Progress and perspective in parameterizing soil respiration responses to temperature and moisture
摘要
Soil respiration (RS) represents the largest carbon flux from terrestrial ecosystems to the atmosphere, substantially influencing the global carbon budget and climate change. RS exhibits vital yet complex nonlinear dependencies on soil temperature and moisture, while its response to these factors demonstrates pronounced spatiotemporal heterogeneity. Most land carbon cycle models use fixed temperature and moisture sensitivities to project RS changes, which may induce substantial uncertainty in RS estimations and projections. This paper reviews recent progress in understanding spatiotemporal variations of RS sensitivities, their responses to global warming, and advances in parameterizing these sensitivities. The exponential temperature response and parabolic moisture response of RS are summarized, alongside their spatiotemporal sensitivities. Although some models have made progress in parameterizing spatiotemporally heterogeneous temperature and moisture sensitivities of RS, critical challenges persist, including insufficient mechanistic explanations, suboptimal validation performance, and poor cross-model consistency. Additionally, limitations in parameterizing the interactive effects of soil temperature and moisture on RS may lead to notable biases in RS estimations. This paper advocates expanding in situ measurements of RS across climatic zones and land cover types, and further deepening the analysis of these data with advanced techniques (e.g., artificial intelligence) to establish more comprehensive relationships between RS and soil temperature and moisture. Such improvements would optimize land carbon cycle model parameterization, reduce estimation biases, enhance simulation precision, and ultimately provide robust scientific foundations for global carbon budgeting and climate policy formulation to support carbon neutrality goals.