摘要
为揭示凋落物去除和添加处理对草原生态系统碳通量的影响,2013和2014年连续两年在成熟群落围封样地进行凋落物去除实验、在退化群落放牧样地进行凋落物添加实验,并运用静态箱法探讨碳通量变化规律并分析其主要影响因子。结果表明:两种群落的净生态系统CO_2交换(NEE)有明显的季节性变化。对成熟群落而言,去除50%凋落物显著增加了NEE,去除100%凋落物显著降低了NEE,而对生态系统总初级生产力(GEP)和生态系统呼吸(ER)均无显著影响;对退化群落而言,凋落物添加显著增加了GEP和NEE,而对ER无显著影响。两种群落的GEP与10 cm土壤温度显著正相关,但NEE和GEP的变化规律与土壤温度相反,与10 cm土壤湿度相同。由此可见,凋落物去除和添加处理对生态系统碳通量的影响主要是改变土壤湿度和地上生物量,而不是改变土壤温度。该研究为合理利用凋落物改善草地生态系统管理和促进草地恢复提供了理论依据。
Aims Our objectives were to investigate： 1） How does litter affect the ecosystem carbon fluxes in mature and degraded community ecosystems？ and 2） What are the effects of litter on the ecosystem carbon fluxes of the two ecosystems？ Methods The study was carried out at Baiyinxile Ranch experiment site, which is located in the semiarid agriculture-pasture transition region in southeastern Nei Mongol, China. The treatments were litter removal（50% and 100%） in mature community and litter addition（50% and 100%） in degraded community. We measured net ecosystem CO2 exchange（NEE） by the chamber method during the growing season of 2013 and 2014. Important findings Our results showed that there were significant seasonal changes of NEE in both mature and degraded community. After the consecutive treatments for two years, in mature community, the 50% litter removal significantly increased NEE and the 100% litter removal significantly reduced the NEE, while litter removal had no significant effect on the ecosystem gross primary productivity（GEP） and ecosystem respiration（ER）. In the degraded community, litter addition significantly increased NEE and GEP and had no effect on ER. Meanwhile, neither litter removal nor litter addition had significant effect on the total ecosystem respiration（ER）. In both communities, the correlation between GEP and soil temperature at 10 cm was significantly positive（p〈0.05）. However, the changes of GEP and NEE under litter treatments was contrary to the changes of soil temperature, and consistent with the changes of soil moisture content at 10 cm depth. We concluded that the mechanism underlying the effects of litter removal and addition on the carbon flux of ecosystem was mainly attributed to soil moisture and above ground biomass.
作者
张素彦
蒋红志
王扬
张艳杰
鲁顺保
白永飞
ZHANG Su-Yan;JIANG Hong-Zhi;WANG Yang;ZHANG Yan-Jie;LU Shun-Bao;BAI Yong-Fei(Key Laboratory of Poyang Lake Wetland and Watershed Research, Ministry of Education, College of Life Sciences, Key Laboratory of Protection and Utilization of Subtropic Plant Resources, Jiangxi Normal University, Nanchang, 330022, China;State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China)
出处
《植物生态学报》
CAS
CSCD
北大核心
2018年第3期349-360,共12页
Chinese Journal of Plant Ecology
基金
国家科技支撑计划项目(2012BAD16B03)
中国科学院战略性先导科技专项(XDA05050400)
国家自然科学基金(31360136和31560168)
江西省自然科学基金(20161BAB204175)
