat selection by European jays, Garrulus glandarius, for dispersal. The dead pines gradually collapsed and attracted less dispersal, so subsequent seedling cohorts mainly recruited within patches of unburnt pines. These live pines enhanced the survival of the oaks located beneath their canopy but greatly reduced their growth as compared to the other post-fire habitats, thus representing a demographic conflict that was absent elsewhere. As a consequence of the directional shift in the habitat where seedlings recruited, successive seedling cohorts experienced a gradual improvement in their likelihood of survival but a reduction in growth. The progressive intensification of this life-stage conflict hinged on the reduction of vertical structures in the habitat with standing burnt pines. Recruitment success thus involved temporal variation in the habitat where recruitment occurred, likely resulting from changes in the direction of seed dispersal, and spatial variation in habitat suitability for seedling establishment and growth. Temporal changes in habitat structure can indirectly change the environment in which recruitment occurs, and consequently seed dispersal effectiveness, by shifting the direction of seed dispersal., Ministerio de Ciencia e Innovación, Comunidad de Madrid, Ministerio de Ciencia y Educación

Knowledge on the effects of land use on community composition and species abundance is crucial for designing realistic conservation strategies, particularly in highly dynamic systems such as Mediterranean agricultural mosaics that are subjected to intensive cultivation. We investigated these effects on the nocturnal bird species occurring in the study area (Stone Curlew Burhinus oedicnemus, Red-necked Nightjar Caprimulgus ruflcollis, Barn Owl Tyto alba, Eurasian Scops Owl Otus scops, Little Owl Athene noctua, Tawny Owl Strix aluco, Long-eared Owl Asio otus, Short-eared Owl Asio flammeus and Eagle Owl Bubo bubo) across an agricultural-natural habitat mosaic in Central Spain for three consecutive years. Shares of vineyards, scrubland, herbaceous cropland, water bodies, and roads significantly affected the composition of the nocturnal bird community. Herbaceous cropland and olive groves, which covered 50% of the study area, proved to be neutral for all species. Remnant patches of natural and semi-n...

We analysed the physiological bases that explain why large and high nitrogen (N) concentration seedlings frequently have improved survival and growth relative to small seedlings in Mediterranean woodland plantations. Large seedlings of Aleppo pine (Pinus halepensis Mill.) and holm oak (Quercus ilex L.) with high N concentration (L+), and small seedlings with either high (S+) or low (S−) N concentration, were planted on two sites of different weed competition intensity that created contrasting stress conditions. Seedling survival, growth, gas exchange, N remobilization (NR) and uptake (NU), and water potential were assessed through the first growing season. Weeds reduced survival and growth, but seedling response to weed competition varied among phenotypes and between species. At the end of the first growing season, L+ Aleppo pine seedlings had higher survival than both small seedling types in presence of weeds but no differences were observed in absence of weeds. Mortality differences among phenotypes occurred in spring but not in summer. L+ Aleppo pines grew more than small Aleppo pines independently of weed competition. No holm oak seedling type survived in presence of weeds and no mortality differences among phenotypes where observed in absence of weeds, although L+ holm oak seedlings grew more than small seedlings. Mortality and growth differences in Aleppo pine were linked to marked physiological differences among phenotypes while physiological differences were small among holm oak phenotypes. L+ Aleppo pines had greater root growth, gas exchange, NR, and NU than small seedlings, irrespective of their N concentration. Seedling size in Aleppo pine had a greater role in the performance of transplanted seedlings than N concentration. The functional differences among oak phenotypes were small whereas they were large in pine seedlings, which led to smaller differences in transplanting performance in holm oak than in pine. This suggests that the nursery seedling quality improvement for planting in dry sites could depend on the species-specific phenotypic plasticity and functional strategy. Improved transplanting performance in large Aleppo pine seedlings relative to small seedlings was linked to greater gas exchange, root growth and N cycling.

While many studies have explored how previous and current environmental conditions affect the performance of individual organisms, their relative importance as drivers of current diversity and composition of communities is virtually unknown. We evaluated the response of herbaceous communities to previous (experienced during early establishment) and current environmental conditions by comparing their composition and diversity in an abandoned Mediterranean cropland planted with Quercus ilex subsp. ballota L. seedlings. These seedlings received different experimental treatments (summer irrigation and artificial shading) during the first three years after planting, and were interrupted from then on. We tested two complementary hypotheses: (i) the previous environments experienced by the herbaceous communities during their establishment have a long-term carry-over effect on diversity and composition of species assemblages and (ii) these communities are influenced by their current environment, particularly by the woody layer and the soil conditions. Overall, we observed an important contribution of initial environmental conditions in determining the current diversity and composition of herbaceous communities. Amelioration of environmental conditions, particularly water stress, during community establishment resulted in a decrease in alpha and beta diversity, possibly as a consequence of decreasing environmental heterogeneity. Previous environments accounted for 26.3% of the explained variance in current community composition. Annuals, legumes and forbs also responded significantly to previous environments, which explained 27.9%, 36.2% and 30.1%, respectively, of the variance in their composition. Our results suggest that those species present at a particular site early in succession pre-empt the site and influence vegetation dynamics on that site for a long time. This study provides important insights for understanding the mechanisms underlying the ecological effects of issues like cropland reforestation and woody vegetation encroachment.

Living organisms respond both to current and previous environments, which can have important consequences on population dynamics. However, there is little experimental evidence based on long-term field studies of the effects of previous environments on the performance of individuals. We tested the hypothesis that trees that establish under different environmental conditions perform differently under similar post-establishment conditions. We used the slow-growing, evergreen Mediterranean oak Quercus ilex subsp. rotundifolia as target species. We analyzed the effects of previous environments, competition effects and tradeoffs among life-history traits (survival, growth, and reproduction). We enhanced seedling establishment for three years by reducing abiotic environmental harshness by means of summer irrigation and artificial shading in 12 experimental plots, while four plots remained as controls. Then these treatments were interrupted for ten years. Seedlings under ameliorated environmental conditions survived and grew faster during early establishment. During the post-management period, previous treatments 1) did not have any effect on survival, 2) experienced a slower above-ground growth, 3) decreased root biomass as indicated from reflectivity of Ground Penetration Radar, 4) increased acorn production mostly through a greater canopy volume and 5) increased acorn production effort. The trees exhibited a combination of effects related to acclimation for coping with abiotic stress and effects of intra-specific competition. In accordance with our hypothesis, tree performance overall depended on previous environmental conditions, and the response was different for different life-history traits. We recommend early management because it increased plot cover, shortened the time to attain sexual maturity and increased the amount of acorn production. Plots such as those assessed in this study may act as sources of propagules in deforested agricultural landscapes thus aiding natural establishment of new plants.

We tested how the conditions resulting from alternative management strategies addressed to mitigate abiotic and biotic limitations to plant establishment affect the performance of planted Quercus coccifera seedlings. This species is a xerophytic and heliophillous Mediterranean shrub, of interest for the restoration of abandoned farmland. We hypothesised that release from herb competition by clipping would allow Q. coccifera seedlings to cope more efficiently with water shortage by adjusting their mass allocation pattern. We established three environments of herb competition: absence of competition (AC), reduced competition by clipping (RC), and total competition (TC); and applied two irrigation treatments: low and high irrigation. We measured soil moisture at different depths, above- and below-ground herb biomass, and evaluated seedling responses, such as mortality, growth, biomass allocation, and morphological and physiological features. The TC treatment reduced water availability more than the RC treatment, in agreement with the highest water stress of seedlings under TC conditions. Irrigation increased above- and below-ground herb biomass, whereas clipping reduced herb production. Release of herb competition by clipping increased seedling survivorship by one order of magnitude and resulted in a growth rate comparable to the absence of competition. This growth was mostly related to carbon gain allocated to roots. The competition intensity imposed by treatments was related to a parallel reduction in total plant leaf area, biomass allocated to leaves and shoot:root ratio, and an increase in biomass allocated to roots and leaf mass area. The negative effects of herbs on Q. coccifera seedlings seem the result of competition for both water and light, in contrast with previous research with more mesic Quercus species, for which competition is primarily for water. Clipping of herbs is a feasible technique that greatly improved seedling performance, and thus a valuable alternative to herbicide application, common in native plantations aimed at restoring Mediterranean farmland.

Las figuras y material suplementario que contiene el documento se localizan al final del mismo., Planted woodland islets act as sources of seed that may accelerate woodland development in extensive agricultural landscapes. We assessed a 1-ha plot that was planted with 16 100-m2 islets of holm oak Quercus ilex subsp. ballota seedlings near Toledo (Spain) in 1993. In spring 2014 we measured (1) acorn predation and (2) seedling emergence from seeded acorns at different distances from and orientations around the islets with half of the acorns protected to prevent predation, (3) survival of emerged seedlings, and (4) natural tree establishment outside of the planted islets. Most (96.9 %) unprotected acorns were removed or predated. Seedling emergence from protected acorns ranged from 42.9 % on the northern side of the islets to 13.2 % on the southern side, suggesting a less stressful microclimate on the northern side. Survival of naturally established seedlings was 28.6 % by the end of first summer; seedling mortality was chiefly due to drought (45.0 %) and herbivory (35.0 %). Density of emerged seedlings, surviving seedlings after first dry season, and established oaks >1-year old was similar at different distances from the islets. Over the 21 year time period, 58 new oak individuals >1-year old have established (an average of 3.3 established individuals per ha per year) at an average distance of 6.3 ± 5.4 m away from the closest islet. We conclude that initial oak regeneration triggered by small planted islets in Mediterranean abandoned farmland is slowed down by high acorn predation, seedling herbivory, and stressful microclimatic conditions. Regardless, these islets are a viable tool for regeneration of Mediterranean oak woodland., Projects from the Spanish Ministry of Science and Education (CGL2010-18312 and CGL2014-53308-P) and the Government of Madrid (S2013/MAE-2719, REMEDINAL-3) are currently providing financial support for this body of research. We are indebted to Aurora Mesa and Paula Meli for their help for acorn seeding and to Laura Ferna´ndez and Luis Cayuela for their input with some statistical analyses. The subject editor and two anonymous reviewers provided valuable comments on a former version of this manuscript.

A large proportion of European biodiversity today depends on habitat provided by low‐intensity farming practices, yet this resource is declining as European agriculture intensifies. Within the European Union, particularly the central and eastern new member states have retained relatively large areas of species‐rich farmland, but despite increased investment in nature conservation here in recent years, farmland biodiversity trends appear to be worsening. Although the high biodiversity value of Central and Eastern European farmland has long been reported, the amount of research in the international literature focused on farmland biodiversity in this region remains comparatively tiny, and measures within the EU Common Agricultural Policy are relatively poorly adapted to support it. In this opinion study, we argue that, 10 years after the accession of the first eastern EU new member states, the continued under‐representation of the low‐intensity farmland in Central and Eastern Europe in the international literature and EU policy is impeding the development of sound, evidence‐based conservation interventions. The biodiversity benefits for Europe of existing low‐intensity farmland, particularly in the central and eastern states, should be harnessed before they are lost. Instead of waiting for species‐rich farmland to further decline, targeted research and monitoring to create locally appropriate conservation strategies for these habitats is needed now., Volkswagen Foundation

Afforestation programs such as the one promoted by the EU Common Agricultural Policy have spread tree plantations on former cropland. These afforestations attract generalist forest and ubiquitous species but may cause severe damage to open habitat species, especially birds of high conservation value. We investigated the effects of young (, Ministerio de Ciencia y Educación, Comunidad de Madrid, Fundación Internacional para la Restauración de Ecosistemas

Virologic failure seems to occur more frequently in HIV-infected patients treated with triple nucleoside analogue (NA) combinations than with regimens including nonnucleoside reverse transcriptase inhibitors or protease inhibitors. However, the rate of failure and resistance profiles may differ with distinct triple NA combinations. A retrospective review of all HIV-infected individuals who received triple NA combinations at our institution was conducted. Virologic failure was defined as lack of achievement of plasma HIV-RNA50 copies/ml at week 16 following initiation of antiretroviral therapy or as viral rebound in subjects with prior undetectable viremia. Genotypic analyses were performed at the time of first virological failure. Of the 261 patients identified, 13 were drug naive, 126 had underwent simplification, and 122 were antiretroviral-experienced patients with detectable viral load. Virologic failure was recorded in 95 (36.4%) after an average follow-up of 19 months. Rates were 0.67 in drug-naive, 0.55 in simplification, and 2.38 in rescue interventions for 100 persons-month follow-up. Factors associated with virologic failure in the multivariate Cox regression analysis were rescue vs naive or simplification strategies (OR 2.6; 95% CI 1.6-4.2) and using tenofovir as part of the combination (OR 2.04; 95% CI 1.3-3.2). In contrast, the use of AZT prevented virologic failure (OR 0.52; 95% CI 0.3-0.8). M184V was the most frequent resistance mutation (75.4%), followed by T215Y (52.5%) and K65R (14.8%). Of note, K65R did not develop in patients taking AZT nor in those with prior thymidine-associated mutations (TAMs). Conversely, subjects who developed K65R did not accumulate TAMs. Virologic failure is relatively frequent in patients treated only with triple NA regimens, particularly in the setting of rescue therapy. The use of TDF might be associated with a higher risk of virologic failure and, conversely, AZT might be protective. The presence of TAMs precluded the selection of K65R in patients treated with TDF. Resistance pathways for TDF and thymidine analogues seem to be divergent and could be the basis to explore a synergism between these drugs.

Background Cyclosporiasis is a disease due to Cyclospora cayetanensis , an emerging coccidian parasite first described in 1979. It is an orally transmitted disease that is more frequent in tropical and subtropical areas. Cyclospora cayetanensis has been mainly described as a cause of travelers’ diarrhea. This pathogen has given rise to a number of epidemic outbreaks attributable to ingestion of imported foods, particularly from tropical areas. Methods Descriptive study of clinical and epidemiological data of a small epidemic outbreak of C cayetanensis –induced gastroenteritis. Results Seven confirmed cases of C cayetanensis among Spanish nationals who had traveled to Antigua Guatemala are described. The incubation period was 6 days. Diarrhea, asthenia, anorexia, borborygmi, flatulence, and abdominal distension were present in all cases. Fever and heart burn in 85.7%. Weight loss in 71.4%. Abdominal pain, rectal tenesmus, and nausea in 42.8%. Vomiting and eructation in 14.2%. Heart burn was a frequent symptom, a finding not often previously described. The infection was probably acquired from raspberry juice. All cases improved with trimethoprim/sulphametoxazol. Conclusions Cyclosporiasis is a cause of travelers’ diarrhea. Parasitology laboratories must be advised of clinical suspicion of cyclosporiasis so that they can conduct a suitable targeted study; otherwise, false negative results may arise.

Secondary succession was studied in a Mexican cloud forest region along a chronosequence of 15 abandoned pastures (0.25–80 y). Our objective was to determine the effects of distance from the forest border on successional vegetation structure and woody species richness along the chronosequence. Vegetation structure similar to that of mature forests recovered over 40–50 y, both close to (0–10 m) and away from (40–50 m) the border. Total woody species richness was similar for both distances but species composition differed significantly. When primary forest species were analysed separately, basal area, height, abundance and richness were all significantly higher close to the forest border. Primary species such as Quercus spp. (barochorous-synzoochorous) and Carpinus caroliniana (anemochorous) had lower basal area, density and height away from the border than close to it. Secondary species such as Lippia myriocephala (anemochorous) and Myrsine coriacea (endozoochorous) did not differ in their rate of colonization between distances. The limitation of seed dispersal and establishment for primary woody species away from forest borders suggests that propagules need to be introduced to accelerate forest restoration.

The processes underlying the positive effect exerted by woody species on other plant species can be grouped into a physical effect due to the canopy itself (mainly amelioration of temperature and light extremes), and an edaphic effect (nutrient enrichment). Both groups of effects are present in the savanna-like systems originated by Retama sphaerocarpa in the Iberian Peninsula. The consequences of these shrubs for the spatial heterogeneity induced in the herbaceous community are not well known. The herbaceous community was sampled by means of radial transects around 20 adult shrubs, from the canopy centre to the open areas among the shrubs, both northwards and southwards. Floristic composition, diversity and pasture mean height change both along the inside–outside gradient, and from north to south. As a nutrient enriched environment, the centre of the understorey showed the lowest species richness and evenness, and the highest standing crop. In contrast, the environmentally stressful open areas showed the highest number of species and evenness, and the lowest standing crop. This general effect is only partially due to nutrient availability, and is not homogeneous around the shrub, as open area conditions penetrate into the understorey driving the herbaceous community towards that of open areas. An individual shrub effect is also suggested by our results. Different conditions are thus provided by R. sphaerocarpa understoreys, favouring different subsets of species from the general pool, and therefore defining shrub canopies as sources of spatial heterogeneity in the whole savanna-like system.

The combination of didanosine (ddI) and tenofovir (TDF) has potential advantages, but because of several pitfalls (unexpected decreases in CD4+ T cells, increased risk of pancreatitis) its use has been questioned. Since anecdotal cases of transient insulin-dependent diabetes mellitus were seen in our clinic in patients on ddI + TDF-containing regimens, we explored the rate of this complication in more detail. Retrospective analysis of plasma glucose levels in patients who completed 12 months of treatment with three different triple antiretroviral regimens including ddI + TDF, TDF, or ddI was done. Patients taking antidiabetic drugs and/or those with baseline glucose levels >125 mg/dl were excluded. Weight, age, concomitant antiretrovirals, and ddI dose were assessed. At 12 months without treatment changes, fasting glucose levels were compared to baseline. A multivariate analysis was performed to evaluate which variables were associated with glucose elevations. A total of 177 HIV-infected patients were assessed (78 on ddI + TDF, 42 on TDF, and 57 on ddI). Mean baseline features were well balanced between groups for age (mean, 39 years), gender (78% male), CD4+ count (mean, 507 cells/mm3), weight (mean, 67 kg), and glucose level (mean, 95 mg/dl). There were only significant differences between groups for baseline viral load and protease inhibitor (PI) use (13% in the ddI + TDF arm vs. 7% and 9% in the TDF and ddI arms, respectively). At 12 months, 60% of the patients in the ddI + TDF arm were taking ddI 250 mg/day and the rest were on ddI 400 mg/day. At 12 months, hyperglycemia was significantly more frequent in the ddI + TDF arm (33%) when compared to patients on TDF or ddI separately (5% and 10%, respectively). In the multiple linear regression analysis, a lower weight (beta -0.35; 95% CI -0.67 to -0.03; p = 0.033) and use of ddI + TDF (beta: 13.05; 95% CI: 0.2 to 26; p = 0.047) were independently associated with a higher risk of developing hyperglycemia. The risk of hyperglycemia is increased in patients treated with ddI + TDF, particularly in those with lower weight. As high ddI exposure has been associated with endocrine pancreatic dysfunction and diabetes, ddI "overdosing" as result of concomitant TDF use and low weight might explain our findings. These results add a further note of caution to the use of TDF and ddI in combination.

Large areas of abandoned cropland in the world can be reforested with native shrubs and trees to gain a number of environmental benefits. In abandoned Mediterranean croplands, establishment and growth of woody plants are limited by high radiation and low water availability during summer, and weeds are strong competitors for resources, particularly water. We conducted a 3-year experiment in central Spain to study the response of three Quercus species (Q. coccifera, Q. ilex and Q. faginea) that differ in their habitat requirements under four treatment field conditions resulting from the combination of full-light versus artificial shading and weed presence versus weed mowing. We measured seedling survival, resprouting capability and growth, weed production, microclimate (incident photosynthetic active radiation (PAR), air temperature, soil water evaporation and effective precipitation) and soil moisture. Shading and weeds reduced PAR reaching the seedlings and soil water evaporation, and shading also reduced effective precipitation. Shading and mowing increased soil moisture. We found a clear positive synergic effect of shading and mowing on seedling performance. Weed competition limited seedling survival in all species more than high radiation, whereas the relative importance of these factors in limiting growth depended on the growth measure and species. As hypothesised, the effects of stress release on plot cover, an integrated performance index that combines survival and growth, were most noticeable in Q. faginea, the most mesic species, and least in Q. coccifera, the most xerophytic species. The release of weed competition allowed Q. ilex seedlings to invest resources in above-ground and, apparently, in below-ground growth. Shading increased simultaneous growth in diameter and volume only for Q. faginea. It is important that planted Quercus seedlings in abandoned Mediterranean cropland take advantage of a low competitive environment from weeds during the period before the first dry season. Once seedlings have established, an artificially shaded environment would provide benefits in terms of plot cover by the oaks, particularly for mesic species. Studies like this will be of great interest to optimize resource investment in active restoration of other ecosystems of the world.

In revegetation projects, distinguishing species that can be passively restored by natural regeneration from those requiring active restoration is not a trivial decision. We quantified tree species dominance (measured by an importance value index, IVIi) and used abundance‐size correlations to select those species suitable for passive and/or active restoration of disturbed riparian vegetation in the Lacandonia region, Southern Mexico. We sampled riparian vegetation in a 50 ×10‐m transect in each of six reference (RE) and five disturbed (DE) riparian ecosystems. Those species representing more than 50% of total IVI in each ecosystem were selected, and Spearman rank correlation between abundance and diameter classes was calculated. For eight species, it was determined that passive restoration could be sufficient for their establishment. Another eight species could be transplanted by means of active restoration. Five species regenerate well in only one ecosystem type, suggesting that both restoration strategies could be used depending on the degree of degradation. Finally, two species were determined to not be suitable for restoration in the RE (based on the above selection criteria) and were not selected during this initial stage of our restoration project. The high number of tree species found in the RE suggests that the species pool for ecological restoration is large. However, sampling in both ecosystem types helped us reduce the number of species that requires active restoration. Restoration objectives must guide the selection of which methods to implement; in different conditions, other criteria such as dispersal syndrome or social value could be considered in the species selection.

Physical factors that may account for regional patterns of plant species diversity remain controversial. We aim to determine the relationship of tree species diversity to environmental factors identifiable at regional scale in the northern Neotropics. We use a high-resolution data set based on herbarium collections of all native tree species known to occur in the highly diverse and physiographically heterogeneous Mexican state of Chiapas. We analyzed 114 grid cells (5 min latitude /5 min longitude each) with 40 or more vouchers. We obtained from maps (scale 1:250 000) data on temperature, rainfall, elevation, and soils, and calculated for each grid cell mean actual evapotranspiration (AET), its ratio during the rainy and dry seasons (RET), average fertility/quality of soils (SFQ), and elevation (coarse-scale topography) variance (SDE). These variables were largely independent of each other, and were entered in multiple regression models to predict species diversity assessed with Simpson’s index of concentration. A model that accounted for 41.4% of the total variance in tree diversity showed positive effects of AET and seasonality (RET), whereas SFQ had a negative effect. A curvilinear model described well the relationship between tree diversity and AET (R 2 /0.45), and an intermediate maximum was detected. The data pattern suggested an asymptotic relationship as well, which was confirmed with a two-part regression. Regression quantiles provided better estimates of the effect of SFQ with the upper envelope of the data (0.85/0.90 quantiles). Minimum diversity at intermediate rainfall values hints at a bimodal model of tree diversity along a rainfall gradient, in opposition to the frequent contention of a positive linear relationship. We suggest that broad-scale climatic gradients interact with intraregional landscape-level influences, thus leading to the observed nonlinear responses of tree diversity to environmental predictors.

Retama sphaerocarpa is a Mediterranean shrub that when adult, facilitates the establishment of herbaceous plants under its canopy. We test the hypothesis that during the establishment of R. sphaerocarpa seedlings, the interaction with the herbaceous plants is negative. We carried out a greenhouse experiment in which seedlings of R. sphaerocarpa were grown under different conditions of competition with herbs, watering and date of emergence. Measurements of seedling mortality, biomass and growth were taken during the first growing season. We found a significant relationship between R. sphaerocarpa seedling mortality and competition in early spring, presumably due to higher water demand of herbaceous plants. Generally, presence of herbaceous species, lower availability of water and late emergence had negative effects on biomass and growth of Retama seedlings. Additional water compensated for the negative effects of competition, except on leaves and cladodes of Retama seedlings, suggesting that other resources, such as light, could be the subject of competition. In contrast, Retama seedlings exerted a positive influence on the herbaceous plants by increasing their survival and biomass, probably as a consequence of the high availability of nutrients provided by the Rhizobia nodules in the roots of Retama seedlings. We concluded that, at the regeneration stage of the shrub, the interaction between the herbaceous vegetation and the shrub is negative for the shrub and positive for the herbs. This suggests a shift from competition to facilitation with age of Retama, as reciprocal positive interactions have been described between herbaceous plants and adult individuals of the shrub. © 2004 Elsevier SAS. All rights reserved.

Resveratrol (RES), a natural phytoalexin, has antiproliferative activity in human-derived cancer cells and in rodent models of tumor development. We have previously shown that RES induced apoptotic death in estrogen-responsive MCF-7 human breast cancer cells. Recent data have indicated that the estrogen receptor-α (ERα), through interaction with p85, regulates phosphoinositide 3-kinase (PI3K) activity, revealing a physiologic, nonnuclear function of the ERα potentially relevant in cell proliferation and apoptosis. In our study, using MCF-7, we have analyzed the ability of RES to modulate the ERα-dependent PI3K pathway. Immunoprecipitation and kinase activity assays showed that RES increased the ERα-associated PI3K activity with a maximum stimulatory effect at concentrations close to 10 μM; concentrations >50 μM decreased PI3K activity. Stimulation of PI3K activity by RES was ERα-dependent since it could be blocked by the antiestrogen ICI 182,780. RES did not affect p85 protein expression but induced the proteasome-dependent degradation of the ERα. Nevertheless, the amount of PI3K immunoprecipitated by the ERα remained unchanged in presence of RES, indicating that ERα availability was not limiting PI3K activity. Phosphoprotein kinase B (pPKB/AKT) followed the pattern of PI3K activity, whereas RES did not affect total PKB/AKT expression. PKB/AKT downstream target glycogen synthase kinase 3 (GSK3) also showed a phosphorylation pattern that followed PI3K activity. We propose a mechanism through which RES could inhibit survival and proliferation of estrogen-responsive cells by interfering with an ERα-associated PI3K pathway, following a process that could be independent of the nuclear functions of the ERα. © 2003 Wiley-Liss, Inc.

We tested simulated effects of herb competition on the performance of planted seedlings of Quercus faginea ssp. faginea in Mediterranean abandoned cropland. We produced three types of environment with respect to herb competition: absence of competition (AC), below-ground competition (BGC), and total competition (TC). We assessed the performance of Q. faginea seedlings in each treatment in five ways: (1) seedling mortality, (2) leaf length and total plant leaf area, (3) water potential, (4) total biomass and biomass allocation, and (5) non-structural carbohydrate storage in different plant organs. We also measured (6) soil moisture at different depths and (7) biomass production of herbs. The TC treatment reduced water availability more than the BGC treatment, in agreement with the most pronounced water stress in seedlings under TC conditions. BGC and TC treatments showed a high and similar seedling mortality, which was one order of magnitude higher than that in the AC treatment. Competition treatments affected glucose concentration in both shoots and roots, and followed the rank TC > BGC > AC. Q. faginea seedlings might compensate a lower water availability through glucose accumulation in leaves to reduce the osmotic potential. There was a maximum starch concentration in the BGC treatment that hints that a moderate resource limitation would limit tissue growth but not carbon assimilation. We conclude that the negative effects of herbs on Q. faginea seedlings are mostly a result of competition for water, and that this competition is noticeable since the earliest stages of the establishment. Complete weed removal is a technique that would strongly improve seedling survivorship., This research has been funded by the projects Factores limitantes de la revegetación con especies leñosas autóctonas de áreas degradadas en ambientes mediterráneos. Rendimiento de distintas actuaciones de manejo (REN2000-745), granted by the CICYT (Spanish government) and Estrategias para la restauración de paisajes degradados en zonas secas (E040/2001), granted by the Universidad de Alcalá. We are indebted to the students Olivier Pastre and Antoine Aubeneau for their assistance in field and lab work. We acknowledge the comments on a preliminary version of this manuscript from our colleagues Fernando Valladares, Pedro Villar, and Miguel A. Zavala. Peter Buckley and an anonymous reviewer improved its final version.

Retama sphaerocarpa is a leguminous shrub whose important role in the semi-arid regions of south-eastern Spain has already been assessed: shrub canopies reduce light intensity, and thus evapotranspiration; also their extensive radical system take water and nutrients from great volumes of soil, concentrating them in the understorey. Consequently, subcanopy vegetation benefits from these facilitation processes, increasing its productivity. However, these shrublands have been rarely studied at a broader scale, i.e. as a savannah-like system composed of a variable number of shrubs scattered in a herbaceous matrix. As the microenvironmental conditions associated to the understorey are rather different from those of the open spaces among shrubs, species composition of the herbaceous matrix is expected to change accordingly. Thus, R. sphaerocarpa would be an important and still unknown source of spatial heterogeneity to the system. Our main purpose was to evaluate, through the soil seed bank, the heterogeneity in the herbaceous community induced by this shrub species. Soil samples were collected around adult shrubs from three positions relative to the canopy: near the centre of the shrubs, at the edge of the understorey, and completely outside the canopy. Floristic composition was evaluated by germination under greenhouse conditions. The results show that each position has a different floristic composition, characterised by a group of different species. The herbaceous species associated with the external position have functional traits which enable them to resist water stress and herbivore pressure, such as hairs, CAM metabolism, early flowering, horizontal growth or tiny stature. The species associated with the central position lack those traits, and are more competitive in more mesic environments, rich in nitrogen. The lowest number of seedlings and species was found in the internal position, suggesting that in our study the facilitation process may have less importance for community dynamics due to less stressful environmental conditions.

Large amounts of former cropland are being abandoned in developedregions. To formulate guidelines for land reclamation programmes, we exploredthe effects of artificial shading, irrigation, and removal of weed competitionon the performance of Retama sphaerocarpa (L.) Boiss.seedlings in a factorial experiment located in an abandoned cropland in CentralSpain. R. sphaerocarpa is of interest for revegetationbecause it is a drought tolerant leguminous shrub that is a major structuralcomponent of the native plant community. Seedling performance was evaluated inthree ways: seedling survivorship, growth, and photochemical efficiency. Wealsomeasured soil moisture and weed biomass production and found that bothincreasedunder artificial shading conditions. Soil moisture increased very slightlywhereweeds were removed. Thus, increased transpiration from weeds outweighed reducedevaporation from soils due to shading by weeds. Artificial shading was the mosteffective treatment for seedling survivorship, followed by removal ofcompetition by weeds. After summer, 34 % of the seedlings survived in the mostfavourable conditions (artificially shaded plots where weeds were removed),compared to ca. 1 % in full-light plots with no removal of weed competition. Apositive effect of irrigation was found for growth of seedling cover and heightin shaded plots. The analysis of photochemical efficiency pointed out therelevance of weed competition removal, and confirmed the usefulness of fastfluorescence transient techniques for the quantification of seedlingperformance. The data suggest that competition between seedlings and weeds wasprimarily for water rather than for light. We conclude that i) artificialshading improved seedling performance, but this is a little practical techniquebecause of its cost; ii) as weeds compete with, rather than facilitate, plantedseedlings, weed clipping around the seedlings is a feasible technique thatwouldimprove seedling survival; and iii) seedling performance could alsoconsiderablyimprove with a higher irrigation than was used in this experiment(75lm−2 per growth period), provided that weedsare removed.

A small-scale field study was conducted to explain seedling emergence and recruitment of reproductive individuals in a four-year-old Mediterranean annual plant community. The analyzed levels were populations, functional types, and total number of individuals in the community. We hypothesized that the number of germinable seeds positively affects the number of emerged seedlings, which positively affects the number of reproductive individuals. We hypothesized as well that litter mass, biomass of established adults, and number of non-conspecific emerged seedlings negatively affect the numbers of emerged seedlings and reproductive individuals. The results supported our multivariate causal explanation of plant recruitment, although concordances with the initial hypotheses were more frequent at the community level. The effect of the number of germinable seeds on the number of emerged seedlings was found to be robust only at the community level. At the population level, this relationship did not have a consistent tendency and depended on species identity and range of seed density experienced. Litter had negative effects on total number of individuals in the community, and usually non-significant effects at the population level. Litter effects were found to be inversely related to seed mass, and sharper cotyledons did not improve seedling emergence likely by favoring litter mat penetration. Interactions among plant species appeared not to have any effect on seedling emergence and survival, and had positive effects on certain populations. Biomass of established adult plants exerted no influence on seedling emergence and survival, probably due to their low abundance in this community during the germination period. Results permitted the inference of the main stages in the recruitment process and causal factors. They provided evidence for the greater importance of germination and emergence in comparison with seedling survival to insure reproductive recruitment in this community.

Can the interaction of episodic and chronic distur- bances explain the maintenance of savanna-like patterns? We explored the morphological and spatial patterns of the leguminous shrub Retama sphaerocarpa in a Mediterranean environment in relation to disturbance. Various morphological variables of R. sphaerocarpa shrubland were found to be deter- mined by a combination of two types of disturbance: (1) mechanical cutting: an episodic, heavy, short-term distur- bance of anthropogenic origin for management purposes, and (2) herbivore activity primarily by rabbits: generally a chronic, more lenient, long-term disturbance. The intensities of these two types of disturbance were not correlated. Me- chanical cutting effects on R. sphaerocarpa shrubland mor- phology predominated quantitatively over herbivore effects. Herbivores generally produced open shrubland with fewer, more scattered, thicker branched, l arger R. sphaerocarpa shrubs. In contrast, intense sprouting after cutting produced a higher density of smaller R. sphaerocarpa shrubs with denser aerial biomass. However, heavy herbivory in abnormally dry peri- ods produced some effects similar to those of mechanical cutting. The size of R. sphaerocarpa shrubs was positively related to seed production. Thus, the means of propagation depended upon the type of disturbance: episodic disturbances resulted in intense sprouting, whereas chronic herbivore activ- ity resulted in the formation of thick branches that produced a large number of seeds. The combination of these two distur- bances determine, in part, space occupancy patterns of domi- nant woody species in this Mediterranean landscape and simi- lar savanna-type ecosystems. Investigations of environmental constraints on vegetation distribution and abundance should take into account the historical role of herbivores in shaping present systems.

We sampled red fir ( Abies magnifica ) clearcuts of various age to identify site factors that predict successful regeneration. During three field seasons, 113 clearcuts were sampled in five national forests along the western slope of the Sierra Nevada between 37 and 40°N latitude. They were 4–32 years old and 2028 ha in area, had slopes of 3–30° that cumulatively faced all directions, and were situated on slope faces that ranged from concave, convex, constant, to mixed. We recorded the cover of all herbs, shrubs, and tree saplings, and the density of saplings by age class. A total of 208 taxa were encountered. Both red fir regeneration (represented by sapling cover) and invasiveness (the reciprocal of clearcut age minus average red fir sapling age) were maximum on gentle, northeast-facing, concave slopes; in clearcuts with maximum edge (the ratio of perimeter to area); and a relatively high latitudes and relatively low elevations. Both shrub and herb cover were positively correlated with red fir regeneration, indicating that management suppression of these species is not necessary. Microclimate models showed that regeneration, invasiveness, and canopy growth were most negatively correlated with daily summer insolation and most positively correlated with late snow melt, the latter resulting from deep snowpacks and/or late snow melt on north-facing slopes. In general, abundant natural red fir regeneration occurred only after a post-logging lag phase of 12 years.

En Europe, de nombreuses terres agricoles ont ete boisees. La politique agricole de l'Union europeenne subventionne actuellement la transformation de terres cultivees en foret avec une attention speciale accordee aux especes feuillues. Pour evaluer les pratiques de boisement, nous avons analyse la croissance et la survie de 800 plants de Quercus ilex sub-espece ballota sur une ancienne terre agricole soumise aux conditions climatiques semi-arides du climat mediterraneen du Centre de l'Espagne. Apres plantation, la survie et la croissance des plants ont ete suivies pendant trois ans. Le dispositif incluait quatre combinaisons : 1) irrigation ou non irrigation pendant la saison seche, 2) ombrage artificiel ou non ombrage. Les traitements ont differe en evapotranspiration potentielle (ETP) (p < 0,0002) et evapotranspiration reelle (ETR) (p < 0,0001). Ces traitements ont induit des differences dans la production d'adventices (p < 0,0001) lesquelles etaient uniquement affectees par l'irrigation. L'irrigation, l'ombrage et l'interaction entre l'irrigation et l'ombrage ont induit un effet positif sur la survie des plants (valeurs-p plus petites que 0,007, 0,0007 et 0,01 respectivement). Les plus grandes differences en terme de survie des plants sont apparues au cours de la fin de la premiere saison seche. La survie ne differait cependant pas de facon significative entre les traitements d'irrigation, d'ombrage et combine. En revanche, chacun des trois traitements ont induit de maniere significative moins de mortalite que le temoin. La forte survie des plants du traitement irrigue non ombrage coincidait avec une forte couverture des adventices (Amaranthus retroflexus L.) au cours de la premiere annee. Des effets significatifs des traitements sur la croissance des plants ont ete notes: p < 0,002 pour le diametre de la tige, et p < 0,0001 pour la hauteur et la surface projetee du houppier (SPH). L'effet de l'ombrage etait significatif pour toutes les mesures de croissance (p < 0,003 diametre de la tige et p < 0,0001 pour la hauteur et la SPH). L'irrigation seule a eu un effet significatif sur le diametre de la tige (p < 0,03) et l'interaction entre l'irrigation et l'ombrage a produit un effet significatif sur la croissance en diametre (p