Forest Ecosystems最新文献

{"title":"Patterns and impacts of an unprecedented outbreak of bark beetles in Central Europe: A glimpse into the future?","authors":"Prosper Washaya,&nbsp;Roman Modlinger,&nbsp;Daniel Tyšer,&nbsp;Tomáš Hlásny","doi":"10.1016/j.fecs.2024.100243","DOIUrl":"10.1016/j.fecs.2024.100243","url":null,"abstract":"<div><p>Natural disturbances have significantly intensified across European forests, with bark beetle outbreaks being the most rapidly escalating disturbance type. Since 2018, the Czech Republic (Central Europe) has become a Europe's disturbance epicentre due to the unprecedented outbreak of spruce bark beetle <em>Ips typographus</em> in the forests dominated by Norway spruce <em>Picea abies</em>. Here we provide novel insights into the impacts and dynamics of this disturbance from 2016 to 2022. The investigation is based on annual forest change maps developed by the classification of optical and Synthetic Aperture Radar satellite imagery. We identified seven major outbreak foci across the country, where the outbreaks culminated between 2018 and 2021. Most of the outbreak waves exhibited a symmetric shape, characterized by a three-year build-up phase, a single culmination year, and the subsequent decline. The substantial proportion of spruce remaining in the outbreak areas after the culmination point implies that resource depletion is an improbable cause for the outbreak's retreat. In the year of retreat, the proportion of spruce in the forest ranged between 26% and 36% in most of the outbreak areas. The disturbance dynamics manifested a transition from the emergence of new tree mortality spots in the early outbreak phase to their short-range expansion, suggesting density-dependent changes in bark beetle dispersal during the studied period. The core disturbance zone, pinpointed in 2022, covered an area of 9,000 ​km² and experienced a 38% loss in forest cover. Within this area, forest fragmentation increased significantly, leading to a greater forest patch complexity and reduced connectivity among the patches. The presented findings can serve as a glimpse into the future for other European regions, revealing the potential impacts of natural disturbances amplified by climate change.</p></div>","PeriodicalId":54270,"journal":{"name":"Forest Ecosystems","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2197562024000794/pdfft?md5=973190be6475a2c1740df30a981e3664&pid=1-s2.0-S2197562024000794-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142164652","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Land-use legacies affect the composition and distribution of tree species and their belowground functions in a succession from old-field to mature temperate forest","authors":"Gisselle A. Mejía ,&nbsp;Chenyang Su ,&nbsp;David Allen ,&nbsp;V. Bala Chaudhary ,&nbsp;Theresa W. Ong","doi":"10.1016/j.fecs.2024.100249","DOIUrl":"10.1016/j.fecs.2024.100249","url":null,"abstract":"<div><div>Forests undergoing ecological succession following abandonment from agricultural use (i.e., old fields) are ubiquitous in temperate regions of the U.S. and Europe. Ecological succession in old fields involves changes in vegetation composition influenced by factors such as land-use history, soil conditions, and dispersal limitations. Species’ behavioral, morphological, physiological and life-history attributes influence the outcomes of environmental and biotic filters on distribution and abundance. However, many studies have focused on aboveground attributes, while less attention has been placed on belowground species characteristics that influence community assembly and function. In this study, we used a trait-based approach to examine how aboveground plant composition and distribution vary with plant root functional traits (e.g., mycorrhizal association) that mediate access for nutrients such as nitrogen (N) and phosphorous (P). We inventoried every tree stem (<em>n</em> ​= ​11,551) in a 10-ha forested area containing old-field and historical forests and matched every species with root functional traits (<em>n</em> ​= ​33) from established databases. We found that land-use history influences community composition and distribution in old-field forests, which also varied with belowground root functional traits. Community composition in old-field forests, which were dominated by <em>Acer saccharum</em> and non-native species, were largely associated with arbuscular mycorrhizae (AM) and higher root nutrient concentrations. On the other hand, community composition in historical forests – largely dominated by <em>Tsuga canadensis</em> – were associated with ectomycorrhiza (EcM) and more variation of root length and depth. These results suggest that changes in aboveground communities have implications for belowground ecosystem services (e.g., nutrient cycling) which are important to forest ecosystem development. Trait-based approaches can elucidate mechanisms of community assembly, and understanding how traits influence species coexistence and interactions can inform management decisions related to biodiversity conservation and restoration efforts in disturbed or altered forests.</div></div>","PeriodicalId":54270,"journal":{"name":"Forest Ecosystems","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142326794","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Drivers of spatial structure in thinned forests","authors":"Zichun Wang ,&nbsp;Yaoxiang Li ,&nbsp;Guangyu Wang ,&nbsp;Zheyu Zhang ,&nbsp;Ya Chen ,&nbsp;Xiaoli Liu ,&nbsp;Rundong Peng","doi":"10.1016/j.fecs.2024.100182","DOIUrl":"10.1016/j.fecs.2024.100182","url":null,"abstract":"<div><h3>Background</h3><p>As is widely known, an increasing number of forest areas were managed to preserve and enhance the health of forest ecosystems. However, previous research on forest management has often overlooked the importance of structure-based.</p></div><div><h3>Aims</h3><p>Our objectives were to define the direction of structure-based forest management. Subsequently, we investigated the relationships between forest structure and the regeneration, growth, and mortality of trees under different thinning treatments. Ultimately, the drivers of forest structural change were explored.</p></div><div><h3>Methods</h3><p>On the basis of 92 sites selected from northeastern China, with different recovery time (from 1 to 15 years) and different thinning intensities (0–59.9%) since the last thinning. Principal component analysis (PCA) identified relationships among factors determining forest spatial structure. The structural equation model (SEM) was used to analyze the driving factors behind the changes in forest spatial structure after thinning.</p></div><div><h3>Results</h3><p>Light thinning (0–20% trees removed) promoted forest regeneration, and heavy thinning (over 35% of trees removed) facilitated forest growth. However, only moderate thinning (20%–35% trees removed) created a reasonable spatial structure. While dead trees were clustered, and they were hardly affected by thinning intensity. Additionally, thinning intensity, recovery time, and altitude indirectly improve the spatial structure of the forest by influencing diameter at breast height (DBH) and canopy area.</p></div><div><h3>Conclusion</h3><p>Creating larger DBH and canopy area through thinning will promote the formation of complex forest structures, which cultivates healthy and stable forests.</p></div>","PeriodicalId":54270,"journal":{"name":"Forest Ecosystems","volume":null,"pages":null},"PeriodicalIF":4.1,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2197562024000186/pdfft?md5=3d2e4a437ffa319bf5d770b6f360e37b&pid=1-s2.0-S2197562024000186-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140188949","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Plant life form determines spatiotemporal variability and climate response of plant seed rain in subtropical forests","authors":"Yuyang Xie ,&nbsp;Zehao Shen ,&nbsp;Xuejing Wang ,&nbsp;Liu Yang ,&nbsp;Jie Zhang","doi":"10.1016/j.fecs.2024.100181","DOIUrl":"https://doi.org/10.1016/j.fecs.2024.100181","url":null,"abstract":"<div><p>Spatiotemporal variation of seed rain reflects the response of plants in terms of their reproductive strategy to environmental gradients. In this study, we collected seeds from four sites in the Dalaoling Nature Reserve, Hubei Province, China, between 2011 and 2014, measured seed output and seed mass as seed rain traits, and compared their interannual and elevational variation. Then, we ran phylogenetic generalized mixed linear models (PGLMMs) to explore the effects of temperature and precipitation as well as interspecific differences on seed rain, and fitted the best regression models for seed rain vs. weather of canopy and understory species. The results showed no correlation between values of seed output and seed mass. However, the variation of the two traits showed significantly positive correlation. Seed output of canopy species generally decreased with increasing elevation, and showed significant interannual difference; however, seed output of understory species and seed mass for both canopy and understory species did not show consistency tends along elevational or in interannual variation. Seed output was significantly affected by temperature and precipitation, while seed mass mainly varied due to interspecific differences. Weather explained more the variation of the seed output of canopy species than that of understory species, with <em>R</em>² values of 43.0% and 29.9%, respectively. These results suggested that canopy plants contributed more to the reproductive dynamics of the whole communities, and the canopy's buffer effect on the underground weakened the response of understory plants to weather variation in terms of their reproductive strategy.</p></div>","PeriodicalId":54270,"journal":{"name":"Forest Ecosystems","volume":null,"pages":null},"PeriodicalIF":4.1,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2197562024000174/pdfft?md5=2bd9fc9d63bff38e157a048c780d17df&pid=1-s2.0-S2197562024000174-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140142035","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The unimodal latitudinal pattern of K, Ca and Mg concentration and its potential drivers in forest foliage in eastern China","authors":"Zhijuan Shi ,&nbsp;Sining Liu ,&nbsp;Yahan Chen ,&nbsp;Dongdong Ding ,&nbsp;Wenxuan Han","doi":"10.1016/j.fecs.2024.100193","DOIUrl":"https://doi.org/10.1016/j.fecs.2024.100193","url":null,"abstract":"<div><p>Potassium (K), calcium (Ca), and magnesium (Mg) are essential elements with important physiological functions in plants. Previous studies showed that leaf K, Ca, and Mg concentrations generally increase with increasing latitudes. However, recent meta-analyses suggested the possibility of a unimodal pattern in the concentrations of these elements along latitudinal gradients. The authenticity of this unimodal latitudinal pattern, however, requires validation through large-scale field experimental data, and exploration of the underlying mechanisms if the pattern is confirmed. Here, we collected leaves of common species of woody plants from 19 montane forests in the north-south transect of eastern China, including 322 species from 160 genera, 67 families; and then determined leaf K, Ca, and Mg concentrations to explore their latitudinal patterns and driving mechanisms. Our results support unimodal latitudinal patterns for all three elements in woody plants across eastern China, with peak values at latitude 36.5 ​± ​1.0° N. The shift of plant-functional-type compositions from evergreen broadleaves to deciduous broadleaves and to conifers along this latitudinal span was the key factor contributing to these patterns. Climatic factors, mainly temperature, and to a lesser extent solar radiation and precipitation, were the main environmental drivers. These factors, by altering the composition of plant communities and regulating plant physiological activities, influence the latitudinal patterns of plant nutrient concentrations. Our findings also suggest that high leaf K, Ca, and Mg concentrations may represent an adaptive strategy for plants to withstand water stress, which might be used to predict plant nutrient responses to climate changes at large scales, and broaden the understanding of biogeochemical cycling of K, Ca, and Mg.</p></div>","PeriodicalId":54270,"journal":{"name":"Forest Ecosystems","volume":null,"pages":null},"PeriodicalIF":4.1,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2197562024000290/pdfft?md5=30830bb7dfb76103f05e8ba9dc7f3a79&pid=1-s2.0-S2197562024000290-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140604949","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Short lifespan and ‘prime period’ of carbon sequestration call for multi-ages in dryland tree plantations","authors":"Chongyang Xu ,&nbsp;Xiuchen Wu ,&nbsp;Yuhong Tian ,&nbsp;Liang Shi ,&nbsp;Yang Qi ,&nbsp;Jingjing Zhang ,&nbsp;Hongyan Liu","doi":"10.1016/j.fecs.2024.100224","DOIUrl":"10.1016/j.fecs.2024.100224","url":null,"abstract":"<div><p>Enhancing forest cover is important for effective climate change mitigation. Studies suggest that drylands are promising areas for expanding forests, but conflicts arise with increased forest area and water consumption. Recent tree mortality in drylands raises concerns about carbon sequestration potential in tree plantations. Using Chinese dryland tree plantations as an example, we compared their growth with natural forests. Our results suggested plantation trees grew 1.6–2.1 times faster in juvenile phases, significantly shortening time to maturity (13.5 vs. 30 years) compared to natural forests, potentially stemming from simple plantation age structures. Different from natural forests, 74% of trees in plantations faced growth decline, indicating a short “prime period” for carbon sequestration and even a short lifespan. Additionally, a negative relationship between evapotranspiration and tree growth was observed in tree plantations since maturity, leading to high sensitivities of trees to vapor pressure deficit and soil water. However, this was not observed in natural forests. To address this, we suggest afforestation in drylands should consider complex age structures, ensuring a longer prime period for carbon sequestration and life expectancy in tree plantations.</p></div>","PeriodicalId":54270,"journal":{"name":"Forest Ecosystems","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2197562024000605/pdfft?md5=90ec1f78de6c44c98c81a11a1e29efe9&pid=1-s2.0-S2197562024000605-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141786054","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Diversity-biomass relationships are shaped by tree mycorrhizal associations and stand structural diversity at different spatial scales","authors":"Rui Zhang ,&nbsp;Shuaifeng Li ,&nbsp;Xiaobo Huang ,&nbsp;Cong Li ,&nbsp;Chonghua Xu ,&nbsp;Jianrong Su","doi":"10.1016/j.fecs.2024.100234","DOIUrl":"10.1016/j.fecs.2024.100234","url":null,"abstract":"<div><p>Diversity-biomass relationships (DBRs) in terrestrial ecosystems tend to vary across spatial scales, but, particularly in hyperdiverse forests, the mechanisms driving these trends remain uncertain. Until now, few have simultaneously investigated the connections between tree species diversity, stand structural diversity, mycorrhizal associations, and ecosystem functioning. In addition, DBRs have only been studied at limited spatial scales, with limited focus on the direct and indirect effects of environmental factors. We addressed these research gaps using a 30-ha forest dynamics plot located in Pu'er City, Southwest China. Through piecewise structural equation models, we quantified the direct effects of tree species diversity (α, β, γ), stand structural diversity, mycorrhizal associations (AM, EcM), and the environmental factors (soil fertility and topography), as well as the indirect effects of the environmental factors on aboveground tree biomass across spatial scales ranging from 400 to 230,400 ​m². We hypothesized that complex interactions among these factors underpin the variation in DBRs in natural ecosystems across spatial scales. Our results showed that environmental conditions indirectly affected the tree biomass via changes in tree species diversity, and these effects became stronger as the spatial scale increased. At small to moderate spatial scales, environmental factors were more predictive of tree biomass than tree species diversity (or its components); the effects of stand structural diversity on biomass also gradually increased with spatial scale. Conversely, from the intermediate to the largest spatial scales, mycorrhizal associations gradually became the best predictors of DBR dynamics. Our research offers novel empirical evidence demonstrating the importance of environmental conditions, structural diversity, and mycorrhizal associations in shaping cross-scale DBRs. Future comprehensive studies should consider these factors to assess the mechanisms shaping scale-dependent DBRs in complex natural ecosystems.</p></div>","PeriodicalId":54270,"journal":{"name":"Forest Ecosystems","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2197562024000708/pdfft?md5=c070897fb67d8d0fd2e305025df45572&pid=1-s2.0-S2197562024000708-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142075863","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nexus of certain model-based estimators in remote sensing forest inventory","authors":"Yan Zheng ,&nbsp;Zhengyang Hou ,&nbsp;Göran Ståhl ,&nbsp;Ronald E. McRoberts ,&nbsp;Weisheng Zeng ,&nbsp;Erik Næsset ,&nbsp;Terje Gobakken ,&nbsp;Bo Li ,&nbsp;Qing Xu","doi":"10.1016/j.fecs.2024.100245","DOIUrl":"10.1016/j.fecs.2024.100245","url":null,"abstract":"<div><p>Remote sensing (RS) facilitates forest inventory across a wide range of variables required by the UNFCCC as well as by other agreements and processes. The Conventional model-based (CMB) estimator supports wall-to-wall RS data, while Hybrid estimators support surveys where RS data are available as a sample. However, the connection between these two types of monitoring procedures has been unclear, hindering the reconciliation of wall-to-wall and non-wall-to-wall use of RS data in practical applications and thus potentially impeding cost-efficient deployment of high-end sensing instruments for large area monitoring. Consequently, our objectives are to (1) shed further light on the connections between different types of Hybrid estimators, and between CMB and Hybrid estimators, through mathematical analyses and Monte Carlo simulations; and (2) compare the effects and explore the tradeoffs related to the RS sampling design, coverage rate, and cluster size on estimation precision. Primary findings are threefold: (1) the CMB estimator represents a special case of Hybrid estimators, signifying that wall-to-wall RS data is a particular instance of sample-based RS data; (2) the precision of estimators in forest inventory can be greater for stratified non-wall-to-wall RS data compared to wall-to-wall RS data; (3) otherwise cost-prohibitive sensing, such as LiDAR and UAV, can support large scale monitoring through collecting RS data as a sample. These conclusions may reconcile different perspectives regarding choice of RS instruments, data acquisition, and cost for continuous observations, particularly in the context of surveys aiming at providing data for mitigating climate change.</p></div>","PeriodicalId":54270,"journal":{"name":"Forest Ecosystems","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2197562024000812/pdfft?md5=769ca58bb6904eacbac71214b1f655d0&pid=1-s2.0-S2197562024000812-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142230687","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Litter quality and decomposer complexity co-drive effect of drought on decomposition","authors":"Shumei Wang ,&nbsp;Junwei Luan ,&nbsp;Siyu Li ,&nbsp;Jinhao Ma ,&nbsp;Lin Chen ,&nbsp;Yi Wang ,&nbsp;Shirong Liu","doi":"10.1016/j.fecs.2024.100194","DOIUrl":"https://doi.org/10.1016/j.fecs.2024.100194","url":null,"abstract":"<div><p>Litter decomposition is key to ecosystem carbon (C) and nutrient cycling, but this process is anticipated to weaken due to projected more extensive and prolonged drought. Yet how litter quality and decomposer community complexity regulate decomposition in response to drought is less understood. Here, in a five-year manipulative drought experiment in a Masson pine forest, leaf litter from four subtropical tree species (<em>Quercus griffithii</em> Hook.f. &amp; Thomson ex Miq., <em>Acacia mangium</em> Willd., <em>Pinus massoniana</em> Lamb., <em>Castanopsis hystrix</em> Miq.) representing different qualities was decomposed for 350 ​d in litterbags of three different mesh sizes (i.e., 0.05, 1, and 5 ​mm), respectively, under natural conditions and a 50% throughfall rain exclusion treatment. Litterbags of increasing mesh sizes discriminate decomposer communities (i.e., microorganisms, microorganisms and mesofauna, microorganisms and meso- and macrofauna) that access the litter and represent an increasing complexity. The amount of litter C and nitrogen (N) loss, and changes in their ratio (C/N_loss), as well as small and medium-sized decomposers including microorganisms, nematodes, and arthropods, were investigated. We found that drought did not affect C and N loss but decreased C/N_loss (i.e., decomposer N use efficiency) of leaf litter irrespective of litter quality and decomposer complexity. However, changes in the C/N_loss and the drought effect on C loss were both dependent on litter quality, while drought and decomposer complexity interactively affected litter C and N loss. Increasing decomposer community complexity enhanced litter decomposition and allowing additional access of meso- and macro-fauna to litterbags mitigated the negative drought effect on the microbial-driven decomposition. Furthermore, both the increased diversity and altered trophic structure of nematode due to drought contributed to the mitigation effects via cascading interactions. Our results show that litter quality and soil decomposer community complexity co-drive the effect of drought on litter decomposition. This experimental finding provides a new insight into the mechanisms controlling forest floor C and nutrient cycling under future global change scenarios.</p></div>","PeriodicalId":54270,"journal":{"name":"Forest Ecosystems","volume":null,"pages":null},"PeriodicalIF":4.1,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2197562024000307/pdfft?md5=d6b9daf948b6e70e1c9585558bbb1e42&pid=1-s2.0-S2197562024000307-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140639384","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Stand dynamics of old-growth hemlock forests in central Bhutan are shaped by natural disturbances","authors":"Karma Tenzin ,&nbsp;Craig R. Nitschke ,&nbsp;Kathryn J. Allen ,&nbsp;Raphaël Trouvé ,&nbsp;Thiet V. Nguyen ,&nbsp;Patrick J. Baker","doi":"10.1016/j.fecs.2024.100204","DOIUrl":"10.1016/j.fecs.2024.100204","url":null,"abstract":"<div><p>Understanding how past disturbances have influenced the development of forests is critical for deciphering their current structure and composition and forecasting future changes. In this study, dendrochronological methods were applied to uncover the disturbance history of old-growth hemlock-dominated forests in central Bhutan. Analysis of tree-ring samples from two old-growth hemlock stands, located in two different topographic settings, identified the importance of gap-phase dynamics in facilitating recruitment and growth releases and producing complex, multi-aged structures over time. One site showed evidence of a near stand-replacing disturbance in the late 1700s, while the other showed no evidence of high-severity disturbance at any time over the last 400 years. At both sites low-to medium-severity disturbances, some of which appear to be associated with cyclones originating in the Bay of Bengal, dominated the disturbance regime. The hemlock stands exhibited a significant positive association between cyclone occurrence and growth release events and between recruitment pulses and growth release events. From 1800 to 1970 there was an increase in recruitment of angiosperm tree species at most sites and a corresponding decline in conifer recruitment. Over the past 50 years there has been little new recruitment; this may be due to light limitation in the understory from shade-tolerant angiosperms and bamboo in the lower strata of these stands. Significant variations in disturbance dynamics and recruitment were observed across the study sites, suggesting that other factors, such as topography and climate, may be influencing long-term stand development patterns. This study highlights the complex interplay between historical disturbance regimes and tree recruitment in shaping the age and size structures of old-growth hemlock forests in central Bhutan. It also provides new insights into the dynamics of these forests that can be used to support effective forest conservation and management in the future.</p></div>","PeriodicalId":54270,"journal":{"name":"Forest Ecosystems","volume":null,"pages":null},"PeriodicalIF":4.1,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S219756202400040X/pdfft?md5=408f24328e44a7dbb7bbbf81fb1c4e11&pid=1-s2.0-S219756202400040X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141056163","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}