Effects of Tree Diversity, Functional Composition, and Large Trees on the Aboveground Biomass of an Old-Growth Subtropical Forest in Southern China
Forest aboveground biomass (AGB) plays an important role in regulating the global carbon cycle and is thus an essential component of ecosystem functioning. In the relationships between biodiversity and ecosystem functioning (BEF), studies have shown that many biotic factors (e.g., species, functiona...
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-05-01
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| Series: | Forests |
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| Online Access: | https://www.mdpi.com/1999-4907/14/5/994 |
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| author | Yaoyi Wang Zheng Song Xiongqing Zhang Hongxiang Wang |
| author_facet | Yaoyi Wang Zheng Song Xiongqing Zhang Hongxiang Wang |
| author_sort | Yaoyi Wang |
| collection | DOAJ |
| description | Forest aboveground biomass (AGB) plays an important role in regulating the global carbon cycle and is thus an essential component of ecosystem functioning. In the relationships between biodiversity and ecosystem functioning (BEF), studies have shown that many biotic factors (e.g., species, functional traits, and large trees) and abiotic factors have significant impacts on AGB. However, the relative strength of these affecting factors remains unclear. In this study, we analyzed woody plants (diameter at breast height [<i>DBH</i>] ≥ 1 cm) within a 1.6 ha plot in an old-growth subtropical natural forest in southern China. We used structural equation models to test the effects of tree diversity (species, phylogenetic, functional, and size inequality), functional composition, large trees, and environmental factors (topography, soil nutrients, and understory light) on AGB. Our results indicated that size inequality, the community-weighted mean of maximum <i>DBH</i> (CWM_MDBH), and large trees had significant, positive effects on AGB (<i>p</i> < 0.001), while lower soil phosphorus content was found to promote an increase in AGB. Furthermore, large trees, which were mostly composed of dominant tree species, were the main driver of AGB, and the effect of functional composition (e.g., CWM_MDBH) on AGB was substantially reduced by large trees. We argue that the selection effect plays a key role in regulating BEF relationships in subtropical natural forests and conclude that retaining large-diameter trees and dominant species, along with sustaining a complex stand structure, are key measures for improving productivity. |
| first_indexed | 2024-03-11T03:44:14Z |
| format | Article |
| id | doaj.art-effdcb8690c44df8a608ec396a9b7c4b |
| institution | Directory Open Access Journal |
| issn | 1999-4907 |
| language | English |
| last_indexed | 2024-03-11T03:44:14Z |
| publishDate | 2023-05-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Forests |
| spelling | doaj.art-effdcb8690c44df8a608ec396a9b7c4b2023-11-18T01:24:44ZengMDPI AGForests1999-49072023-05-0114599410.3390/f14050994Effects of Tree Diversity, Functional Composition, and Large Trees on the Aboveground Biomass of an Old-Growth Subtropical Forest in Southern ChinaYaoyi Wang0Zheng Song1Xiongqing Zhang2Hongxiang Wang3Guangxi Key Laboratory of Forest Ecology and Conservation, College of Forestry, Guangxi University, Nanning 530004, ChinaResearch Institute of Forestry Policy and Information, Chinese Academy of Forestry, Beijing 100091, ChinaKey Laboratory of Tree Breeding and Cultivation of the National Forestry and Grassland Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, ChinaGuangxi Key Laboratory of Forest Ecology and Conservation, College of Forestry, Guangxi University, Nanning 530004, ChinaForest aboveground biomass (AGB) plays an important role in regulating the global carbon cycle and is thus an essential component of ecosystem functioning. In the relationships between biodiversity and ecosystem functioning (BEF), studies have shown that many biotic factors (e.g., species, functional traits, and large trees) and abiotic factors have significant impacts on AGB. However, the relative strength of these affecting factors remains unclear. In this study, we analyzed woody plants (diameter at breast height [<i>DBH</i>] ≥ 1 cm) within a 1.6 ha plot in an old-growth subtropical natural forest in southern China. We used structural equation models to test the effects of tree diversity (species, phylogenetic, functional, and size inequality), functional composition, large trees, and environmental factors (topography, soil nutrients, and understory light) on AGB. Our results indicated that size inequality, the community-weighted mean of maximum <i>DBH</i> (CWM_MDBH), and large trees had significant, positive effects on AGB (<i>p</i> < 0.001), while lower soil phosphorus content was found to promote an increase in AGB. Furthermore, large trees, which were mostly composed of dominant tree species, were the main driver of AGB, and the effect of functional composition (e.g., CWM_MDBH) on AGB was substantially reduced by large trees. We argue that the selection effect plays a key role in regulating BEF relationships in subtropical natural forests and conclude that retaining large-diameter trees and dominant species, along with sustaining a complex stand structure, are key measures for improving productivity.https://www.mdpi.com/1999-4907/14/5/994aboveground biomassfunctional compositionlarge treesselection effect hypothesisniche complementarity hypothesistree size inequality |
| spellingShingle | Yaoyi Wang Zheng Song Xiongqing Zhang Hongxiang Wang Effects of Tree Diversity, Functional Composition, and Large Trees on the Aboveground Biomass of an Old-Growth Subtropical Forest in Southern China Forests aboveground biomass functional composition large trees selection effect hypothesis niche complementarity hypothesis tree size inequality |
| title | Effects of Tree Diversity, Functional Composition, and Large Trees on the Aboveground Biomass of an Old-Growth Subtropical Forest in Southern China |
| title_full | Effects of Tree Diversity, Functional Composition, and Large Trees on the Aboveground Biomass of an Old-Growth Subtropical Forest in Southern China |
| title_fullStr | Effects of Tree Diversity, Functional Composition, and Large Trees on the Aboveground Biomass of an Old-Growth Subtropical Forest in Southern China |
| title_full_unstemmed | Effects of Tree Diversity, Functional Composition, and Large Trees on the Aboveground Biomass of an Old-Growth Subtropical Forest in Southern China |
| title_short | Effects of Tree Diversity, Functional Composition, and Large Trees on the Aboveground Biomass of an Old-Growth Subtropical Forest in Southern China |
| title_sort | effects of tree diversity functional composition and large trees on the aboveground biomass of an old growth subtropical forest in southern china |
| topic | aboveground biomass functional composition large trees selection effect hypothesis niche complementarity hypothesis tree size inequality |
| url | https://www.mdpi.com/1999-4907/14/5/994 |
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