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Background: Mineral-rich licks are known to provide mineral supplements to wildlife species, including mammals. Artificial salt licks have been provided as habitat enrichment in protected areas and secondary forests in Peninsular Malaysia since 2012. However, few studies have investigated artificial salt licks, particularly their mineral composition and roles in different habitats. We used 40 camera traps to assess mammal species diversity and assemblages at 20 salt licks (nine natural and 11 artificial licks) in three forest reserves in Peninsular Malaysia. Nine mineral elements from water and soil samples from natural and artificial licks in primary and secondary forests were analysed. Results: Twenty-nine mammal species were identified across salt licks, with 16 species being salt lick users, including eight herbivorous, five frugivorous and three carnivorous mammals, most of which moved in groups and solitarily. The mammal species assemblages across both salt lick and habitat types demonstrated a predominantly nested pattern, with herbivorous and frugivorous mammals being the primary users. The artificial salt licks in both habitats showcased the same feeding guilds including species that are resilient to habitat changes. The visitation frequency at both types of licks and habitats suggests that each salt lick user had its own preferences for minerals from salt lick water and soil. Conclusions: This study suggests that artificial licks may be as effective as natural licks in providing minerals to many mammal species both in primary and secondary forests. Thus, they could be used to enrich degraded habitats. Enriching degraded habitats is essential for supporting the ecosystem, especially in carbon reduction, biodiversity conservation and connectivity between degraded forests and intact forests. [ABSTRACT FROM AUTHOR]

Context: Clearcutting of forests reduces food, cover, and stand structure attributes for tree squirrels (Tamiasciurus hudsonicus , Glaucomys sabrinus), small mustelids (Mustela richardsonii , Neogale frenata), and other mammal species. Forest restoration is urgently needed and stand thinning of second-growth forests may help restore habitats for mammals. Aims: We tested the hypotheses that in thinned stands of second-growth lodgepole pine (Pinus contorta var. latifolia) at 30–36 years post-thinning: (H1) tree dimensions would be comparable to, or higher than those in uncut old-growth forest; activity of tree squirrels, weasels, and mammalian species richness would be higher in (H2) heavily thinned than lightly thinned stands, and (H3) higher in uncut old-growth forest than in second-growth thinned stands. Methods: We measured stand structure attributes and activity of tree squirrels, weasels, and mammalian species richness with camera traps from 2021 to 2023 in replicated (n = 3) treatments of three densities of thinned pine stands and uncut old-growth forest in south-central British Columbia (BC), Canada. Key results: Thinned and old-growth stands had mean tree diameters ranging from 18 to 22 cm, but mean tree heights were highest in the old-growth stands. Low-density stands tended to have large diameter crop trees with substantial crowns. There was no evidence for a difference in mean activity of T. hudsonicus and G. sabrinus , other common mammal species, and overall species richness among stands. There were more weasel detections per camera-day in the low-density and old-growth stands than other thinned stands. Conclusions: Comparison of stand structure attributes showed partial support for H1. There was insufficient evidence to detect biologically meaningful effects among stands in a mean index of activity for T. hudsonicus , G. sabrinus , other common mammal species, and overall species richness, and hence did not support H2 or H3. There was weak support for H2 and H3 with limited weasel activity. Implications: Thinned second-growth stands ≤1000 stems/ha may provide habitat at least for the mammal species and post-treatment period outlined in this study. To our knowledge, this is the first convergence of managed coniferous stands (age 43 years) with old-growth forest (age 140–187 years) in terms of some components of stand structure and mammalian species richness. Forest restoration strategies are most successful when they accelerate development of habitat features that support wildlife. We evaluated mammal use of second-growth lodgepole pine stands that had been thinned. Thinned stands provided habitats for tree squirrels, weasels, and mammalian species richness at 30–36 years after treatment. Availability of wildlife habitats in managed stands may converge with those of older natural stands. Photograph by T. Sullivan. [ABSTRACT FROM AUTHOR]

Primary forests are of paramount importance for biodiversity conservation and the provision of ecosystem services. In Europe, these forests are scarce and threatened by human activities. However, a comprehensive assessment of the magnitude of disturbances in these forests is lacking, due in part to their incomplete mapping. We sought to provide a systematic assessment of disturbances in primary forests in Europe based on remotely sensed imagery from 1986 to 2020. We assessed the total area disturbed, rate of area disturbed, and disturbance severity, at the country, biogeographical, and continental level. Maps of potential primary forests were used to mitigate gaps in maps of documented primary forests. We found a widespread and significant increase in primary forest disturbance rates across Europe and heightened disturbance severity in many biogeographical regions. These findings are consistent with current evidence and associate the ongoing decline of primary forests in Europe with human activity in many jurisdictions. Considering the limited extent of primary forests in Europe and the high risk of their further loss, urgent and decisive measures are imperative to ensure the strict protection of remnants of these invaluable forests. This includes the establishment of protected areas around primary forests, expansion of old‐growth zones around small primary forest fragments, and rewilding efforts. [ABSTRACT FROM AUTHOR]

Abstract Background Mineral-rich licks are known to provide mineral supplements to wildlife species, including mammals. Artificial salt licks have been provided as habitat enrichment in protected areas and secondary forests in Peninsular Malaysia since 2012. However, few studies have investigated artificial salt licks, particularly their mineral composition and roles in different habitats. We used 40 camera traps to assess mammal species diversity and assemblages at 20 salt licks (nine natural and 11 artificial licks) in three forest reserves in Peninsular Malaysia. Nine mineral elements from water and soil samples from natural and artificial licks in primary and secondary forests were analysed. Results Twenty-nine mammal species were identified across salt licks, with 16 species being salt lick users, including eight herbivorous, five frugivorous and three carnivorous mammals, most of which moved in groups and solitarily. The mammal species assemblages across both salt lick and habitat types demonstrated a predominantly nested pattern, with herbivorous and frugivorous mammals being the primary users. The artificial salt licks in both habitats showcased the same feeding guilds including species that are resilient to habitat changes. The visitation frequency at both types of licks and habitats suggests that each salt lick user had its own preferences for minerals from salt lick water and soil. Conclusions This study suggests that artificial licks may be as effective as natural licks in providing minerals to many mammal species both in primary and secondary forests. Thus, they could be used to enrich degraded habitats. Enriching degraded habitats is essential for supporting the ecosystem, especially in carbon reduction, biodiversity conservation and connectivity between degraded forests and intact forests.

Following old‐growth forest loss and subsequent land abandonment, secondary forest grows throughout the Amazon biome. For Amazonas, agricultural colonization was unsuccessful in many regions, leading to the regeneration of secondary forest and carbon storage under favorable climate conditions. Herein, the extent of regeneration in Amazonas and its timescale are investigated, including a granular analysis of its 62 municipalities, based on the MapBiomas dataset from 1985 to 2021. By 2021, 10,495 km2 of secondary forest had grown, corresponding to 28% of the lost old‐growth forest. After normalization for algorithmic differences, this estimate was 17%–38% lower than prior studies for Amazonas that used earlier versions of the MapBiomas dataset, indicating increased accuracy in landcover assignments for more current versions of the dataset. For the northeastern microregion, representing the 15 municipalities of economic and population dominance in Amazonas, the growth of secondary forest varied from 3.0% to 9.8% of the total land area. For the southern microregion, constituting seven municipalities adjacent to large‐scale deforestation of Mato Grosso and Rondônia, regeneration of secondary forest constituted 0.4%–1.2% of the land area. For the remaining interior municipalities, the regeneration was 0.0%–1.9%. Among the municipalities, the median regeneration interval, corresponding to the duration between the loss of old‐growth forest and the appearance of secondary forest, ranged from 2 to 7 years. The median regeneration intervals of the interior, northeastern, and southern microregions were 3, 4, and 5 years, respectively. Even as the secular trend of deforestation continues in the Amazon biome and encroaches into the southern border of Amazonas state, the results herein indicate a possible resiliency toward secondary forest for undisturbed land on a timescale of several years, at least for mixed pasture‐forest landscapes of kilometer‐scale heterogeneity and assuming that a favorable climate persists for regeneration even as global change occurs. [ABSTRACT FROM AUTHOR]

Restoration of the pool of coarse woody debris after disturbances is one of the mechanisms for maintaining the stability of forest biogeocenoses. The studies of coarse woody debris have been carried out in the “Vepssky Forest” Reserve in the Leningrad Region on 8 sample plots established in primary forests (4 sample plots) and in secondary forests of the 1st generation after logging in 1973–1974 (4 sample plots), where the composition and structure of the stand, as well as the site conditions have been identical to those in primary forests. The coarse woody debris has been inventoried on transects. The stocks of coarse woody debris in primary stands have ranged from 104 to 233 m3 ha–1. Windfall and leaning trees have prevailed. The proportion of deadwood in both primary and secondary forests has been low. Clear cutting has significantly changed not only the stock of coarse woody debris, but also its distribution by decay classes and substrate categories. The stocks of coarse woody debris in secondary forests have ranged from 8 to 40 m3 ha–1, and have been mainly represented by stumps. The coarse woody debris of the 4th and 5th decay classes has almost been absent in primary forests, while in secondary forests the proportion of highly decomposed wood remaining after cutting has been about 50 %. The ratio of coarse woody debris and growing stocks has been on average 1:1 and 1:5 in the biogeocenoses of primary and secondary forests, respectively. The annual carbon balance of coarse woody debris (the difference in fluxes due to the loss of growing forest and the decay of coarse woody debris) has ranged from 0,40 to 2,80 t C ha–1 year–1, averaging 1,75 and 0,63 t C ha–1 year–1 in secondary and primary forests, respectively. The positive annual carbon balance in the coarse woody debris is due to the predominance of the rate of the loss of growing forest over the rate of the decay of coarse woody debris in primary forests as a result of wind disturbances and as a result of self-thinning of the stand in secondary forests.

This study examines the structural dynamics and species composition of the "Ravna Vala" old-growth forest on Bjelašnica Mountain, focusing on neighborhood effects on tree growth. Data from a permanent 1-hectare plot, measured 2012 and 2023, revealed that silver fir (Abies alba Mill.) constitutes nearly 73% of the total volume, while beech (Fagus sylvatica L.) dominates in tree numbers. The forest displays a reverse J-curve pattern, with significant mortality in smaller diameter classes. Using indices for species intermingling, aggregation, and competition, the study found that diameter at breast height (dbh) and the aggregation index significantly influenced growth, especially for silver fir and beech. Additional factors like the mixing index and competition index were significant for beech growth. These results underscore the complexity of species interactions and the importance of tailored management strategies. Future research should explore factors limiting fir regeneration and the link between disturbances and beech recruitment. Management practices that mimic natural disturbances, such as creating larger gaps, are recommended to enhance species diversity and forest resilience. [ABSTRACT FROM AUTHOR]

Secondary tropical forests play an increasingly important role in carbon budgets and biodiversity conservation. Understanding successional trajectories is therefore imperative for guiding forest restoration and climate change mitigation efforts. Forest succession is driven by the demographic strategies—combinations of growth, mortality and recruitment rates—of the tree species in the community. However, our understanding of demographic diversity in tropical tree species stems almost exclusively from old‐growth forests. Here, we assembled demographic information from repeated forest inventories along chronosequences in two wet (Costa Rica, Panama) and two dry (Mexico) Neotropical forests to assess whether the ranges of demographic strategies present in a community shift across succession. We calculated demographic rates for >500 tree species while controlling for canopy status to compare demographic diversity (i.e., the ranges of demographic strategies) in early successional (0–30 years), late successional (30–120 years) and old‐growth forests using two‐dimensional hypervolumes of pairs of demographic rates. Ranges of demographic strategies largely overlapped across successional stages, and early successional stages already covered the full spectrum of demographic strategies found in old‐growth forests. An exception was a group of species characterized by exceptionally high mortality rates that was confined to early successional stages in the two wet forests. The range of demographic strategies did not expand with succession. Our results suggest that studies of long‐term forest monitoring plots in old‐growth forests, from which most of our current understanding of demographic strategies of tropical tree species is derived, are surprisingly representative of demographic diversity in general, but do not replace the need for further studies in secondary forests. [ABSTRACT FROM AUTHOR]

Forest fires and logging drive the structure of boreal forest landscapes. According to recent studies, stand origin is a key driver of the variation in wood properties in black spruce (Picea mariana (Mill.) BSP.), although the underlying mechanisms remain to be elucidated. By comparing post-cut, post-fire and old-growth forests, this study aimed to better distinguish the effects of stand structure from those of the seed or layer origin of the trees on wood properties. We conducted comparative analyses based on ecological characteristics of the sites and static bending tests of small, defect-free wood specimens. Black spruce stands with a regular structure established after logging or fire exhibited higher stiffness at a given cambial age than old-growth forests with irregular structures, as well as lower wood density in the first 40 rings near the pith. However, the bending strength was comparable in all three types of forests studied. Differences in wood stiffness among stand types appeared to be driven more by stand structure than by the seed or layer origin of the stems. [ABSTRACT FROM AUTHOR]

Background and objectives: Forests are one of the most significant sources of species diversity in the biosphere, playing a crucial role in protecting endangered species. With a total of 115 indigenous plant species, Hyrcanian forests are considered one of the most valuable ecosystems in Iran and the world. Deadwood is one of the significant structural characteristics of these natural forests. Deadwood, as habitat trees, plays an essential role in maintaining biodiversity. Saproxylic species are invertebrates that depend on rotting wood, deadwood (standing or fallen), fungi, and other living organisms during part of their life cycle. Therefore, this study investigates and analyzes the need to replace the proposed word خشک دارزی instead of "saproxylic." Methodology: The method in this study involved a review of previous studies and the authors' research related to the comprehensive plan of saproxylic species diversity in northern Iran. Based on this, the study investigates and evaluates the most important reasons for using the Persian word خشک دارزی instead of "saproxylic" in seven different cases. These include a specialized review of the word "saproxylic," examining the distinction between obligatory and optional users of deadwood, estimating species related to deadwood, analyzing the variables affecting the abundance of saproxylic individuals, the relationship between the loss of biodiversity of Saproxylic species and the absence of deadwood, forest plantations and saproxylic individuals, and comparing the word "خشک دارزی with other similar words. Results: The specialized examination of the word "saproxylic" showed that this term forms the basis of biodiversity assessment in deadwood and describes insects living in decaying wood. Saproxylic organisms (hereafter: خشک دارزی ) directly and indirectly use deadwood as a source of energy or habitat. Twenty to twenty-five percent of the insects living in the forest are species related to deadwood. The results of examining the variables affecting the abundance of Saproxylic individuals showed that deadwood volume, the degree of deadwood decay, and the volume of living trees had significant effects on the frequency of Saproxylic individuals. Various studies also showed the relationship between the loss of biodiversity of Saproxylic individuals and the absence of deadwood, with traps (window and pit) always installed where deadwood is present. On the other hand, although plantations for wood production are one of the most important sources of wood on a wide scale, there is no sign of deadwood and, consequently, no presence of saproxylic individuals in these areas compared to natural forests. While the meaning of deadwood is a dried tree, in nature, deadwood is not always a completely dead tree. In many cases, only part of the trunk or crown of the tree is dead, while other parts are healthy. This term is known to all experts in forest ecology as referring to any part of a completely dead tree, aligning with the term deadwood. Conclusion: Therefore, the word "خشک دارزی instead of "Saproxylic" can effectively describe this category of species in the Persian language. Finally, the necessity of replacing non-Persian words with suitable Persian words and equating these words in scientific research writings, while preserving their expressive meaning in Persian, can be a positive step towards specialized vocabulary. [ABSTRACT FROM AUTHOR]

The reverse J-shaped diameter distribution is considered an inherent attribute of natural forests, crucial for forest resource utilization and community stability. However, in karst regions, intense habitat heterogeneity might alter species composition, spatial distribution, growth, biomass allocation, and mortality processes, yet its impact on diameter structure remains unclear. A fixed plot of 200 m × 110 m was established in the Nanpan River Basin, Southwest China, within an old-growth oak forest (> 300 years old), and the influence of site substrates (i.e., rock and soil), topographic factors, sample area, and orientation on diameter distribution was analyzed. Trees on both rock and soil exhibited a reverse-J shape, quantifiable through the Weibull function. The substrates had a similar density, approximately 2100 plants/ha. However, the average and range of diameter of trees on rock were smaller than those on soil, suggesting that rock constrains tree growth. The diameter distribution of trees across microtopography also displayed a reverse-J shape. Yet, higher elevations and sunny slopes showed a greater curvature of diameter classes compared to lower elevations and shady slopes, indicating habitat preferences in karst trees. Sample area and orientation had minimal effects on diameter class curve that reached stability when the plot size was 6000 m2. These results suggest that the reverse J-shaped diameter distribution prevails at small scales in karst old-growth forests, encompassing multiple curvatures and spanning forest ecosystems. [ABSTRACT FROM AUTHOR]

Forest diversity is the outcome of multiple species-specific processes and tolerances, from regeneration, growth, competition and mortality of trees. Predicting diversity thus requires a comprehensive understanding of those processes. Regeneration processes have traditionally been overlooked, due to high stochasticity and assumptions that recruitment is not limiting for forests. Thus, we investigated the importance of seed production and seedling survival on forest diversity in the Pacific Northwest (PNW) using a forest gap model (ForClim). Equations for regeneration processes were fit to empirical data and added into the model, followed by simulations where regeneration processes and parameter values varied. Adding regeneration processes into ForClim improved the simulation of species composition, compared to Forest Inventory Analysis data. We also found that seed production was not as important as seedling survival, and the time it took for seedlings to grow into saplings was a critical recruitment parameter for accurately capturing tree species diversity in PNW forest stands. However, our simulations considered historical climate only. Due to the sensitivity of seed production and seedling survival to weather, future climate change may alter seed production or seedling survival and future climate change simulations should include these regeneration processes to predict future forest dynamics in the PNW. This article is part of the theme issue 'Ecological novelty and planetary stewardship: biodiversity dynamics in a transforming biosphere'. [ABSTRACT FROM AUTHOR]

Successional, second-growth forests dominate much of eastern North America; thus, patterns of biomass accumulation in standing trees and downed wood are of great interest for forest management and carbon accounting. The timing and magnitude of biomass accumulation in later stages of forest development are not fully understood. We applied a "chronosequence with resampling" approach to characterize live and dead biomass accumulation in 16 northern hardwood stands in the White Mountains of New Hampshire. Live aboveground biomass increased rapidly and leveled off at about 350 Mg/ha by 145 years. Downed wood biomass fluctuated between 10 and 35 Mg/ha depending on disturbances. The species composition of downed wood varied predictably with overstory succession, and total mass of downed wood increased with stand age and the concomitant production of larger material. Fine woody debris peaked at 30–50 years during the self-thinning of early successional species, notably pin cherry. Our data support a model of northern hardwood forest development wherein live tree biomass accumulates asymptotically and begins to level off at ∼140–150 years. Still, 145-year-old second-growth stands differed from old-growth forests in their live (p = 0.09) and downed tree diameter distributions (p = 0.06). These patterns of forest biomass accumulation would be difficult to detect without a time series of repeated measurements of stands of different ages. [ABSTRACT FROM AUTHOR]

This study discusses changes observed in the vascular flora of an old-growth forest on Dome Island in Lake George over a 50-yr period and compares it with observations made by two earlier studies. Our initial surveys conducted in 1973 identified 133 taxa. Repeated surveys brought the total to 165 taxa. During this period one canopy species that was prominent in 1973, Pinus resinosa Aiton, disappeared entirely by 2015. Although nonnative species became established on the island at least as early as 1961, only 16 taxa identified on the island are nonnative, including 3 species considered invasive in New York. Most of the nonnative species are found along the margins of the island, carried to the island from the mainland either by wave action, by birds, or accidentally by people attempting to control shoreline erosion. [ABSTRACT FROM AUTHOR]

The article presents the results of a lichenological inventory carried out in the "Tabórz Pine" nature reserve, which protects a unique old-growth forest dominated by Scots pine and European beech. The aim of the research was to document the taxonomic and ecological diversity of the lichen biota in the reserve and, on this basis, determine the role and importance of this site as a refuge for stenoecious forest lichens. In an area of 95.32 ha, 118 species of lichens were found, including 43 species included in the Polish national Red List along with 17 species having the status of lowland old-growth forests in Poland. These values allow the reserve to be included in the group of important forest lichen refuges in north-eastern Poland. The obtained results also prove that mixing tree species with complementary ecological features can modify the functioning of the forest not only in terms of its economic features, but also its ecological role in shaping and protecting the species diversity of forest lichens. [ABSTRACT FROM AUTHOR]

Although anthropogenic climate change has resulted in significant alterations of ocean environments, the degree to which marine organisms can respond behaviorally to climate effects remains poorly understood, especially for species with increased extinction risk. We monitored marine space use and movement of the threatened marbled murrelet (Brachyramphus marmoratus) along the central coast of Oregon, USA during the 2017–2019 breeding seasons to quantify marine habitat selection patterns across a range of ocean conditions. We hypothesized that marine locations characterized by upwelling, nearshore areas adjacent to old-growth forest nesting habitat, and protected marine areas would be preferentially selected by tagged birds. Using >4800 locations collected from >180 individuals, we found that murrelets selected areas near small estuaries and with localized upwelling (as characterized by decreased sea-surface temperatures and high salinity), both of which are expected to lead to greater food availability during periods when sea-surface temperatures are elevated and coastal upwelling is reduced (i.e., poor ocean conditions). In addition, we found that individuals did not preferentially select marine areas adjacent to potential old-growth nesting habitat, and that murrelets exhibited limited overlap with protected marine areas regardless of ocean conditions. Unexpectedly, the majority (62%) of tagged individuals moved beyond the boundaries of our 135-km long study area in the year with the poorest ocean conditions (2017), with 15% of birds moving >500 km from their capture location. Our results confirm that marine habitat selection in murrelets becomes decoupled from terrestrial nesting habitat during periods of poor ocean conditions, and that such conditions are associated with low breeding propensity and long-distance movements during the breeding season. In addition to demonstrating murrelets undertake fine- and coarse-scale movements to buffer against poor ocean conditions, our study also emphasizes the importance of considering broad spatial scales in the marine environment when undertaking measures to conserve murrelet populations.

Aims: The few remaining old-growth forests in the northeastern United States are often comprised of ectomycorrhizal (EM) tree-dominated patches surrounded by arbuscular mycorrhizal (AM) tree-dominated secondary forests. We examined how (1) distance from old growth and tree neighborhood composition influenced EM colonization, fungal richness, and fungal community composition of Betula lenta L. (black birch) seedlings, a common EM tree that colonizes abandoned agricultural fields, and (2) potential effects of EM fungal genera on seedling physiological performance. Methods: We sampled soils and tree composition from the edge of an EM-dominated old-growth forest into an adjacent AM-dominated secondary forest. We used soils to grow black birch seedlings in a growth chamber bioassay. We measured seedling EM colonization and investigated effects of EM fungi and soil characteristics on seedling physiological performance. Results: We identified 20 EM fungal species and found decreases in EM colonization and fungal richness with distance from old growth, with many taxa present only near the edge. Neighborhood EM tree abundance best explained EM colonization while distance interacted with EM tree basal area to best explain EM fungal richness of seedlings. Soils from neighborhoods lacking EM trees resulted in sparse EM colonization of seedlings. We found no clear effects of EM fungal genera on seedling performance, but we detected a slight decrease in seedling photosynthetic rate with distance from old growth. Conclusions: Old-growth forests can be reservoirs of EM fungi, and EM tree patches can function as localized inoculum sources in AM-dominated secondary forests, potentially facilitating EM tree establishment. [ABSTRACT FROM AUTHOR]

In boreal old-growth forests, advance regeneration typically attains canopy dominance through growth release events following partial disturbances. We sampled competing Picea mariana (Mill.) and Abies balsamea (L.) in disturbed old-growth stands in Quebec, Canada, to understand the intra- and interspecific size hierarchy development. We reconstructed tree size development and examined the role of initial size difference, time between germination and a disturbance, and the strength of response to the disturbance in determining tree size hierarchies. Trees that regenerated first generally dominated their intraspecific competitors also following a disturbance event. However, prolonged time between germination and disturbance resulted in a less deterministic outcome. Tree size difference prior to disturbance also influenced the development of size hierarchies. In interspecific competition between individuals of the same diameter, A. balsamea had a 61% probability of gaining dominance over P. mariana, the probability being 50% if P. mariana was 5 mm larger than A. balsamea. Dominant trees generally had the strongest response to the disturbance, reinforcing the existing size hierarchies. The largest trees typically gain dominance after a partial disturbance. However, interspecific competition is less predictable than intraspecific competition, small initial size difference, and prolonged time in suppression potentially changing tree size hierarchies. [ABSTRACT FROM AUTHOR]

Copyright of Fire Ecology is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Understanding how habitat fragmentation affects individual species is complicated by challenges associated with quantifying species‐specific habitat and spatial variability in fragmentation effects within a species' range. We aggregated a 29‐year breeding survey data set for the endangered marbled murrelet (Brachyramphus marmoratus) from >42,000 forest sites throughout the Pacific Northwest (Oregon, Washington, and northern California) of the United States. We built a species distribution model (SDM) in which occupied sites were linked with Landsat imagery to quantify murrelet‐specific habitat and then used occupancy models to test the hypotheses that fragmentation negatively affects murrelet breeding distribution and that these effects are amplified with distance from the marine foraging habitat toward the edge of the species' nesting range. Murrelet habitat declined in the Pacific Northwest by 20% since 1988, whereas the proportion of habitat comprising edges increased by 17%, indicating increased fragmentation. Furthermore, fragmentation of murrelet habitat at landscape scales (within 2 km of survey stations) negatively affected occupancy of potential breeding sites, and these effects were amplified near the range edge. On the coast, the odds of occupancy decreased by 37% (95% confidence interval [CI] –54 to 12) for each 10% increase in edge habitat (i.e., fragmentation), but at the range edge (88 km inland) these odds decreased by 99% (95% CI 98 to 99). Conversely, odds of murrelet occupancy increased by 31% (95% CI 14 to 52) for each 10% increase in local edge habitat (within 100 m of survey stations). Avoidance of fragmentation at broad scales but use of locally fragmented habitat with reduced quality may help explain the lack of murrelet population recovery. Further, our results emphasize that fragmentation effects can be nuanced, scale dependent, and geographically variable. Awareness of these nuances is critical for developing landscape‐level conservation strategies for species experiencing broad‐scale habitat loss and fragmentation. [ABSTRACT FROM AUTHOR]

Old-growth forests (OGF) provide valuable ecosystem services such as habitat provision, carbon sequestration or recreation maintaining biodiversity, carbon storage, or human well-being. Long-term human pressure caused OGFs in Europe to be rare and scattered. Their detailed extent and current status are largely unknown. This review aims to identify potential methods to map temperate old-growth forests (tOGF) by remote sensing (RS) technology, highlights the potentials and benefits, and identifies main knowledge gaps requesting further research. RS offers a wide range of data and methods to map forests and their properties, applicable from local to continental scale. We structured existing mapping approaches in three main groups. First, parameter-based approaches, which are based on forest parameters and usually applied on local to regional scale using detailed data, often from airborne laser scanning (ALS). Second, direct approaches, usually employing machine learning algorithms to generate information from RS data, with high potential for large-area mapping but so far lacking operational applications and related sound accuracy assessment. Finally, indirect approaches integrating various existing data sets to predict OGF existence. These approaches have also been used for large area mapping with a main drawback of missing physical evidence of the identified areas to really hold OGFs as compared to the likelihood of OGF existence. In conclusion, studies dealing with the mapping of OGF using remote sensing are quite limited, but there is a huge amount of knowledge from other forestry-related applications that is yet to be leveraged for OGF identification. We discuss two scenarios, where different data and approaches are suitable, recognizing that one single system cannot serve all potential needs. These may be hot spot identification, detailed area delineation, or status assessment. Further, we pledge for a combined method to overcome the identified limitations of the individual approaches. [ABSTRACT FROM AUTHOR]

Copyright of Forestry Chronicle is the property of Canadian Institute of Forestry and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Beech stands are considered part of the ancient forest ecosystems in the northern hemisphere. In mixed stands in beach forest ecosystems, the type of associated tree species can significantly affect soil functions, but their influence on microbial activity, nutrient cycling and belowground properties is unknown. Here, we considered forest patches in northern Iran that are dominated by different tree species: Fagus orientalis Lipsky, Quercus castaneifolia C. A. Mey., Pterocarya fraxinifolia (Lam.), Tilia begonifolia Stev., Zelkova carpinifolia Dippe, Acer cappadocicum Gled, Acer velutinum Boiss., Fraxinus excelsior L., Carpinus betulus L., and Alnus subcordata C. A. Mey. For each forest patch–tree species, litter and soil samples (25× 25 × 10 cm, 100 of each) were analyzed for determine soil and litter properties and their relationship with tree species. The litter decomposition rate during a 1-year experiment was also determined. A PCA showed a clear difference between selected litter and soil characteristics among tree species. F. orientalis, Q. castaneifolia, P. fraxinifolia, T. begonifolia, Z. carpinifolia, A. cappadocicum, and A. velutinum enhanced soil microbial biomass of carbon, whereas patches with F. excelsior, C. betulus and A. subcordata had faster litter decomposition and enhanced biotic activities and C and N dynamics. Thus, soil function indicators were species-specific in the mixed beech forest. A. subcordata (a N-fixing species), C. betulus and F. excelsior were main drivers of microbial activities related to nutrient cycling in the old-growth beech forest. [ABSTRACT FROM AUTHOR]

Among the protected sites of the Eastern Carpathians, the Synevyr National Nature Park (NNP) in the Zakarpattia region of Ukraine is one of the most valuable and was created to preserve its unique mountain beech and spruce forest communities. The importance of the conservation of typical natural virgin forest ecosystems of the Central European mountain systemis emphasized. The aim of this article was to determine the state of the naturalness of virgin forests in the territory of Synevyr NNP, to analyse their syntaxonomy, and to establish the floristic and geobotanical characteristics of its virgin forests and to distinguish the existing biodiversity threats. It was established that the studied plots of beech and spruce forests within the territory of the Synevyr NNP have a distinct virgin nature based on their structure, forest valuation parameters, spontaneous dynamics and other features. Syntaxonomically the virgin forests of the park belong to two associations: Symphyto cordati-Fagetum Vida (1959) 1963 (alliance Fagion sylvaticae Luquet 1926, order Fagetalia sylvaticae Pawłowski 1928, class Сarpino-Fagetea sylvaticae Jakucs ex Passarge 1968) and Luzulo luzuloidis-Fagetum (Du Rietz 1923) Markgraf 1932 (alliance Luzulo-Fagion sylvaticae Lohmeyer & Tx. in Tx. 1954, order Luzulo-Fagetalia Scamoni & Passarge 1959, class Quercetea roboripetraeae Br.-Bl. & Tx. ex Oberd. 1957). The natural and anthropogenic biodiversity threats of these virgin forests are summarized. The results of the research formed the basis for the inclusion of the beech virgin forests of Synevyr NNP as a UNESCO World Heritage Site in the list of objects on “Beech virgin forests and ancient forests of the Carpathians and other regions of Europe”.

Habitat loss is a potential long-term effect of projected climate change for Mediterranean forest ecosystems. Here, we investigated the effectiveness of a close-to-nature silvicultural practice to conserve an old-growth white oak forest patch in Sicily (Italy) and promote regeneration dynamics. The study area, although small, is distinctive for its isolation, position and environmental characteristics. We conducted a Before–After Control–Impact (BACI) study to analyse the responses of different taxonomic groups (vascular plants and birds) to silvicultural treatments (selection thinning, no thinning), and to determine whether close-to-nature silviculture practices may cause significant shifts in the investigated communities. Specifically, we assessed the responses of (1) vascular plants by means of species diversity and taxonomic distinctness indices and (2) birds in terms of diversity, abundance and forest specialisation. Preliminary results suggest that cautious close-to-nature silviculture practice could—by mimicking natural gap dynamics—contribute to maintaining old-growth forest patches and promote oak seedling emergence without short-term detrimental impacts on biodiversity. Although the monitoring has to be repeated over the long-term, the multi-taxon approach and indices incorporating information on taxonomic relationships into diversity measures were demonstrated to be valuable tools for interpreting biotic community structure and dynamics. [ABSTRACT FROM AUTHOR]

The changing climate is worsening the threats to forests, such as insect outbreaks, fires, and drought, especially old-growth forest, which is more susceptible to disturbance. Therefore, it is important to detect the disturbance areas, identify the disturbance agents, and evaluate the disturbance intensity in old-growth forest. We tried to derive the forest disturbance information based on multiple remote sensing datasets (Global Forest Change, MODIS, and ERA5-Land) from 2000 to 2021 in Changbai Mountain, Northeast China, and explored their relationship with climate factors. The results showed that (1) wind damage and insect outbreaks are two main forest disturbance agents, (2) the increasing temperature during overwintering periods and the decreasing precipitation during activity periods increase the risk of insect outbreaks, and (3) disturbances lead to significant changes in forest structure and functional indices, which can be well captured by the remote sensing data. In the study, we creatively combined low-frequency remote sensing images and high-frequency meteorological data to determine the specific time of wind damage. The final results suggested that the vulnerability of old-growth forest to climate change may be mainly reflected through indirect implications, such as the increased risk of strong winds and insect disturbances. [ABSTRACT FROM AUTHOR]

The present study aims to analyze the set-aside effect on the current structure diversity of mountain temperate forests from the Natura 2000 site Rarău-Giumalău. In the past 80 years, the area of entirely protected forests successively increased to up to 77% of the site. The description of past structure diversity was based on the analysis of management plans drawn up for these ecosystems after 1940, while their current structure diversity was based on a tree census carried out in 2015. The forests' structure diversity was described in relation to: tree dimensional heterogeneity; wood volumes homogeneity of the living trees throughout the site; variability of the standing and lying dead wood volume; number and basal area of large trees; natural regeneration. The results show that forest stands where no harvest has ever been registered record the highest level of tree size heterogeneity, while in previously managed forests, the current structure diversity was influenced by the harvesting intensity. The dimensional diversity of trees also depends on the structure, density and age of forest stands at the moment when they are set aside. We observed that the volume of dead wood on the ground greatly increases after abandonment of timber production and that there is a progressive decrease in the number and percentage of large trees in the first 40 years after the last timber harvest, accompanied by a significant decrease in living trees volume. Nevertheless, the number of large trees in stands where the last timber harvesting occurred more than six decades ago is 1.8 times higher than that of the corresponding number in stands where no harvesting was ever performed. The time elapsed since the last harvest generated important changes in the regeneration process, which seems to stabilize after three decades. The forest stands' reaction after set-aside very much depends on their characteristics at the time of exclusion from timber production, especially their age and structure. After 80 years since set-aside, the ecosystem processes and descriptors begin to look very much like those in the forests unaffected by human actions, but the old-growth characteristics have not entirely recovered. [ABSTRACT FROM AUTHOR]

The interest to assess the relationship between forest gap characteristics and topography features has been growing in the last decades. However, such an approach has not been studied in undisturbed mixed sessile oak–beech old-growth forests. Therefore, the present study carried out in one of the best-preserved sessile oak–beech old-growth forests in Europe, aims to assess the influence of topographic features (slope, altitude and aspect) on (i) some characteristics of canopies and expanded gaps (surface, diameter and perimeter) and (ii) the proportion of beech and sessile oak as bordering trees, gap fillers and gap makers. Through a complete gap survey on an area of 32 ha, 321 gaps were identified and mapped. The largest gaps and also the highest gap frequency (140) was found in the slope class (15.1–20°), while the gap frequency increased with altitude, with 99 gaps being recorded at 601–650 m a.s.l. The size and perimeter of the canopy and expanded gaps, as well as the number of gap makers, were negatively related to the slope and altitude. The expanded gap to canopy gap size ratio decreased with the slope and was positively related to the altitude, while a significant negative decrease in gap filler density with altitude was encountered. The sessile oak participation ratio as bordering trees forming the gap increased not only with the altitude but also with the slope. The topography plays an important role in the formation of gaps as well as in the characteristics of the future stand. This study provides valuable insights into the relationship between canopy gap characteristics and topography, which is useful information for forest owners that pursue the design of forest management toward nature-based solutions. [ABSTRACT FROM AUTHOR]

Understanding how anthropogenetic change affects populations of species is crucial to halt the loss of biodiversity. Although habitat loss and degradation are key drivers of population declines, the exact demographic mechanisms are seldom well understood. Here, we investigated how habitat availability and changes in habitat availability were related to large-scale changes in the breeding and winter populations of a rapidly declining forest species, the willow tit Poecile montanus , in Northern Europe. In addition, we examined the effects of potential competitors (the great tit Parus major and the blue tit Cyanistes caeruleus) and their predator (the great spotted woodpecker Dendrocopos major) on long-term population changes. We also investigated long-term trends in adult survival and recruitment. Changes in breeding numbers were positively associated with the availability of older forest and changes in great tit numbers, but not significantly associated to short-term changes in forest cover or the abundance of nest predator, great spotted woodpeckers. Site level population changes during winter – a proxy for survival rates – were positively associated with the amount of older forest, but were not affected by temperature. The capture-recapture study showed a strong decline in adult survival, but the per capita recruitment rate showed no clear trend. As adult survival has a large contribution to the population growth rate, our results suggest that the willow tit population decline is mainly caused by decreased adult survival rates during non-breeding season. Given that logging volumes have been increasing in recent decades in the area, the reduced habitat quality and loss of older forests are likely the key drivers of the overall population decline. • Examination of large-scale factors affecting the decline of threatened willow tit. • Summer and winter numbers were positively connected with the amount of older forest. • Great tits and great spotted woodpecker numbers did not have negative impacts. • Adult survival of willow tits has declined, but productivity has not changed. • Reduced adult survival due to increased logging likely explains willow tit decline. [ABSTRACT FROM AUTHOR]

Entomological survey of the oldgrowth forest in Salajka National Nature Reserve in the Moravian-Silesian Beskids was conducted in 2019. In total, 638 individuals belonging to 19 species of ground beetles (Carabidae) were collected using pitfall traps with vinegar. Saproxylic beetles were captured using flight interception traps with salt solution. A total of 104 species belonging to 27 families were collected. Including beetles obtained by supplementary hand collecting, 19 species listed in the Czech Red list of endangered species were found. Rare saproxylic fauna was represented by Peltis grossa (Trogossitidae), Ceruchus chrysomelinus (Lucanidae) and Lacon lepidopterus (Elateridae), which are considered primeval forest relict species. Most important species of epigeic beetles were Carabus variolosus and Pterostichus rufitarsis cordatus. These findings underline the high conservation value of the Salajka National Nature Reserve in protecting endangered saproxylic and epigeic species. [ABSTRACT FROM AUTHOR]

Main stand characteristics and tree species composition were studied in managed and old-growth Oriental beech (Fagus orientalis L.) forests in eastern Georgia (Caucasus). Oriental beech dominates both the regeneration layer and the upper story in old-growth forest. In managed forests, Caucasian hornbeam (Carpinus orientalis) and Oriental beech co-dominate the tree layer as well as the regeneration layer. Tree species diversity and deadwood proportion are higher in managed forests than in old-growth forests. However, the absolute deadwood proportion is similar in both studied forest types. Hence, deadwood proportion is not a suitable indicator to assess the naturalness or management intensity of forests in the study area. The observed proportions of Caucasian hornbeam in managed forests raise concerns about the sustainable use of beechwood in the long term. Harvesting hornbeam and smaller removals of beech are recommended to maintain the uneven-aged forest ecosystem, with Oriental beech as the dominant tree species. The established long-term study plots are important to observe and improve future stand development and forest management. [ABSTRACT FROM AUTHOR]

Copyright of Avian Conservation & Ecology is the property of Resilience Alliance and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

There is mounting evidence that top‐down control by natural enemies helps maintain plant diversity in natural ecosystems. Previous work has concentrated on either forest trees or grassland herbs. Our knowledge of how natural enemies affect herb diversity in forests is limited.We used fungicides and insecticide to experimentally examine the effects of fungi and insects on herb abundance and diversity at the community‐wide scale and within groups of species with certain traits. We also assessed how the effects of fungi and insects on herb assemblages were modified by neighbouring tree diversity and composition in an old‐growth temperate forest.We found that fungicides increased overall herb abundance by 7% while decreasing herb diversity by 5%. This effect of fungicides on both herb abundance and diversity weakened with the increase of neighbouring tree diversity. Insecticide did not affect either herb abundance or diversity noticeably, except in areas dominated by deciduous trees where insecticide application reduced herb diversity.Fungicides and insecticide decreased the diversity of relatively less defended species (i.e. thin‐leaved and non‐clonal) but had no effect on the diversity of herbs with stronger defensive traits (i.e. thick‐leaved and clonal). Fungicides increased the abundance of non‐mycorrhizal (NM) species but not arbuscular‐mycorrhizal (AM) species, although the effect of fungicides on herb diversity was unrelated to species' mycorrhizal association. Insecticide had stronger effects on the abundance and diversity of NM species than AM species.Synthesis. We conclude that fungi and insect herbivores are critical to regulating herb abundance and diversity in this temperate forest, with their effects dependent on species' traits and neighbouring tree diversity and composition. Our results highlight the importance of top‐down control of understory herb communities by natural enemies in temperate forests, advancing our understanding of the processes shaping plant diversity in natural ecosystems. [ABSTRACT FROM AUTHOR]

Although ecological restoration has entered the global agenda to reverse different anthropogenic disturbances, we still know little about how this solution interacts with other conservation strategies, to avoid the progressive loss of species and ecosystem services.Here we evaluate one of the pioneering restoration programs in the southern Brazilian Atlantic Forest, where the combination of conservation and restoration efforts has been carried out for 20 years. Specifically, we tested how landscape characteristics, restoration strategies and environmental characteristics affect the results of the restoration of pastures.We established 65 circular plots (total 4.0 ha) along restoration areas (3–10 years) and sampled trees and shrubs composing the canopy (DBH ≥ 5 cm) and understorey (DBH < 5 cm, height > 1.3 m). We analysed the landscape metrics (proportion of old‐growth forests in 200, 500 and 1,000 m buffers around each plot; and area and distance of the nearest‐neighbouring old‐growth forests). We explored the multiple effects of landscape, restoration strategy (reforestation, natural regeneration) and environmental variables (soil, pasture grass types) on the species composition and multiple diversity metrics of restoration areas.The species composition was very similar among restoration ages and restoration strategies. We found positive and strong effects of old‐growth forest (200 m buffer) proportion on the species richness and Shannon diversity (canopy and understorey), above‐ground biomass (canopy) and functional diversity (understorey) of restoration areas. The restoration strategies affected forest structure, and, in general, the reforestation strategy increased above‐ground biomass, Shannon, functional and phylogenetic diversities (in canopy), and percentage of endemic species and biomass (understorey), when compared to natural regeneration.The 20‐year experience in the southern Atlantic Forest showed that programs focused on landscape conservation associated with a mixture of restoration strategies (i.e. natural regeneration in larger areas and active restoration in more disturbed sites), can be an efficient strategy to ensure biodiversity and ecosystem services in tropical landscapes.Synthesis and applications. To manage degraded tropical lands and achieve global targets for biodiversity and ecosystem services, it is necessary to first ensure the conservation of natural remnants and then use multiple restoration strategies in less resilient areas. [ABSTRACT FROM AUTHOR]

Abstract The global expansion of forest plantations at the expense of natural forests, especially old‐growth forests, raises concerns about habitat loss and a decline in ecosystem services. Natural regeneration of second‐growth forests with minimal human assistance has been suggested as a cost‐effective way to restore forests and increase forest ecosystem service potential. However, it is unclear whether natural regeneration will lead to the development of second‐growth forests similar to natural forests because most naturally regenerated second‐growth forests are still young. We present a case study of a very old second‐growth forest in southeastern China in which a forest plantation established approximately six centuries ago has now developed into an old forest with extraordinary high biodiversity levels, an immense carbon pool, and a rich culture. The forest was established in the 14th century because of a charitable contribution, became protected under the Chinese cultural norm of ‘unity between humans and the nature’, and was conserved because of the belief that the prosperity of people is closely linked to the prosperity of trees. The recent designation of the forest as a nature reserve further protects it from development despite competing land‐use demands related to recent economic growth. This case illustrates that, although human activity is the main cause for the disappearance and degradation of many forests, when human interests and cultural values align second‐growth restoration and subsequent forest conservation can lead to the successional development of old‐growth forests. Because this development takes multiple centuries, the protection of current second‐growth forests within conservation easements (e.g. nature reserves) and the reformation of culture values for the linkage of forests to human well‐being are key aspects of the continued conservation‐aided succession of second‐growth forests. A free Plain Language Summary can be found within the Supporting Information of this article.

Abstract Background Baseline levels of tree mortality can, over time, contribute to high snag densities and high levels of deadwood (down woody debris) if fire is infrequent and decomposition is slow. Deadwood can be important for tree recruitment, and it plays a major role in terrestrial carbon cycling, but deadwood is rarely examined in a spatially explicit context. Methods Between 2011 and 2019, we annually tracked all trees and snags ≥1 cm in diameter and mapped all pieces of deadwood ≥10 cm diameter and ≥1 m in length in 25.6 ha of Tsuga heterophylla / Pseudotsuga menziesii forest. We analyzed the amount, biomass, and spatial distribution of deadwood, and we assessed how various causes of mortality that contributed uniquely to deadwood creation. Results Compared to aboveground woody live biomass of 481 Mg ha−1 (from trees ≥10 cm diameter), snag biomass was 74 Mg ha−1 and deadwood biomass was 109 Mg ha−1 (from boles ≥10 cm diameter). Biomass from large-diameter trees (≥60 cm) accounted for 85%, 88%, and 58%, of trees, snags, and deadwood, respectively. Total aboveground woody live and dead biomass was 668 Mg ha−1. The annual production of downed wood (≥10 cm diameter) from tree boles averaged 4 Mg ha−1 yr−1. Woody debris was spatially heterogeneous, varying more than two orders of magnitude from 4 to 587 Mg ha−1 at the scale of 20 m × 20 m quadrats. Almost all causes of deadwood creation varied in importance between large-diameter trees and small-diameter trees. Biomass of standing stems and deadwood had weak inverse distributions, reflecting the long period of time required for trees to reach large diameters following antecedent tree mortalities and the centennial scale time required for deadwood decomposition. Conclusion Old-growth forests contain large stores of biomass in living trees, as well as in snag and deadwood biomass pools that are stable long after tree death. Ignoring biomass (or carbon) in deadwood pools can lead to substantial underestimations of sequestration and stability.

Abstract Background Tree-related microhabitats (hereafter, “TreMs”) are key components of forest biodiversity but they are still poorly known in North American hardwood forests. The spatial patterns of living trees bearing TreMs (hereafter, “TreM-trees”) also remain to be determined. As logging practices can lead to a loss of TreM-trees and of their associated biodiversity, it is essential to identify the factors explaining TreM occurrence to better integrate them into forest management. We therefore inventoried TreMs in 4 0.5-ha survey strips in northern hardwood forests in Quebec, Canada, while recording the spatial location of each tree. Two strips were located in unmanaged old-growth forests, and 2 were in forests managed under selection cutting. All 4 stands were dominated by sugar maple (Acer saccharum Marsh.) and American beech (Fagus grandifolia Ehrn.). Beech bark disease, an exotic pathology, was observed in all the strips. Results Large diameter at breast height and low tree vigor were the main characteristics explaining the presence of TreMs at the tree scale. TreM-trees presented slight spatial aggregation patterns. These aggregates, however, were not well-defined and were generally constituted by a large number of trees bearing few different types of TreMs. Two TreM classes (broken branch or top and woodpecker lodge) also presented a spatial aggregation. Logging practices had no significant effect on TreM occurrence. Beech bark disease increased the frequency of senescent beeches. The impact of this pathology on TreMs was however mitigated by the small size of infected trees and probably by the short time elapsed since its appearance. Conclusion The factors explaining the presence and abundance of TreMs on trees has so far been little studied in North American hardwood forests. Our results highlight that TreM-tree characteristics in the surveyed forests are consistent with those of previous studies conducted in other forest types and regions (e.g., Europe or Northwestern America). To our knowledge, this study is also the first to identify a spatial aggregation of TreM-trees and of specific TreM classes. It will be nevertheless necessary to determine whether the small impact of logging activities we observed results from current or past management practices.

Although successional changes in the functional diversity (FD) of plant communities have been reported in earlier studies, the processes driving these changes remain unclear. Based on the datasets of a long-term tree census conducted during a secondary succession, we comprehensively investigated the FD and its rate of change during a secondary succession in cool, temperate secondary forests in Chichibu, Central Japan. Data from more than 30-years of observations in plots of secondary forest stands with a wide range of stand ages were used to test changes in species diversity, community-weighted means (CWMs) of each trait, FD, and their change rates. Although species diversity decreased constantly with stand age, the FD (Rao's Q) of all traits decreased significantly at the mid-successional stage, corresponding to the stem-exclusion stage. Changes in CWMs of traits indicated the directional shifts of species composition from resource-acquisitive to resource-conservative along succession, especially at the stem exclusion stage. Although the FD of each trait changed differently with succession, that of several resource-conserving traits decreased significantly at the stem exclusion stage. Based on long-term multiple chronosequence resampling, we found that stem exclusion significantly decreased the FD along a secondary succession in cool temperate forests. This sheds light on the critical role of the stem exclusion stage in shaping plant community traits, indicating the importance of this stage in forest management strategies. • We used long-term tree census data from secondary forest succession. • Analyzing functional diversity change over time using long-term and multiple chronosequence resampling techniques. • Finding the decrease in functional diversity as forests advance through the stem exclusion stage. • Highlights the crucial role of stem exclusion phase in shaping plant trait diversity. [ABSTRACT FROM AUTHOR]

Habitat loss is a potential long-term effect of projected climate change for Mediterranean forest ecosystems. Here, we investigated the effectiveness of a close-to-nature silvicultural practice to conserve an old-growth white oak forest patch in Sicily (Italy) and promote regeneration dynamics. The study area, although small, is distinctive for its isolation, position and environmental characteristics. We conducted a Before–After Control–Impact (BACI) study to analyse the responses of different taxonomic groups (vascular plants and birds) to silvicultural treatments (selection thinning, no thinning), and to determine whether close-to-nature silviculture practices may cause significant shifts in the investigated communities. Specifically, we assessed the responses of (1) vascular plants by means of species diversity and taxonomic distinctness indices and (2) birds in terms of diversity, abundance and forest specialisation. Preliminary results suggest that cautious close-to-nature silviculture practice could—by mimicking natural gap dynamics—contribute to maintaining old-growth forest patches and promote oak seedling emergence without short-term detrimental impacts on biodiversity. Although the monitoring has to be repeated over the long-term, the multi-taxon approach and indices incorporating information on taxonomic relationships into diversity measures were demonstrated to be valuable tools for interpreting biotic community structure and dynamics.

• Origin, age, size and competition influence the growth sensitivity to climate. • These variables are interrelated and have a complex influence on the sensitivity. • Sensitivity increases with: > age, > diameter, afforested origin, < competition. • Resilience increases with: > age, < diameter, afforested origin, < competition. • Resilience increases with: > age, > diameter, natural origin, < competition. The sensitivity of tree growth to climate is conditioned by several variables, often intermingled, such as the origin of the forest (natural vs. artificial), tree age, tree size and tree-to-tree competition. The effect of these variables is usually inferred from average growth series obtained at the stand level, thus ignoring the differences at the individual tree level and their drivers. Our objective is to disentangle the effects of stand origin, age, size, competition and social status on the sensitivity of tree growth to climate, including the effects of extreme climatic events, such as droughts, on resistance and resilience, and also to show the advantages of using a tree-level approach. To this end, we compared four stands of Pinus sylvestris with contrasting characteristics: young afforested, young of natural origin, old afforested and old of natural origin. We analyzed differences in growth sensitivity to climate at both stand and tree levels to compare both approaches. Our results show the great complexity of the relationships of the variables considered with the sensitivity of growth to climate. All these variables are important and with strong interactions between them, which makes their effects not unidirectional and strongly dependent on the site conditions. While the stand approach hides these interactions, the tree-level approach makes it possible to analyze them in detail. In general, the sensitivity of growth to climate increases with age, diameter, afforested origin, decreasing competition and higher social status; growth resistance increases with age, decreasing diameter, afforested origin, decreasing competition and higher social status; and growth resilience increases with age, diameter, natural origin, decreasing competition and higher social status. We show the usefulness of the analysis of data at individual tree level, which, combined with the joint analysis at stand level, allows us to obtain more accurate and detailed information. [ABSTRACT FROM AUTHOR]

Old-growth forests represent a very valuable field for research of natural processes. The application of remote sensing was carried out on two old-growth forests in the northwestern part of the Republic of Srpska. The sample plots from OG Janj show relatively higher mean values (NDVI, SAVI and EVI) compared to OG Lom, with the exception of the VARI. Karstified terrain and poor delay of snags in the top-layer of stand due to the impact of weather disasters and the tendency of OG Janj toward the terminal phase of old-growth forest development are potential reasons for the higher mean value of the VARI index. [ABSTRACT FROM AUTHOR]

Even‐aged silviculture based on short‐rotation clearcuts had severely altered boreal forests. Silvicultural alternatives (e.g. continuous cover or retention forestry) have the potential to restore and protect the habitats and functions of boreal forests. These alternatives are however often restricted to structurally complex old‐growth forest, which are particularly threatened by anthropogenic disturbances. Increasing the use of alternatives to even‐aged silviculture in early‐successional stands could help recruit more structurally complex forests, with characteristics closer to the old‐growth. In this article, we therefore evaluate the potential for silvicultural alternatives to even‐aged management in boreal forests that burned less than a century ago.We analysed 1085 field plots in a 243,000 km2 area situated in the boreal forest of eastern Canada. These plots burned 30–100 years before the survey and had not been subjected to previous or subsequent anthropogenic disturbance; they hence represent young primary forests. The main patterns of tree diameter distribution variation within the plots were identified using k‐means clustering. Stand structure, tree species composition and environmental variables that most explained the differences among the clusters were identified with a random forest model, and then compared using Kruskal–Wallis and Fisher's exact tests.The majority (>75%) of the plots presented an irregular structure of stem diameters (i.e. non‐normally distributed, with many small diameter trees). The understorey was generally dominated by black spruce (Picea mariana [Mill.] BSP), a shade‐tolerant species. Irregular structures were observed in both forests of high and low productivity, implying that different processes (e.g. early regeneration, variable tree growth) can lead to observed early irregular structure. Regular structures were generally characterized by a higher productivity and abundance in hardwood species compared to the irregular structures.Synthesis and applications. Many boreal forests of eastern Canada progress towards an irregular structure in the decades following the last stand‐replacing fire. A substantial part of these early‐successional forests may be suitable for alternatives to even‐aged silviculture that better maintains habitats and functions of preindustrial boreal forests. [ABSTRACT FROM AUTHOR]

Copyright of Biotropica is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Karst made up of limestone is widely considered a "Noah's ark" of biodiversity. Rock and soil substrates comprise two different site types in karst terrain, although both can support dense forests. However, it is unclear whether and how the presence of exposed rock affects forest diversity and tree size. We established a 2.2 ha plot (200 × 110 m) in an old-growth oak forest (> 300 years) in karst terrain in southwestern China. We classified the plot into rock and soil components; we analyzed plant diversity and tree size in each component using species diversity indices (richness, number of individuals, Shannon–Wiener index, and Pielou evenness index), stand spatial structure parameters, diameter at breast height (DBH), tree height (TH), and tree basal area (BA). We also analyzed the distributional patterns of species at the sites using non-metric multidimensional scaling, then assessed the effects of abiotic environmental variables on diversity and tree size using redundancy analysis. Our results indicated that both site types (i.e., rock and soil) had similar overall species diversity; trees and shrubs were largely distributed at random within the study site. Tree size was evenly differentiated in the community, and trees were dominant, particularly on soil. Trees on rock were in a status of medium mixture, whereas shrubs on rock were highly mixed. The opposite trend was observed for trees and shrubs growing on soil. The DBH, TH, and BA were smaller in trees growing on rock than in trees growing on soil. Abiotic environmental variables had varying effects on the diversity and size of trees at the two site types; they only explained 21.76 and 14.30% of total variation, respectively. These results suggest that exposed rock has the effect of reducing tree size, but not diversity, thus highlighting the important role of rock in maintaining diversity; moreover, the results imply that karst microhabitats may mitigate the impacts of topography on tree diversity and growth. Greater attention should be focused on exposed rock in the conservation and management of karst forests and the restoration of degraded forest ecosystems. [ABSTRACT FROM AUTHOR]

Monitoring studies at the base site, the Aktru glacier basin (Severo-Chuisky glaciation center, central Russian Altai Mountains), have been ongoing for 22 years and correspond to the global focus of scientific efforts on the study of mountain ecosystems. This article describes the main approaches to monitoring mountain ecosystems and their climatic response based on the leading role of their autotrophic block, especially edificator species of Altai forest ecosystems: Siberian larch and Siberian stone pine. This paper presents the main results of monitoring in old-growth forests, the forest–tundra ecotone, and ecosystems emerging on young moraines of valley glaciers. The authors provide information about the life forms of Siberian stone pine and Siberian larch, the structure of forest stands, and the species diversity of communities. The formation of tree generations in the course of supersecular warming/cooling cycles and the relationship of tree growth with secular and intrasecular climatic changes are considered; a comparative analysis of seed cone production in forests and ecotones is carried out. The current position of the tree lines (groups and single trees, reproductive) in the forest–tundra ecotone is considered, and their shift upwards the slopes as a response to climate change is found. The course of primary successions on young moraines of the Maly Aktru and Levy Bolshoi Aktru glaciers is described. [ABSTRACT FROM AUTHOR]