Soil Carbon in Forest Ecosystems: Stocks, Stability, and Vulnerability to Global Change

Dear Colleagues,

Forest soils represent one of the largest terrestrial reservoirs of organic carbon, playing a critical role in the global carbon cycle and climate regulation. Beyond their storage function, soil carbon pools in forest ecosystems influence soil fertility, water retention, nutrient cycling, and biodiversity support. However, these stocks are increasingly vulnerable to global change drivers, including climate warming, altered precipitation regimes, wildfire frequency intensification, and land-use conversion. Understanding the quantity, distribution, stability, and vulnerability of soil organic carbon in forests has therefore become a scientific priority of global significance.

Soil carbon is not a uniform entity. Its persistence is governed by complex interactions among plant inputs, microbial transformation, mineral association, aggregate formation, and environmental controls. Recent advances in analytical techniques—such as biomarker analysis, stable and radiocarbon isotopic approaches, nuclear magnetic resonance (NMR), and high-throughput metagenomics—have revealed that carbon stability is more strongly linked to molecular diversity, microbial accessibility, and physicochemical protection than previously assumed. These insights challenge traditional models and open up new avenues for predicting soil carbon dynamics under changing environmental conditions.

In parallel, global change is reshaping forest soil carbon in ways that remain poorly constrained. Warming accelerates decomposition, potentially transforming forests from carbon sinks to sources. Drought alters root exudation and microbial activity. Increased tree mortality and wildfire severity lead to abrupt carbon losses. At the same time, elevated CO₂ may enhance plant productivity and carbon inputs to soil, but whether this leads to net carbon storage remains uncertain due to priming effects and microbial feedbacks. These nonlinear responses and feedback loops underscore the urgency of integrated, process-based understanding.

This Special Issue of Forests invites contributions that address the ecological, biogeochemical, and modeling dimensions of soil carbon in forest ecosystems across spatial and temporal scales. We welcome research articles, reviews, and short communications that explore, but are not limited to, the following topics:

• Quantification of soil organic carbon stocks and their spatial heterogeneity in different forest types (boreal, temperate, tropical, and Mediterranean);
• Mechanisms of soil carbon stabilization, including mineral–organic associations, aggregate occlusion, and biochemical recalcitrance;
• Microbial regulation of soil carbon turnover, including priming effects, necromass accumulation, and enzymatic decomposition;
• Vulnerability of soil carbon to climate change, fire, drought, and land-use disturbance;
• Effects of forest management (e.g., thinning, prescribed burning, afforestation, clear-cutting) on soil carbon persistence;
• Novel analytical and modeling approaches to predict soil carbon dynamics under future scenarios;
• Interactions between soil carbon, forest productivity, and biodiversity.

By synthesizing empirical, experimental, and theoretical advances, this Special Issue aims to provide an integrated perspective on the future of forest soil carbon in a rapidly changing world. We extend our sincere gratitude in advance to all authors for their valuable contributions.

Dr. Shuai Wang
Dr. Yang Wang
Guest Editors

Manuscript Submission Information

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Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-anonymized peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Forests is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

• forest soil carbon
• carbon stability and persistence
• global change vulnerability
• microbial carbon dynamics
• mineral–organic associations
• fire and drought effects
• forest management and carbon sequestration