研究了腾格里沙漠东南缘沙坡头地区不同建植年限（16、21、27、44和52a）人工植被区中发育藻结皮的净光合速率、年固碳量和累计固碳量变化特征,并分析了其与结皮生物学参数（盖度和生物量）和土壤表层0-3 cm有机碳含量的相关关系。结果表明：1）随着人工植被区建植年限的增加,藻结皮的最大净光合速率显著增加,从植被建植16a藻结皮的1.63μmol m^-2s^-1增加至植被建植52a的2.81μmol m^-2s^-1;藻结皮的最大光合速率与结皮生物量和结皮盖度呈显著正相关关系;2）藻结皮的年固碳量随植被区建植年限的延长呈指数增加,随着人工植被区建植年限的增加,藻结皮的年固碳量显著增加,从建植16a藻结皮的C 0.2 g m^-2a^-1增加到52a的C 2.78 g m^-2a^-1;3）植被区建植后,藻结皮的固碳总量经历两个阶段的变化,建植16a到27a,藻结皮固碳总量在C 2.2-6.2 g m^-2,建植44a后,固碳总量增加到C 23.9 g m^-2;并且,藻结皮的固碳总量与土壤表层有机碳含量呈显著线性正相关关系。以上研究结果说明,随着人工植被固沙区的演替,藻结皮发育成熟度逐渐提高,其光合固碳能力显著提高,有利于干旱区土壤有机碳的累计。
Soil water is the key abiotic limiting factor in desert areas and hydrological processes determine the vegetation composition, patterns and processes in desert regions. The hydrological processes can be altered by vegetation succession. In this paper, we review the major advances in ecohydrological research and their potential impact on plant-water relations in revegetated desert communities. The major advances in ecohydrological research over the past 50 years in desert areas were analyzed using a case study that investigated the long-term ecosystem effects of sand-binding vegetation in the Tengger Desert. Key challenges and opportunities for ecohydrology research in the future are also discussed in the context of the major scientific issues affecting sand binding vegetation.
