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Wild insects provide pollination services in agroecosystems. Avocado is an economically important crop grown in the Chilean Mediterranean climate region and exported worldwide. Avocado pollination is managed using honeybee hives, while the role of wild insects as pollinators remains poorly known. We quantified the relative contributions of wild floral visitors and honeybees to the fruit set of avocados in two contrasting seasons (2015 and 2016) in Central Chile. Observations were made in 60 trees grown nearby (~300 m) to remnant patches of native sclerophyll vegetation. We found that honeybees and wild insects accounted for 48.6% and 51.4% of total floral visitation, respectively, with a 68% taxonomic similarity of floral visitors between seasons. The presence of honeybees significantly modulated the floral visitor composition and modified plant-pollination network parameters, which resulted in the biotic homogenization of the interaction network, through the increase of shared tree–floral visitor interactions, to the detriment of exclusive interactions. Finally, wild insects were more effective than honeybees in pollinating avocado trees and their contribution was greatest during the dry year. Thus, honeybees alone cannot be relied upon to deliver maximum pollination. We highlight ecological intensification practices to encourage wild insect visits and avoid native vegetation replacement with orchards. Therefore, we emphasize that future ecological intensification research should address agricultural practices to promote wild insects and evaluate the role of native vegetation as wild pollinator habitat in agricultural landscapes.

Different conceptions of disturbance differ in the degree to which they appeal to mechanisms that are general and equivalent, or species‐, functional group‐, or interaction‐specific. Some concepts of disturbance, for example, predict that soil disturbances and herbivory have identical impacts on species richness via identical mechanisms (reduction in biomass and in competition). An alternative hypothesis is that the specific traits of disturbance agents (small mammals) and plants differentially affect the richness or abundance of different plant groups. We tested these hypotheses on a degu (Octodon degus) colony in central Chile. We ask whether native and non‐native forbs respond differently to degu bioturbation on runways versus herbivory on grazing lawns. We ask whether this can explain the increase in non‐native plants on degu colonies. We found that biopedturbation did not explain the locations of non‐native plants. We did not find direct evidence of grazing increasing non‐native herbs either, but a grazing effect appears to be mediated by grass, which is the dominant cover. Further, we provide supplementary evidence to support our interpretation that a key mechanism of non‐native spread is the formation of dry soil conditions on grazing lawns. Thus, ecosystem engineering (alteration of soil qualities) may be an outcome of disturbances, in which each interacts with specific plant traits, to create the observed pattern of non‐native spread in the colony. Based on these results, we propose to extend Jentsch and White (Ecology, 100, 2019, e02734) concept of combined pulse/ disturbance events to the long‐term process duality of ecosystem engineering/ disturbance., Non‐native plant species accumulate on the centers of native degu (Octodon degus) colonies. We show that this is the result of the interaction and accumulation of two kinds of disturbances (biopedturbation and herbivory) with different effects on plant species over time. Although disturbance is usually represented as different from, or indeed opposite to, ecosystem engineering, we show that ecosystem engineering best explains the outcome of these two disturbances over time.

Biosphere reserves have among their functions to support scientific research, education, training and monitoring. In the Cape Horn Biosphere Reserve (RBCH), created in 2005, these functions have been accomplished with the creation of the Omora Ethnobotanical Park in 2000, and its implementation in 2008 as a co-founder site of the Chilean Network of Studies Long-term Socio-Ecological (LTSER-Chile). In 2016, this network has been strengthened with the addition of the new Cape Horn Long-Term Socio-Ecological Research Network (LTSER-Cape Horn). The latter includes the Omora Ethnobotanical Park, and three new sites added to the monitoring of the sub-Antarctic Magellanic ecoregion of South America. From south to north, the four sites are: (1) Gonzalo Island (56°31’S; 68°43’O), at the southern end of the Diego Ramirez archipelago, with sub-Antarctic vegetation dominated by grasses and cryptogams, devoid of woody species; (2) Horn Island (55°58’S; 67°13’O), at the southern end of the Cape Horn Islands archipelago, hosting the southernmost forest ecosystems on the planet, which are dominated by Magellan’s coigue (Nothofagus betuloides); (3) Omora Ethnobotanical Park (54°56’S; 67’40’O), Navarino Island, an ideal site for studies on climate change and its impact on biota and sub-Antarctic ecosystems, since it protects a watershed that includes a representative mosaic of characteristic habitats of the RBCH in an altitudinal gradient with a thermal decrease analogous to that which occurs with increases in latitude; and (4) Caleta 2 de Mayo Site (54°52’S; 68’41’O), Yendegaia Bay, in an ecotonal zone between evergreen and deciduous forests (product of the local climate gradient), at a site that will be central to future connectivity between Continental Chile, Tierra del Fuego, Navarino Island, and the RBCH. In 2015, UNESCO approved the Report of the First Periodic Review of the RBCH that proposed the protection of the Diego Ramirez Archipelago and the creation of the Diego Ramirez Islands Marine Park-Drake Pass (creation decree published in the Diario Oficial of Chile in January 2019). In this context, the new LTSER-Cape Horn network acquires great local, national and global relevance. At the local scale, it covers a representative environmental heterogeneity of the great diversity of landscapes and terrestrial, freshwater and marine ecosystems of the RBCH and the sub-Antarctic Magellanic ecoregion. At the national scale, it incorporates sub-Antarctic monitoring sites, located at the southern end of South America, to LTSER-Chile and to the Monitoring Network of the Ministry of the Environment. On a global scale, the terrestrial ecosystems of the LTSER-Cape Horn network stands out for two main reasons: (1) these sub-Antarctic ecosystems lack a geographical replicate in the southern hemisphere, and (2) high latitude ecosystems are especially sensitive to global climate change. Thus, the LTSER-Cape Horn network helps to overcome critical geographical gaps in the implementation of the International Network for Long-Term Ecological Research (ILTER). In order to articulate these four sites and strengthen the training of technical capacities and knowledge transfer to decision makers in the area of special interest tourism and other sustainable economic activities, the LTSER-Cape Horn network will be managed locally from the new Cape Horn Sub-Antarctic Center (Cape Horn Center) that will be inaugurated in Puerto Williams in 2020. The implementation of the LTSER-Cape Horn network is based on a close collaboration with various actors: Ministry of National Assets, Ministry of Environment, Subsecretary of Fisheries and Aquaculture of the Ministry of Economy Development and Tourism, National Forestry Corporation (CONAF), General Water Directorate of the Ministry of Public Works, Navy of Chile, Chilean Police (Carabineros), Municipality of Cape Horn, Provincial Government of Chilean Antarctica, and the Regional Government of Magallanes and Chilean Antarctica. In the following phases, the LTSER-Cape Horn network and the Cape Horn Center aim to strengthen the participation of the local community, especially the Yahgan Indigenous Community of Bahia Mejillones, artisanal fisheries, tour operators, and the educational community, including private actors. Located at the “southern summit” of the Americas, Puerto Williams, capital of the Chilean Antarctic Province emerges as a global hub for transdisciplinary sub-Antarctic research, equipped with a new center and network of long-term socio-ecological studies. Collaboration with regional, national and international actors will allow the LTSER-Cape Horn network and the Cape Horn Center to: (i) provide critical data, which will open up new opportunities for monitoring climate change and its impact on biodiversity and ecosystems in sub-Antarctic latitudes; (ii) consolidate long-term monitoring, which is an essential component to effectively design mitigation and adaptation actions; (iii) strengthen a local sustainable development model that, associated with the Cape Horn Biosphere Reserve, contributes from the south of the world, to a biocultural conservation model that meets the needs of socio-economic well-being and environmental sustainability at multiple regional and planetary scales.

We argue that the need for a quality seed supply chain is a major bottleneck for the restoration of Chile's native ecosystems, thus supplementing the list of bottlenecks proposed by Bannister et al. in 2018. Specifically, there is a need for defining seed transfer zones, developing standards and capacities for properly collecting and storing seeds, reducing information gaps on seed physiology and longevity, and implementing an efficient seed supply chain with certification of seed origin and quality. Without such capacities, countries are unlikely to meet their restoration commitments. Although we focus on bottlenecks in Chile, the issues we raise are relevant to other countries and thus the global agenda for ecological restoration.

Mediterranean central Chile is globally recognized as a hotspot for terrestrial biodiversity due to its high endemism and massive habitat loss. However, within the rural landscape of central Chile, significant extents of natural areas remain, especially on less productive, steep slopes, and vegetation strips extending from the surrounding hills to agricultural areas. Accordingly, vegetation strips or corridors, within lowland farms, constitute key elements to support the conservation of biodiversity in rural landscapes. To assess the ecological performance of corridors in 22 commercials vineyards in central Chile, we characterized them in terms of width-, length-, area-, and perimeter-to-area ratios, as well as the number of connections with natural areas. Based on a set of previously defined ecological indicators (species, functional groups, and structural components), we compared their occurrence in corridors within vineyards and in the surrounding natural areas. We evaluated the effects of corridor attributes on the occurrence of the selected ecological indicators, using a generalized linear mixed model with each vineyard as a random factor. The area, width, and length of vegetation corridors varied widely (1.2–86.3 ha, 10.5–95 m, and 380–5000 m, respectively). We found significant differences in the occurrence of indicators between corridors and natural areas. All sampled ecological indicators in corridors showed a negative relationship with the distance to the nearest natural area. Vegetation strips within vineyards represent important opportunities for biodiversity conservation that significantly enhance habitat quality in the agricultural landscape for biodiversity and habitat connectivity.

Several species of the family Orchidaceae have limited distribution and small populations, in which the probability of extinction is much higher than in broadly distributed species. As orchid seeds are very small and lack energy reserves, they require association with compatible mycorrhizal fungi that provide nutrients and carbon needed for germination and early development. Therefore, identification of putative orchid mycorrhizal partners is essential for the design of conservation strategies for these species. We investigated the mycorrhizal associations of two endangered rare species of orchids, Bipinnula apinnula and B. volckmannii, and compared our results with the mycorrhizal associations of two broadly distributed species of Bipinnula. We isolated mycorrhizal fungi and directly amplified DNA from colonized root segments and found an extremely low diversity of mycorrhizal fungi. The rarefaction curves of rare species populations saturated at a single OTU, showing a highly specialized association and considerably lower diversity than the other two species of Bipinnula. Nevertheless, symbiotic germination experiments with fungal strains of this specific fungal OTU only reached the stage of seed coat rupture in both orchid species, without formation of protocorms. Our results suggest that seeds may require additional treatment for successful germination and that fungal partners isolated from adult plants may not be the same that support the germination of seeds. Further studies are needed to improve germination of thiese orchid species and to contribute to their conservation.

Economic development of rural people is not always feasible along with concomitant forest restoration, especially when meager reforestation incentives are oriented to poor rural people who probably are not willing to plant native species in their small plots of land. Forest restoration incentives have been created by the Chilean government to engage poor rural people in reforestation using native tree species to recover degraded lands. Our objective was to compare the willingness of people from rural communities to plant native species if they had to bear the costs or if the government did, and we related the answers to environmental and socioeconomic variables. Of the 217 respondents 53.9% were interested in planting native trees if subsidies became available. Interest decreased if the respondents had to pay for the cost, but only slightly. The willingness to reforest was significantly greater at lower distance from the community to the nearest native forest for those with lower income level, and was higher when there was use of nontimber forest products or wood by the respondents. However, in spite of the positive disposition to plant native trees, only 23% of the respondents were interested in planting on their own land, which is a requirement to receive the economic incentives. Most respondents were willing to plant in open sites and on degraded hillsides that surround their communities. We conclude that despite monetary incentives, benefits cannot reach most rural inhabitants because of their lack of interest in reforesting their own land.

Peatlands are characterized by their large carbon (C) storage capacity and represent important C sinks globally. In southern Chile, young peatlands (few centuries old) have originated due to clearcutting or fire at forest sites with high precipitation on poorly drained soils. These novel ecosystems are called anthropogenic peatlands here. Their role in the regional C cycle remains largely unknown. Here, we present 18 months of eddy covariance measurements of net ecosystem exchange (NEE) of carbon dioxide (CO2) in an anthropogenic peatland in northern Chiloe Island, part of which is kept undisturbed for 30–40 years, by excluding human uses, and another section of the same peatland that has been disturbed by cattle grazing and Sphagnum moss extraction. Gross primary productivity (GPP) and ecosystem respiration (Reco) were modeled from NEE, based on measured photosynthetically active radiation and air temperature, separately for each section of the peatland. Uncertainties of the annual flux estimates were assessed from the variability of modelled fluxes induced by applying different time-windows for model development between 10 and 20 days. The undisturbed area of the peatland was on average (± SD) a larger net CO2 sink (NEE = − 135 ± 267 g CO2 m−2 year−1) than the disturbed area (NEE = − 33 ± 111 g CO2 m−2 year−1). These NEE CO2 balances are small even though GPP and Reco were larger compared with other peatlands. Reco had a direct relationship with water table depth (from soil surface) and a negative relationship with soil water fraction. Our results show that the disturbance by moss extraction and cattle grazing is likely to reduce the CO2 sink function of many anthropogenic and natural peatlands on Chiloe Island, which are subjected to the same impacts.

Ecosystem functions in forests can vary significantly after disturbance, depending on changes in vegetation structure during succession and soil biophysical characteristics. We examined streamflow regulation, water storage and soil protection functions in small catchments covered by evergreen temperate rain forests, developed over volcanic ash soils, in southern South America. Our aims were to understand the differences in ecosystem functioning among catchments representing different forest stages following human disturbance, from scrubland to old-growth forest condition. In these catchments (n = 3 per condition), we assessed and compared eco-hydrological functions over 21 months. In old-growth (OG) forest catchments, streamflow for the entire study period averaged 2102 ± 110 mm, followed by secondary forest (SF) catchments with an average of 1770 ± 284 mm and finally scrub catchments (CH) with 1684 ± 267 mm. Evapotranspiration showed higher values in SF catchments (643 mm), followed by CH catchments (612 mm) and OG catchments (346 mm). OG and CH catchments had the lowest sediment export in streamflow, without statistical difference between them, while SF catchments had the highest sediment concentrations in all seasons of the year. Principal component analysis revealed that soil physical properties, vegetation structure and catchment morphometry were all relevant to explain the differences among the three forest successional stages compared. We validate the hypotheses that streamflow regulation and soil water storage capacity are greatly enhanced in old-growth forests, while the soil protection function is maximized in both early (bamboo-dominated) and advanced forest stages.

BackgroundSecondary foundation species (FS) are organisms that inhabit ecosystems structurally defined by a primary foundation species, providing additional structure to habitats and communities. Trash-basket epiphytes (TBE) are secondary FS that enhance arboreal soil accumulation, providing shelter to animals, and rooting sites for plants. While their importance may vary across biomes, TBE have been overlooked as drivers of biodiversity and ecosystem functions. Here, we discuss the prevalence of TBE across biomes, their effects on biodiversity and ecosystem functions, and future research directions.MethodsWe performed a systematic literature review of articles, books and theses and collated and synthesised information about the taxonomic distribution of TBE, their effects on ecosystem functions, and reports of plant-animal and plant-plant interactions. Then, we analysed the global distribution of TBE using a generalized linear model and summarised two studies to assess their effects on soil invertebrates.ResultsWe identified 120 publications describing 209 species of TBE. Most TBE belong to Araceae (43%), Polypodiaceae (23%), and Orchidaceae (14%) and occur in all tropical and southern temperate forests. TBE richness peaks in the South-American Pacific mangroves, Eastern Cordillera Real, and the Napo moist forests. TBE effects on ecosystem functions include arboreal soil accumulation, water retention and temperature regulation in the canopy, and nutrient leaching through stem-flow. TBE provide shelter to species in more than 97 animal families, including from invertebrates to mammals, while 72 vascular plants have been reported to root in arboreal soil of TBE.ConclusionsTBE are a compelling group of model organisms that can be used to study ecological processes such as facilitation cascades, niche construction, extended phenotypes, or the effects of secondary FS on biodiversity and ecosystem functioning. TBE should also be included in forest management plans to enhance the availability of microhabitats in the canopy supporting its associated flora and fauna.

Global afforestation/deforestation processes (e.g., Amazon deforestation and Europe afforestation) create new anthropogenic controls on carbon cycling and nutrient supply that have not been fully assessed. Here, we use a watershed-lake dynamics approach to investigate how human-induced land cover changes have altered nutrient transference during the last 700 years in a mediterranean coastal area (Vichuquen Lake). We compare our multiproxy reconstruction with historical documentation and use satellite images to reconstruct land use/cover changes for the last 45 years. Historical landscape changes, including those during the indigenous settlements, Spanish conquest, and the Chilean Republic up to mid-20th century did not significantly alter sediment and nutrient fluxes to the lake. In contrast, the largest changes in the lake-watershed system occurred in the mid-20th century and particularly after the 1980s-90s and were characterized by a large increase in total nitrogen and organic carbon fluxes as well as negative shifts in sediment δ15N and δ13C values. This shift was coeval with the largest land cover transformation in the Vichuquen watershed, as native forests nearly disappeared while anthropogenic tree plantations expanded up to 60% of the surface area.

Globally, soils store two to three times as much carbon as currently resides in the atmosphere, and it is critical to understand how soil greenhouse gas (GHG) emissions and uptake will respond to ongoing climate change. In particular, the soil‐to‐atmosphere CO2 flux, commonly though imprecisely termed soil respiration (R S), is one of the largest carbon fluxes in the Earth system. An increasing number of high‐frequency R S measurements (typically, from an automated system with hourly sampling) have been made over the last two decades; an increasing number of methane measurements are being made with such systems as well. Such high frequency data are an invaluable resource for understanding GHG fluxes, but lack a central database or repository. Here we describe the lightweight, open‐source COSORE (COntinuous SOil REspiration) database and software, that focuses on automated, continuous and long‐term GHG flux datasets, and is intended to serve as a community resource for earth sciences, climate change syntheses and model evaluation. Contributed datasets are mapped to a single, consistent standard, with metadata on contributors, geographic location, measurement conditions and ancillary data. The design emphasizes the importance of reproducibility, scientific transparency and open access to data. While being oriented towards continuously measured R S, the database design accommodates other soil‐atmosphere measurements (e.g. ecosystem respiration, chamber‐measured net ecosystem exchange, methane fluxes) as well as experimental treatments (heterotrophic only, etc.). We give brief examples of the types of analyses possible using this new community resource and describe its accompanying R software package., Here we describe the lightweight, open source COSORE (COntinuous SOil REspiration) database and software. COSORE focuses on automated, continuous and long‐term greenhouse gas flux datasets, and is intended to serve as a community resource for earth sciences, climate change syntheses and model evaluation.

Scientific interest in traditional and local knowledge (TLK) has grown in recent decades, because of the potential of TLK for improving management and conservation practices. Here, we synthesize and evaluate TLK studies in Chile, discuss how this progress compares to the international scientific literature in the field, and contextualize our results according to the multiple evidence base approach. We found 77 publications on the subject, a steady increase since 1980, and a peak production in the 1990s and the 2010s decades. Publications most often provide basic information on species names and lists of resource uses in terrestrial rather than marine ecosystems. Papers had an emphasis on natural, rather than social sciences. Work was concentrated on the extreme northern and southern regions of Chile where more indigenous populations are found. Indigenous ethnic groups received greater attention than non-indigenous people. Future work in Chile must broaden its attention to local and urban communities and focus on how TLK can contribute to management and sustainability, rather than only acquiring the basic knowledge contained in local and traditional communities. To better comprehend TLK’s contribution to policy measures, an interdisciplinary approach must be present to address these knowledge gaps.

During the last decades, climate and land use changes led to an increased prevalence of megafires in Mediterranean-type climate regions (MCRs). Here, we argue that current wildfire management policies in MCRs are destined to fail. Focused on fire suppression, these policies largely ignore ongoing climate warming and landscape-scale buildup of fuels. The result is a 'firefighting trap' that contributes to ongoing fuel accumulation precluding suppression under extreme fire weather, and resulting in more severe and larger fires. We believe that a 'business as usual' approach to wildfire in MCRs will not solve the fire problem, and recommend that policy and expenditures be rebalanced between suppression and mitigation of the negative impacts of fire. This requires a paradigm shift: policy effectiveness should not be primarily measured as a function of area burned (as it usually is), but rather as a function of avoided socio-ecological damage and loss., This work was financed by national funds through FCT—Foundation for Science and Technology, within the scope of project PCIF/AGT/0136/2017 (People&Fire: reducing risk, living with risk) and PTDC/AGR-FOR/2586/2014 (RurIntFIre: Fire in the Rural-Urban Interface: characterisation, risk mapping, and fuel break design). FM was funded through contract IF/01053/2015 (FCT). JMCP was supported by the Forest Research Centre, a research unit funded by Foundation for Science and Technology I.P. (FCT), Portugal (UID/AGR/00239/2019). PF work was carried under project UID/AGR/04033/2019 supported by FCT. JMM acknowledges funding from Ministerio de Ciencia, Innovación y Universidades (project CGL2016-78357-R)

Plant spatial patterns in semiarid environments are often driven by a patchy availability of resources. We examined here drivers of forest patterns in a landscape where tree and shrub patches coexist in an herbaceous matrix on fog-inundated coastal hilltops in semiarid Chile, aiming to identify factors that set off forest patch formation and development. We hypothesized that a successional process driven by plant-plant interactions would start when tree seedlings establish in shrub patches, eventually leading to resource accumulation and increased diversity. Within shrub patches, soil moisture increased with increasing cover of a common shrub, Baccharis vernalis, unlike another shrub species, Griselinia scandens. Soil nutrients increased with patch size, but soil moisture remained similar among patches. Forest patches showed differences regarding soil moisture between wet windward and dry leeward edges, and these were associated with differences in community composition. While Baccharis patches were similar to windward forest edges, leeward edges were more similar to open areas. Patterns of species richness and diversity showed a shift in plant-plant interactions from positive to negative along successional transition from Baccharis to forest patches. Outside forest patches, tree species are rare but become established and survive under Baccharis vernalis, most likely thanks to a combination of fog-interception capacity, soil nutrient availability and low competition. Therefore, forest patch formation is strongly dependent on fog water interception and community composition. While some shrubs like Baccharis vernalis facilitate tree establishment and eventually initiate new forest patches, others compete with tree seedlings preventing establishment. Hence, a facilitation-competition balance between shrubs and trees explains the spatial arrangement of the forest-shrub patch mosaic in this semiarid environment.

The Mediterranean region of central Chile is experiencing extensive “mega-droughts” with detrimental effects for the environment and economy of the region. In the northern hemisphere, nitrogen (N) limitation of Mediterranean ecosystems has been explained by the decoupling between N inputs and plant uptake during the dormant season. In central Chile, soils have often been considered N-rich in comparison to other Mediterranean ecosystems of the world, yet the impacts of expected intensification of seasonal drought remain unknown. In this work, we seek to disentangle patterns of microbial N transformations and their seasonal coupling with climate in the Chilean sclerophyll forest-type. We aim to assess how water limitation affects microbial N transformations, thus addressing the impact of ongoing regional climate trends on soil N status. We studied four stands of the sclerophyll forest-type in Chile. Field measurements in surface soils showed a 67% decline of free-living diazotrophic activity (DA) and 59% decrease of net N mineralization rates during the summer rainless and dormant season, accompanied by a stimulation of in-situ denitrification rates to values 70% higher than in wetter winter. Higher rates of both free-living DA and net N mineralization found during spring, provided evidence for strong coupling of these two processes during the growing season. Overall, the experimental addition of water in the field to litter samples almost doubled DA but had no effect on denitrification rates. We conclude that coupling of microbial mediated soil N transformations during the wetter growing season explains the N enrichment of sclerophyll forest soils. Expected increases in the length and intensity of the dry period, according to climate change models, reflected in the current mega-droughts may drastically reduce biological N fixation and net N mineralization, increasing at the same time denitrification rates, thereby potentially reducing long-term soil N capital.

Premise of the study Plant responses to past climate change could have been shaped by life-history traits. Here we explore the influence of life form on the response of xerophytic plants to Quaternary climate fluctuations, through a comparison of genetic patterns of codistributed herbaceous and shrubby lineages of the genus Nolana. Methods We reconstructed the phylogeographic history of a herbaceous lineage of three species of Nolana distributed from a northern arid zone (30°S) to a southern wet-temperate (42°S) zone, by sequencing two cpDNA regions. Results were compared with similar data published earlier for a congeneric, codistributed shrubby lineage. Key results We detected significant genetic differentiation among populations. Divergence of all haplotypes occurred during the Pleistocene, between 245 and 62 kyr ago. For both the shrubby and herbaceous lineages, the greatest haplotype diversity was found in their northern range. However, herbs also retained some diversity at higher latitude. Herbaceous populations were less genetically structured and less differentiated than shrubby ones. Conclusion Genetic evidence revealed that both lineages of Nolana survived climate change through the Quaternary, experiencing population collapses and recoveries. Phylogeographic histories present similarities between the two lineages, but also marked differences that can be explained by their differences in life form and life cycle. While the shrubby lineage followed the classical pattern of postglacial expansion toward higher latitudes, species in the herbaceous lineage showed evidence of long-lasting persistence at the southern edge of their current range, suggesting for the first time multiple glacial refugia for a xerophytic plant in southern South America.

Countries that are signatories of the Convention of Biological Diversity are committed to the goal of protecting 17% of their natural ecosystems by 2020. The lack of an up-to-date, operational classification and cartography of regional ecosystems seriously limits the assessment of progress towards this goal. Here, we present a broad ecosystem framework, which combines land use, functional traits of dominant plant species, and climatic factors for the classification of terrestrial ecosystems and apply this framework to classify Chilean terrestrial ecosystems. This new classification is consistent with the recently proposed IUCN framework to assess ecosystem conservation status. Using this framework, we identified and described 30 Chilean terrestrial ecosystems, including land units of natural and anthropogenic origin. We also provide a cartographic representation of ecosystems for land planning purposes and an overall assessment of their conservation status. We evaluated the representation of the 30 ecosystems in the Chilean National System of Protected Areas (NSPA) and in Private Protected Areas (PPA), identifying 15 ecosystems underrepresented (below the 17% target) in the NSPA, in contrast to only 11 when the area of NSPA+PPA was considered. The proposed classification can be broadly applicable to assess the conservation status of ecosystems elsewhere, using similar conceptual and methodological tools. The development of functional ecosystem classifications for different countries must be encouraged to facilitate monitoring of global conservation targets.

We tested the main hypothesis that nutrient accumulation during late stages of postglacial succession would decrease nutrient limitation of diazotrophic activity. We tested this hypothesis by adding carbon (C), phosphorus (P), and molybdenum (Mo) independently or in combination, and nitrogen (N) only to symbiotic, epiphylls on bryophytes, and free-living diazotrophs in three stages of glacier foreland succession in Cordillera Darwin (55°S), southern South America. Experiments were run in spring 2013 and 2014 and in autumn 2015. Diazotrophic activity (DA) was assessed by the acetylene reduction assay. Results showed no effect of C, P, or Mo added either singly or in combination in the spring incubations. During autumn, DA was enhanced by adding a mix of C, P, and Mo to the symbiotic N2-fixing Gunnera magellanica from young successional sites, while in the late successional sites, adding C and Mo alone to the diverse bryophyte carpet on the forest floor enhanced DA. Nitrogen added as ammonium sulfa...

Freezing temperatures and water availability shape the distribution of evolutionary lineages of angiosperm trees in the Americas., The historical course of evolutionary diversification shapes the current distribution of biodiversity, but the main forces constraining diversification are still a subject of debate. We unveil the evolutionary structure of tree species assemblages across the Americas to assess whether an inability to move or an inability to evolve is the predominant constraint in plant diversification and biogeography. We find a fundamental divide in tree lineage composition between tropical and extratropical environments, defined by the absence versus presence of freezing temperatures. Within the Neotropics, we uncover a further evolutionary split between moist and dry forests. Our results demonstrate that American tree lineages tend to retain their ancestral environmental relationships and that phylogenetic niche conservatism is the primary force structuring the distribution of tree biodiversity. Our study establishes the pervasive importance of niche conservatism to community assembly even at intercontinental scales.

The global expansion of tree plantations is often claimed to have positive effects for mitigating global warming, preventing soil erosion, and reducing biodiversity loss. However, questions remain unanswered about the impacts of plantations on belowground diversity and soil properties. Here, we examine how forestry plantations of exotic trees affect critical soil functions and the composition of invertebrate assemblages, by comparing invertebrate diversity and soil physico-chemical properties between non-native Pinus radiata plantations, and nearby native forests in a region of extensive plantation activity in south-central Chile. We quantified differences in diversity, abundance, and community composition of soil invertebrates, as well as fundamental soil properties such as soil water content, water infiltration, nutrient status, and pH. We show that in this landscape mosaic of native forest and plantations, both soil invertebrate communities and physical soil properties differed significantly between systems, despite similar soil origins and topographies. We found a significant loss of soil carbon and a major reduction in taxonomic and functional diversity of soil invertebrates in pine plantation sites. Soil biotic and abiotic characteristics of plantations differed significantly from native forests in plantation-dominated south-central Chile, with profound consequences for ecosystem processes and resilience to future climate change.

Biological nitrogen fixation is a key ecosystem function incorporating new nitrogen (N) during primary successions. Increasing evidence from tropical and northern temperate forests shows that phosphorus (P) and molybdenum (Mo) either alone or in combination limit the activity of free-living diazotrophs. In this study, we evaluated the effects of Mo, P, and carbon (C) addition, either singly or in combination, and moisture, on diazotrophic activity in a post-volcanic forest chronosequence in south-fentral Chile. Diazotrophic activity, both free-living (associated with fine litter) and symbiotic (associated with the moss Racomitrium lanuginosum and the cyanolichens Pseudocyphellaria berberina and P. coriifolia), was evaluated by incubation of samples and subsequent acetylene reduction assays conducted in the field and laboratory, in winter, spring and autumn of two consecutive years. Results showed that diazotrophic activity varied with the season of the year (lowest during the drier spring season), successional stage (highest in the maximal stage), and N-fixer community type (highest in symbiotic diazotrophs). In general, C+P+Mo limitation was documented for heterotrophic diazotrophs and P+Mo limitation for symbiotic diazotrophs. Limitation of diazotrophic activity was not associated with soil nutrient and C status in the chronosequence. Strong inhibition of diazotrophic activity by high N addition and by low moisture suggests that reductions in precipitation expected for south-central Chile under climate change, as well as increasing inputs of reactive N from atmospheric deposition due to increasing use of N fertilizers, may drastically alter the composition and functional role of cryptogamic assemblages in native forests.

BACKGROUND AND AIMS Mycorrhizal associations are influenced by abiotic and biotic factors, including climate, soil conditions and the identity of host plants. However, the effect of environmental conditions on orchid mycorrhizal associations remains poorly understood. The present study examined how differences in soil nutrient availability are related to the diversity and composition of mycorrhizal fungi associated with two terrestrial orchid species from central Chile. METHODS For 12 populations of Bipinnula fimbriata and B. plumosa, OTU (operational taxonomic unit) richness, phylogenetic diversity and community composition of mycorrhizal fungi in root samples were estimated using internal transcribed spacer (ITS) sequences. Then, these mycorrhizal diversity variables were related to soil nutrients and host species using generalized linear models and non-metric multidimensional scaling. KEY RESULTS Variation in OTU composition of mycorrhizal fungi among sites was explained mainly by orchid host species. Fungi in Tulasnellaceae and Ceratobasidiaceae were isolated from both orchid species, but the former were more frequent in B. fimbriata and the latter in B. plumosa. Soil nutrients and orchid host species had significant effects on OTU richness and phylogenetic diversity. Mycorrhizal diversity decreased in habitats with higher N in both species and increased with P availability only in B. fimbriata CONCLUSIONS The results suggest that soil nutrient availability modulates orchid mycorrhizal associations and provide support for the hypothesis that specialization is favoured by higher soil nutrient availability. Inter-specific differences in mycorrhizal composition can arise due to a geographical pattern of distribution of orchid mycorrhizal fungi, host preferences for fungal partners or differential performance of mycorrhizal fungi under different nutrient availabilities. Further experiments are needed to evaluate these hypotheses.

Ecological processes in the upper canopy of temperate forests have been seldom studied because of the limited accessibility. Here, we present the results of the first survey of the pollinator assemblage and the frequency of insect visits to flowers in the upper branches of ulmo, Eucryphia cordifolia Cav., an emergent 30-40 m-tall tree in rainforests of Chiloé Island, Chile. We compared these findings with a survey of flower visitors restricted to lower branches of E. cordifolia 1- in the forest understory, 2- in lower branches in an agroforestry area. We found 10 species of pollinators in canopy, and eight, 12 and 15 species in understory, depending of tree locations. The main pollinators of E. cordifolia in the upper canopy differed significantly from the pollinator assemblage recorded in lower tree branches. We conclude that the pollinator assemblages of the temperate forest canopy and interior are still unknown.

After catastrophic disturbances, depleted substrates are readily colonised by organisms that capture nitrogen from the atmosphere and extract phosphorus from minerals. Our main objective was to compare the pattern of ecosystem development following deglaciation in Chile and New Zealand. Results show a similar pattern of C and N accumulation and decline in soil chronosequences, similar decline in biological nitrogen fixation (BNF) and similar δ15N-enriched signal at later stages, providing evidence for the existence of progressive, maximal and retrogressive phases of ecosystem development. However, contrasting patterns between Chilean and New Zealand sites are evident during the progressive phase, when higher C/N, C/P and N/P ratios are found in soils and leaves in Chile than in New Zealand, suggesting a higher nutrient limitation and nutrient use efficiency in the former. Highest rates of BNF were found at the early stages of both the Chilean and New Zealand chronosequences. Contrasting patterns a...

The floristic and ecological parallels between the forests of southeastern Australia, New Zealand and southern South America are striking. Forests of these distant areas have strong similarities in...

Scientists are increasingly interested in the evolutionary responses of organisms to unpredictable, variable, and extreme climate changes. In semiarid environments, inter-annual variability in the frequency and amount of rainfall affects both the growth and recruitment of plant species, especially annuals. In these inherently variable environments, individual selection should favor demographic responses that spread the risk of mortality over time and enhance long-term reproductive success (i.e., bet-hedging strategies). However, the same processes that allow the persistence and recruitment of native species could facilitate the introduction and establishment of exotics. We assessed whether native and exotic annuals in semiarid Chile displayed similar or contrasting bet-hedging traits, and discuss mechanisms of coexistence of both types of species and their demographic variation under interannual rainfall variability driven by El Nino Southern Oscillation (ENSO). We analyzed a proxy of long-term fitness, i.e., the variability of seed density over 17 years, for the two most common native and two exotic annual plant species present in the study area. We experimentally tested whether the quality of the maternal environment (soil water supply in a given year) had an extended effect (e.g. the next year) on the proportion of seed germination or on the mean and/or variability of seed size and seed dormancy. Results showed that native and exotic species in this annual plant assemblage displayed contrasting bet-hedging strategies as evolutionary responses to variable rainfall. Although rainfall variability promotes the evolution of bet-hedging strategies, the nature of these strategies varies across species, presumably to minimize competitive exclusion. In semiarid Chile, the success of two exotic ephemerals that are components of a diverse community of native annual species seems to reflect bet-hedging germination strategies that complement rather than compete with those expressed in dominant natives.

Ecosystems where carbon fluxes are being monitored on a global scale are strongly biased toward temperate Northern Hemisphere latitudes. However, forest and moorland ecosystems in the Southern Hemisphere may contribute significantly to the global and regional C balance and are affected by different climate systems. Here, we present the first data from an old‐growth forest representative of temperate, broad‐leaved rainforests from southern South America. Carbon fluxes monitored over two years using the eddy covariance technique showed that this rainforest acts as an annual sink (−238 ± 31 g C/m2). However, there were significant pulses of carbon emission associated with dry episodes during the summer months (i.e., peak of the growing season) and periods of significant carbon fixation during the cold austral winter, indicating that the carbon balance in this forest is very sensitive to climate fluctuations. The carbon fixation surges in winter seem to be related to the mild temperatures recorded during this period of the year under the prevailing oceanic climate. Winter carbon gain was more relevant in determining the annual carbon balance than summer pulse emissions. Regarding the annual carbon balance, this southern forest resembles the patterns observed in montane tropical forests more than the behavior of narrow‐leaved evergreen temperate forests from the Northern Hemisphere. These patterns make this southern forest type relevant to understanding the mechanisms and thresholds that control ecosystem shifts from carbon sinks and sources and will provide key data to improve global dynamic vegetation models., This work was supported by FONDEQUIP AIC-37, Iniciativa Científica Milenio grant P05-002 and CONI-CYT grant PFB-23 to the Institute of Ecology and Biodiversity-Chile (IEB), FONDECYT grant 1130935 to JPQ, and the LINCGlobal research program funded by CSIC-Spain and Catholic University of Chile. The authors thank Robert Cook and Alison Boyer, who kindly provided the FLUXNET database 2015. The authors are grateful to Paul Reich (USDA) for sharing the Biome database, Sebastiaan Luyssaert for providing them with the database of CO2 balance of forest ecosystems, and an anonymous reviewer whose comments helped them to improve the manuscript. This is a contribution to the Research Program of Senda Darwin Biological Station and the Chilean Long-Term Socio-Ecological Research Network (LTSER-Chile), affiliated with ILTER, AMERIFLUX, and FLUXNET.

Nitrogen and phosphorus are the main elements limiting net primary production in terrestrial ecosystems. When growing in nutrient-poor soils, plants develop physiological mechanisms to conserve nutrients, such as reabsorbing elements from senescing foliage (i.e. nutrient retranslocation). We investigated the changes in soil N and P in post-fire succession in temperate rainforests of southern Chile. In this area, forest recovery often leads to spatially scattered, discrete regeneration with patches varying in age, area, species richness and tree cover, representing different degrees of recovery from disturbance. We hypothesized that soil nutrient concentrations should differ among tree regenerating patches depending on the progress of forest regeneration and that nutrient resorption should increase over time as colonizing trees respond to limited soil nutrients. To evaluate these hypotheses, we sampled 40 regeneration patches in an area of 5 ha, spanning a broad range of vegetation complexity, and collected soil, tree foliage and litter samples to determine N and P concentrations. Nutrient concentrations in leaf litter were interpreted as nutrient resorption proficiency. We found that soil P was negatively correlated with all the indicators of successional progress, whereas total soil N was independent of the successional progress. Foliar N and P were unrelated to soil nutrient concentrations; however, litter N was negatively related to soil N, and litter P was positively related with soil P. Finally, foliar N:P ratios ranged from 16 to 25, which suggests that P limitation can hamper post-fire regeneration. We provide evidence that after human-induced fires, succession in temperate forests of Chile can become nutrient limited and that high nutrient retranslocation is a key nutrient conservation strategy for regenerating tree communities.

The tropical conservatism hypothesis (TCH) suggests that phylogenetic niche conservatism (the tendency for traits to be maintained during diversification) should be the main driver of latitudinal diversity gradients. For example, the tropical–temperate diversity gradient for woody angiosperms should reflect the tropical, older origin of most clades, the constrained evolution of cold tolerance, and the fact that few clades were able to persist in temperate zones after the beginning of the global cooling in the Eocene. Evidence for this explanation has been discussed primarily from a Northern Hemisphere perspective. Recently, two studies have presented diversity and clade–age relationships in South American forests that are inconsistent with the TCH, with older woody families being more frequent at higher latitudes and higher elevations in the Andes. We argue that a broader framework considering the ancient history of the Southern Hemisphere flora and the recent history of the Andean flora can help explain these discordant patterns. Here, we provide an initial discussion of this new perspective, emphasizing the historical development of a unique and rich palaeoflora of Gondwanan ancestry at mid- to high latitudes of South America and Antarctica. We suggest that the idea of Austral niche conservatism (ANC) of a warm-temperate Antarctic–South American biota should be explored further to improve our understanding of biogeographical patterns in the Southern Hemisphere.