Forest Soil Carbon Cycle in Response to Global Change

A special issue of Forests (ISSN 1999-4907). This special issue belongs to the section "Forest Soil".

Deadline for manuscript submissions: closed (31 October 2023) | Viewed by 17903

Special Issue Editors

School of Geographical Sciences, Fujian Normal University, Fuzhou 350007, China
Interests: soil carbon priming effect; soil carbon formation; global change

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Guest Editor
School of Geographical Sciences, Fujian Normal University, Fuzhou 350007, China
Interests: ecological restoration; global change ecology

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Guest Editor
Department of Ecology, School of Life Sciences, State Key Laboratory of Biocontrol, Sun Yat-Sen University, Guangzhou 510275, China
Interests: forest management; soil organic matter formation and persistence

Special Issue Information

Dear Colleagues,

Forests of trees are reservoirs of biodiversity, sustaining a web of life while sequestering carbon, and modulating regional climates. Forests are key components of the global carbon cycle storing more than 39% of the total terrestrial organic carbon both below and above ground. A growing number of studies suggest that tree species mixture can enhance forest productivity. Knowledge of the diversity of plant species' effect on soil organic carbon formation and storage is limited. A better understanding of the relationships between biodiversity, productivity, and carbon sequestration may help in maintaining forest productivity and improving terrestrial carbon cycling, feedback, and their future projection in the context of global change. This Special Issue aims to synthesize the current understanding of relationships between forest productivity, biodiversity, microbial diversity, and carbon persistence and formation, to solve the mechanisms of species diversity affecting soil organic carbon accumulations, and to illustrate how this knowledge could be translated into forest management strategies and long-term carbon sequestrations sustainably in the context of global change.

Manuscripts focusing on forest species diversity, carbon cycling, microbial diversity, soil carbon, litter decomposition and soil carbon formation and persistence are welcomed in this Special Issue.

Dr. Maokui Lyu
Prof. Dr. Jingsheng Xie
Dr. Minhuang Wang
Guest Editors

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Keywords

  • forest ecosystem
  • species diversity
  • forest productivity
  • soil carbon decomposition and formation
  • microbial diversity
  • global change

Published Papers (11 papers)

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Editorial

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3 pages, 659 KiB  
Editorial
Forest Soil Carbon Cycle in Response to Global Change
by Minhuang Wang, Jinsheng Xie and Maokui Lyu
Forests 2023, 14(11), 2242; https://doi.org/10.3390/f14112242 - 14 Nov 2023
Cited by 1 | Viewed by 843
Abstract
Forests constitute a critical component of terrestrial carbon reservoirs, with a substantial amount of carbon stored in soil as organic carbon, holding significant potential for climate change mitigation [...] Full article
(This article belongs to the Special Issue Forest Soil Carbon Cycle in Response to Global Change)

Research

Jump to: Editorial

19 pages, 5398 KiB  
Article
Keystone Soil Microbial Modules Associated with Priming Effect under Nitrogen- and Glucose-Addition Treatments
by Min Xu, Quanxin Zeng, Yuanyuan Liu, Chengchung Liu, Qiufang Zhang, Kongcan Mei, Xiaochun Yuan, Xiaoqing Zhang and Yuehmin Chen
Forests 2023, 14(6), 1207; https://doi.org/10.3390/f14061207 - 11 Jun 2023
Cited by 1 | Viewed by 977
Abstract
The priming effect (PE) is important for understanding the decomposition of soil organic matter (SOM) and forecasting C-climate feedback. However, there are limited studies on microbial community-level properties and the keystone taxa involved in the process. In this study, we collected soil from [...] Read more.
The priming effect (PE) is important for understanding the decomposition of soil organic matter (SOM) and forecasting C-climate feedback. However, there are limited studies on microbial community-level properties and the keystone taxa involved in the process. In this study, we collected soil from a subtropical Phyllostachys edulis forest undergoing long-term N-addition and conducted an incubation experiment to evaluate the effects of single and repeated addition of 13C-labeled glucose. Our results demonstrated that previously N-fertilized soil had a smaller cumulative PE compared with that of the control (11% average decrease). This could be primarily explained (26%) by the lower abundance of bacterial r-strategy group members (B_mod#2, constituting Proteobacteria, Firmicutes, and Actinobacteria phyla) under N-addition treatments. A single C-addition induced a greater PE than that of repeated C-additions (2.66- to 3.11-fold). Single C addition led to greater C to N ratios of microbial biomass and fungi to bacteria, positively impacting cumulative PE, indicating that the shifts in fungal/bacterial dominance play an important role in regulating PE. Moreover, a saprophytic taxa group (F_Mod#3, primarily composed of the phyla Ascomycota) explained 62% of the differences in cumulative PE between single and repeated C-additions. Compared with repeated C-additions, a greater abundance of B_Mod#2 and F_Mod#3, as well as C-related hydrolase activity, was observed under single C-addition, inducing greater cumulative PE. Therefore, sufficient C may facilitate the proliferation of r-strategy bacterial taxa and saprophytic fungal taxa, thereby increasing SOM decomposition. Our findings provide novel insights into the relationship between microbial community-level properties and PE. Full article
(This article belongs to the Special Issue Forest Soil Carbon Cycle in Response to Global Change)
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13 pages, 2590 KiB  
Article
Long-Term Nitrogen Addition Exerts Minor Effects on Microbial Community but Alters Sensitive Microbial Species in a Subtropical Natural Forest
by Min He, Xiaojian Zhong, Yun Xia, Linglin Xu, Quanxin Zeng, Liuming Yang and Yuexin Fan
Forests 2023, 14(5), 928; https://doi.org/10.3390/f14050928 - 30 Apr 2023
Cited by 5 | Viewed by 1391
Abstract
Increasing nitrogen (N) deposition profoundly affects nutrient cycling in soil, thereby influencing forest ecosystem productivity and function. Soil microorganisms are integral in driving nutrient turnover; the changes in microbial communities in response to N deposition and the associated soil nutrient availability, especially of [...] Read more.
Increasing nitrogen (N) deposition profoundly affects nutrient cycling in soil, thereby influencing forest ecosystem productivity and function. Soil microorganisms are integral in driving nutrient turnover; the changes in microbial communities in response to N deposition and the associated soil nutrient availability, especially of limited nutrients, are far from clear. To explore the changes in soil bacterial and fungal communities and their key environmental drivers under N deposition, we conducted a multilevel field N addition experiment in a Castanopsis carlesii natural forest. Soil properties and bacterial and fungal communities were investigated. There were no significant changes in alpha diversities (presented as Chao1 and Shannon’s indexes) and beta diversities of bacteria and fungi among the three treatments. Consistently, the relative abundances of dominant bacterial phyla (i.e., Proteobacteria, Acidobacteria, Actinobacteria, Chloroflexi, and Planctomycetes) and fungal phyla (i.e., Basidiomycota, Ascomycota, and Rozellomycota) did not change following N addition. These results suggest that N deposition did not alter microbial community diversity and structure. In addition, the results of the Mantel test showed that soil pH, NO3-N, dissolved organic N (DON), and total phosphorus (TP) predominantly influenced the community diversity and structure in bacteria, but not in fungi. Meanwhile, the relative abundance of some sensitive microbial genera, such as Bryobacter, Bradyrhizobium, Sorangium, and Archaeorhizomyces, were significantly decreased. These results indicate a decreased microbial ability for N fixation and P mobilization induced by N deposition. Moreover, there were significant relationships between Bryobacter, Bradyrhizobium, and Archaeorhizomyces and NO3-N and available P (AP), suggesting that the responses of sensitive microbial groups to N deposition likely depend on the changes in available nutrients in soil, especially limited N or P. Collectively, 6 years of N addition had no significant influence on microbial communities, but some sensitive microbial groups were associated with N or P turnover. This finding emphasizes the critical roles of sensitive microbial species in meditating limited nutrient cycling in soil under climate change. Full article
(This article belongs to the Special Issue Forest Soil Carbon Cycle in Response to Global Change)
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22 pages, 3738 KiB  
Article
Influence of Tree Vegetation and The Associated Environmental Factors on Soil Organic Carbon; Evidence from “Kulon Progo Community Forestry,” Yogyakarta, Indonesia
by Siswo, Hojin Kim, Jeongeun Lee and Chung-Weon Yun
Forests 2023, 14(2), 365; https://doi.org/10.3390/f14020365 - 11 Feb 2023
Cited by 2 | Viewed by 1738
Abstract
This study aimed to assess the influence of tree vegetation and some environmental factor on soil organic carbon (SOC), which is part of soil organic matter (SOM). Vegetation survey and soil sampling were carried out in five stand types in the protected forest [...] Read more.
This study aimed to assess the influence of tree vegetation and some environmental factor on soil organic carbon (SOC), which is part of soil organic matter (SOM). Vegetation survey and soil sampling were carried out in five stand types in the protected forest of Kulon Progo Community Forestry, including Pinus (PN), Aleurites-Swietenia (AS), Swietenia-Acacia (SA), Melaleuca-Acacia (MA) and Tectona-Dalbergia (TD). Tree vegetation composition and characteristics (diversity, basal area, density, canopy height and canopy cover), SOC and SOM were analyzed using some comparative analyses. The influence of tree vegetation characteristics and environmental factors related to topographic, edaphic and anthropogenic aspects on SOC was performed by employing principal component analysis (PCA) and redundancy analysis (RDA). Our result confirmed that species composition among stand types was significantly different. Characteristically, PN was relatively close to MA, having similarities in canopy cover, canopy height and basal area. While AS, SA and TD were relatively similar to each other in diversity, basal area, density and canopy cover. Moreover, PN and MA similarly hold less SOC and SOM compared to TD, while AS and SA showed not significantly different from TD. RDA confirmed the high influence of tree vegetation, where the most influencing factor for SOC and SOM was an interaction among canopy cover, canopy height and below-stand utilization, where canopy cover was directly proportional to canopy height and increased with decreasing below-stand utilization. We concluded that in relatively small variations of environmental factors, selecting dense-canopy trees and adaptive management of below-stand utilization promised SOC sequestration and storage. Our findings provide fundamental information for maximizing the potential of forest carbon to meet the global payments for ecosystem services and contribute to low-carbon development strategies and emission reduction. Full article
(This article belongs to the Special Issue Forest Soil Carbon Cycle in Response to Global Change)
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16 pages, 2930 KiB  
Article
Relationship between the Floristic Composition and Soil Characteristics of a Tropical Rainforest (TRF)
by Nurrunnuha Isa, Sarah Abdul Razak, Rosazlin Abdullah, Muhammad Nauman Khan, Siti Nasuha Hamzah, Alevcan Kaplan, Hubert Olivier Dossou-Yovo, Baber Ali, Abdul Razzaq, Sana Wahab, Izhar Ullah, Mohamed A. El-Sheikh and Romina Alina Marc
Forests 2023, 14(2), 306; https://doi.org/10.3390/f14020306 - 03 Feb 2023
Cited by 3 | Viewed by 2323
Abstract
Hutan Rimba Alam (HRA), Putrajaya is an urban forest which is the habitat for various tropical rainforest species. A field survey was undertaken to state the floristic composition, investigate the soil characteristics and identify the relationship between the recorded plant communities and soil [...] Read more.
Hutan Rimba Alam (HRA), Putrajaya is an urban forest which is the habitat for various tropical rainforest species. A field survey was undertaken to state the floristic composition, investigate the soil characteristics and identify the relationship between the recorded plant communities and soil characteristics. Six plots sized 10 × 10 m square were established in a lowland area of which 93 individual trees were identified. Moreover, the floristic composition revealed vascular tree communities consisting of 10 botanical families, 15 genera, and 27 species with Dipterocarpaceae as being predominant. Based on the important value index (IVI), Mangifera odorata (Anacardiaceae) was the highest (IVI = 68.80%). Furthermore, large trees such as Koompassia excelsa (Becc.) Taub. (Fabaceae) and Sandoricum koetjape (Burm.f.) Merr. (Meliaceae), with heights ranging from 17 m to 24 m, indicated that HRA is on the way to becoming a mature forest. The soil pH in all plots showed acidic properties, with a mean pH of 4.69 that is considered normal for tropical rainforests. The pH of the soils in HRA, Putrajaya had a positive correlation with the CEC and with nitrogen, but the value was low; however, the correlation was negative with C and P. The CEC had a relatively low correlation with C, N and P. Carbon had a very high correlation with N but low with P. Meanwhile, nitrogen had a very negatively low correlation with P. Extractable phosphorus exhibited a mean of 2.22 mg/kg which is normally used in plants for fruits, roots, and flower development. The present study revealed that plant communities in the urban forest in Putrajaya, meaning the diversity of the plant species belonging to a wide range of families, were established on acid soil, matching with the overall characteristics of tropical forest soils. With regard to the climate change context, which is leading to many altered ecosystems, the authors expect that the outputs of this research will be valued by decision makers for a better management of the forest. Full article
(This article belongs to the Special Issue Forest Soil Carbon Cycle in Response to Global Change)
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15 pages, 4469 KiB  
Article
Drought Changes the Trade-Off Strategy of Root and Arbuscular Mycorrhizal Fungi Growth in a Subtropical Chinese Fir Plantation
by Jie Dong, Yongmeng Jiang, Maokui Lyu, Cong Cao, Xiaojie Li, Xiaoling Xiong, Weisheng Lin, Zhijie Yang, Guangshui Chen, Yusheng Yang and Jinsheng Xie
Forests 2023, 14(1), 114; https://doi.org/10.3390/f14010114 - 07 Jan 2023
Cited by 5 | Viewed by 2282
Abstract
As a consequence of changing global rainfall patterns, frequent extreme droughts will significantly affect plant growth and ecosystem functions. Fine roots and arbuscular mycorrhizal fungi (AMF) both facilitate Chinese fir nutrient uptake. However, how the growth of fine roots and AMF is regulated [...] Read more.
As a consequence of changing global rainfall patterns, frequent extreme droughts will significantly affect plant growth and ecosystem functions. Fine roots and arbuscular mycorrhizal fungi (AMF) both facilitate Chinese fir nutrient uptake. However, how the growth of fine roots and AMF is regulated for the Chinese fir under drought conditions is unclear. This study used a precipitation reduction treatment (−50% throughfall) to study the seasonal effects of drought on a subtropical Chinese fir plantation. The effects measured included the fine root production, root diameter, specific root length, specific surface area, root tissue density, mycorrhizal hyphal density, spore number, mycorrhizal infection rate and total glomalin. Drought had no significant effect on Chinese fir fine root production but decreased the diameter and tissue density of primary and secondary roots while increasing the specific surface area of secondary roots. Additionally, drought significantly decreased the arbuscular mycorrhizal infection rate and significantly increased hyphal density. The results showed that drought caused the decrease in root diameter, which decreased the surface area available for AMF infection and led to the increase in mycorrhizal hyphal density. Redundancy analyses showed that soil-dissolved organic carbon and nitrogen were the key factors affecting AMF. Our results show that drought could enhance the cooperative strategy of nutrient and moisture absorption by roots and mycorrhizae of the Chinese fir, improving the resistance of Chinese fir growth to drought. Full article
(This article belongs to the Special Issue Forest Soil Carbon Cycle in Response to Global Change)
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15 pages, 3410 KiB  
Article
Soil Fungal Diversity and Functionality Changes Associated with Multispecies Restoration of Pinus massoniana Plantation in Subtropical China
by Linfang Wu, Luhong Zhou, Bingzhang Zou, Sirong Wang, Yong Zheng, Zhiqun Huang and Ji-Zheng He
Forests 2022, 13(12), 2075; https://doi.org/10.3390/f13122075 - 06 Dec 2022
Cited by 4 | Viewed by 1316
Abstract
Soil fungi play a critical role in the carbon and nutrient cycling of forest ecosystems. Identifying the composition of soil fungi in response to the broadleaf restoration of Pinus massoniana plantation is essential for exploring the mechanistic linkages between tree species and ecological [...] Read more.
Soil fungi play a critical role in the carbon and nutrient cycling of forest ecosystems. Identifying the composition of soil fungi in response to the broadleaf restoration of Pinus massoniana plantation is essential for exploring the mechanistic linkages between tree species and ecological processes, but remains unexplored. We compared the shifts in soil fungal diversity and guilds by high–throughput sequencing between two P. massoniana plantations at different stand ages, two modes of restoration with broadleaf trees, and a secondary forest in subtropical China. We found that soil fungal taxonomic and functional compositions significantly differed among forests. The highest Chao 1, Shannon, and phylogenetic diversity indices were consistently observed in the two P. massoniana monocultures, followed by the two modes of broadleaf mixing, and the secondary forests. Fungal communities transitioned from Ascomycota-dominated at P. massoniana plantations to Basidiomycota-dominated at other forests in the topsoil. Furthermore, saprotrophs and symbiotrophs were favoured in plantations and secondary forests, respectively. Soil pH exerted the most significant effect on the relative abundance of Ascomycota and Rozellomycota, as well as the saprotrophs. Moreover, the dominant phyla of Ascomycota, Mucoromycota, and Rozellomycota were negatively related to soil microbial biomass nitrogen, ammonium nitrogen, and total nitrogen contents; however, Mortierellomycota benefited from the elevated soil ammonium nitrogen content. On the other hand, soil nitrate nitrogen and available phosphorus contents strongly and negatively influenced the ectomycorrhizal fungi, while the other fungal guilds were mainly affected by soil pH. Our findings guide an evaluation of the consequences of forest restoration and contribute to an improved understanding of the mechanisms behind soil biogeochemical cycling in subtropical forest ecosystems. Full article
(This article belongs to the Special Issue Forest Soil Carbon Cycle in Response to Global Change)
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14 pages, 2686 KiB  
Article
Response of Soil Respiration to Simulated Acid Rain with Different Ratios of SO42 to NO3 in Cunninghamia lanceolata (Lamb.) Hook. and Michelia macclurei Dandy Plantations
by Jiao Wang, Qingpeng Yang, Weidong Zhang, Longchi Chen, Xin Guan, Ke Huang, Renshan Li, Wenhui Zheng, Qingkui Wang and Silong Wang
Forests 2022, 13(11), 1915; https://doi.org/10.3390/f13111915 - 15 Nov 2022
Cited by 2 | Viewed by 1144
Abstract
Acid rain is one of the most serious environmental issues in Southern China. The composition of acid rain has gradually changed from sulfuric acid rain (SAR) to nitric acid rain (NAR) due to the rapid development of industry, and controls on SO2 [...] Read more.
Acid rain is one of the most serious environmental issues in Southern China. The composition of acid rain has gradually changed from sulfuric acid rain (SAR) to nitric acid rain (NAR) due to the rapid development of industry, and controls on SO2 emissions. However, a comprehensive understanding of how changes in the type of acid rain affect soil respiration (Rs) in forest ecosystems is still lacking. In this study, we investigated the influence of simulated acid rain with different SO42/NO3 ratios, namely, SAR (4:1), MAR (mixed acid rain, 1:1), and NAR (1:4), on Rs in Cunninghamia lanceolata (Lamb.) Hook. (CL) and Michelia macclurei Dandy (MM) plantations from 2019 to 2020. A trenching method was used to partition Rs into heterotrophic respiration (Rh) and autotrophic respiration (Ra). The results showed that acid rain did not significantly influence Rs in the two plantations, which could be mainly attributed to the unchanged soil pH. Neither SAR, MAR, nor NAR affected Ra in the two plantations, possibly due to the unchanged root biomass. The SAR treatment only significantly increased Rh in the MM plantation, not in the CL plantation. The temperature sensitivity (Q10) of Rs and its components was not significantly different among different acid rain types in either of the plantations. Our results suggest that the impact of acid rain on Rs and its components depends on the forest ecosystem and the type of acid rain. Different biological processes complicate the response of soil CO2 emissions to acid rain pollution. Full article
(This article belongs to the Special Issue Forest Soil Carbon Cycle in Response to Global Change)
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16 pages, 2057 KiB  
Article
Differential Response of Soil Respiration and Total Belowground Carbon Allocation to Simulated Nitrogen and Phosphorus Deposition in Moso Bamboo Forests
by Jingji Li, Zhihan Yang, Xiaolu Tang, Liang Liu, Yunsen Lai, Junjie Lei, Changli Zeng, Xinshan Ma, Manyi Du, Chunju Cai and Shaohui Fan
Forests 2022, 13(11), 1860; https://doi.org/10.3390/f13111860 - 07 Nov 2022
Cited by 2 | Viewed by 1221
Abstract
Elevated nitrogen (N) and phosphorus (P) depositions have greatly affected belowground carbon processes in forest ecosystems. However, open questions still remained on the effects of N and P depositions on belowground carbon processes, including soil respiration (RS), its source components—autotrophic respiration (RA) and [...] Read more.
Elevated nitrogen (N) and phosphorus (P) depositions have greatly affected belowground carbon processes in forest ecosystems. However, open questions still remained on the effects of N and P depositions on belowground carbon processes, including soil respiration (RS), its source components—autotrophic respiration (RA) and heterotrophic respiration (RH), and total belowground carbon allocation (TBCA) in Moso bamboo forests—one of the most important forest types with wide distributions in subtropical China. To fill this knowledge gap, a two-year N, P, and NP experiment was conducted in Moso bamboo forests. Results showed that RS, RA, and RH had a strong seasonal variability and were exponentially correlated with soil temperature. N and P depositions did not change RS and RA. However, P deposition increased RH due to the stimulation of microbial activities, indicating a significant soil carbon loss under P deposition. N and P depositions did not affect TBCA. However, NP deposition significantly increased root carbon-use efficiency. Net ecosystem production (NEP) varied from 198 ± 104 to 529 ± 225 g C m−2 year−1, indicating that Moso bamboo is an important carbon sink. P deposition marginally decreased NEP, while N and NP depositions did not affect NEP, which indicates that N deposition alleviated the suppression of P deposition on NEP. These findings highlight the inconsistent responses of RA, RH, and NEP to N, P, and NP depositions, which should be differently considered to increase the accuracy of predicting belowground carbon dynamics. Full article
(This article belongs to the Special Issue Forest Soil Carbon Cycle in Response to Global Change)
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17 pages, 10067 KiB  
Article
Carbon and Nitrogen Availability Drives Seasonal Variation in Soil Microbial Communities along an Elevation Gradient
by Xiaoling Xiong, Maokui Lyu, Cui Deng, Xiaojie Li, Yuming Lu, Weisheng Lin, Yongmeng Jiang and Jinsheng Xie
Forests 2022, 13(10), 1657; https://doi.org/10.3390/f13101657 - 09 Oct 2022
Cited by 8 | Viewed by 1706
Abstract
Changes in soil abiotic and biotic properties can be powerful drivers of feedback between plants and soil microbial communities. However, the specific mechanisms by which seasonal changes in environmental factors shape soil microbial communities are not well understood. Here, we collected soil samples [...] Read more.
Changes in soil abiotic and biotic properties can be powerful drivers of feedback between plants and soil microbial communities. However, the specific mechanisms by which seasonal changes in environmental factors shape soil microbial communities are not well understood. Here, we collected soil samples from three sites along an elevational gradient (200–1200 m) in subtropical forests with unvarying canopy vegetation. We used an elevation gradient with similar annual precipitation but a clear temperature gradient, and phospholipid fatty acids (PLFAs) were measured to determine the seasonal variations in the composition of soil microbial communities in response to rising temperatures. Our results showed that the abundance of Gram-negative bacteria and total PLFAs were the lowest at low elevations in winter, and the ratio of Gram-positive to Gram-negative bacteria decreased with increasing elevation. However, the biomass of other microbial groups was the highest at medium elevations in summer, with the exception of actinomycetes species and fungi. Regardless of seasonal changes, soil fungal biomass tended to increase with increasing elevation. Moreover, in summer, microbial carbon use efficiency (CUE) increased with increasing elevation, whereas an opposite trend was observed in winter. Redundancy analysis and structural equation modeling showed that the dissolved organic carbon in soil was the main factor affecting the microbial communities along the elevation gradient in winter, whereas in summer, the microbial community structure was driven by shifting nitrogen availability, with both being associated with changing microbial CUE. As such, this study demonstrates distinct seasonal changes in the soil microbial community composition across an elevation gradient that are driven by carbon and nitrogen resource availability and shifts in microbial CUE. Furthermore, our results suggest that the interaction of underground plant roots and microbes drives changes in resource availability, thereby resulting in seasonal variation in soil microbial community composition across an elevation gradient. Full article
(This article belongs to the Special Issue Forest Soil Carbon Cycle in Response to Global Change)
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15 pages, 3248 KiB  
Article
Experimental Precipitation Reduction Slows Down Litter Decomposition but Exhibits Weak to No Effect on Soil Organic Carbon and Nitrogen Stocks in Three Mediterranean Forests of Southern France
by Mathieu Santonja, Susana Pereira, Thierry Gauquelin, Elodie Quer, Guillaume Simioni, Jean-Marc Limousin, Jean-Marc Ourcival, Ilja M. Reiter, Catherine Fernandez and Virginie Baldy
Forests 2022, 13(9), 1485; https://doi.org/10.3390/f13091485 - 14 Sep 2022
Cited by 5 | Viewed by 1784
Abstract
Forest ecosystems are some of the largest carbon (C) reservoirs on earth. Pinus halepensis Mill., Quercus ilex L. and Quercus pubescens Willd. represent the dominant tree cover in the Mediterranean forests of southern France. However, their contributions to the French and global forest [...] Read more.
Forest ecosystems are some of the largest carbon (C) reservoirs on earth. Pinus halepensis Mill., Quercus ilex L. and Quercus pubescens Willd. represent the dominant tree cover in the Mediterranean forests of southern France. However, their contributions to the French and global forest C and nitrogen (N) stocks are frequently overlooked and inaccurately quantified and little is known about to what extent the ongoing climate change can alter these stocks. We quantified the soil organic C (SOC) and N (SN) stocks in Mediterranean forests dominated by these tree species and evaluated to what extent an experimental precipitation reduction (about −30% yearly) affects these stocks and the litter decomposition efficiency. Litter mass losses were 55.7, 49.8 and 45.7% after 24 months of decomposition in Q. ilex, Q. pubescens and P. halepensis forests, respectively, and were 19% lower under drier climatic conditions. The SOC stocks were 14.0, 16.7 and 18.5 Mg ha−1 and the SN stocks were 0.70, 0.93 and 0.88 Mg ha−1 in Q. ilex, Q. pubescens and P. halepensis forests, respectively. The shallowness and stoniness of these Mediterranean forests could explain these limited stocks. By distinguishing the organic from the organo–mineral layer, we showed 74% less SOC in the organic layer of the P. halepensis forest under drier conditions, while no difference was detected in the organo–mineral layer or in the two oak forests. This last finding deserves further investigation and points out the necessity to distinguish the organic from the organo–mineral layer to detect the first impacts of climate change on SOC stocks. Full article
(This article belongs to the Special Issue Forest Soil Carbon Cycle in Response to Global Change)
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