Lin Weishan, De Kejia, Xiang Xuemei, Feng Tingxu, Li Fei, Wei Xijie
Academy of Animal Husbandry and Veterinary Medicine, Qinghai University, Xining, China.
Front Plant Sci. 2025 Apr 3;16:1549867. doi: 10.3389/fpls.2025.1549867. eCollection 2025.
Litter, as a major carbon source in alpine meadow ecosystems, seriously affect the variation of plant-microbe carbon pools in alpine meadows. In order to study the response of plant-microbial biomass carbon pool trade-offs in degraded alpine meadow to litter inputs.
We investigated the effects of different levels of litter inputs on the carbon pools of alpine meadows plant aboveground communities, the carbon pools of the root, and the total carbon pools of the plant communities and the soil microbial biomass carbon pools, and clarified the variable factors that affect the balance of the plant-microbial biomass carbon pools and the process of influencing the trade-offs.
(1) Litter inputs had a positive effect on plant carbon pools, and the aboveground community carbon pools, root carbon pools, total plant community carbon pools and soil microbial biomass carbon pools of alpine meadows were all maximized in the T3 treatment. (2) The trade-off analyses showed that the trade-off relationships of ungrazed alpine meadows TPCPMBCP in the following order under different levels of litter treatments: T1(0.0414) > T2 (0.0269) > T0 (0.0086) > T3 (0.0012), the trade-off relationship of TPCP-MBCP in lightly grazed alpine meadows was in the order of T2 (0.0494) > T3 (0.0140) > T0 (0.0097) > T1 (0.002), and the tradeoff relationship of TPCP-MBCP in moderately grazed alpine meadows was in the order of T3 (0.0383) > T1 (0.0307) > T2 (0.0196) > T0 (0.0005). (3) Propensity analysis showed that the TPCP-MBCP trade-offs tended to favor MBCP under ungrazed, lightly grazed and moderately grazed meadows under the T1 treatment. (4) Structural equation modeling showed that RB and APC were positively correlation, RCP was significantly negatively correlated with the TPCPMBCP trade-off in lightly grazed grassland (<0.05), and MBC was significantly positively correlated with the TPCP-MBCP trade-off in moderately grazed grassland (<0.05).
There was no uniform pattern in TPCP-MBCP trade-off and propensities in ungrazed, lightly grazed, and moderately grazed alpine meadows under different levels of litter inputs. This study can help to optimize the grazing management measures, predict the changes of carbon pools in alpine meadows and clarify the transfer and storage of carbon pools between plants and microorganisms, so as to provide a theoretical basis for the study of carbon pools in degraded alpine meadows.
凋落物作为高寒草甸生态系统中的主要碳源，严重影响着高寒草甸植物-微生物碳库的变化。为了研究退化高寒草甸中植物-微生物生物量碳库权衡对凋落物输入的响应。
我们研究了不同水平的凋落物输入对高寒草甸植物地上群落碳库、根系碳库、植物群落总碳库以及土壤微生物生物量碳库的影响，并阐明了影响植物-微生物生物量碳库平衡及其权衡过程的可变因素。
（1）凋落物输入对植物碳库有积极影响，高寒草甸的地上群落碳库、根系碳库、植物群落总碳库和土壤微生物生物量碳库在T3处理中均达到最大值。（2）权衡分析表明，在不同水平的凋落物处理下，未放牧高寒草甸的TPCP-MBCP权衡关系依次为：T1（0.0414）>T2（0.0269）>T0（0.0086）>T3（0.0012），轻度放牧高寒草甸的TPCP-MBCP权衡关系依次为：T2（0.0494）>T3（0.0140）>T0（0.0097）>T1（0.002），中度放牧高寒草甸的TPCP-MBCP权衡关系依次为：T3（0.0383）>T1（0.0307）>T2（0.0196）>T0（0.0005）。（3）倾向分析表明，在T1处理下，未放牧、轻度放牧和中度放牧草甸的TPCP-MBCP权衡倾向于有利于MBCP。（4）结构方程模型表明，RB与APC呈正相关，在轻度放牧草地中RCP与TPCP-MBCP权衡显著负相关（<0.05），在中度放牧草地中MBC与TPCP-MBCP权衡显著正相关（<0.05）。
在不同水平的凋落物输入下，未放牧、轻度放牧和中度放牧的高寒草甸中TPCP-MBCP权衡及其倾向没有统一模式。本研究有助于优化放牧管理措施，预测高寒草甸碳库变化，阐明植物与微生物之间碳库的转移与储存，为退化高寒草甸碳库研究提供理论依据。
