古尔班通古特沙漠南缘梭梭(Haloxylon ammodendron)群落土壤呼吸对生态系统呼吸的贡献
收稿日期: 2015-01-08
修回日期: 2015-03-04
网络出版日期: 2016-05-20
基金资助
国家自然科学基金项目(41301279,41201041,41171049);"西部之光"西部博士项目(XBBS201204)
The Contribution of Soil Respiration to Ecosystem Respiration of Haloxylon ammodendron Community in the South of Gurbantunggut Desert
Received date: 2015-01-08
Revised date: 2015-03-04
Online published: 2016-05-20
土壤呼吸作为生态系统呼吸的主要贡献者,其贡献率往往超过50%,而干旱区土壤呼吸与生态系统呼吸的比值在季节上的变化尚不明确。利用涡度相关技术与多通道土壤呼吸观测技术,对古尔班通古特沙漠南缘的梭梭(Haloxylon ammodendron)群落生长季CO2通量进行连续观测,探讨了土壤呼吸对生态系统呼吸的贡献及其在生长季变化特征。结果表明:(1)在整个生长季,生态系统呼吸呈单峰式变化,峰值出现在7月,为0.75 g·m-2·d-1;最小值出现在3月,为0.09 g·m-2·d-1;土壤呼吸在5-7月变化不大(0.34~0.51 g·m-2·d-1),7月底以后呈逐渐减小的趋势;(2)土壤呼吸与生态系统呼吸的比值(Rsoil/Reco)在整个生长季为0.38~0.98,平均0.67;季节变化上总体呈"U"型,即生长季初期和末期较高,而生长季中期较低;(3)Rsoil/Reco与梭梭同化枝生物量显著负相关(R2=0.458,P<0.05),说明随着梭梭同化枝生物量的增加,其对生态系统呼吸的贡献升高,导致了植物生长季中期Rsoil/Reco的下降。
杨洁 , 刘冉 , 马杰 , 唐立松 , 李彦 . 古尔班通古特沙漠南缘梭梭(Haloxylon ammodendron)群落土壤呼吸对生态系统呼吸的贡献[J]. 中国沙漠, 2016 , 36(3) : 726 -733 . DOI: 10.7522/j.issn.1000-694X.2015.00037
Soil respiration (Rsoil) typically performs as the main contributors to the annual total ecosystem respiration (Reco) in ecosystem, but the seasonal variation of the Rsoil/Reco has not been investigated. The objective of this study was to investigate the characteristics of soil respiration and ecosystem respiration in a Haloxylon ammodendron community, located in the southern margin of Gurbantunggut Desert in western China. Special attention was paid on the seasonal variation of the Rsoil/Reco. The results showed that: (1) The Reco was unimodal distribution during the whole growing season, the maximum Reco was 0.75 g·m-2·d-1 and the minimum was 0.09 g·m-2·d-1. The Rsoil was little changed during May to July (0.34-0.51 g·m-2·d-1), and began decreasing since the end of July. (2) The Rsoil/Reco ranged from 0.38 to 0.98, with an average of 0.67 across the whole growing season. On a seasonal basis, Rsoil/Reco presented an obvious "U" pattern: the value of Rsoil/Reco was 0.71 at the beginning of growing season; in the middle of growing season, the value of Rsoil/Reco reduced (about 0.43) as the plants into rapid growth period because of plants senesced; at the end of growing season, the Rsoil/Reco increased. (3) There was a significant linear correlation between the Rsoil/Reco and biomass of H.ammodendron assimilating twigs (R2=0.458, P<0.05), indicated that as the H.ammodendron growth, the contribution of H.ammodendron aboveground respiration (especially with leaf respiration) to Reco also increased.
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