Wenfang Li, Hui Xu, Yong Wu, Xiaoli Zhang, Chunxiao Liu, Chi Lu, Zhibo Yu, Guanglong Ou
Using various biomass factors, such as biomass expansion factor (BEF) and biomass conversion and expansion factor (BCEF), yields different results for estimating forest biomass. Therefore, ensuring compatibility between total biomass and its components when employing different biomass factors is crucial for developing a set of rapid and efficient models for large-scale biomass calculation. In this study, allometric equations were utilized to construct independent models and the proportional values (root-to-shoot ratio (Rra), crown-to-stem ratio (Rcs), bark-to-wood ratio (Rbw), foliage-to-bark ratio (Rfb), and wood biomass-to-wood volume (ρ)) by using the mean height (Hm) and the mean diameter at breast height (Dg) of 98 Pinus densata plots in Shangri-La, Yunnan province, China. The compatible methods were applied to reveal the compatibility between the total biomass and each component’s biomass. The results showed the following: (1) Both the independent model and compatible model had a higher accuracy. The values were greater than 0.7 overall, but the foliage biomass accuracy was only 0.2. The total biomass and the component biomass showed compatibility. (2) The accuracy of BEF and BCEF exceeded 0.87 and the total error was less than 0.1 for most components. (3) The mean BEF (1.6) was greater than that of the Intergovernmental Panel on Climate Change (IPCC) (M = 1.3), and the mean BCEF was smaller than that of the IPCC; the values were 0.6 and 0.7, respectively. The range of BEF (1.4–2.1) and BCEF (0.44–0.89) were all within the range of the IPCC (1.15–3.2, 0.4–1.0). This study provides a more convenient and accurate method for calculating conversion coefficients (BEF and BCEF), especially when only Rcs data is available.
{"title":"A Compatible Estimation Method for Biomass Factors Based on Allometric Relationship: A Case Study on Pinus densata Natural Forest in Yunnan Province of Southwest China","authors":"Wenfang Li, Hui Xu, Yong Wu, Xiaoli Zhang, Chunxiao Liu, Chi Lu, Zhibo Yu, Guanglong Ou","doi":"10.3390/f15010026","DOIUrl":"https://doi.org/10.3390/f15010026","url":null,"abstract":"Using various biomass factors, such as biomass expansion factor (BEF) and biomass conversion and expansion factor (BCEF), yields different results for estimating forest biomass. Therefore, ensuring compatibility between total biomass and its components when employing different biomass factors is crucial for developing a set of rapid and efficient models for large-scale biomass calculation. In this study, allometric equations were utilized to construct independent models and the proportional values (root-to-shoot ratio (Rra), crown-to-stem ratio (Rcs), bark-to-wood ratio (Rbw), foliage-to-bark ratio (Rfb), and wood biomass-to-wood volume (ρ)) by using the mean height (Hm) and the mean diameter at breast height (Dg) of 98 Pinus densata plots in Shangri-La, Yunnan province, China. The compatible methods were applied to reveal the compatibility between the total biomass and each component’s biomass. The results showed the following: (1) Both the independent model and compatible model had a higher accuracy. The values were greater than 0.7 overall, but the foliage biomass accuracy was only 0.2. The total biomass and the component biomass showed compatibility. (2) The accuracy of BEF and BCEF exceeded 0.87 and the total error was less than 0.1 for most components. (3) The mean BEF (1.6) was greater than that of the Intergovernmental Panel on Climate Change (IPCC) (M = 1.3), and the mean BCEF was smaller than that of the IPCC; the values were 0.6 and 0.7, respectively. The range of BEF (1.4–2.1) and BCEF (0.44–0.89) were all within the range of the IPCC (1.15–3.2, 0.4–1.0). This study provides a more convenient and accurate method for calculating conversion coefficients (BEF and BCEF), especially when only Rcs data is available.","PeriodicalId":12339,"journal":{"name":"Forests","volume":"8 3","pages":""},"PeriodicalIF":2.9,"publicationDate":"2023-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138944905","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Michael S. Watt, Dilshana De Silva, H. Estarija, Warren Yorston, P. Massam
Despite the utility of thermal imagery for characterising the impacts of water stress on plant physiology, few studies have been undertaken on plantation-grown conifers, including the most widely planted exotic species, radiata pine. Using data collected from a pot trial, where water was withheld from radiata pine over a nine-day period, the objectives of this study were to (i) determine how rapidly key physiological traits change in response to water stress and (ii) assess the utility of normalised canopy temperature, defined as canopy temperature–air temperature (Tc–Ta), for detecting these physiological changes. Volumetric water content remained high in the well-watered control treatment over the course of the experiment (0.47–0.48 m3 m−3) but declined rapidly in the water stress treatment from 0.47 m3 m−3 at 0 days after treatment (DAT) to 0.04 m3 m−3 at 9 DAT. There were no significant treatment differences in measurements taken at 0 DAT for Tc–Ta, stomatal conductance (gs), transpiration rate (E) or assimilation rate (A). However, by 1 DAT, differences between treatments in tree physiological traits were highly significant, and these differences continued diverging with values in the control treatment exceeding those of trees in the water stress treatment at 9 DAT by 42, 43 and 61%, respectively, for gs, E and A. The relationships between Tc–Ta and the three physiological traits were not significant at 0 DAT, but all three relationships were highly significant from as early as 1 DAT onwards. The strength of the relationships between Tc–Ta and the three physiological traits increased markedly over the duration of the water stress treatment, reaching a maximum coefficient of determination (R2) at 7 DAT when values were, respectively, 0.87, 0.86 and 0.67 for gs, E and A. The early detection of changes in tree physiology from 1 DAT onwards suggests that thermal imagery may be useful for a range of applications in field-grown radiata pine.
尽管热图像可用于描述水分胁迫对植物生理的影响，但针对种植园栽培的针叶树（包括种植最广泛的外来物种辐射松）的研究却很少。本研究利用从盆栽试验中收集到的数据，在为期九天的时间内不给辐射松浇水，其目的是：(i) 确定关键生理特征在应对水分胁迫时的变化速度；(ii) 评估归一化冠层温度（定义为冠层温度-空气温度 (Tc-Ta)）在检测这些生理变化方面的效用。在实验过程中，水分充足的对照处理的体积含水量仍然很高（0.47-0.48 立方米/立方米），但在水分胁迫处理中，体积含水量迅速下降，从处理后 0 天（DAT）的 0.47 立方米/立方米降至处理后 9 天（DAT）的 0.04 立方米/立方米。在 0 DAT 时测量的 Tc-Ta、气孔导度（gs）、蒸腾速率（E）或同化速率（A）没有明显的处理差异。然而，到 1 日龄时，各处理之间的树木生理性状差异非常显著，而且这些差异还在继续扩大，到 9 日龄时，对照处理的 gs、E 和 A 值分别比水胁迫处理的树木值高出 42%、43% 和 61%。随着水分胁迫处理持续时间的延长，Tc-Ta 与三种生理性状之间的关系强度明显增加，在 7 DAT 时达到最大决定系数 (R2)，此时 gs、E 和 A 的值分别为 0.87、0.86 和 0.67。
{"title":"Detecting the Short-Term Effects of Water Stress on Radiata Pine Physiology Using Thermal Imagery","authors":"Michael S. Watt, Dilshana De Silva, H. Estarija, Warren Yorston, P. Massam","doi":"10.3390/f15010028","DOIUrl":"https://doi.org/10.3390/f15010028","url":null,"abstract":"Despite the utility of thermal imagery for characterising the impacts of water stress on plant physiology, few studies have been undertaken on plantation-grown conifers, including the most widely planted exotic species, radiata pine. Using data collected from a pot trial, where water was withheld from radiata pine over a nine-day period, the objectives of this study were to (i) determine how rapidly key physiological traits change in response to water stress and (ii) assess the utility of normalised canopy temperature, defined as canopy temperature–air temperature (Tc–Ta), for detecting these physiological changes. Volumetric water content remained high in the well-watered control treatment over the course of the experiment (0.47–0.48 m3 m−3) but declined rapidly in the water stress treatment from 0.47 m3 m−3 at 0 days after treatment (DAT) to 0.04 m3 m−3 at 9 DAT. There were no significant treatment differences in measurements taken at 0 DAT for Tc–Ta, stomatal conductance (gs), transpiration rate (E) or assimilation rate (A). However, by 1 DAT, differences between treatments in tree physiological traits were highly significant, and these differences continued diverging with values in the control treatment exceeding those of trees in the water stress treatment at 9 DAT by 42, 43 and 61%, respectively, for gs, E and A. The relationships between Tc–Ta and the three physiological traits were not significant at 0 DAT, but all three relationships were highly significant from as early as 1 DAT onwards. The strength of the relationships between Tc–Ta and the three physiological traits increased markedly over the duration of the water stress treatment, reaching a maximum coefficient of determination (R2) at 7 DAT when values were, respectively, 0.87, 0.86 and 0.67 for gs, E and A. The early detection of changes in tree physiology from 1 DAT onwards suggests that thermal imagery may be useful for a range of applications in field-grown radiata pine.","PeriodicalId":12339,"journal":{"name":"Forests","volume":"22 6","pages":""},"PeriodicalIF":2.9,"publicationDate":"2023-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138947448","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Small scattered plots of a few hundred square meters well reflect structural variability at stand level, but not at small spatial scales as the data between plots is missing. Information about structural similarities between managed and unmanaged stands, especially based on large sample plots, is still scarce. Our first objective was to quantify and illustrate structural variability of a selection-managed stand and a corresponding old-growth (OG) stand at small spatial scales. The second goal was to find out if there is a positive autocorrelation among neighboring patches in these stands regarding tree density (N) and basal area (BA). Tree positions and their diameters were recorded in 1.5 ha plots. Structural variation was examined at scales from 0.01 ha to 0.36 ha. Spatial correlation of N and BA was examined by applying experimental semivariograms. The variability of N was similar in both stands, whereas it significantly differed regarding BA (α = 0.05). Semivariance did not detect positive spatial autocorrelation of BA, while adjacent plots appeared to be more similar (autocorrelated) regarding N in both stands. Despite statistical difference regarding BA variability, the selection-managed stand exhibited many structural similarities to the OG stand, which makes it potentially suitable for modulating, if needed, to bring it step closer to an old-growth structure.
几百平方米的零星小块能很好地反映林分层面的结构变化，但由于缺少小块之间的数据，因此不能反映小空间尺度上的结构变化。关于有管理和无管理林分之间结构相似性的信息，尤其是基于大样地的信息，仍然非常稀缺。我们的第一个目标是在小空间尺度上量化和说明选择管理林分和相应的老林地（OG）的结构变异性。第二个目标是找出这些林分中相邻斑块之间在树木密度（N）和基部面积（BA）方面是否存在正的自相关性。在 1.5 公顷的地块上记录了树木的位置和直径。在 0.01 公顷到 0.36 公顷的范围内对结构变化进行了研究。应用实验半变量图检验了 N 和 BA 的空间相关性。氮的变异在两个林分中相似，而在 BA 方面则有显著差异（α = 0.05）。半方差没有检测到 BA 的正空间自相关性，而在两个林分中，相邻地块的氮似乎更相似（自相关）。尽管在 BA 变异性方面存在统计差异，但选择管理的林分在结构上与 OG 林分有许多相似之处，这使其可能适合在必要时进行调节，使其更接近于老生林分结构。
{"title":"Fine-Scale Spatial Variability of Stand Structural Features under Selection Management and Strict Protection: An Example from the Dinaric Mountains","authors":"Srdjan Keren, Wojciech Ochał, V. Dukić","doi":"10.3390/f15010032","DOIUrl":"https://doi.org/10.3390/f15010032","url":null,"abstract":"Small scattered plots of a few hundred square meters well reflect structural variability at stand level, but not at small spatial scales as the data between plots is missing. Information about structural similarities between managed and unmanaged stands, especially based on large sample plots, is still scarce. Our first objective was to quantify and illustrate structural variability of a selection-managed stand and a corresponding old-growth (OG) stand at small spatial scales. The second goal was to find out if there is a positive autocorrelation among neighboring patches in these stands regarding tree density (N) and basal area (BA). Tree positions and their diameters were recorded in 1.5 ha plots. Structural variation was examined at scales from 0.01 ha to 0.36 ha. Spatial correlation of N and BA was examined by applying experimental semivariograms. The variability of N was similar in both stands, whereas it significantly differed regarding BA (α = 0.05). Semivariance did not detect positive spatial autocorrelation of BA, while adjacent plots appeared to be more similar (autocorrelated) regarding N in both stands. Despite statistical difference regarding BA variability, the selection-managed stand exhibited many structural similarities to the OG stand, which makes it potentially suitable for modulating, if needed, to bring it step closer to an old-growth structure.","PeriodicalId":12339,"journal":{"name":"Forests","volume":"10 3","pages":""},"PeriodicalIF":2.9,"publicationDate":"2023-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138947759","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this study, carbon and nitrogen contents in the undisturbed terrestrial ecosystems in the northern taiga zone of Russia’s Murmansk region were estimated. The goal of this study was to examine the carbon and nitrogen dynamics in atmospheric precipitation, assimilating organs of coniferous trees (Picea obovata and Pinus sylvestris), needle litter, soils, and soil water. The objects of our research were the most common dwarf shrub-green moss spruce forests and lichen-dwarf shrub pine forests of the boreal zone. The study was carried out on permanent plots between 1999 and 2020. The long-term dynamics of carbon concentrations in snow demonstrated a trend towards increasing carbon concentrations in forested and treeless areas of the Murmansk region. It was shown that in representative spruce and pine forests, the concentrations and atmospheric precipitation of carbon compounds and carbon leaching with soil water were higher below the tree crowns, compared to between the crowns. In soil water, a decrease was found in carbon concentration with the soil profile depth. For soils, the highest carbon concentrations were found in the organic and illuvial soil horizons. The main soil sinks of carbon and nitrogen in northern taiga forests were found to be located in the organic soil horizon below the crowns. In northern taiga forests, the carbon content of living Picea obovata and Pinus sylvestris needles and Pinus sylvestris needle litter had minor variability; no significant interbiogeocoenotic and age differences were found. We found that the nitrogen content in brown needles and needle litter was significantly lower compared to photosynthetically active needles, probably due to retranslocation processes (withdrawal before needle abscission), corroborating the literature in the results session. The largest stocks of carbon and nitrogen in northern taiga forests are concentrated in the soil organic horizon, and the removal of these elements with soil water is insignificant. Carbon and nitrogen stocks in living and fallen needles are lower than in soil. The least amount of carbon and nitrogen is contained in atmospheric precipitation.
{"title":"Estimation of Carbon and Nitrogen Contents in Forest Ecosystems in the Background Areas of the Russian Arctic (Murmansk Region)","authors":"Vyacheslav Ershov, Tatyana Sukhareva, Nickolay Ryabov, Ekaterina Ivanova, Irina Shtabrovskaya","doi":"10.3390/f15010029","DOIUrl":"https://doi.org/10.3390/f15010029","url":null,"abstract":"In this study, carbon and nitrogen contents in the undisturbed terrestrial ecosystems in the northern taiga zone of Russia’s Murmansk region were estimated. The goal of this study was to examine the carbon and nitrogen dynamics in atmospheric precipitation, assimilating organs of coniferous trees (Picea obovata and Pinus sylvestris), needle litter, soils, and soil water. The objects of our research were the most common dwarf shrub-green moss spruce forests and lichen-dwarf shrub pine forests of the boreal zone. The study was carried out on permanent plots between 1999 and 2020. The long-term dynamics of carbon concentrations in snow demonstrated a trend towards increasing carbon concentrations in forested and treeless areas of the Murmansk region. It was shown that in representative spruce and pine forests, the concentrations and atmospheric precipitation of carbon compounds and carbon leaching with soil water were higher below the tree crowns, compared to between the crowns. In soil water, a decrease was found in carbon concentration with the soil profile depth. For soils, the highest carbon concentrations were found in the organic and illuvial soil horizons. The main soil sinks of carbon and nitrogen in northern taiga forests were found to be located in the organic soil horizon below the crowns. In northern taiga forests, the carbon content of living Picea obovata and Pinus sylvestris needles and Pinus sylvestris needle litter had minor variability; no significant interbiogeocoenotic and age differences were found. We found that the nitrogen content in brown needles and needle litter was significantly lower compared to photosynthetically active needles, probably due to retranslocation processes (withdrawal before needle abscission), corroborating the literature in the results session. The largest stocks of carbon and nitrogen in northern taiga forests are concentrated in the soil organic horizon, and the removal of these elements with soil water is insignificant. Carbon and nitrogen stocks in living and fallen needles are lower than in soil. The least amount of carbon and nitrogen is contained in atmospheric precipitation.","PeriodicalId":12339,"journal":{"name":"Forests","volume":"22 11","pages":""},"PeriodicalIF":2.9,"publicationDate":"2023-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138947446","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xue Wang, Longfeng Gong, Junkang Zhang, Lei Wang, Di Wu, Jichen Xu
Alternative splicing (AS) is an important post-transcriptional regulatory model that can change the normal transcript expression level and possibly result in protein diversity. In this study, we conducted the full-length transcript sequencing of Salix matsudana Koidz 9901 leaves under salt treatment using the PromethION platform. A total of 4786 AS genes (9307 AS events) were determined, accounting for 7.45% of all the transcribed genes. Of them, intron retention (IR) events accounted for the most AS events (46.05%), followed by alternative 3′ splice sites (A3SS). During salt stress, the percentage of IR events decreased, and the percentage of the others increased. Statistical results showed that 5′GG was the most common motif at the 5′ end of the intron in the AS events, and GG3′ was the most common motif at the 3′ end. 5′GG-AG3′ was the most common splice mode in the AS events. The occurrence of AS events was significantly related to the exon number, exon length, intron length, GC content, and expression abundance of the genes. During salt stress, the number of AS genes gradually increased, and they mainly participated in purine and chlorophyll metabolism, RNA transport, and autophagy. Meanwhile, the AS sites of the gene increased during salt treatment, indicating the complexity of the AS events by salt stress. A comparison of differentially expressed genes (DEGs) and differentially alternative splicing (DAS) genes during salt stress revealed that they had a different mechanism of gene expression regulation when subjected to salt stress. These results expand our knowledge of AS events and shed light on and improve our understanding of plant resistance to salt tolerance in willow.
替代剪接（AS）是一种重要的转录后调控模式，可改变正常的转录本表达水平，并可能导致蛋白质的多样性。本研究利用 PromethION 平台对盐处理条件下的 Salix matsudana Koidz 9901 叶片进行了全长转录本测序。共测定了 4786 个 AS 基因（9307 个 AS 事件），占所有转录基因的 7.45%。其中，内含子保留（IR）事件占AS事件的大多数（46.05%），其次是替代3′剪接位点（A3SS）。在盐胁迫期间，IR事件的比例下降，其他事件的比例上升。统计结果表明，在AS事件中，5′GG是内含子5′端最常见的基序，GG3′是3′端最常见的基序。5′GG-AG3′是AS事件中最常见的剪接模式。AS事件的发生与基因的外显子数、外显子长度、内含子长度、GC含量和表达丰度有明显关系。在盐胁迫期间，AS基因的数量逐渐增加，它们主要参与嘌呤和叶绿素代谢、RNA转运和自噬。同时，盐胁迫期间基因的AS位点增加，表明盐胁迫引起的AS事件的复杂性。通过比较盐胁迫期间差异表达基因（DEGs）和差异替代剪接基因（DAS），发现它们在盐胁迫下具有不同的基因表达调控机制。这些结果拓展了我们对AS事件的认识，阐明并加深了我们对柳树植物耐盐性的理解。
{"title":"The Genome-Wide Profiling of Alternative Splicing in Willow under Salt Stress","authors":"Xue Wang, Longfeng Gong, Junkang Zhang, Lei Wang, Di Wu, Jichen Xu","doi":"10.3390/f15010030","DOIUrl":"https://doi.org/10.3390/f15010030","url":null,"abstract":"Alternative splicing (AS) is an important post-transcriptional regulatory model that can change the normal transcript expression level and possibly result in protein diversity. In this study, we conducted the full-length transcript sequencing of Salix matsudana Koidz 9901 leaves under salt treatment using the PromethION platform. A total of 4786 AS genes (9307 AS events) were determined, accounting for 7.45% of all the transcribed genes. Of them, intron retention (IR) events accounted for the most AS events (46.05%), followed by alternative 3′ splice sites (A3SS). During salt stress, the percentage of IR events decreased, and the percentage of the others increased. Statistical results showed that 5′GG was the most common motif at the 5′ end of the intron in the AS events, and GG3′ was the most common motif at the 3′ end. 5′GG-AG3′ was the most common splice mode in the AS events. The occurrence of AS events was significantly related to the exon number, exon length, intron length, GC content, and expression abundance of the genes. During salt stress, the number of AS genes gradually increased, and they mainly participated in purine and chlorophyll metabolism, RNA transport, and autophagy. Meanwhile, the AS sites of the gene increased during salt treatment, indicating the complexity of the AS events by salt stress. A comparison of differentially expressed genes (DEGs) and differentially alternative splicing (DAS) genes during salt stress revealed that they had a different mechanism of gene expression regulation when subjected to salt stress. These results expand our knowledge of AS events and shed light on and improve our understanding of plant resistance to salt tolerance in willow.","PeriodicalId":12339,"journal":{"name":"Forests","volume":"93 5","pages":""},"PeriodicalIF":2.9,"publicationDate":"2023-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138994203","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
N. Fedorov, I. Tuktamyshev, Ilnur Bikbaev, P. Shirokikh, Svetlana Zhigunova, Elvira Baisheva, V. Martynenko
Silver birch (Betula pendula Roth) is one of the fast-growing tree species that often colonize abandoned agricultural lands in Europe and the European part of Russia. The purpose of this article is to analyze the spatiotemporal dynamics of Betula pendula crown cover on abandoned arable lands in a zone of broad-leaved forests of the Bashkir Cis-Ural (Russia, Republic of Bashkortostan). The assessment of current and retrospective values of crown cover was carried out using a regression model of the dependence of crown cover on the values of red channel brightness in early-spring images from Landsat 5–8 and Sentinel-2 satellites from 2012–2022. To estimate the number and height of trees, a survey was carried out using a LiDAR camera mounted on a UAV. After calculating the crown cover in grid squares and their distance from the seed source in QGIS, variance analysis was carried out to assess the influence of the factor of distance from the seed source on the crown cover. The influence of the factor of distance from the seed source on the crown cover was higher at earlier stages of overgrowth of abandoned agricultural lands. An exception to this dependence was only one sample plot where the prevailing wind direction was opposite to the direction of seed dispersal. The leading factors affecting the distribution of birch on abandoned agricultural lands were wind direction, height of seed trees, and grazing. In the parts of the sample plots that were furthest away from seed sources, the trees were 1–3 years younger or the same age, and stand density was lower than in sites located closer to the seed trees. In general, the results of the present study indicate two opposite relationships between seedling survival and distance to seed trees: (1) seed fall and seedling density decrease with increasing distance from the seed tree, and (2) the probability of seed/seedling survival increases due to decreased competition.
{"title":"Spatiotemporal Dynamics of Betula pendula Crown Cover on Abandoned Arable Land in a Broad-Leaved Forest Zone of Bashkir Cis-Ural","authors":"N. Fedorov, I. Tuktamyshev, Ilnur Bikbaev, P. Shirokikh, Svetlana Zhigunova, Elvira Baisheva, V. Martynenko","doi":"10.3390/f15010034","DOIUrl":"https://doi.org/10.3390/f15010034","url":null,"abstract":"Silver birch (Betula pendula Roth) is one of the fast-growing tree species that often colonize abandoned agricultural lands in Europe and the European part of Russia. The purpose of this article is to analyze the spatiotemporal dynamics of Betula pendula crown cover on abandoned arable lands in a zone of broad-leaved forests of the Bashkir Cis-Ural (Russia, Republic of Bashkortostan). The assessment of current and retrospective values of crown cover was carried out using a regression model of the dependence of crown cover on the values of red channel brightness in early-spring images from Landsat 5–8 and Sentinel-2 satellites from 2012–2022. To estimate the number and height of trees, a survey was carried out using a LiDAR camera mounted on a UAV. After calculating the crown cover in grid squares and their distance from the seed source in QGIS, variance analysis was carried out to assess the influence of the factor of distance from the seed source on the crown cover. The influence of the factor of distance from the seed source on the crown cover was higher at earlier stages of overgrowth of abandoned agricultural lands. An exception to this dependence was only one sample plot where the prevailing wind direction was opposite to the direction of seed dispersal. The leading factors affecting the distribution of birch on abandoned agricultural lands were wind direction, height of seed trees, and grazing. In the parts of the sample plots that were furthest away from seed sources, the trees were 1–3 years younger or the same age, and stand density was lower than in sites located closer to the seed trees. In general, the results of the present study indicate two opposite relationships between seedling survival and distance to seed trees: (1) seed fall and seedling density decrease with increasing distance from the seed tree, and (2) the probability of seed/seedling survival increases due to decreased competition.","PeriodicalId":12339,"journal":{"name":"Forests","volume":"11 7","pages":""},"PeriodicalIF":2.9,"publicationDate":"2023-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138944293","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Elevated nitrogen (N) deposition may stimulate a plant’s dependency on arbuscular mycorrhizal (AM) fungi in phosphorus (P)-deficient subtropical forests. However, the ecological assembly processes and the responses of AM fungal diversity and community structure to N deposition in both the roots and rhizosphere are still unclear. We collected root and soil samples from a Cunninghamia lanceolata plantation forest after four years of N addition and examined the community structure and assembly of AM fungi. Elevated N deposition decreased the AM fungal community diversity in both rhizosphere soil and roots. Glomeraceae was the dominant family of the AM fungal community in both soil and roots across all N addition treatments, followed by Gigasporaceae and Ambisporaceae. However, N addition induced differential variation in the community composition of AM fungi between soil and roots. For soil AM fungi, N addition decreased the Glomeraceae abundance and increased the Gigasporaceae and Ambisporaceae abundance. In contrast, the root AM fungal community was dominated by Glomeraceae under N addition treatments. Furthermore, N addition increased the deterministic community assembly that acted as an environmental filter for soil AM fungi. In contrast, N addition decreased the importance of determinism, implying that the selection of plants on root AM fungi decreased with increasing N addition. Altogether, our findings suggest that the community structure of AM fungi responds differently to N deposition in the soil and roots in subtropical forests and highlight the important role of soil AM fungi in helping host plants respond to N deposition.
在缺磷的亚热带森林中，高浓度的氮（N）沉积可能会刺激植物对丛枝菌根真菌（AM）的依赖。然而，根部和根圈的生态组装过程以及 AM 真菌的多样性和群落结构对氮沉积的反应仍不清楚。我们在添加氮四年后收集了杉木人工林的根部和土壤样本，研究了AM真菌的群落结构和组装情况。氮沉积的增加降低了根圈土壤和根部的 AM 真菌群落多样性。在所有氮添加处理中，根瘤菌科（Glomeraceae）都是土壤和根部 AM 真菌群落的优势科，其次是巨孢菌科（Gigasporaceae）和安比孢菌科（Ambisporaceae）。然而，氮添加会导致土壤和根系中 AM 真菌群落组成的差异。在土壤 AM 真菌中，氮添加量降低了团伞花科的丰度，增加了巨孢科和伏孢科的丰度。相比之下，在添加氮的处理中，根部 AM 真菌群落以革兰科为主。此外，氮添加增加了确定性群落的组合，为土壤 AM 真菌起到了环境过滤器的作用。相反，氮添加量降低了决定性的重要性，这意味着植物对根部 AM 真菌的选择随着氮添加量的增加而减少。总之，我们的研究结果表明，在亚热带森林中，AM 真菌的群落结构对土壤和根部的氮沉积有不同的响应，并突出了土壤 AM 真菌在帮助寄主植物响应氮沉积方面的重要作用。
{"title":"Different Responses of Arbuscular Mycorrhizal Fungal Community Compositions in the Soil and Roots to Nitrogen Deposition in a Subtropical Cunninghamia lanceolata Plantation in China","authors":"Yu Han, Zhiyuan Liu, Siyao Li, Faying Lai, Chunghao Chi, Yusheng Yang, Jiling Cao","doi":"10.3390/f15010027","DOIUrl":"https://doi.org/10.3390/f15010027","url":null,"abstract":"Elevated nitrogen (N) deposition may stimulate a plant’s dependency on arbuscular mycorrhizal (AM) fungi in phosphorus (P)-deficient subtropical forests. However, the ecological assembly processes and the responses of AM fungal diversity and community structure to N deposition in both the roots and rhizosphere are still unclear. We collected root and soil samples from a Cunninghamia lanceolata plantation forest after four years of N addition and examined the community structure and assembly of AM fungi. Elevated N deposition decreased the AM fungal community diversity in both rhizosphere soil and roots. Glomeraceae was the dominant family of the AM fungal community in both soil and roots across all N addition treatments, followed by Gigasporaceae and Ambisporaceae. However, N addition induced differential variation in the community composition of AM fungi between soil and roots. For soil AM fungi, N addition decreased the Glomeraceae abundance and increased the Gigasporaceae and Ambisporaceae abundance. In contrast, the root AM fungal community was dominated by Glomeraceae under N addition treatments. Furthermore, N addition increased the deterministic community assembly that acted as an environmental filter for soil AM fungi. In contrast, N addition decreased the importance of determinism, implying that the selection of plants on root AM fungi decreased with increasing N addition. Altogether, our findings suggest that the community structure of AM fungi responds differently to N deposition in the soil and roots in subtropical forests and highlight the important role of soil AM fungi in helping host plants respond to N deposition.","PeriodicalId":12339,"journal":{"name":"Forests","volume":"51 29","pages":""},"PeriodicalIF":2.9,"publicationDate":"2023-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138946315","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The natural distribution of Cycas micronesica includes three island groups. Damage to the widespread tree from the armored scale Aulacaspis yasumatsui was initiated with the 2003 invasion of Guam and the 2007 invasion of Rota. This herbivore has threatened the unique gymnosperm species with extinction. The number and identity of co-occurring consumers are dissimilar among disjunct insular subpopulations, and six of these habitats were used to assess tree mortality trends to confirm that A. yasumatsui stands alone as the greatest threat to species persistence. Following the initial infestation outbreak of this pest into each new subpopulation, the standing seedlings and saplings were the first to be culled, the juvenile plants were the next to be culled, and then the adult trees were killed more slowly thereafter. The timing of this plant population behavior did not differ among habitats with five other consumers, three other consumers, one other consumer, or no other consumers. We have shown that A. yasumatsui acting as the sole biotic threat in an isolated subpopulation can generate a decline in survival that is as rapid as when it is acting in conjunction with up to five other consequential consumers. This armored scale is the most acute threat to C. micronesica, and adding other specialist herbivores to the scale herbivory does not alter the speed and extent of initial plant mortality.
{"title":"Insular Cycas micronesica Habitats Respond Similarly to Aulacaspis yasumatsui Invasion, Regardless of Co-Occurring Consumers","authors":"T. Marler, Gil N. Cruz","doi":"10.3390/f15010022","DOIUrl":"https://doi.org/10.3390/f15010022","url":null,"abstract":"The natural distribution of Cycas micronesica includes three island groups. Damage to the widespread tree from the armored scale Aulacaspis yasumatsui was initiated with the 2003 invasion of Guam and the 2007 invasion of Rota. This herbivore has threatened the unique gymnosperm species with extinction. The number and identity of co-occurring consumers are dissimilar among disjunct insular subpopulations, and six of these habitats were used to assess tree mortality trends to confirm that A. yasumatsui stands alone as the greatest threat to species persistence. Following the initial infestation outbreak of this pest into each new subpopulation, the standing seedlings and saplings were the first to be culled, the juvenile plants were the next to be culled, and then the adult trees were killed more slowly thereafter. The timing of this plant population behavior did not differ among habitats with five other consumers, three other consumers, one other consumer, or no other consumers. We have shown that A. yasumatsui acting as the sole biotic threat in an isolated subpopulation can generate a decline in survival that is as rapid as when it is acting in conjunction with up to five other consequential consumers. This armored scale is the most acute threat to C. micronesica, and adding other specialist herbivores to the scale herbivory does not alter the speed and extent of initial plant mortality.","PeriodicalId":12339,"journal":{"name":"Forests","volume":"50 9","pages":""},"PeriodicalIF":2.9,"publicationDate":"2023-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138952025","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Forest gaps, which are formed by small-scale disturbances that often occur in forest communities, are the most dominant form of disturbance in many types of forests around the world and play an essential role in the dynamics of forest regeneration, plant diversity conservation, nutrient cycling, and forest succession. Forest gaps are one of the vital directions in forest research. Dynamic disturbance and vegetation regeneration are important elements of forest gap research. The research on forest gaps has a history spanning over 70 years, but there is a lack of a systematic overview of the process. Therefore, this review outlines the spatial changes in the whole process of forest gap development by systematically analyzing the occurrence, basic characteristics, micro-environmental changes, and the effects of forest gap disturbance processes on understory animals, plants, soil microorganisms, and forest regeneration and succession. The results contribute to a better understanding of forest gaps and their impacts on forest regeneration and management. Based on this, we remapped the forest gap process during forest succession. We suggest directions and recommendations for improvements in response to the dilemmas and challenges facing the future of forest gaps.
{"title":"Research History of Forest Gap as Small-Scale Disturbances in Forest Ecosystems","authors":"Aolei Tian, Ü. Halik, Wentao Fu, Subinur Sawirdin, Shengyuan Cheng, Jiaqiang Lei","doi":"10.3390/f15010021","DOIUrl":"https://doi.org/10.3390/f15010021","url":null,"abstract":"Forest gaps, which are formed by small-scale disturbances that often occur in forest communities, are the most dominant form of disturbance in many types of forests around the world and play an essential role in the dynamics of forest regeneration, plant diversity conservation, nutrient cycling, and forest succession. Forest gaps are one of the vital directions in forest research. Dynamic disturbance and vegetation regeneration are important elements of forest gap research. The research on forest gaps has a history spanning over 70 years, but there is a lack of a systematic overview of the process. Therefore, this review outlines the spatial changes in the whole process of forest gap development by systematically analyzing the occurrence, basic characteristics, micro-environmental changes, and the effects of forest gap disturbance processes on understory animals, plants, soil microorganisms, and forest regeneration and succession. The results contribute to a better understanding of forest gaps and their impacts on forest regeneration and management. Based on this, we remapped the forest gap process during forest succession. We suggest directions and recommendations for improvements in response to the dilemmas and challenges facing the future of forest gaps.","PeriodicalId":12339,"journal":{"name":"Forests","volume":"138 41","pages":""},"PeriodicalIF":2.9,"publicationDate":"2023-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138953395","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Gruber, Gerhard Wieser, Marion Fink, W. Oberhuber
Due to land use change, green alder (Alnus alnobetula), formerly restricted to moist slopes, is now expanding to drier sun-exposed sites at the alpine treeline. The highly productive shrub is forming closed thickets, establishing nitrogen-saturated species in poor shrublands. To evaluate wood anatomical adaptations to changing environmental conditions, we analyzed vessel characteristics (mean vessel area, MVA; vessel density, VD; and theoretic conductive area, TCA) and axial parenchyma abundance, as well as their distribution in the annual ring at a moist north-facing and a dry south-facing site at the alpine treeline on Mt. Patscherkofel (Central European Alps, Austria). Results revealed that lower soil water availability and enhanced evaporative demand did not affect MVA while VD and TCA were significantly reduced at the dry south-facing site. This suggests that in green alder, vessel size is a static trait whereas vessel number isresponds plastic. Limited water availability also triggered a significant increase in axial parenchyma, confirming the important role of xylem parenchyma in water relations. Harsh environmental conditions at the distributional limit of green alder may have affected xylogenesis, leading to a near semi-ring-porous distribution of vessels and an accumulation of parenchyma in the late growing season. We conclude that in a warmer and drier climate, growth limitation and physiological stress may set limits to the distribution of Alnus alnobetula at drought-prone sites in the alpine treeline ecotone.
{"title":"Impact of Environmental Conditions on Wood Anatomical Traits of Green Alder (Alnus alnobetula) at the Alpine Treeline","authors":"A. Gruber, Gerhard Wieser, Marion Fink, W. Oberhuber","doi":"10.3390/f15010024","DOIUrl":"https://doi.org/10.3390/f15010024","url":null,"abstract":"Due to land use change, green alder (Alnus alnobetula), formerly restricted to moist slopes, is now expanding to drier sun-exposed sites at the alpine treeline. The highly productive shrub is forming closed thickets, establishing nitrogen-saturated species in poor shrublands. To evaluate wood anatomical adaptations to changing environmental conditions, we analyzed vessel characteristics (mean vessel area, MVA; vessel density, VD; and theoretic conductive area, TCA) and axial parenchyma abundance, as well as their distribution in the annual ring at a moist north-facing and a dry south-facing site at the alpine treeline on Mt. Patscherkofel (Central European Alps, Austria). Results revealed that lower soil water availability and enhanced evaporative demand did not affect MVA while VD and TCA were significantly reduced at the dry south-facing site. This suggests that in green alder, vessel size is a static trait whereas vessel number isresponds plastic. Limited water availability also triggered a significant increase in axial parenchyma, confirming the important role of xylem parenchyma in water relations. Harsh environmental conditions at the distributional limit of green alder may have affected xylogenesis, leading to a near semi-ring-porous distribution of vessels and an accumulation of parenchyma in the late growing season. We conclude that in a warmer and drier climate, growth limitation and physiological stress may set limits to the distribution of Alnus alnobetula at drought-prone sites in the alpine treeline ecotone.","PeriodicalId":12339,"journal":{"name":"Forests","volume":"38 11","pages":""},"PeriodicalIF":2.9,"publicationDate":"2023-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138952499","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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