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Secondary forests may act as buffer area and serve as reservoir for biotic components that are lost from primary forest due to anthropogenic disturbances. This study investigated the floristic composition, diversity and community structure of Cocoa Research Institute of Nigeria (CRIN), Idi-Ayunre, Ibadan, Nigeria. Twenty-five main plots (each 50 m × 50 m) were randomly mapped out to enumerate tree species, five 10 m × 10 m sub-plots were systematically mapped out within each main plot to enumerate shrubs and three quadrats (1 m × 1 m) were laid in each sub-plot to enumerate herbaceous species in Wet Season (WS) and Dry Season (DS). Relative Importance Value (RIV), Taxa, Individuals, Dominance, Shannon-Wiener, Equitability and Jaccard similarity index were determined. A total of 181 plant species from 145 genera and 54 families which included 63 trees, 33 shrubs and 85 herbaceous species were enumerated. In wet season, Triplochiton scleroxylon, Lonchocarpus griffonianus and Chromolaena odorata had the highest RIV while in dry season, Terminalia superba, Lonchocarpus cyanescens and C. odorata were the highest for trees, shrubs and herbs, respectively. Low dominance but high equitability and Shannon-Weiner values indicated inter-specificity among trees, shrubs and herbs. It was only in herbs that Jaccard-similarity was less than 100% across seasons. Resilience for keystone species conservation is possible due to flora species heterogeneity of the study site. Key words: Forest ecosystem, biodiversity, anthropogenic activities, relative importance value, ecosystem services.

Primary forests, defined here as forests where the signs of human impacts, if any, are strongly blurred due to decades without forest management, are scarce in Europe and continue to disappear. Despite these losses, we know little about where these forests occur. Here, we present a comprehensive geodatabase and map of Europe’s known primary forests. Our geodatabase harmonizes 48 different, mostly field-based datasets of primary forests, and contains 18,411 individual patches (41.1 Mha) spread across 33 countries. When available, we provide information on each patch (name, location, naturalness, extent and dominant tree species) and the surrounding landscape (biogeographical regions, protection status, potential natural vegetation, current forest extent). Using Landsat satellite-image time series (1985–2018) we checked each patch for possible disturbance events since primary forests were identified, resulting in 94% of patches free of significant disturbances in the last 30 years. Although knowledge gaps remain, ours is the most comprehensive dataset on primary forests in Europe, and will be useful for ecological studies, and conservation planning to safeguard these unique forests., Measurement(s)Geographic DistributionTechnology Type(s)digital curationFactor Type(s)countrySample Characteristic - Environmentprimary forestSample Characteristic - LocationEurope Machine-accessible metadata file describing the reported data: 10.6084/m9.figshare.14540625

Forest structure and composition change are driven by complex interactions among local site factors, past site history, and region-specific socio-demographic factors. Previous studies suggest the structural, functional, taxonomic, and carbon storage potential of vegetation increases during succession. However, information on these attributes along an altitudinal gradient from the North East India is lacking for the old growth secondary forests. Therefore, the present study investigates (i) tree diversity and biomass carbon storage, and (ii) dominating and carbon important tree species, along an altitudinal gradient (30–700 m) in the tropical semi-evergreen forests of southern Assam. Random quadrats of 0.1 ha were laid over selected elevation gradient of secondary forest to evaluate tree diversity, density, basal area, and biomass carbon stock. Shannon–wiener index increases from 2.88 (at 30 m) to 3.33 (at 700 m) indicating an increase in species diversity with elevation. The stand density ranges from 920–1630 stems ha−1 and reciprocally related to the altitude. Palaquium polyanthum, Dysoxylum binectariferum, and Maniltoa polyandra were the most dominant species at 30 m, 300 m and 700 m, respectively. Biomass carbon stock decreases with the increase in altitude and ranges from 71.20 to 77.47 Mg ha−1. Palaquium ployanthum, Sterculia sp. and Syzygium cumini were the most carbon important species at 30 m, 300 m and 700 m, respectively. Present study suggests conservation and management of old-growth secondary forests have carbon storage and regional climate benefits. Management of such secondary forests can also enhance the resiliency of forest ecosystems to nature conservancy.

Old-growth forests have an important role in maintaining animal and plant diversity, are important carbon (C) reservoirs and are privileged sites to study long-term plant physiological responses, long-term forest dynamics and climate change impact on forest ecosystems. Several studies have highlighted how old-living trees undergo age-related declines with hydraulic limitations and reduction in photosynthesis, though some recent works have suggested that such a decline is not always observed. Our study aims at understanding the role of atmospheric CO2 increase on tree C uptake and stomatal conductance (gs) in old-living trees by analysing the long-term patterns of tree growth and intrinsic water use efficiency (iWUE) in three old-growth forests in the Balkans (Bosnia-Herzegovina and Montenegro), using dendrochronology and isotopic analysis. We hypothesised a long-term increase in iWUE in the studied old-growth forests, mostly related to enhanced photosynthesis rather than reduced stomatal conductance. Tree cores were sampled from dominant silver fir (Abies alba Mill.) trees in each forest. Tree-ring widths were measured and basal area increments (BAI) were assessed for each sampled tree and, from the six longest chronologies, five decades were chosen for cellulose extraction, its isotopic analysis (δ13C, δ18O), iWUE and leaf water 18O evaporative enrichment above the source water (Δ18OL) determination. We observed a continuous and significant increase in iWUE from 1800 to 2010 in the sampled dominant trees at all the three old-growth forests. Our BAI data and our estimates of Δ18OL across the study period support the idea that enhanced photosynthesis rather than reduced stomatal conductance is the major driver of the measured iWUE increase. Thus, our results support some recent findings challenging the hypothesis that iWUE in forests is primarily the result of a CO2-induced reduction in stomatal conductance as well as the so called hydraulic limitation hypothesis.

The consequences of rapid rainforest clearance on native avifauna are poorly understood. In Southeast Asia, Singapore, a newly developing country, has had 95% of its native lowland rainforest cleared. Most of the rainforest was lost in the mid- to late-nineteenth century. We compared avifauna checklists from 1923, 1949, and 1998 to determine the extent of extinctions between 1923 and 1998 in Singapore. Of 203 diurnal bird species, 65 were extirpated in Singapore in the past 75 years. Four of these species were nonforest- dependent species, whereas 61 (94%) were forest bird species dependent on the primary or old secondary forest to survive. Twenty-six forest bird species became extinct between 1923 and 1949, whereas 35 forest species disappeared after 1949. We compared the body lengths, feeding guilds, and vertical feeding zones between extinct and extant forest bird species to determine whether extinction patterns were dependent on these characteristics. Larger forest bird species went extinct between 1923 and 1949. Body sizes, however, did not affect the loss of forest bird species between 1949 and 1998. We observed high losses of insectivorous birds; the insectivore-carnivore and insectivore-granivore guilds lost80% of the species present in 1923. The highest losses were among birds that fed in the canopy. None of the forest bird species are currently common (100 individuals/species) within Singapore. Our study shows that more than half the forest avifauna became locally extinct after extensive deforestation. Based on this fact, the countries within Southeast Asia should reconsider their heavy deforestation practices.Las consecuencias de la tala rápida del bosque lluvioso sobre la avifauna nativa son poco conocidas. En Asia sudoriental, Singapur, un país en desarrollo, un 95% de su bosque nativo de tierras bajas ha sido talado. La mayoríia del bosque se perdió entre mediados y finales del siglo diecinueve. En este trabajo comparamos las listas de avifauna de 1923, 1949 y 1998 para determinar la extensión de las extinciones en Singapur entre 1923 y 1998. Sesenta y cinco de las 203 especies diurnas de aves fueron extirpadas de Singapur en los últimos 75 años. Cuatro de estas especies fueron especies no dependientes del bosque, mientras que 61 (94%) fueron especies de aves del bosque (especies que dependen del bosque primario o secundario viejo para sobrevivir). Veintiséis de las especies de aves del bosque se extinguieron entre 1923 y 1949, mientras que 35 especies del bosque desaparecieron después de 1949. Comparamos las longitudes del cuerpo, los gremios de alimentación y las zonas de alimentación vertical entre especies de aves de bosque extintas y existentes para determinar si los patrones de extinción fueron dependientes de estas características. Las especies de aves grandes del bosque se extinguieron entre 1923 y 1949. Sin embargo, el tamaño del cuerpo no afectó la pérdida de especies del bosque entre 1949 y 1998. Observamos altas pérdidas de aves insectívoras; los gremios de insectívoros-carnívoros e insectívoros-granívoros perdieron80% de las especies que estaban presentes en 1923. Los números más altos de pérdidas fueron de aves que se alimentan en el dosel. Ninguna de las especies de aves del bosque es común en la actualidad (100 individuos/especie) dentro de Singapur. Nuestro estudio muestra que más de la mitad de la avifauna del bosque se ha extinguido localmente después de una deforestación extensiva. Con base en este hecho, los países dentro de Asia Sudoriental deberían reconsiderar sus prácticas de intensa deforestación.

The earth’s climate has a direct impact on the spatial distribution of the vegetation cover. Forests are one of the most prevalent ecosystems on earth. The forest’s structure, if unaltered, can be an indicator of some climate patterns. This paper proposes an algorithm for identifying vegetation inversions within mountain forest ecosystems in the eastern Carpathians of Romania, using freely available GIS and remote sensing data. Air temperature has a direct impact on the spatial distribution of tree species. Therefore, temperature-inversion spatial patterns can be estimated.

Dead trees, and particularly downed logs, play an important role in the dynamics of forest ecosystems. The contribution of decaying wood to the carbon and nutrient pool of forest soils depends on tree species and the degree of wood decay but the extent to which downed logs affect forest properties in temperate forests has rarely been quantified. In order to investigate the impact of decaying wood on soil properties, we carried out a study in a mixed beech forest of the Liresar district (Mazandaran province, northern Iran). We first investigated if and how the presence of downed logs affects soil quality and function by comparing soils underneath degraded logs and nearby soils of the two dominant forest species, beech and hornbeam. Then, we explored how these effects occur as downed logs decompose by comparing wood with four degrees of decomposition of both tree species. The decay degree of downed logs was classified in four classes (DC1 to DC4). Eight dead trees of each tree species were selected as the center of each sample plot and three composite soil samples under each decaying log and 100 cm near a decaying log (soil around logs) were collected at two soil depths (i.e., 0–15 and 15–30 cm) and then analyzed for main physico-chemical characteristics and microbial activity. Our study showed that downed logs affected physical (5% wetter than control soils), chemical (lower by 2% the pH, increased 100% organic C, and total N in the case of hornbeam and P by 2%) and biological (i.e., soil microbial respiration was enhanced by 10% and , microbial biomass of C 620 mg kg−1, 351.5 mg kg−1 and N 66.47 mg kg−1, 32.18 mg kg−1 by, respectively) characteristics of soils, thus resulting in downed tree soil microsites that strongly differ from those without downed logs. The presence of down logs increased soil microbial activity and soil fertility as wood decayed. Thus, the presence of downed logs should be considered as an important factor influencing forest soils and should be taking into account in forest management practices.

As currently framed, the forest cycle model that underlies close-to-nature management in temperate beech forests throughout the globe specifies an orderly sequence of temporal development within even-aged patches comprising the forest mosaic. Although this model has been widely applied to European beech (Fagus sylvatica L.) forests, the underlying assumptions of disturbance-induced even-agedness (i.e., within-patch age homogeneity) and competition-induced size differentiation (i.e., within-patch size heterogeneity) have not been tested in natural beech forests due to prohibitions on tree coring in primeval forest reserves. In a rare and unprecedented test dataset of spatially explicit tree ages in an old-growth European beech forest, we employed triangulated irregular networks of Delaunay triangles to objectively identify natural tree neighborhoods to determine if neighboring (i.e., within-patch) trees were even- or, at most, two-aged. Age differences among neighboring trees (summarized in 25-yr age classes) were rarely 50 yrs, while the few "even-aged" patches were very small (100 m2) and relatively young (

The impact of anthropogenic habitat alteration on amphibians was investigated, employing an investigative focus on leaf-litter and semi-aquatic species across different habitat alteration types. The habitat alteration types which include primary forest, selectively logged primary forest, secondary forest, abandoned farm areas and pasture (this represents a gradient of habitat alteration ranging from least altered to most altered, respectively) also encompass two habitat types: stream and terrestrial. Species assemblage was compared between habitat alteration types and habitat types, where a total 360 leaf-litter and semi-aquatic amphibians were observed (15 species, 6 families). It was found that amphibian abundance was significantly higher in both forest and stream habitat, and species richness did not differ with respect to habitat alteration type. It was determined, however, that species richness was highly dependent on habitat type (significantly higher in stream habitat). Meanwhile, diversity (Shannon–Wiener) was significantly higher in both forest and stream habitat, and species composition differed markedly between habitat alteration types for stream strip plots. Forest habitat exhibited domination by forest specialist species, while altered habitat (abandoned farm areas and pasture) exhibited domination by open-habitat specialist species. Additionally, strong relationships were found between species composition and abundance, as well as richness and diversity (within the measured habitat structures and observed microclimatic conditions). Analyses determined that the higher abundance of leaf-litter and semi-aquatic amphibians was best explained by higher DBH (1.3 m from the ground) and lower temperature and the higher species richness was best explained by higher understorey density. Additionally, higher diversity was associated with increasing understorey density, tree density and temperature. In general, the assemblage of leaf-litter and semi-aquatic amphibians in the lowland tropical rainforest in northeastern Leyte was affected by habitat alteration, highlighting the on-going importance of conservation efforts.

The unique results of the 25-year monitoring of forest vegetation of the buffer zone at the Novopolotsk Refinery Complex (NIRC) were summarized. The analysis of quantitative and qualitative changes in the buffer zone, which occurred during the period 1990–2015 years of operation of NRC’s enterprises, is given. Detailed analysis of vegetation organization has shown that the most transformed forest areas are directly adjacent to the enterprises from the leeward side. During the 25-year period of research, the area of primary forest fragments in the 500-meter zone of NRC impact has decreased by 2.6 times. Derivatives of small-leaved communities formed at the place of dead coniferous stands immediately after the commissioning of the plants are presented here. The technogenic press reduction in the 1990s resulted in the active demutation transformations of vegetation. Recently, there has also been a dominance of restoration processes, but the change of the main pine and spruce stands to derivatives continues, which is reflected in the prolonged decomposition of fragments of previously disturbed stands. The direction and rates of change of some plant groups by others depend on the initial state of plants, species and age structure of communities, conditions of their growth and environmental factors. In general, it is noted that forest ecosystems of the region have retained the ability to regenerate the composition and structure.

The importance of dead wood in forest ecosystems for the existence of invertebrates has been widely discussed in the literature. The major aim of this study is to test the hypothesis that the presence of dead wood in forests considerably increases the species diversity of Uropodina (Acari: Parasitiformes) communities in a given area. The areas selected for the study are unique from a natural point of view. They are the Białowieża Primeval Forest, Cisy Staropolskie im. Leona Wyczółkowskiego Nature Reserve, and five oak-hornbeam nature reserves in western Poland. The study is based on materials collected since the 1960s of the last century. The highest number of species (37) both in soil and dead wood microhabitats was recorded in the Białowieża Primeval Forest and Cisy Staropolskie Nature Reserve, though the dead wood material from the second area contained the highest number of species (33). The results of the analysis show that the presence of dead wood increases species diversity of Uropodina communities in all locations under scrutiny. Moreover, dead wood increases the species diversity of Uropodina communities by attracting rare and stenotopic species, and therefore leaving dead trees in forests is extremely important for the habitat protection of these species.

Brazil contains two-thirds of remaining Amazonian rainforests and is responsible for the most Amazon forest loss. Primary forest loss in the Brazilian Amazon has declined considerably since 2004 but secondary forest loss has never been quantified. We use a recently developed high-resolution land use/land cover dataset to track secondary forests in the Brazilian Amazon over 14 yr, providing the first estimates of secondary forest loss for the region. We find that secondary forest loss increased by (187 ± 48)% from 2008 to 2014. Moreover, the proportion of total forest loss accounted for by secondary forests rose from (37 ± 3)% in 2000 to (72 ± 5)% in 2014. The recent acceleration in secondary forests loss occurred across the entire region and was not driven simply by increasing secondary forest area but probably a conscious preferential shift towards clearance of a little-protected forest ecosystem (secondary forests). Our results suggest that secondary forests loss has eased deforestation pressure on primary forests. However, this has been at the expense of a lost carbon sequestration opportunity of 2.59–2.66 Pg C over our study period. Deforestation in the Brazilian Amazon affects both older (primary) and younger (secondary) forests. This study finds that most forest loss over the period 2008–2014 was from secondary forests and that the almost 190% rise in deforestation buffered losses from primary forests.

Despite improvements of dendrochronological techniques in many forest ecosystems, studies describing the growth responses of trees following disturbance events including comprehensive data on factors and processes behind tree-growth release are rare, especially for European temperate forests, limiting the interpretation and generalization of dendroecological studies. Here we examine the effect of key factors on the growth reaction of Fagus sylvatica L. to disturbances in 8 old-growth forests in the Czech Republic, independently dated using three different data sources – tree censuses, dendrochronology and historical aerial photographs. Using 117 increment cores, we studied four parameters of radial tree-growth surrounding canopy gaps: magnitude, duration, abruptness and response shift, in relation to factors of different spatial scales, i.e. tree-, gap- and stand-level variables. Our results indicate that the beech growth response to gap formation strongly differs across a complex of factors at diverse spatial levels, frequently occurring in noteworthy interactions. A positive trend for the gap size * radiation interaction in the analysis of magnitude was found, suggesting that the effect of gap area differs among topographical features. As for duration and abruptness, the interaction of distance and mortality mode was identified, indicating a longer and more gradual reaction along with increasing distance of the cored tree from the gap centre, varying by the type of the gap maker’s death. In addition, an altitudinal gradient was found to predict the magnitude of growth changes and the time interval between the disturbance and the reaction of nearby trees. Surprisingly, the diameter of the surviving trees was not a good predictor of radial growth, with a significant positive relationship to just abruptness. An effect of locality was not observed, facilitating the broad applicability of our findings across a wide range of beech-dominated temperate forests. Our results emphasize the general limits of dendrochronological data in disturbance spatial pattern studies, as indicated by the considerable variability in the responses of neighbouring trees to identical disturbance event. A detailed examination of the growth reaction, considering not only the response magnitude but also other important parameters, plays a key role in the precision of detecting growth releases as well as in reducing the sample size required for summary disturbance history evaluations. In focusing on this issue we believe we contribute to future dendroecological research by demonstrating the need for more precise disturbance history evaluations.

Restoring the structural characteristics of secondary old-growth forests that were previously managed is increasingly debated to help increase the area of more complex forests which provide a broader array of forest services and functions. The paucity of long-term data sets in Central Europe has limited our ability to understand the ongoing ecological processes required for effective restoration programs for old-growth forests. To address this, we used repeated census data from eight permanent plots to evaluate forest structural dynamics over a 12-year period in the largest complex of European beech (Fagus sylvatica L.) forests in the Czech Highlands without intensive forestry intervention for almost 50 years. Our results showed that previously managed forests can exhibit structural qualities typically associated with old-growth forests after management has ceased for a period. The stand structural characteristics (e.g., density of large and old trees) is comparable with protected reserves of old-growth European beech-dominated forests. The average stand age was 196 years, but the oldest tree was 289 years old. The annual mortality rate was 0.43% for all species, and the U-shaped distribution indicating size-dependent mortality is likely an important process that is balanced by the turnover of new tree recruitment. During the study period, we detected that the diameter distribution tended towards a rotated sigmoid distribution. The lasting effects of the most recent forest management are evident in the scarcity of dead wood, and a prolonged process of dead wood accumulation has begun. Thus, the abandonment of all management activities in near-natural forest reserves, including dead wood removal, will ensure that the forests will develop characteristics typical of old-growth forests.

The effects of logging on forest ecosystems are severe and long-lasting. In addition, these effects are often paralleled with shifts in soil fungal community composition and functional guilds with potential feedbacks on ecosystem functioning. Clarifying how soil fungal communities are linked to the effects of historical logging could help us better understand the ecological consequences of logging. Here, we collected soils from 61 25 m × 25 m quadrats across a 160-km2 tropical rainforest in Hainan Island, China, which had been partially clear cut or selectively harvested and left to recover for up to 50 years. Soil fungal community composition and species co-variation networks were investigated in the selectively harvested (select cut) and clear cut forest stands and were compared to data from the primary stands without a history of logging. Historical logging shifted fungal community composition from Zygomycota towards Basidiomycota domination mainly through modifying vegetation composition and soil properties. The relative abundance of root associated fungi (i.e., ectomycorrhizal and ericoid mycorrhizal), animal pathogens and wood saprotrophs increased 50 years after logging, while the relative abundance of undefined saprotrophs decreased. In select cut stands, the fungal community was better organized with higher numbers of functionally interrelated operational taxonomic units (OTUs) and more generalist OTUs. In contrast, the number of functionally interrelated OTUs was lowest in the fungal network in clear cut stands. By comparing the topological roles of the shared OTUs among the three types of forest stands, we found role-shifts among fungal members from the specialists in the primary stands to the generalists in the select cut stands. Ascomycota and Basidiomycota were the major phyla involved in the role-shifts. Moreover, the fungal network in primary stands was positively associated with litter nutrients, while that in select cut stands was positively related to soil nutrients content. This indicated that the major drivers of fungal community organization shifted from litter nutrients content in the primary forest towards soil nutrients content in the selectively harvested forest. In the clear cut stands, however, the associations between fungal network and both litter and soil nutrients content decreased when compared with those in the primary and select cut stands. More than 60% of the total links among fungal members in clear cut stands were negative, implying a trend of niche partitioning among fungal groups with a half-century recovery after clearcutting in the tropical rainforest.

Assessing long-term changes in biomass of old-growth forests is critical in evaluating forest ecosystem functions under a changing climate. Long-term biomass changes are the result of accumulated short-term changes, which can be affected by endogenous processes such as gap filling in small-scale canopy openings. Here, we used 26 years (1993–2019) of repeated tree census data in an old-growth, cool-temperate, deciduous mixed forest that contains three topographic units (riparian, denuded slope, and terrace) in northern Japan to document decadal changes in aboveground biomass (AGB) and their processes in relation to endogenous processes and climatic factors. AGB increased steadily over the 26 years in all topographic units, but different tree species contributed to the increase among the topographic units. AGB gain within each topographic unit exceeded AGB loss via tree mortality in most of the measurement periods despite substantial temporal variation in AGB loss. At the local scale, variations in AGB gain were partially explained by compensating growth of trees around canopy gaps. Climate affected the local-scale AGB gain: the gain was larger in the measurement periods with higher mean temperature during the current summer but smaller in those with higher mean temperature during the previous autumn, synchronously in all topographic units. The decadal climate trends of warming are likely to have contributed to the steady increase in AGB in this old-growth forest.

Current trends emphasize the importance of the examination of the functional composition of lichens, which may provide information on the species realized niche diversity and community assembly processes, thus enabling one to understand the specific adaptations of lichens and their interaction with the environment. We analyzed the distribution and specialization of diverse morphological, anatomical and chemical (lichen secondary metabolites) traits in lichen communities in a close-to-natural forest of lowland Europe. We considered these traits in relation to three levels of forest ecosystem organization: forest communities, phorophyte species and substrates, in order to recognize the specialization of functional traits to different levels of the forest complexity. Traits related to the sexual reproduction of mycobionts (i.e., ascomata types: lecanoroid apothecia, lecideoid apothecia, arthonioid apothecia, lirellate apothecia, stalked apothecia and perithecia) and asexual reproduction of mycobionts (pycnidia, hyphophores and sporodochia) demonstrated the highest specialization to type of substrate, tree species and forest community. Thallus type (foliose, fruticose, crustose and leprose thalli), ascospore dark pigmentation and asexual reproduction by lichenized diaspores (soredia and isidia) revealed the lowest specialization to tree species and substrate, as well as to forest community. Results indicate that lichen functional trait assemblage distribution should not only be considered at the level of differences in the internal structure of the analyzed forest communities (e.g., higher number of diverse substrates or tree species) but also studied in relation to specific habitat conditions (insolation, moisture, temperature, eutrophication) that are characteristic of a particular forest community. Our work contributes to the understanding of the role of the forest structure in shaping lichen functional trait composition, as well as enhancing our knowledge on community assembly rules of lichen species.

Large trees have survived for a long time, and their complex crown structure serves as habitat for epiphytic plants. Canopy plants are not as well studied in the temperate zones as in the tropics, because many of them are accidental epiphytes, epiphytic individuals of normally terrestrial species. We hypothesized that the canopy can serve as a refuge for terrestrial species that have difficulty establishing on the ground (e.g., insufficient light, over-browsing), promoting and conserving forest species diversity. Terrestrial species may also vary in their ability to adapt to canopy growth conditions. Here, we investigated canopy vascular plants hosted on a large Cercidiphyllum japonicum tree in a temperate old-growth forest, Japan. The canopy plant community was diverse with 39 vascular plant species, including 31 accidental epiphytes and six threatened, obligate epiphytes. High numbers of canopy plant species, including most accidental epiphytes, were found where multiple, large reiterated trunks as well as on large horizontal branches. Canopy plants leaves exhibited higher water use efficiency and higher nitrogen concentration compared to plants on the ground, but were controlled by transpirational water loss rather than by investing in leaf nitrogen with increasing height. We found at least 14 species could escape over-browsing by establishing in the canopy and may function as seed-sources for future re-colonization on the ground. Our results show one large tree crown can be defined as a local hotspot for current and future plant species diversity in a temperate old-growth forest, reinforcing its ecological value for conservation purposes.

Trees in the upper canopy contribute disproportionately to forest ecosystem productivity. The large, canopy-emergent Bertholletia excelsa also supports a multimillion-dollar commodity crop (Brazil nut), harvested almost exclusively from Amazonian forests. B. excelsa fruit production, however is extremely variable within populations and years, destabilizing local harvester livelihoods and the extractive economy. To understand this variability, data were collected in Acre, Brazil over 10 years at two sites with similar climate and forest types, but different fruit production levels, despite their proximity (~ 30 km). One site consistently produced more fruit, showed less individual- and population-level variability, and had significantly higher soil P and K levels. The strongest predictor of fruit production was crown area. Elevation and sapwood area also significantly impacted fruit production, but effects differed by site. While number of wet days and dry season vapor pressure prior to flowering were significant production predictors, no climatic variables completely captured annual observed variation. Trees on the site with higher available P and K produced nearly three times more fruits, and appeared more resilient to prolonged drought and drier atmospheric conditions. Management activities, such as targeted fertilization, may shield income-dependent harvesters from expected climate changes and production swings, ultimately contributing to conservation of old growth forests where this species thrives.

International audience; Context In the framework of climate change, decreased tree growth and enhanced mortality induced by hot and dry conditions are increasing in many forests around the world, and particularly in Mediterranean forests.• Aims Our aim was to estimate tree growth and mortality in a Mediterranean holm oak forest, using remote sensing data from MODIS.• Methods We monitored annual increases of aboveground biomass by measuring tree basal area, and we determined tree mortality by counting dead stems. We analyzed the relationships between forest growth and mortality with mean annual values of some MODIS products and meteorological data.• Results Mortality and increases of aboveground biomass correlated well with precipitation, September standardized precipitation/evapotranspiration indices (SPEI), and some MODIS products such as NDVI and enhanced vegetation index EVI. Other MODIS products such as gross primary production (GPP) and net photosynthesis, however, showed no clear relationship with tree mortality or measured increases of biomass.• Conclusion The MODIS products as proxies of ecosystemic productivity (gross primary productivity, net photosynthesis) were weakly correlated with biomass increase, and did not reflect the mortality following the drought of autumn 2011. Nevertheless, NDVI and EVI were efficient indicators of forest productivity and dieback

We present gridded 8 km-resolution data products of the estimated stem density, basal area, and biomass of tree taxa at Euro-American settlement of the midwestern United States during the middle to late 19th century for the states of Minnesota, Wisconsin, Michigan, Illinois, and Indiana. The data come from settlement-era Public Land Survey (PLS) data (ca. 0.8-km resolution) of trees recorded by land surveyors. The surveyor notes have been transcribed, cleaned, and processed to estimate stem density, basal area, and biomass at individual points. The point-level data are aggregated within 8 km grid cells and smoothed using a generalized additive statistical model that accounts for zero-inflated continuous data and provides approximate Bayesian uncertainty estimates. The statistical modeling smooths out sharp spatial features (likely arising from statistical noise) within areas smaller than about 200 km2. Based on this modeling, presettlement Midwestern landscapes supported multiple dominant species, vegetation types, forest types, and ecological formations. The prairies, oak savannas, and forests each had distinctive structures and spatial distributions across the domain. Forest structure varied from savanna (averaging 27 Mg/ha biomass) to northern hardwood (104 Mg/ha) and mesic southern forests (211 Mg/ha). The presettlement forests were neither unbroken and massively-statured nor dominated by young forests constantly structured by broad-scale disturbances such as fire, drought, insect outbreaks, or hurricanes. Most forests were structurally between modern second growth and old growth. We expect the data product to be useful as a baseline for investigating how forest ecosystems have changed in response to the last several centuries of climate change and intensive Euro-American land use and as a calibration dataset for paleoecological proxy-based reconstructions of forest composition and structure for earlier time periods. The data products (including raw and smoothed estimates at the 8-km scale) are available at the LTER Network Data Portal as version 1.0.

Tree-related microhabitats (hereafter TreMs) are structures occurring on trees, such as rot holes, cavities, large nests, mould, fruiting bodies and mycelia of decomposer fungi. TreMs have been widely recognized as important substrates and structures useful for biodiversity conservation in forest ecosystems, and they can be used as indicators for describing and monitoring forest naturalness. However, most studies on the occurrence of TreMs have been mainly done in forest ecosystems of Central Europe, while less research has been conducted in Mediterranean mountain forests. In this study, we investigated the diversity and abundance of 23 types of TreMs on living trees and on deadwood in seven Mediterranean mountains unmanaged forests located in the Apennines (Italy). The abundance of TreMs was evaluated by counting the number of TreMs per tree, while the diversity of TreMs was evaluated by means of the Shannon-Wiener index. We focused on the relationships between diversity and abundance of TreMs, and tree size (e.g., diameter, height, volume), and the time since the last harvest. Among the investigated stands, 2612 living trees, 457 standing dead trees and snags, and 1247 lying deadwood pieces were analysed. For living trees, a generalized linear mixed model was applied to test the effect of several variables on the abundance of TreMs per tree. Diameter at breast height (DBH) of tree stems influenced the abundance and diversity of TreMs. The time since the last harvest also significantly affected the probability that TreMs could be formed in a long-term perspective. The interaction of the predictors “DBH2” and “Years since the last harvest” generated a better model than the one in which the two variables were kept separate. Indeed, these two factors together would better represent the transition of a previously managed forest to a more natural state over time. This study might provide useful information to land managers committed to forestry practices towards sustainable management and biodiversity conservation, especially referring to survey and inventory of forests of high nature value.

The area of tropical secondary forests is increasing rapidly, but data on the physical and biological structure of the canopies of these forests are limited. To obtain such data and to measure the ontogeny of canopy structure during tropical rainforest succession, we studied patch-scale (5 m2) canopy structure in three areas of 18–36 year-old secondary forest in Costa Rica, and compared the results to data from old-growth forest at the same site. All stands were sampled with a stratified random design with complete harvest from ground level to the top of the canopy from a modular portable tower. All canopies were organized into distinct high- and low-leaf-density layers (strata), and multiple strata developed quickly with increasing patch height. The relation of total Leaf Area Index (LAI, leaf area per area of ground) to patch canopy height, the existence of distinct high and low leaf- density layers (strata and free air spaces), the depth and LAI of the canopy strata and free air spaces, and the relation of the number of strata to patch canopy height were remarkably constant across the entire successional gradient. Trees were the most important contributor to LAI at all stages, while contribution of palm LAI increased through succession. We hypothesize that canopy physical structure at the patch scale is driven by light competition and discuss how this hypothesis could be tested. That canopy physical structure was relatively independent of the identity of the species present suggests that canopy physical structure may be conserved even as canopy floristics shift due to changing climate.

(1) Research Highlights: The work studied the beta diversity patterns of epiphytic lichens as a function of their reproductive strategies in old-growth and non-old growth forests from the Mediterranean area. (2) Background and Objectives: The reproductive strategies of lichens can drive the dispersal and distribution of species assemblages in forest ecosystems. To further investigate this issue, we analyzed data on epiphytic lichen diversity collected from old-growth and non-old growth forest sites (36 plots) located in Cilento National Park (South Italy). Our working hypothesis was that the dispersal abilities due to the different reproductive strategies drove species beta diversity depending on forest age and continuity. We expected a high turnover for sexually reproducing species and high nestedness for vegetative ones. We also considered the relationship between forest continuity and beta diversity in terms of species rarity. (3) Materials and Methods: we used the Bray&ndash, Curtis index of dissimilarity to partition lichen diversity into two components of beta diversity for different subsets (type of forest, reproductive strategy, and species rarity). (4) Results: The two forest types shared most of the common species and did not show significant differences in alpha and gamma diversity. The turnover of specific abundance was the main component of beta diversity, and was significantly greater for sexually reproducing species as compared to vegetative ones. These latter species had also the least turnover and greater nestedness in old-growth forests. Rare species showed higher turnover than common ones. (5) Conclusions: Our results suggest that sexually reproducing lichen species always have high turnover, while vegetative species tend to form nested assemblages, especially in old-growth forests. The rarity level contributes to the species turnover in lichen communities. Contrary to what one might expect, the differences between old-growth and non-old growth forests are not strong.

Ecosystems of the Bialowieza Primeval Forest are characterized by a high degree of naturalness and biodiversity. Changes in species and age structure in the long-term period resulted from both natural processes and human impact (indirectly and directly). The assessment of changes and knowledge about the current state allows to decide what protective measures should be taken to improve the condition of forest ecosystems. One can also evaluate the processes taking place and their direction, and therefore also assess the need for any actions. In the conducted research, the changes occurring in forest ecosystems with particular emphasis on spruce were assessed. An almost 100-year process of evolution of the species share in stands was analyzed up to 2015 using historical forest management and present spatial information data. Habitat data were used to assess the suitable and unsuitable conditions for spruce dominance. In addition, long-term development model was used for forecasting of the share of this species using data from beginning of 2015. Those results were compared with data from more than 500 sample plots measured in 2016–2018, just after bark beetle (Ips typographus) outbreak in 2015. Spruce has doubled, from 12% to 25%, its share of the Bialowieza Forests area in the first half of 20th century and was stable for the second half. The development model run just before the outbreak suggested stable decrease of spruce share in the horizon of 2065 down to 23%. The habitat model from 2015 was suggesting that spruce suitable sites covered only 12% of the area and only 50% of that area being dominated by spruce; the residue growing in unfavorable habitat conditions. The recent outbreak, with no management control, has dwindled spruce share down below 9%, showing habitual model results being better than the development model scenario.

This paper explores which traits are correlated with fine-scale (0.25 m2) species persistence patterns in the herb layer of old-growth forests. Four old-growth beech forests representing different climatic contexts (presence or absence of summer drought period) were selected along a north–south gradient in Italy. Eight surveys were conducted in each of the sites during the period spanning 1999–2011. We found that fine-scale species persistence was correlated with different sets of plant functional traits, depending on local ecological context. Seed mass was found to be as important for the fine-scale species persistence in the northern sites, while clonal and bud-bank traits were markedly correlated with the southern sites characterised by summer drought. Leaf traits appeared to correlate with species persistence in the drier and wetter sites. However, we found that different attributes, i.e. helomorphic vs scleromorphic leaves, were correlated to species persistence in the northernmost and southernmost sites, respectively. These differences appear to be dependent on local trait adaptation rather than plant phylogenetic history. Our findings suggest that the persistent species in the old-growth forests might adopt an acquisitive resource-use strategy (i.e. helomorphic leaves with high SLA) with higher seed mass in sites without summer drought, while under water-stressed conditions persistent species have a conservative resource-use strategy (i.e. scleromorphic leaves with low SLA) with an increased importance of clonal and resprouting ability.

Headwater forest ecosystems of the western U.S. generate a large portion of the dissolved organic matter (DOM) transported across North America. Land cover changes that alter forest structure and forest species composition affect the quantity and composition of DOM transferred to aquatic ecosystems. Clear-cut harvesting effects ~1% of the forest area of North America annually, leaving most forests in varying stages of successional regrowth, and the total area of old-growth forest decreasing. The consequences of this widespread management practice on watershed carbon cycling remain unknown. We investigated the role of land cover change from old-growth subalpine forest to lodgepole pine dominated second-growth on the character and reactivity of DOM hillslope exports. We evaluated inputs of DOM from litter leachates and export of DOM collected at the base of trenched hillslopes during a three-year period (2016-2018) at the Fraser Experimental Forest in northcentral Colorado, USA. Dissolved organic carbon (DOC) and total dissolved nitrogen (TDN) were higher in lateral subsurface flow draining old- versus secondary-growth forest. Fluorescence spectroscopy showed that the DOM exported from the old-growth forest was more heterogeneous and aromatic and that proteinaceous, microbially processed DOM components were more prevalent in the second-growth forest. Biological oxygen demand (BOD) assays revealed much lower microbial metabolism of both DOM inputs from litter leachate and subsurface exports from old-growth forest. Old-growth and second-growth forests are co-mingled in managed ecosystems, and our findings demonstrate that the influence of species composition on DOM inputs can affect the reactivity of DOM transferred from terrestrial to aquatic ecosystems.

Quantification of leaf area index (LAI) is essential for understanding forest productivity and the atmosphere&ndash, vegetation interface, where the majority of gas and energy exchange occurs. LAI is one of the most difficult plant variables to adequately quantify, owing to large spatial and temporal variability, and few studies have examined the horizontal and vertical distribution of LAI in forest ecosystems. In this study, we demonstrated the LAI distribution in each layer from the understory to canopy using multiple-point measurements (121 points) and examined the relationships among layers in a cool-temperate deciduous forest. LAI at each point, and the spatial distribution of LAI in each layer, varied within the forest. The spatial distribution of LAI in the upper layer was more heterogeneous than that of LAI at the scale of the entire forest. Significant negative correlations were observed between the upper- and lower-layer LAI. Our results indicate that the understory compensates for gaps in LAI in the upper layer, thus, the LAI of the entire forest tends to remain spatially homogeneous even in a mature forest ecosystem.

Raul&iacute, (Nothofagus alpina (Poepp. &amp, Endl.)) and Ulmo (Eucryphia cordifolia Cav.) are mid-tolerant tree species in the Coihue-Raul&iacute, Tepa (ca. 0.55 mill ha) and Evergreen (ca. 4.1 mill ha) forest types in south-central Chile, respectively. These species have been selectively logged in old-growth forests especially during the 20th century, Raul&iacute, mostly for its highly valuable timber, and Ulmo for its highly demanded firewood and bark for the tannery industry. Natural regeneration of these species occurs mostly through canopy gaps, but it can be retarded, or even inhibited, when the cover of the understory vegetation becomes unusually dense, such as in high-graded forests. Although underplanting is possible for these species, the knowledge about their growth in forest understories is scarce, and necessary to inform restoration programs. Therefore, we evaluated short-term responses (two years) of underplanted containerized seedlings in root-collar diameter, height, stem volume, and in the slenderness index, as a function of canopy openness (%, continuous variable) and three restoration treatments (categorical variables, plus one control treatment) at two different sites with high-graded old-growth forests for each forest type. By using generalized linear mixed-effects models (GLMMs) we determined that Raul&iacute, was more sensitive to the influence of both canopy openness and restoration treatments, while Ulmo was mostly influenced by canopy openness. Specifically, Raul&iacute, was positively influenced by canopy openness and restoration treatments in all response variables except for the slenderness index. Conversely, Ulmo was influenced by canopy openness in all response variables except the slenderness index, which was influenced by both predictor variables (canopy openness and restoration treatments). Thus, prospects for restoration with these species are discussed, including possible ontogenetic changes in their responses to light that may demand continuous silvicultural operations to recover the productive and functional roles of these species in these forest ecosystems.

Globally, the conversion of primary forests to plantations and agricultural landscapes is a common land use change. Kauri (Agathis australis) is one of the most heavily impacted indigenous tree species of New Zealand with, Shifts in soil microbial communities surrounding fragmented kauri forests due to pine plantation establishment may impact forest health already under threat from the spread of an invasive pathogen.

Forest ecosystems are critical for adjusting the dynamic balance of the hydrological cycle. This balance is affected by vegetation community types, phenology, and forest density. Previous long-term catchment-scale model studies have focused on changes in forest areas while ignoring the above factors. Since the 1980s, climate change caused by increases in atmospheric CO2 levels has enhanced forest growth. Moreover, amendments to forest management policies, including intermediate cuttings caused by economic factors, have yielded unprecedented changes in forest ecosystems. In this study, we designed a methodology and created a credible model using the Soil and Water Assessment Tool (SWAT) that can precisely reflect water balance variations caused by different ecosystem situations during long-term changes in forest density. We focused on the Yamato River catchment in Western Japan, which includes three planted forests and one primeval forest, each markedly different with respect to vegetation community composition and management policy. In the process, we examined the ratio of coniferous vegetation and broad-leaved vegetation in different forest areas, used remote sensing methods to quantify the maximum and minimum leaf area index (LAI) of each forest region over 40 years, and calibrated the model by comparing the LAI growth curve, evapotranspiration, and streamflow with observed data. Moreover, we separated the decadal canopy evaporation, transpiration, and soil evaporation from the SWAT output results. We found that (1) forest evapotranspiration has increased in recent decades because of the above reasons; (2) in young or well-managed forests, the forest water balance may have changed significantly with forest growth. For long-term studies, it is necessary to distinguish the growth characteristics of different forests during different periods, and a detailed definition of a mixed forest is required. The forest parameters and growth characteristics are critical for understanding forest ecosystems and cannot be ignored at catchment-scale.

The combined effects of various disturbance types have lasting consequences on forest ecosystems and the services they provide. We examined inter-specific differences in the responses of European beech, silver fir and Norway spruce to canopy disturbance across four life stages (small seedlings, tall seedlings, saplings and pole-sized trees) in two Carpathian old-growth mixed beech forests located in the Gorce National Park (GNP) and Babia Gora National Park (BGNP), Poland. Both study sites were recently affected by spruce bark beetle outbreak. We compared the composition of tree regeneration between forest plots, canopy gaps and expanded areas (i.e. areas located under tree crowns). Moreover, we studied how various gap properties (size, expanded gap to canopy gap size ratio, shape) and other factors (browsing, plant and advanced regeneration cover) shaped regeneration patterns. Inter-specific differences in species abundance relative to gap properties and intra-specific differences in species response across various life stages to gap properties were found. Gap properties had more pronounced effects on saplings and pole-sized trees than on small and tall seedlings. Gap size had the most noticeable effect on beech across all regeneration classes. However, its effect varied from negative to positive depending on life stage. Pole-sized trees of all species responded positively to gap size. Thus, it seems that large gaps provided an opportunity for all species to recruit to canopy. Fir and spruce responded contrastingly to expanded gap to canopy gap size ratio, which reflects differences in their ability to adapt to high-intensity solar radiation. With the exception of beech, the ‘forest-gap’ gradient only affected trees in the advanced life stages (saplings and pole-sized trees). Beech and fir sapling densities and fir pole-sized tree densities were higher when under forest canopy, but spruce pole-sized trees were slightly more abundant in expanded areas. Browsing rates differed between the two study sites; they were more severe in BGNP, where deer densities in the last twenty years have been significantly higher. This intense deer browsing kept silver fir regeneration below the height of 0.5 m and prevented any recruitment to sapling stage. We conclude that even though the recent spruce mortality caused by bark beetle outbreak improved light conditions in both study areas, thus providing good regeneration opportunities to both beech and fir, deer browsing may have long-lasting effects on successional patterns by hindering fir recruitment in BGNP.

Increased nitrogen (N) deposition endangers the biodiversity and stability of forest ecosystems, and much of the original phosphorus (P) parent material continues to decrease in most lowland tropical forests. It remains poorly understood as to how soil microbial diversity at a molecular level responds to the addition of excess N and mitigation of soil P limitation, as well as their influencing factors, in the N-rich tropical forest ecosystems. To reach a better understanding, we conducted a six-year N and P-addition experiment consisting of three treatments: N-addition (150 kg N ha−1 yr−1), P-addition (150 kg P ha−1 yr−1), and NP-addition (150 kg N ha−1 yr−1 plus 150 kg P ha−1 yr−1), besides a control treatment in an old-growth tropical forest in southern China. We examined the snapshot responses of soil bacterial richness and community composition to the elevated N and P levels after six years using a 16S rRNA gene MiSeq sequencing method. The soil bacterial α-diversity, which is represented by Chao1 index in terms of bacterial richness, was 783 ± 87 (mean ± SD) across all samples in this study. The N addition caused a decline in soil bacterial richness, most likely through its negative effect on soil pH. The decrease in soil pH resulted from the direct N input and indirect NO3− increase. However, the P treatment had no effect on soil bacterial richness. The NP treatment also reduced the soil bacterial richness as the N addition. These results suggested that the P input could not alleviate the loss of soil bacterial richness induced by excess N deposition in the old-growth N-rich tropical forest. The Acidobacteria, which comprised 31.1% of the soil bacterial community, were the most dominant bacteria across all samples. The addition of P shifted the soil bacterial community composition. The elevated P availability with P-addition and the decreased understory plant coverage in the N-input treatment altered the soil bacterial β-diversity. Our results highlight the different roles of N and P depositions in shaping the soil bacterial richness and community composition, thereby causing concomitant changes in understory plant and underground microbial communities in this ecosystem.

Logging and restoration practices have significant impacts on the biodiversity of forest ecosystems. We studied the plant diversity patterns in temperate forests with different logging and restoration histories: the primary forest (no logging history), the secondary forest (natural recovery after logging) and the plantation forest (human planting after logging). In 2014 and 2015, we selected 12 plots with 24 trees, 48 shrub and 48 grass-herb quadrates on the southern slope of the Qinling Mountains in northwest China. We measured tree, shrub and grass-herb species in selected quadrates. Our results showed that: (1) the diversity indexes of the secondary and plantation forests were not significantly lower than those of the primary forests; (2) the secondary forest had the highest tree and shrub species richness, followed by the low-elevation primary forest and the plantation forest respectively; (3) the high-elevation primary forest had the most unique tree and grass-herb species while the low-elevation primary forest had the most unique shrub species; and (4) compared with the primary forests, the species composition similarity indexes of the secondary forest and plantation forest had little difference. Our results indicate that primary forests play an irreplaceable role in forest biodiversity whereas secondary forests and plantation forests are still of biodiversity importance. We suggest that primary forests should be prioritized for protection while natural recovery as secondary forests in Qinling temperate region is an effective approach for maintaining biodiversity.

The maintenance of old-growth stands is important for sustaining natural forest ecosystems, but fire disturbances and commonly-used timber harvest practices exert adverse impacts on the retention of old-growth forests. Forest management planning prescribes harvest levels based on the planning policy and models, but the impact of the management strategies on the retention of old-growth forests has not been well studied. The objectives of this study were to examine: a) the impact of implementing three different harvest policies on the retention of old-growth forest and b) the impact of implementing a policy of maintaining a targeted minimum of 20% old-growth area on the harvest revenue that would be generated over a long planning horizon. To simulate the implementation of these policies, we developed three strategic timber harvest-scheduling models. The first model (Model 1) maximizes harvest timber volume; Model 2 maximizes the net present value (NPV) of the timber harvested; and Model 3 maximizes the NPV of value-added products at the primary processing mills. The value-added products we considered were lumber, chips and sawdust. The models were solved for three forest management units with different fire regimes. Solutions to models that did not include a strict constraint on old-growth forest area retention did not retain the targeted level of old-growth forest over a 150-year planning horizon. When an old-growth constraint was implemented, Model 3 produced the greatest revenue with the least variation by 5-year period over the planning horizon. The probability of finding a feasible solution to our optimization Model 3 with an old-growth forest constraint increased to 0.87–1.0 compared with 0.71–0.83 using Model 1, and 0.78–0.87 using Model 2. We conclude that the value-added policy model increases the probability of sustaining the bioeconomy while preserving forest ecosystems initiated by disturbance.

Roztochya Nature Reserve is a nature conservation unit and research institution, which turned 33 years old. Therefore, it is important to summarize and make scientifically substantiated conclusions regarding the results of the introduction of an absolute reserve regime in this territory. The purpose of the work is to analyse the state of conservation and transformation of forest biodiversity in a time period of thirty-three years. The object of research is biodiversity of forests of Roztochya Nature Reserve. The subject of research is the processes of natural and anthropogenic transformation that took place on the territory of the protected object. The research methodology included the analysis of the Chronicle of Nature and scientific references devoted to research in the reserve. The influence of the protected regime on the state of conservation and transformation of ecosystems biodiversity in Roztochya Nature Reserve in the period of thirty-three years is described. The species composition of forest ecosystems is identified to remain stable. There were overgrown logs, where continuous felling was carried out before the formation of the reserve, therefore berries disappeared, which attracted certain species of birds and other animals, the processes of sylvatization extended to meadows in the vicinity of Lelehkhivka village and Zalyvky Tract. It is noted that about 33 % of the reserve is occupied by forests older than 100 years old, marked by the gradual extinction of old trees. There are gaps in old growth forests and a lot of dead wood, which is an important element of protected ecosystems. In the formed gaps there is an intensive natural regeneration of the maple, hornbeam, beech, and oak depending on the forest types and conditions of location. Long-term monitoring studies have shown that in the conditions of the reserve, the most stable ecosystems are beech forests that are capable for self-reproduction, the most productive and with a great variety of pine-oak-beech forests. The largest transformation in the last decades has been Zalyvky Tract, a meadow bog massif, in the floodplain of the Vereshchytsia River and its left tributary of Stavchanka. Thus, the positive influence of Roztochya Nature Reserve on the species richness and composition of the fauna and the animal population was noted.

Frugivorous birds or avian frugivores play important role in seed dispersal cycle and forest regeneration in forest ecosystem of Papua. Despite the high diversity of avian frugivores dwelling in Papuan rainforest, and the fact that this region faces alarming rate of forest disturbance, little is known of their current presence in the lowland forest habitat. We surveyed the variety of frugivorous birds in three different habitats of lowland forest in Cyclop Mountains Nature Reserve and Nimbokrang District. The methods used were line and point transects and identification was done during the survey. A total of 36 frugivorous birds from eight families was found in both sites. There were 33 species of 8 families in Nimbokrang forest and 16 species of 7 families were encountered in the Nature Reserve. The primary forest has high diversity of frugivorous birds compared to that in secondary forest and forest garden. It was found that several species of Family Columbidae such as Macropygia amboinensis, Ducula pinon dan Reindwaedtoena reinwardtii moved and foraged along the forest edge and also visited degraded areas that still provided vegetation trees and perches. These findings might have importance for forest management and reforestation programmes in Papuan lowland forest.Key words: Frugivorous birds, diversity, lowland forest, Mountain Cyclops Nature Reserve, Nimbokrang.

Knowledge on how historical disturbances shaped the long-term development of forests is essential for understanding the present forest structure and for predicting the future forest ecosystem dynamics. In this study, dendroecological methods were used to reconstruct the disturbance history of an old-growth subalpine larch (Larix chinensis) forest in the Qinling Mountains of north-central China. Growth patterns of 690 and 582 increment cores extracted respectively from two climatically and topographically different larch stands in the northern and southern slope of the Qinling Mountains were examined for abrupt increases in radial growth indicating formation of past canopy gaps and for rapid early growth rates indicating recruitment in former canopy gaps. The findings demonstrated that there were no large-scale, stand-replacing disturbances during the past more than two centuries. Low- and medium-severity disturbance events predominated, which were probably caused by windthrows due to strong winds. The stand was unevenly aged, and the recruitment pulses associated with disturbance peaks could be distinguished. There were considerable spatio-temporal differences in disturbance dynamics of the subalpine larch stand between the topographically and climatically different sites, manifesting that the larch stand in the northern slope experienced frequent moderate but rare major disturbance events, contrasting with frequent major and moderate disturbance events in the southern slope. This study provided strong evidences that there were substantial variations in the intensity and frequency of disturbance dynamics, leading to considerable differences in the size and age structures of the subalpine larch forest.