Forest Ecosystems最新文献

{"title":"Evaluating soil acidification risk and its effects on biodiversity–ecosystem multifunctionality relationships in the drylands of China","authors":"Lan Du ,&nbsp;Shengchuan Tian ,&nbsp;Nan Zhao ,&nbsp;Bin Zhang ,&nbsp;Xiaohan Mu ,&nbsp;Lisong Tang ,&nbsp;Xinjun Zheng ,&nbsp;Yan Li","doi":"10.1016/j.fecs.2024.100178","DOIUrl":"10.1016/j.fecs.2024.100178","url":null,"abstract":"<div><h3>Background</h3><p>Soil acidification caused by anthropogenic activities may affect soil biochemical cycling, biodiversity, productivity, and multiple ecosystem-related functions in drylands. However, to date, such information is lacking to support this hypothesis.</p></div><div><h3>Methods</h3><p>Based on a transect survey of 78 naturally assembled shrub communities, we calculated acid deposition flux in Northwest China and evaluated its likely ecological effects by testing three alternative hypotheses, namely: niche complementarity, mass ratio, and vegetation quantity hypotheses. Rao's quadratic entropy and community-weighted mean traits were employed to represent the complementary aspect of niche complementarity and mass ratio effects, respectively.</p></div><div><h3>Results</h3><p>We observed that in the past four decades, the concentrations of exchangeable base cations in soil in Northwest China have decreased significantly to the extent of having faced the risk of depletion, whereas changes in the calcium carbonate content and pH of soil were not significant. Acid deposition primarily increased the aboveground biomass and shrub density in shrublands but had no significant effect on shrub richness and ecosystem multifunctionality (EMF), indicating that acid deposition had positive but weak ecological effects on dryland ecosystems. Community weighted mean of functional traits (representing the mass ratio hypothesis) correlated negatively with EMF, whereas both Rao's quadratic entropy (representing the niche complementarity hypothesis) and aboveground biomass (representing the vegetation quantity hypothesis) correlated positively but insignificantly with EMF. These biodiversity–EMF relationships highlight the fragility and instability of drylands relative to forest ecosystems.</p></div><div><h3>Conclusions</h3><p>The findings from this study serve as important reference points to understand the risk of soil acidification in arid regions and its impacts on biodiversity–EMF relationships.</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/S2197562024000149/pdfft?md5=479da6057cfe3bd7d4a2e539c81fa1f0&pid=1-s2.0-S2197562024000149-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139926882","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":"Carbon stock estimation in halophytic wooded savannas of Uruguay: An ecosystem approach","authors":"Andrés Baietto ,&nbsp;Andrés Hirigoyen ,&nbsp;Carolina Toranza ,&nbsp;Franco Schinato ,&nbsp;Maximiliano González ,&nbsp;Rafael Navarro Cerrillo","doi":"10.1016/j.fecs.2024.100216","DOIUrl":"https://doi.org/10.1016/j.fecs.2024.100216","url":null,"abstract":"<div><p>Savannas constitute a mixture of trees and shrub patches with a more continuous herbaceous understory. The contribution of this biome to the soil organic carbon (SOC) and above-ground biomass (AGB) carbon (C) stock globally is significant. However, they are frequently subjected to land use changes, promoting increases in CO₂ emissions. In Uruguay, subtropical wooded savannas cover around 100,000 ​ha, of which approximately 28% is circumscribed to sodic soils (i.e., subtropical halophytic wooded savannas). Nevertheless, there is little background about the contribution of each ecosystem component to the C stock as well as site-specific allometric equations. The study was conducted in 5 ​ha of subtropical halophytic wooded savannas of the national protected area Esteros y Algarrobales del Río Uruguay. This work aimed to estimate the contribution of the main ecosystem components (e.g., soil, trees, shrubs, and herbaceous plants) to the C stock. Site-specific allometric equations for the most frequent tree species and shrub genus were fitted based on basal diameter (BD) and total height (H). The fitted equations accounted for between 77% and 98% of the aerial biomass variance of <em>Neltuma affinis</em> and <em>Vachellia caven</em>. For shrubs (<em>Baccharis</em> sp.), the adjusted equation accounted for 86% of total aerial biomass. C stock for the entire system was 116.71 ​± ​11.07 ​Mg⋅ha⁻¹, of which 90.7% was allocated in the soil, 8.3% in the trees, 0.8% in the herbaceous plants, and 0.2% in the shrubs. These results highlight the importance of subtropical halophytic wooded savannas as C sinks and their relevance in the mitigation of global warming under a climate change scenario.</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/S2197562024000526/pdfft?md5=5f9dec6fc953566ef624415ffb7503c3&pid=1-s2.0-S2197562024000526-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141582455","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":"What diameter? What height? Influence of measures of average tree size on area-based allometric volume relationships","authors":"Yilin Wang ,&nbsp;John A. Kershaw ,&nbsp;Mark J. Ducey ,&nbsp;Yuan Sun ,&nbsp;James B. McCarter","doi":"10.1016/j.fecs.2024.100171","DOIUrl":"10.1016/j.fecs.2024.100171","url":null,"abstract":"<div><p>Volume is an important attribute used in many forest management decisions. Data from 83 fixed-area plots located in central New Brunswick, Canada, are used to examine how different measures of stand-level diameter and height influence volume prediction using a stand-level variant of Honer’s (1967) volume equation. When density was included in the models (<span><math><mrow><mrow><mtext>Volume</mtext><mo>=</mo><mi>f</mi><mrow><mo>(</mo><mrow><mtext>Diameter</mtext><mo>,</mo><mtext>Height</mtext><mo>,</mo><mtext>Density</mtext></mrow><mo>)</mo></mrow></mrow><mo>)</mo></mrow></math></span> choice of diameter measure was more important than choice of height measure. When density was not included <span><math><mrow><mo>(</mo><mrow><mtext>Volume</mtext><mo>=</mo><mi>f</mi><mrow><mo>(</mo><mrow><mtext>Diameter</mtext><mo>,</mo><mtext>Height</mtext></mrow><mo>)</mo></mrow></mrow><mo>)</mo></mrow></math></span>, the opposite was true. For models with density included, moment-based estimators of stand diameter and height performed better than all other measures. For models without density, largest tree estimators of stand diameter and height performed better than other measures. The overall best equation used quadratic mean diameter, Lorey’s height, and density (root mean square error ​= ​5.26 ​m³⋅ha⁻¹; 1.9 % relative error). The best equation without density used mean diameter of the largest trees needed to calculate a stand density index of 400 and the mean height of the tallest 400 trees per ha (root mean square error ​= ​32.08 ​m³⋅ha⁻¹; 11.8 % relative error). The results of this study have some important implications for height subsampling and LiDAR-derived forest inventory analyses.</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/S2197562024000071/pdfft?md5=0606a356a03de5b8009f12a288c6adc0&pid=1-s2.0-S2197562024000071-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139660045","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":"Quantifying foliar trait variation and covariation in sun and shade leaves using leaf spectroscopy in eastern North America","authors":"","doi":"10.1016/j.fecs.2024.100230","DOIUrl":"10.1016/j.fecs.2024.100230","url":null,"abstract":"<div><p>Characterizing foliar trait variation in sun and shade leaves can provide insights into inter- and intra-species resource use strategies and plant response to environmental change. However, datasets with records of multiple foliar traits from the same individual and including shade leaves are sparse, which limits our ability to investigate trait-trait, trait-environment relationships and trait coordination in both sun and shade leaves. We presented a comprehensive dataset of 15 foliar traits from sun and shade leaves sampled with leaf spectroscopy, including 424 individuals of 110 plant species from 19 sites across eastern North America. We investigated trait variation, covariation, scaling relationships with leaf mass, and the effects of environment, canopy position, and taxonomy on trait expression. Generally, sun leaves had higher leaf mass per area, nonstructural carbohydrates and total phenolics, lower mass-based chlorophyll a + b, carotenoids, phosphorus, and potassium, but exhibited species-specific characteristics. Covariation between sun and shade leaf traits, and trait-environment relationships were overall consistent across species. The main dimensions of foliar trait variation in seed plants were revealed including leaf economics traits, photosynthetic pigments, defense, and structural traits. Taxonomy and canopy position collectively explained most of the foliar trait variation. This study highlights the importance of including intra-individual and intra-specific trait variation to improve our understanding of ecosystem functions. Our findings have implications for efficient field sampling, and trait mapping with remote sensing.</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/S2197562024000666/pdfft?md5=9b0173ddaa85fa069c480c6b9b6f510d&pid=1-s2.0-S2197562024000666-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141915326","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":"Resilience and response: Unveiling the impacts of extreme droughts on forests through integrated dendrochronological and remote sensing analyses","authors":"Han Shi ,&nbsp;Xi Peng ,&nbsp;Yong-Jiao Zhou ,&nbsp;Ai-Ying Wang ,&nbsp;Xue-Kai Sun ,&nbsp;Na Li ,&nbsp;Quan-Sheng Bao ,&nbsp;Gude Buri ,&nbsp;Guang-You Hao","doi":"10.1016/j.fecs.2024.100209","DOIUrl":"https://doi.org/10.1016/j.fecs.2024.100209","url":null,"abstract":"<div><p>Extreme droughts are anticipated to have detrimental impacts on forest ecosystems, especially in water-limited regions, due to the influence of climate change. However, considerable uncertainty remains regarding the patterns in species-specific responses to extreme droughts. Here, we conducted a study integrating dendrochronology and remote sensing methods to investigate the mosaic-distributed maple-oak (native) natural forests and poplar plantations (introduced) in the Horqin Sandy Land, Northeast China. We assessed the impacts of extreme droughts on tree performances by measuring interannual variations in radial growth and vegetation index. The results showed that precipitation and self-calibrated palmer drought severity index (scPDSI) are the major factors influencing tree-ring width index (RWI) and normalized difference vegetation index (NDVI). The severe droughts between 2000 and 2004 resulted in reduced RWI in the three studied tree species as well as led to NDVI reductions in both the maple-oak natural forests and the poplar plantations. The RWI reached the nadir during the 2000–2004 severe droughts and remained at low levels two years after the severe drought, creating a legacy effect. In contrast to the lack of significant correlation between RWI and scPDSI, NDVI exhibited a significant positive correlation with scPDSI indicating the greater sensitivity of canopy performance to droughts than radial growth. Furthermore, interspecific differences in RWI and NDVI responses were observed, with the fast-growing poplar species experiencing a more significant RWI decrease and more negative NDVI anomaly during severe droughts than native species, highlighting the species-specific trade-offs between drought resilience and growth rate. This study emphasizes the importance of combining tree-level radial growth with landscape-scale canopy remote sensing to understand forest resilience and response. Our study improves our understanding of forest responses to extreme drought and highlights species differences in climate responses, offering crucial insights for optimizing species selection in sustainable afforestation and forest management in water-limited regions under the influence of climate change.</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/S2197562024000459/pdfft?md5=8befa74415e8bef3cebd4656408e5c9f&pid=1-s2.0-S2197562024000459-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141422934","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":"Phosphorus limitation on CO2 fertilization effect in tropical forests informed by a coupled biogeochemical model","authors":"Zhuonan Wang ,&nbsp;Hanqin Tian ,&nbsp;Shufen Pan ,&nbsp;Hao Shi ,&nbsp;Jia Yang ,&nbsp;Naishen Liang ,&nbsp;Latif Kalin ,&nbsp;Christopher Anderson","doi":"10.1016/j.fecs.2024.100210","DOIUrl":"10.1016/j.fecs.2024.100210","url":null,"abstract":"<div><p>Tropical forests store more than half of the world's terrestrial carbon (C) pool and account for one-third of global net primary productivity (NPP). Many terrestrial biosphere models (TBMs) estimate increased productivity in tropical forests throughout the 21st century due to CO₂ fertilization. However, phosphorus (P) limitations on vegetation photosynthesis and productivity could significantly reduce the CO₂ fertilization effect. Here, we used a carbon-nitrogen-phosphorus coupled model (Dynamic Land Ecosystem Model; DLEM-CNP) with heterogeneous maximum carboxylation rates to examine how P limitation has affected C fluxes in tropical forests during 1860–2018. Our model results showed that the inclusion of the P processes enhanced model performance in simulating ecosystem productivity. We further compared the simulations from DLEM-CNP, DLEM-CN, and DLEM-C and the results showed that the inclusion of P processes reduced the CO₂ fertilization effect on gross primary production (GPP) by 25% and 45%, and net ecosystem production (NEP) by 28% and 41%, respectively, relative to CN-only and C-only models. From the 1860s to the 2010s, the DLEM-CNP estimated that in tropical forests GPP increased by 17%, plant respiration (Ra) increased by 18%, ecosystem respiration (Rh) increased by 13%, NEP increased by 121% per unit area, respectively. Additionally, factorial experiments with DLEM-CNP showed that the enhanced NPP benefiting from the CO₂ fertilization effect had been offset by 135% due to deforestation from the 1860s to the 2010s. Our study highlights the importance of P limitation on the C cycle and the weakened CO₂ fertilization effect resulting from P limitation in tropical 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/S2197562024000460/pdfft?md5=1dd667881feffca4c9eff7b5c3162b0c&pid=1-s2.0-S2197562024000460-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141281211","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":"Predicting time-to-harvest in mixed-species forests using a random survival forest algorithm","authors":"","doi":"10.1016/j.fecs.2024.100236","DOIUrl":"10.1016/j.fecs.2024.100236","url":null,"abstract":"<div><p>Survival analysis is composed of a group of analytical approaches that can be used to predict the occurrence of harvest activities, which provides insightful information about the dynamics of natural resources utilization in a region. Recently, random survival forest (RSF) has been proposed in survival analysis to capture the complex relationships among variables. The main objective of this study was to employ the RSF algorithm to examine the temporal evolution of tree harvest, accounting for stand and environmental variables. Specifically, the predictability of the RSF model was compared with the Cox proportional hazard (Cox) model, a popular model in survival analysis. Important variables in explaining the variation of harvest time were identified. Data collected by the USDA Forest Service, Forest Inventory and Analysis (FIA) program from permanent plots in the southern Appalachian region were utilized in the analysis. Results showed that the RSF model consistently outperformed the Cox model based on prediction accuracy. Among 14 variables examined, ownership, forest type, elevation, state, and slope emerged as most important. Utilizing only these five variables in a reduced model produced satisfactory prediction accuracy compared to the full model (i.e., the models with all variables included). The findings of this work provide insights for forest managers and policy makers to utilize survival analysis methods in understanding harvest activities at the regional scale.</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/S2197562024000721/pdfft?md5=6ead7827de7a41d9a140180c17125890&pid=1-s2.0-S2197562024000721-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142149644","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":"Variability and determinants of vascular plant species composition in patches of old managed oak forest stands dispersed within Scots pine monocultures","authors":"","doi":"10.1016/j.fecs.2024.100235","DOIUrl":"10.1016/j.fecs.2024.100235","url":null,"abstract":"<div><p>In the temperate zone of Europe, Scots pine forests are expected to occupy the poorest habitats which are unfavourable for deciduous trees. However, as a result of deforestation of the most fertile habitats and the preference for <em>Pinus sylvestris</em> in silviculture, pine forests have become the dominant feature of the landscape in Central Europe. As a result, the area of optimal habitat for deciduous forest flora has been significantly reduced. Nevertheless, remnant patches of deciduous forest persist as habitat islands within extensive pine forest complexes and may serve as important refugia for meso- and eutrophilic forest species. However, the factors that contribute to the variation in species composition of such habitat islands and their role in maintaining biodiversity remain poorly understood. This paper aims to fill this knowledge gap.</p><p>The studied deciduous (oak) stands exhibited a diverse vegetation, with species composition influenced by overstorey attributes, oak age, patch location, and the area and circularity of the deciduous forest. Species traits related to environmental variables included mainly preferences for closed or open forests, requirements for soil moisture, reaction, and fertility, and requirements for light conditions. The key message from our research is that oak islands are not simply patches of trees that are different from the surrounding area. Instead, they represent distinct plant communities that have developed to adapt to the prevailing environmental conditions by recruiting species with particular traits. The presence of oak islands within Scots pine monocultures is therefore important for increasing the diversity of the forest complex.</p><p>The most relevant recommendation from our research for forest management is to maintain as many patches of deciduous tree stands as possible within a single pine forest complex, as even small habitat islands can make a significant contribution to the biodiversity of the forest complex.</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/S219756202400071X/pdfft?md5=f73ede5b90cfb3e6153323f4f0adc46e&pid=1-s2.0-S219756202400071X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142021463","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":"N-fixing tree species promote the chemical stability of soil organic carbon in subtropical plantations through increasing the relative contribution of plant-derived lipids","authors":"","doi":"10.1016/j.fecs.2024.100232","DOIUrl":"10.1016/j.fecs.2024.100232","url":null,"abstract":"<div><p>Biodiversity experiments have shown that soil organic carbon (SOC) is not only a function of plant diversity, but is also closely related to the nitrogen (N) -fixing plants. However, the effect of N-fixing trees on SOC chemical stability is still little known, especially with the compounding effects of tree species diversity. An experimental field manipulation was established in subtropical plantations of southern China to explore the impacts of tree species richness (i.e., one, two, four and six tree species) and with/without N-fixing trees on SOC chemical stability, as indicated by the ratio of easily oxidized organic carbon to SOC (EOC/SOC). Plant-derived C components in terms of hydrolysable plant lipids and lignin phenols were isolated from soils for evaluating their relative contributions to SOC chemical stability. The results showed that N-fixing tree species rather than tree species richness had a significant effect on EOC/SOC. Hydrolysable plant lipids and lignin phenols were negatively correlated with EOC/SOC, while hydrolysable plant lipids contributed more to EOC/SOC than lignin phenols, especially in the occurrence of N-fixing trees. The presence of N-fixing tree species led to an increase in soil N availability and a decrease in fungal abundance, promoting the selective retention of certain key components of hydrolysable plant lipids, thus enhancing SOC chemical stability. These findings underpin the crucial role of N-fixing trees in shaping SOC chemical stability, and therefore, preferential selection of N-fixing tree species in mixed plantations is an appropriate silvicultural strategy to improve SOC chemical stability in subtropical 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/S219756202400068X/pdfft?md5=3cdc145f8d6e830541ec78d6c7cb24bc&pid=1-s2.0-S219756202400068X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142011354","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":"Water use strategies determine divergent growth trends of spruce and juniper on the southeastern Tibetan plateau","authors":"","doi":"10.1016/j.fecs.2024.100248","DOIUrl":"10.1016/j.fecs.2024.100248","url":null,"abstract":"<div><div>Warming and increased CO₂ levels are generally believed to enhance photosynthetic rates (<em>A</em>) and tree growth, especially in alpine treelines. However, this positive effect may be limited by moisture availability. Here we compare the radial growth and intrinsic water use efficiency (iWUE) of two widely-distributed evergreen needleleaf species, Tibetan juniper (<em>Juniperus tibetica</em>) and Balfour spruce (<em>Picea balfouriana</em>), at the same site near the treeline on the southeastern Tibetan Plateau using tree-ring width and dual isotopes (δ¹³C and δ¹⁸O). We observed that with a 70-ppm increase in atmospheric CO₂ from 1954 to 2007, juniper radial growth was significantly stimulated, whereas spruce growth remained constant. Correlation analysis between tree-ring width and climate factors revealed that spruce was more moisture-sensitive than juniper. Although the increases in iWUE for juniper (22%) and spruce (26%) were similar, iWUE changes in spruce were more influenced by stomatal conductance (<em>g</em>_s) rather than <em>A</em>, supporting that moisture availability inhibits spruce growth. Our study implies that predicting growth dynamics in alpine forests based on the growth-temperature relationship may be inadequate, as they are likely moisture-limited. It also suggests that increases in <em>A</em> may not be as widespread as previously thought, which helps improve forest productivity modeling.</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":"142416790","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}