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Zhang B, Xu C, Zhang Z, Hu C, Zhong C, Chen S, Hu G. Elevational patterns of soil organic carbon and its fractions in tropical seasonal rainforests in karst peak-cluster depression region. FRONTIERS IN PLANT SCIENCE 2024; 15:1424891. [PMID: 39439516 PMCID: PMC11493711 DOI: 10.3389/fpls.2024.1424891] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/28/2024] [Accepted: 09/20/2024] [Indexed: 10/25/2024]
Abstract
Karst ecosystems, especially tropical karst forests, are crucial to the global carbon cycle. In mountainous and hilly areas, elevation-related changes in environment and vegetation often lead to shifts in the accumulation and decomposition of soil organic carbon (SOC). However, the elevational patterns and influencing variables of SOC and its fractions in tropical karst forest ecosystems remain largely unexplored. Here, we analyzed the elevational patterns of SOC and its fractions in the topsoil and subsoil in the tropical seasonal rainforests within typical peak-cluster depression region of Southwest China. Our results indicated that the SOC content was highest at 400 m asl, which was significantly higher than that at 200 m asl (p < 0.05). Overall, SOC content demonstrated an increasing trend with rising elevation. Additionally, SOC content was significantly higher in the topsoil compared to the subsoil (p < 0.05). The majority of SOC fractions exhibited an increase with elevation but decrease with soil depth. Notably, only water-soluble organic carbon (WSOC) displayed a decrease with elevation. Meanwhile, recalcitrant organic carbon (ROC, 54.27%), particulate organic carbon (POC, 30.19%), and easily oxidizable organic carbon (EOC, 16.95%) were the main SOC fractions. Labile organic carbon (LOC) in the karst forest soil was predominantly composed of EOC and POC. Correlation analysis unveiled significant positive correlations between SOC and certain fractions with elevation, soil total nitrogen, and exchangeable magnesium. Conversely, significant negative correlations were observed with soil bulk density (SBD), soil total phosphorus, and litter phosphorus (Litter P). Redundancy analysis indicated that elevation, SBD, and Litter P were the main environmental variables influencing shifts in SOC and its fractions. Structural equation models showed that SOC was primarily directly impacted by soil properties but indirectly impacted by elevation. ROC was mainly associated with the direct effects of soil properties and litterfall, although elevation exerted a substantial impact through indirect pathways. Moreover, LOC was predominantly influenced by the direct impact of soil properties. Therefore, this study demonstrates that SOC and its fractions are strongly influenced by elevation in karst peak-cluster depression regions and have important implications for forest management and sustainable ecosystem development in these regions.
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Affiliation(s)
- Bei Zhang
- Key Laboratory of Wildlife Evolution and Conservation in Mountain Ecosystem of Guangxi, Nanning Normal University, Nanning, China
- Key Laboratory of Ministry of Education for Environment Change and Resources Use in Beibu Gulf, Nanning Normal University, Nanning, China
- School of Geography and Planning, Nanning Normal University, Nanning, China
| | - Chaohao Xu
- Key Laboratory of Wildlife Evolution and Conservation in Mountain Ecosystem of Guangxi, Nanning Normal University, Nanning, China
| | - Zhonghua Zhang
- Key Laboratory of Wildlife Evolution and Conservation in Mountain Ecosystem of Guangxi, Nanning Normal University, Nanning, China
- Key Laboratory of Ministry of Education for Environment Change and Resources Use in Beibu Gulf, Nanning Normal University, Nanning, China
- School of Geography and Planning, Nanning Normal University, Nanning, China
| | - Cong Hu
- Key Laboratory of Wildlife Evolution and Conservation in Mountain Ecosystem of Guangxi, Nanning Normal University, Nanning, China
| | - Chaofang Zhong
- Key Laboratory of Wildlife Evolution and Conservation in Mountain Ecosystem of Guangxi, Nanning Normal University, Nanning, China
| | - Siyu Chen
- Key Laboratory of Wildlife Evolution and Conservation in Mountain Ecosystem of Guangxi, Nanning Normal University, Nanning, China
| | - Gang Hu
- Key Laboratory of Wildlife Evolution and Conservation in Mountain Ecosystem of Guangxi, Nanning Normal University, Nanning, China
- Key Laboratory of Ministry of Education for Environment Change and Resources Use in Beibu Gulf, Nanning Normal University, Nanning, China
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Liu Y, Liu R, Chen J, Wei X, Qi L, Zhao L. A global annual fractional tree cover dataset during 2000-2021 generated from realigned MODIS seasonal data. Sci Data 2024; 11:832. [PMID: 39090119 PMCID: PMC11294532 DOI: 10.1038/s41597-024-03671-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2024] [Accepted: 07/23/2024] [Indexed: 08/04/2024] Open
Abstract
Fractional tree cover facilitates the depiction of forest density and its changes. However, it remains challenging to estimate tree cover from satellite data, leading to substantial uncertainties in forest cover changes analysis. This paper generated a global annual fractional tree cover dataset from 2000 to 2021 with 250 m resolution (GLOBMAP FTC). MODIS annual observations were realigned at the pixel level to a common phenology and used to extract twelve features that can differentiate between trees and herbaceous vegetation, which greatly reduced feature dimensionality. A massive training data, consisting of 465.88 million sample points from four high-resolution global forest cover products, was collected to train a feedforward neural network model to predict tree cover. Compared with the validation datasets derived from the USGS circa 2010 global land cover reference dataset, the R2 value, MAE, and RMSE were 0.73, 10.55%, and 17.98%, respectively. This dataset can be applied for assessment of forest cover changes, including both abrupt forest loss and gradual forest gain.
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Affiliation(s)
- Yang Liu
- State Key Laboratory of Resources and Environmental Information System, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China
| | - Ronggao Liu
- State Key Laboratory of Resources and Environmental Information System, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China.
| | - Jilong Chen
- State Key Laboratory of Resources and Environmental Information System, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xuexin Wei
- State Key Laboratory of Resources and Environmental Information System, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Lin Qi
- State Key Laboratory of Resources and Environmental Information System, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China
| | - Lei Zhao
- State Key Laboratory of Resources and Environmental Information System, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
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Wang X, Gong L, Luo Y, Ding Z, Guo Q, Li X, Ma X. Phylogenetic diversity drives soil multifunctionality in arid montane forest-grassland transition zone. FRONTIERS IN PLANT SCIENCE 2024; 15:1344948. [PMID: 38410734 PMCID: PMC10894997 DOI: 10.3389/fpls.2024.1344948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Accepted: 01/26/2024] [Indexed: 02/28/2024]
Abstract
Exploring plant diversity and ecosystem functioning in different dimensions is crucial to preserve ecological balance and advance ecosystem conservation efforts. Ecosystem transition zones serve as vital connectors linking two distinct ecosystems, yet the impact of various aspects of plant diversity (including taxonomic, functional, and phylogenetic diversity) on soil multifunctionality in these zones remains to be clarified. This study focuses on the forest-grassland transition zone in the mountains on the northern slopes of the Tianshan Mountains, and investigates vegetation and soil characteristics from forest ecosystems to grassland ecosystems to characterize plant diversity and soil functioning, as well as the driving role of plant diversity in different dimensions. In the montane forest-grassland transition zone, urease (URE) and total nitrogen (TN) play a major role in regulating plant diversity by affecting the soil nutrient cycle. Phylogenetic diversity was found to be the strongest driver of soil multifunctionality, followed by functional diversity, while taxonomic diversity was the least important driver. Diverse species were shown to play an important role in maintaining soil multifunctionality in the transition zone, especially distantly related species with high phylogeny. The study of multidimensional plant diversity and soil multifunctionality in the montane forest-grassland transition zone can help to balance the relationship between these two elements, which is crucial in areas where the ecosystem overlaps, and the application of the findings can support sustainable development in these regions.
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Affiliation(s)
- Xiaofei Wang
- College of Ecology and Environment, Xinjiang University, Urumqi, China
- Key Laboratory of Oasis Ecology, Ministry of Education, Urumqi, China
| | - Lu Gong
- College of Ecology and Environment, Xinjiang University, Urumqi, China
- Key Laboratory of Oasis Ecology, Ministry of Education, Urumqi, China
| | - Yan Luo
- College of Ecology and Environment, Xinjiang University, Urumqi, China
- Key Laboratory of Oasis Ecology, Ministry of Education, Urumqi, China
| | - Zhaolong Ding
- College of Ecology and Environment, Xinjiang University, Urumqi, China
- Key Laboratory of Oasis Ecology, Ministry of Education, Urumqi, China
| | - Qian Guo
- College of Ecology and Environment, Xinjiang University, Urumqi, China
- Key Laboratory of Oasis Ecology, Ministry of Education, Urumqi, China
| | - Xiaochen Li
- College of Ecology and Environment, Xinjiang University, Urumqi, China
- Key Laboratory of Oasis Ecology, Ministry of Education, Urumqi, China
| | - Xinyu Ma
- College of Ecology and Environment, Xinjiang University, Urumqi, China
- Key Laboratory of Oasis Ecology, Ministry of Education, Urumqi, China
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Braziunas KH, Geres L, Richter T, Glasmann F, Senf C, Thom D, Seibold S, Seidl R. Projected climate and canopy change lead to thermophilization and homogenization of forest floor vegetation in a hotspot of plant species richness. GLOBAL CHANGE BIOLOGY 2024; 30:e17121. [PMID: 38273493 DOI: 10.1111/gcb.17121] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 12/06/2023] [Accepted: 12/15/2023] [Indexed: 01/27/2024]
Abstract
Mountain forests are plant diversity hotspots, but changing climate and increasing forest disturbances will likely lead to far-reaching plant community change. Projecting future change, however, is challenging for forest understory plants, which respond to forest structure and composition as well as climate. Here, we jointly assessed the effects of both climate and forest change, including wind and bark beetle disturbances, using the process-based simulation model iLand in a protected landscape in the northern Alps (Berchtesgaden National Park, Germany), asking: (1) How do understory plant communities respond to 21st-century change in a topographically complex mountain landscape, representing a hotspot of plant species richness? (2) How important are climatic changes (i.e., direct climate effects) versus forest structure and composition changes (i.e., indirect climate effects and recovery from past land use) in driving understory responses at landscape scales? Stacked individual species distribution models fit with climate, forest, and soil predictors (248 species currently present in the landscape, derived from 150 field plots stratified by elevation and forest development, overall area under the receiving operator characteristic curve = 0.86) were driven with projected climate (RCP4.5 and RCP8.5) and modeled forest variables to predict plant community change. Nearly all species persisted in the landscape in 2050, but on average 8% of the species pool was lost by the end of the century. By 2100, landscape mean species richness and understory cover declined (-13% and -8%, respectively), warm-adapted species increasingly dominated plant communities (i.e., thermophilization, +12%), and plot-level turnover was high (62%). Subalpine forests experienced the greatest richness declines (-16%), most thermophilization (+17%), and highest turnover (67%), resulting in plant community homogenization across elevation zones. Climate rather than forest change was the dominant driver of understory responses. The magnitude of unabated 21st-century change is likely to erode plant diversity in a species richness hotspot, calling for stronger conservation and climate mitigation efforts.
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Affiliation(s)
- Kristin H Braziunas
- Ecosystem Dynamics and Forest Management Group, TUM School of Life Sciences, Technical University of Munich, Freising, Germany
| | - Lisa Geres
- Berchtesgaden National Park, Berchtesgaden, Germany
- Faculty of Biological Sciences, Institute for Ecology, Evolution and Diversity, Conservation Biology, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Tobias Richter
- Ecosystem Dynamics and Forest Management Group, TUM School of Life Sciences, Technical University of Munich, Freising, Germany
- Berchtesgaden National Park, Berchtesgaden, Germany
| | - Felix Glasmann
- Professorship of Forest and Agroforest Systems, TUM School of Life Sciences, Technical University of Munich, Freising, Germany
| | - Cornelius Senf
- Ecosystem Dynamics and Forest Management Group, TUM School of Life Sciences, Technical University of Munich, Freising, Germany
| | - Dominik Thom
- Ecosystem Dynamics and Forest Management Group, TUM School of Life Sciences, Technical University of Munich, Freising, Germany
| | - Sebastian Seibold
- Ecosystem Dynamics and Forest Management Group, TUM School of Life Sciences, Technical University of Munich, Freising, Germany
- Berchtesgaden National Park, Berchtesgaden, Germany
- Forest Zoology, Technische Universität Dresden, Tharandt, Germany
| | - Rupert Seidl
- Ecosystem Dynamics and Forest Management Group, TUM School of Life Sciences, Technical University of Munich, Freising, Germany
- Berchtesgaden National Park, Berchtesgaden, Germany
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