干旱区生态环境知识资源中心(Arid): 水热因子对退化草原羊草恢复演替群落土壤呼吸的影响

Arid

	水热因子对退化草原羊草恢复演替群落土壤呼吸的影响
其他题名	Effects of heat and water factors on soil respiration of restoring leymus chinensis steppe in degraded land
	王风玉; 周广胜; 贾丙瑞; 王玉辉
来源期刊	植物生态学报
ISSN	1005-264X
出版年	2003
卷号	27 期号:5 页码:644-649
中文摘要	对内蒙古锡林郭勒白音锡勒牧场退化恢复羊草(Leymus chinensis)草原生态系统土壤呼吸作用的主要影响因子分析表明，环境因子对土壤呼吸作用的影响程度依次表现为：土壤水分>温度；水分对土壤呼吸作用的影响可分成3段，即<7．5％、7．5％～18．4％和>18．4％。当0~10 cm土壤含水量<7．5％时，土壤温度是土壤呼吸作用的主导控制因子，土壤呼吸作用与5 crn土壤温度呈幂函数关系；而当0～10 cm土壤含水量>7．5％时，土壤呼吸作用受土壤水分和土壤温度的共同作用。研究还表明：在植物生长季内，当土壤水分接近羊草草原土壤萎蔫系数6．0％时所测得土壤呼吸作用为植被在干旱胁迫下的土壤呼吸作用，而当土壤水分大于羊草草原土壤萎蔫系数6．0％时，土壤呼吸作用的增加主要是由于植物生长及其引起的根系活动和微生物数量、组成及其活性共同影响的，进而可以解释不同水分条件下土壤及植物根系在土壤呼吸作用中的不同贡献，为建立土壤呼吸作用模型及正确地理解陆地碳收支及其固碳潜力提供依据。
英文摘要	The carbon cycle of restoring steppe in degraded land is one of the important parts of the global terrestrial carbon cycle. The study of soil respiration in restoring steppe plays a very important role in accurately evaluating the carbon budget of restoring steppe and its function in the global carbon budget. As we know, temperature and soil water content are two important environmental factors in understanding the soil respiration process in terrestrial ecosystems. To quantify their allocation and the relationship between soil respiration and temperature and soil moisture, we conducted field experiments to investigate soil respiration from June to September 2001. The effects of heat and water factors on soil respiration of restoring Leymus chinensis steppe in degraded land was studied at Baiyinxile pasture (43°55’N, 116°31’E, with an altitude of about 1 200 m) in Inner Mongolia. This region, un-grazed in June, has a typical temperate and semi-arid climate and the community structure of the vegetation consisted mainly of two species, Leymus chinensis and Stipa grandis ; the soil type was classified as chestnut. Daily variation was investigated by taking measurements once an hour from 6-00 to 19:00 every ten days during the whole growing season using an enclosed chamber method. The results indicated that environmental factors affecting soil respiration ranged as soil water content > temperature, and the soil water content in the upper 10 cm of the soil was of real significance in all of the environmental factors. We analyzed the relationship between daily average soil respiration rate (6:00- 19:00) and daily average soil water content (% ) using the partial correlation analysis of the SPSS and the coefficients showed that soil water content of 7.5% and 18.4% were two thresholds affecting the soil respiration rate. Soil water content could be divided into three levels: <7.5%, 7.5% - 18.4% and > 18.4% based on their effects on soil respiration. When soil water content was less than 7.5%, soil temperature was the dominant factor of soil respiration. Soil respiration ( Rs ) could be expressed as an exponential relationship with soil temperature (t) at the depth of 5 cm and their relationship was Rs = 4.01 t~(1.098)( w < 7.5% , R2=0.49, n = 80, p " 0.01). When soil water content was more than 7.5%, soil respiration was affected by soil temperature (t) , soil moisture ( w ) and the interaction of the two, and their relationship was Rs - - 147.693 + 5.11 w + 6. Ol2t + 1. 214wt (w >7.5%, R~2 = 0. 81, n = 69, p"0.01). When soil water content was close to the water wilting coefficient, about 6.0% , plant root respiration had few contributions to soil respiration. When soil water content was more than 7.5%, soil respiration mainly comes from the metabolism and other living activities of the plants and microbes . Thus, the contributions of soil and plants respectively to soil respiration might be explained from environmental factors. This research will help to develop soil respiration models and to understand accurately the carbon budget of terrestrial ecosystems. Our research implied that drought in the growing season in the year of 2001 tended to reduce the soil respiration rate but temperature did not. There were only three times when the soil water content was more than 18.4% , and so, because of the limitation of the data, the threshold of soil water content of 7.5 % must be verified in future of experiments.
中文关键词	土壤呼吸作用 ; 退化恢复草原 ; 羊草草原 ; 温度 ; 水分
英文关键词	Soil respiration rate Restoring steppe in degraded land Leymus chinensis steppe Temperature Soil water content
语种	中文
国家	中国
收录类别	CSCD
WOS类目	PLANT SCIENCES
WOS研究方向	Plant Sciences
CSCD记录号	CSCD:1315271
来源机构	中国科学院植物研究所
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/204573
作者单位	中国科学院植物研究所, 植被数量生态学重点实验室, 北京 100093, 中国
推荐引用方式 GB/T 7714	王风玉,周广胜,贾丙瑞,等. 水热因子对退化草原羊草恢复演替群落土壤呼吸的影响[J]. 中国科学院植物研究所,2003,27(5):644-649.
APA	王风玉,周广胜,贾丙瑞,&王玉辉.(2003).水热因子对退化草原羊草恢复演替群落土壤呼吸的影响.植物生态学报,27(5),644-649.
MLA	王风玉,et al."水热因子对退化草原羊草恢复演替群落土壤呼吸的影响".植物生态学报 27.5(2003):644-649.