黄土丘陵区3种典型天然草地群落土壤呼吸对模拟降雨的响应

发布时间：2018-11-14 11:52

【摘要】：土壤呼吸是影响陆地生态系统碳循环的关键生态学过程之一,降雨是土壤呼吸变化的重要驱动因子.为探明黄土丘陵区退耕草地群落土壤呼吸对降雨的短期响应规律,选择白羊草(Bothriochloa ischaemum)、达乌里胡枝子(Lespedeza davurica)、铁杆蒿(Artemisia gmelinii)为优势种的3种草地群落为研究对象,于2014年6月和7月,以未降雨群落为对照,对比测定了2种模拟降雨量(15 mm和50 mm)下连续8 d的土壤呼吸速率及土壤水分和土壤温度等.结果表明:2种模拟降雨量对3种草地群落土壤温度和土壤含水量均具有显著影响(p0.05).50 mm降雨下群落土壤呼吸速率增加量高于15 mm降雨.3种群落土壤呼吸对降雨的响应程度存在明显差异,其中,土壤呼吸速率峰值高低顺序为:白羊草(1.75 g·m~(-2)·h~(-1))铁杆蒿(1.69 g·m~(-2)·h~(-1))达乌里胡枝子(1.12 g·m~(-2)·h~(-1)).0~10 cm土壤含水量与土壤呼吸速率呈显著对数函数关系.3种群落土壤呼吸温度敏感性系数Q_(10)值变化范围是1.31~2.01,且月份和降雨量处理间均存在差异.研究表明,准确评估降雨格局改变背景下退耕草地生态系统碳收支需考虑群落类型的差异.
[Abstract]:Soil respiration is one of the key ecological processes affecting the carbon cycle in terrestrial ecosystems. Rainfall is an important driving factor of soil respiration. In order to find out the short-term response of soil respiration to rainfall in returning grassland community in loess hilly region, three grassland communities were selected as the dominant species, (Lespedeza davurica), Artemisia dauricae (Artemisia gmelinii), as the study object. In June and July 2014, the soil respiration rate, soil moisture and soil temperature of two simulated rainfall groups (15 mm and 50 mm) were measured. The results showed that the soil temperature and soil moisture content of three grassland communities were significantly affected by two simulated rainfall (p0.05), and the increase of soil respiration rate in 50 mm rainfall was higher than that in 15 mm rainfall. There were significant differences in the response of soil respiration to rainfall. Of which, The order of peak soil respiration rate is as follows: Leymus chinensis (1.75 g m-2) h-1) Artemisia irradians (1.69 g m-2 h ~ (-1) Lesculia dauri (1.12 g m-1). The correlation between soil moisture content and soil respiration rate was significant in a logarithmic relationship between soil moisture content and soil respiration rate at 10 cm h ~ (-1).), and the soil temperature sensitivity coefficient Q _ (10) of the three communities ranged from 1.31 to 2.01, and the soil temperature sensitivity coefficient (Q10) of the three communities varied from 1.31 to 2.01. There were differences between month and rainfall treatment. The results showed that the difference of community types should be taken into account in assessing the carbon budget of grassland ecosystem under the background of changing rainfall pattern.
【作者单位】：西北农林科技大学黄土高原土壤侵蚀与旱地农业国家重点实验室;中国科学院水利部水土保持研究所;
【基金】：国家自然科学基金(No.41371509) 教育部新世纪优秀人才支持计划(No.NCET-11-0444)~~
【分类号】：S812.2

【相似文献】