title: Physiological regulation of Syntrichia caninervis Mitt. in different microhabitats during periods of snow in the Gurbantünggüt Desert, northwestern China.
abstract: Moss crusts, the most advanced stage of biological soil crust (BSC) development, play important roles in BSC biomass and soil surface stabilization. They usually survive freeze-thaw cycles and remain active during periods of extremely low temperatures. We selected Syntrichia caninervis Mitt., the dominant moss crust species, to study physiological characteristics in winter in three different microhabitats (under the canopy of living shrubs, under dead shrubs, and in exposed areas) in the Gurbantünggüt Desert of northwestern China. The results show that soluble sugar content and antioxidant enzyme activity were significantly higher when heavy snow covered the ground in midwinter, than in early winter and late winter. Soluble protein content was highest in mosses in BSCs under shrub canopies. In contrast, antioxidant enzyme activity was at its maximum in BSCs of exposed areas. Our results indicate that moss crusts have the potential to effectively survive rapid environmental change during winter by an increase in osmoregulatory substances and by increased antioxidant enzymes activity. Mosses in BSCs in exposed areas showed the highest antioxidant enzyme activity, in direct contrast to that of mosses in BSCs growing under canopies of both dead and living shrubs. This may indicate that plants of S. caninervis growing in exposed conditions are better adapted to harsh environmental conditions than plants growing in more sheltered habitats.
authors.affiliation: Xinjiang Institute of Ecology and Geography, Key Laboratory of Biogeography and Bioresource in Arid Land, Chinese Academy of Sciences, Urumqi 830011, China; State Key Laboratory of Earth Surface Processes and Resource Ecology, College of Life Sciences of Beijing Normal University, Beijing 100875, China.
authors.forename: Ben-Feng
authors.initials: BF
authors.lastname: Yin
authors.affiliation: Xinjiang Institute of Ecology and Geography, Key Laboratory of Biogeography and Bioresource in Arid Land, Chinese Academy of Sciences, Urumqi 830011, China. Electronic address: zhangym@ms.xjb.ac.cn.
authors.forename: Yuan-Ming
authors.initials: YM
authors.lastname: Zhang
mesh_terms: D000222:Adaptation, Physiological; D000975:Antioxidants / Q000378:metabolism; D018533:Biomass; D019068:Bryopsida / Q000254:growth & development / Q000502:physiology*; D050260:Carbohydrate Metabolism; D002681:China; D002734:Chlorophyll / Q000378:metabolism; D003889:Desert Climate; D017753:Ecosystem; D005453:Fluorescence; D011392:Proline / Q000378:metabolism; D012914:Snow; D012987:Soil; D014867:Water / Q000502:physiology
chemical_list: D000975:Antioxidants; D012987:Soil; D014867:Water; D002734:Chlorophyll; D011392:Proline
keywords: Antioxidant enzymes; Biological soil crusts; Bryophyte; Chlorophyll fluorescence; Snow; moss