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草业学报 ›› 2024, Vol. 33 ›› Issue (4): 1-11.DOI: 10.11686/cyxb2023198

• 研究论文 •    

围封和施肥对高寒草甸群落特征和植被碳氮库的影响

秦瑞敏1,2(), 程思佳1,3, 马丽1, 张中华1, 魏晶晶1,4, 苏洪烨1,2, 史正晨1,2, 常涛1,2, 胡雪1,2, 阿的哈则1,2, 袁访1, 李珊1, 周华坤1()   

  1. 1.中国科学院西北高原生物研究所,青海省恢复生态学重点实验室,青海 西宁 810008
    2.中国科学院大学,北京 100049
    3.青海大学生态环境工程学院,青海 西宁 810016
    4.青海师范大学地理科学学院,青海 西宁 810008
  • 收稿日期:2023-06-04 修回日期:2023-07-24 出版日期:2024-04-20 发布日期:2024-01-15
  • 通讯作者: 周华坤
  • 作者简介:E-mail: hkzhou@nwipb.cas.cn
    秦瑞敏(1995-),男,山西高平人,在读博士。E-mail: qinruimin1995@163.com
  • 基金资助:
    国家自然科学基金联合基金项目(U20A2006);第二次青藏高原综合科学考察研究项目(2019QZKK0302-02);青海省自然科学基金创新团队项目(2021-ZJ-902)

Effects of grazing exclusion and fertilization on alpine meadow community characteristics and vegetation carbon and nitrogen pools

Rui-min QIN1,2(), Si-jia CHENG1,3, Li MA1, Zhong-hua ZHANG1, Jing-jing WEI1,4, Hong-ye SU1,2, Zheng-chen SHI1,2, Tao CHANG1,2, Xue HU1,2, De-ha-ze A1,2, Fang YUAN1, Shan LI1, Hua-kun ZHOU1()   

  1. 1.Qinghai Provincial Key Laboratory of Cold Regions Restoration Ecology,Northwest Institute of Plateau Biology,Chinese Academy of Sciences,Xining 810008,China
    2.University of Chinese Academy of Sciences,Beijing 100049,China
    3.College of Eco-Environmental Engineering,Qinghai University,Xining 810016,China
    4.College of Geography Science,Qinghai Normal University,Xining 810008,China
  • Received:2023-06-04 Revised:2023-07-24 Online:2024-04-20 Published:2024-01-15
  • Contact: Hua-kun ZHOU

摘要:

为探究不同恢复措施对退化高寒草甸的影响,研究了不同围封年限(0、4、13年)和长期施肥(N、P)下草甸群落特征和碳氮库的变化。结果表明:1)随着围封年限增加,物种丰富度指数和Shannon-Wiener指数显著降低,Simpson指数和Pielou指数呈先上升后下降的特征;长期N和P添加分别显著降低了物种丰富度指数和Shannon-Wiener指数。2)地上生物量和根系生物量在4和13年围封下均显著增加,且在4年围封时最高,而凋落物生物量则随围封年限增加而逐渐增加;长期施肥对生物量的影响不显著。3)围封后,植被碳和氮储量显著增加,其中地上生物量和根系碳、氮库均在4年围封时最高,凋落物碳、氮库则在13年围封时最高;长期施肥对植被碳储量无显著影响,仅长期N添加显著提高了地上生物量氮库。4)偏最小二乘(PLS)路径模型显示:围封和施肥导致环境因子发生变化,抑制了群落多样性,促进了植物生物量和植被碳库的积累,而植被氮库特征在施肥处理下发生变化。综上,围封整体上抑制了物种多样性,但能够促进群落生产力提高和植被碳氮库增汇;长期N添加对物种多样性和植被碳库无显著正效应,但促进了植被氮库增汇。

关键词: 围栏封育, 长期施肥, 群落特征, 植被碳氮库, 高寒草甸

Abstract:

The objective of this study was to determine how two different restoration measures, i.e., grazing exclusion and fertilization, affect degraded alpine meadows. A field study was conducted to compare the effects of grazing exclusion for various periods (0, 4, 13 yrs) and long-term fertilization (with nitrogen, N, and phosphorus, P) on community characteristics and vegetation carbon (C) and N pools. The results showed that: 1) The species richness index and Shannon-Wiener index decreased significantly with increasing years of grazing exclusion, while Simpson’s index and the Pielou index increased and then decreased. The addition of N and P fertilizers significantly decreased the species richness index and Shannon-Wiener index. 2) Aboveground biomass and root biomass were significantly increased after both 4 and 13 years of grazing exclusion, reaching the maximum at 4 years, whereas litter biomass increased gradually with increasing years of grazing exclusion. The effect of long-term fertilization on biomass was not significant. 3) After grazing exclusion, vegetation C and N stocks increased significantly, with aboveground biomass and root C and N pools being highest at 4 years of grazing exclusion, and litter C and N pools being highest at 13 years of grazing exclusion. Long-term fertilization had no significant effect on vegetation C stocks, and only long-term N addition significantly increased the aboveground biomass N pools. 4) Partial least squares path modeling showed that grazing exclusion and fertilization led to changes in environmental factors that restrained community diversity and promoted the accumulation of plant biomass and vegetation C pools, while fertilization affected vegetation N pools. In summary, grazing exclusion generally restrained species diversity, but promoted community productivity and increased vegetation C and N pools, while long-term N addition had no significant positive effect on species diversity and vegetation C pools, but increased vegetation N pools.

Key words: grazing exclusion, long-term fertilization, community characteristics, vegetation carbon and nitrogen pools, alpine meadow