雨量变化,碳循环和植物物种多样性在一个 mesic 草原
Alan K Knapp1, Philip A Fay, John M Blair
1Division of Biology, Kansas State University, Manhattan, KS 66506, USA. aknapp@ksu.edu
概括
降雨量增加的变化,没有改变总降雨量,改变了草原生态系统. 极端天气模式影响了土壤水分,植物多样性,减少了碳循环和生产力.
科学领域:
- 生态生态学 生态生态学
- 气候科学 气候科学
- 环境科学 环境科学
背景情况:
- 一般循环模型预测降雨变化增加.
- 草原生态系统对降水模式的变化很敏感.
- 了解生态系统对降雨变化的反应对于预测未来的环境变化至关重要.
研究的目的:
- 评估降雨变化增加对原生草原生态系统的影响.
- 研究改变风暴频率和强度对土壤水分,植物多样性和碳循环的影响.
- 为了确定土壤湿度变化和地面净初级生产率 (ANPP) 之间的关系.
主要方法:
- 在原生草原上进行了一项为期四年的实验.
- 通过减少风暴频率和增加每次风暴降雨量来操纵降雨模式.
- 测量包括土壤水分,植物物种多样性,土壤二氧化碳流量,二氧化碳吸收和ANPP.
主要成果:
- 更极端的降雨模式增加了土壤水分和植物物种多样性的时间变化.
- 减少了碳循环过程 (土壤二氧化碳流,二氧化碳吸收,ANPP).
- ANPP对土壤水分变化的反应性比对平均土壤含水量的反应性更高.
结论:
- 预计降雨变量的增加可以迅速改变关键的碳循环过程.
- 降雨模式的变化可以独立地影响植物群体的组成,无论总降水量如何.
- 草原生态系统容易受到极端降水变化的影响,影响基本的生态功能.
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