摘要
露水的形成是干旱、半干旱地区生态系统中重要的环境因子。以库布齐沙漠不同发育类型的人工结皮为研究对象,通过每天野外跟踪观测人工结皮的露水凝结量,比较人工结皮露水凝结量的大小及其凝结能力的差异性。试验以人工蓝藻结皮(ACC)、人工藻结皮(AAC)、人工苔藓结皮(AMC)以及自然苔藓结皮(NMC)和流沙(SS)为材料,并以绒布-平板露水测定法(CPM)为参照,试验时间为42d。结果表明,CPM法测定的日平均露水凝结量为0.02～0.35mm,ACC露水凝结量为0.012～0.191mm,AAC为0.032～0.230mm,AMC为0.048～0.274mm,NMC为0.056～0.304mm,SS为0.003～0.083mm。露水凝结量随结皮的发育状况而存在显著差异,露水凝结量大小依次为NMC>AMC>AAC>ACC>SS。结果还发现,人工结皮的形成明显促进了荒漠地表对露水的吸收和保持,结皮能够比沙表面凝结更多的露水,且结皮的露水干化过程比沙表面更慢。推测结皮藻丝体的发育及其胞外分泌物是结皮凝结较多露水的重要原因,同时依赖于结皮表面的微气候环境。本研究揭示了露水在维系结皮生存中的生态学意义,表明人工结皮具有较好的水土保持功能,同时有利于更好地理解生物结皮对露水的凝结机制与吸收利用情况,并为荒漠化地区有限水源条件下人工结皮利用露水等非降雨型水分进行野外生存提供重要的理论支持和试验依据。
Dew is one of important environmental factors for desert ecological system in semiarid and arid re- gions. In this study, the artificial crusts were selected for experimental objects to compare differences of dew condensation amounts between different artificial crusts by means of daily detection for dew condensation on artificial crust surfaces. Concerning the experiment, artificial cyanobacterial crusts （ACC）, artificial algal crusts （AAC）, artificial moss crusts （AMC）, and natural moss crusts （NMC） as well as shifting sands （SS） were selected as experimental materials, respectively. The experiment period was 42 days. Moreover, the cloth-plate method （CPM） was used for comparing dew condensation effects among the crusts. Results showed that the average daily dew amount as measured by CPM was 0.02-0.35 mm and the dew amount of ACC was 0. 012-0. 191 mm. the other dew amounts were 0.032-0. 230 ram, 0. 048-0. 274 mm, and 0.056 -0. 304 mm as well as 0. 003-0. 083 mm occurring on AAC, AMC, NMC and SS, respectively. It was found that there were obvious differences following developmental extents of artificial crusts, and the order of dew amounts in artificial crusts was as follows. NMC〉AMC〉AAC〉ACC〉SS. In addition, it was indi- cated that the formation and development of artificial crusts could accelerate dew deposition and dew assimila- tion, and the crusts could condense and retain more dew than sand. At the same time, there was more slow drying process of dew from the crusts than that from sand. The reason that the artificial crusts could con- dense abundant dew may depend on rich algal filaments, extracellular polymers and microclimatic characteris- tics as well as soil properties within the crusts. It might be necessary for us to fully understanding the mech- anisms of dew condensation and assimilation on surfaces of the artificial crusts, and to further disclose the important ecological sense of dew in survival of the crusts. Furthermore, the research verified that the artifi- cial
出处
《水土保持学报》
CSCD
北大核心
2011年第6期159-164,共6页
Journal of Soil and Water Conservation
基金
中国博士后科学基金资助项目(20100480920)
淡水生态与生物技术国家重点实验室资助项目(2008FBZ21)
武汉市科技局与内蒙古自治区发改委重大科技产业化专项(200720112031)
河南省高等学校青年骨干教师资助计划项目(2010GGJS-106)
关键词
库布齐沙漠
人工结皮
露水凝结
非降雨型水分
水土保持
Hopq desert
artificial crusts
dew condensation
non-rainfall water sources
soil and water con-servation
