State Key Laboratory of Grassland Agro-ecosystems, Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs, Engineering Research Center of Grassland Industry, Ministry of Education, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, 730020, China; Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture, Lanzhou University, Lanzhou, 730020, China.
State Key Laboratory of Grassland Agro-ecosystems, Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs, Engineering Research Center of Grassland Industry, Ministry of Education, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, 730020, China; Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture, Lanzhou University, Lanzhou, 730020, China.
J Environ Manage. 2023 Aug 1;339:117924. doi: 10.1016/j.jenvman.2023.117924. Epub 2023 Apr 14.
Several studies have explored the influence of grazing or precipitation addition (PA), two important components of human activities and global climate change on the structure and function of communities. However, the response of communities to a combination of grazing and PA remains largely unexplored. We investigated the impact of grazing and PA on the relationship between aboveground biomass (AGB) and species richness (SR) of communities in three-year field experiments conducted in a typical steppe in the Loess Plateau, using a split-plot design with grazing as the main-plot factor and PA as the split-plot factor. AGB and SR have response threshold value to PA, which was decreased by grazing for AGB, but increased for SR. This indicates that implementing grazing management strategies is conducive to strengthening the protection of biodiversity in arid and semi-arid grasslands. Grazing promoted the AGB-SR coupling of the community by increasing the SR of medium drought tolerance (MD), low drought tolerance, and grazing tolerant functional groups. Grazing also accelerated the AGB-SR decoupling of the community by changing the AGB of high drought tolerance, MD, high grazing tolerance, and medium grazing tolerance functional groups. PA mediated changes in MD and SR of both drought and grazing tolerant functional groups and AGB of low grazing tolerance promoted the coupling of AGB-SR of the community. The Two-dimension functional groups classification method reflects the changes of AGB and SR in communities more reasonable than the division of single-factor functional groups.
几项研究探讨了放牧或降水添加 (PA) 这两个人类活动和全球气候变化的重要组成部分对群落结构和功能的影响。然而，群落对放牧和 PA 组合的响应在很大程度上仍未得到探索。我们通过在黄土高原典型草原进行的为期三年的野外实验，采用放牧为主区因子、PA 为裂区因子的裂区设计，研究了放牧和 PA 对地上生物量 (AGB)和群落物种丰富度 (SR)之间关系的影响。AGB 和 SR 对 PA 有响应阈值，放牧降低了 AGB 的响应阈值，但增加了 SR 的响应阈值。这表明实施放牧管理策略有利于加强对干旱和半干旱草原生物多样性的保护。放牧通过增加中耐旱性 (MD)、低耐旱性和耐放牧功能组的 SR，促进了群落的 AGB-SR 耦合。放牧还通过改变高耐旱性、MD、高耐放牧性和中耐放牧性功能组的 AGB，加速了群落的 AGB-SR 解耦。PA 介导了耐旱和耐放牧功能组的 MD 和 SR 的变化，以及低耐放牧性的 AGB 促进了群落的 AGB-SR 耦合。二维功能组分类方法比单因素功能组的划分更合理地反映了群落中 AGB 和 SR 的变化。
