青藏高原高寒草甸退化对草地群落生物量及其分配的影响  

Effect of rangeland degradation on biomass allocation in alpine meadows on the Qinghai-Tibet Plateau, China

作　　者：张帆 李元淳 王新 朱剑霄 ZHANG Fan;LI Yuanchun;WANG Xin;ZHU Jianxiao(State Key Laboratory of Grassland Agro-ecosystems/College of Pastoral Agriculture Science and Technology,Lanzhou University,Lanzhou 730020,Gansu,China)

机构地区：[1]兰州大学草地农业生态系统国家重点实验室/兰州大学草地农业科技学院,甘肃兰州730020

出　　处：《草业科学》2021年第8期1451-1458,共8页Pratacultural Science

基　　金：国家重点研发计划项目(2019YFC0507704)。

摘　　要：青藏高原高寒草甸退化严重影响了草地群落结构与生产力。为揭示草地退化对高寒草甸群落结构和生物量地上/地下分配的影响,采用随机区组设计,在青海省海北州选择3个小区,每个小区设置完整的未退化、轻度退化、中度退化和重度退化4个退化梯度,于2020年8月对样地进行群落调查,同时采集植物样品。结果表明,随着退化程度加剧:1)草地的盖度、高度和地上植物生物量均显著下降;2)地上生物量在不同功能群的分配发生显著变化,物种逐步从以禾草类为优势转变为以杂类草为优势的群落;3)地下生物量显著下降,深层土壤根系生物量占比增加。研究结果表明:随着退化加剧群落结构发生颠覆性变化,且地上和地下生物量同步出现严重衰退。因此,针对该区域退化草地的植被恢复应考虑草地物种组配以及地上和地下生物量同步恢复的相应措施。Rangeland degradation has serious impacts on grassland community structure and productivity in alpine meadows across the Qinghai-Tibet Plateau, China. In order to reveal the impact of rangeland degradation on the community structure and aboveground/underground biomass distribution in alpine meadows, we selected three blocks near the Haibei Alpine Meadow Ecosystem Research Station in Qinghai Province that were within the random block design. There were four types of degradation in each block, which were intact, slightly degraded, moderately degraded, and severely degraded. In August 2020, plant sampling and a community survey were carried out at the same time. Our results showed that as the degradation got worse: 1) the grassland coverage, height, and aboveground biomass significantly decreased;2) there was a significant change in the proportion of aboveground biomass allocated to different functional groups and the dominance species gradually changed from grasses into forbs;and 3) the underground biomass significantly decreased, but the proportion of biomass in deep soil increased. These results indicated that as the degradation intensified, the community structure underwent subversive changes, and the aboveground and underground biomass severely declined. Therefore, restoration plans for degraded grassland in this area should consider the grassland species composition, and corresponding measures for restoring aboveground and underground biomass should occur simultaneously.

关 键 词：地上生物量 地下生物量 功能群 随机区组 退化梯度 高寒草甸 

分 类 号：S812[农业科学—草业科学]