Shuai Wang , Xinshan Ma , Yan Yue , Tao Zhou , Zhihan Yang , Benjamin Laffitte , Songyu Fu , Xiaolu Tang
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引用次数: 0
Abstract
Grassland biomass is a key indicator for assessing the health and productivity of grassland ecosystems. Over the past two decades, China’s grasslands have undergone substantial changes. However, accurately estimating grassland biomass and its response to driving factors remains challenging. In this study, we predicted the spatiotemporal patterns of aboveground and belowground biomass (AGB and BGB) and examined their driving mechanisms at a 500 m resolution from 2000 to 2022, using a modified multi-layer perceptron (MLP) neural network combined with 2233 AGB and 1093 BGB observations, along with environmental variables across China. The MLP model demonstrated strong predictive performance for AGB (R2 = 0.79, RMSE = 20.02 g C m−2 yr−1) and BGB (R2 = 0.87, RMSE = 223.65 g C m−2 yr−1). Spatially, average AGB decreased from southeastern to northwest China, while BGB was highest along the eastern edge of the Qinghai-Tibet Plateau. Temporally, AGB increased by 1.27 Tg C yr−1 over the past 23 years, covering 68.19 % of grassland areas, whereas BGB showed no significant trend. Projections indicate that AGB will increase in 48.6 % and BGB in 34.81 % of grassland areas in the future. Total AGB and BGB were estimated at 163.5 and 1044.5 Tg C, respectively. Temperature and precipitation were the primary drivers of both AGB (23.47 % and 20.21 % of grassland areas) and BGB (25.24 % and 21.05 %). For AGB, the remaining drivers, in descending order of influence, were vegetation, human activity intensity, soil physical properties, soil chemical properties, and terrain. For BGB, they were human activity intensity, followed by vegetation, soil physical properties, soil chemical properties, and terrain. This study offers critical insights for grassland biomass dynamics and their driving mechanisms, providing a scientific foundation for policy-making and adaptive management to ensure the long-term resilience of grassland ecosystems.
期刊介绍:
Agricultural and Forest Meteorology is an international journal for the publication of original articles and reviews on the inter-relationship between meteorology, agriculture, forestry, and natural ecosystems. Emphasis is on basic and applied scientific research relevant to practical problems in the field of plant and soil sciences, ecology and biogeochemistry as affected by weather as well as climate variability and change. Theoretical models should be tested against experimental data. Articles must appeal to an international audience. Special issues devoted to single topics are also published.
Typical topics include canopy micrometeorology (e.g. canopy radiation transfer, turbulence near the ground, evapotranspiration, energy balance, fluxes of trace gases), micrometeorological instrumentation (e.g., sensors for trace gases, flux measurement instruments, radiation measurement techniques), aerobiology (e.g. the dispersion of pollen, spores, insects and pesticides), biometeorology (e.g. the effect of weather and climate on plant distribution, crop yield, water-use efficiency, and plant phenology), forest-fire/weather interactions, and feedbacks from vegetation to weather and the climate system.