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The limited role of snow water in the growth and development of ephemeral plants in a cold desert
Author(s) -
Fan LianLian,
Tang LiSong,
Wu LinFeng,
Ma Jian,
Li Yan
Publication year - 2014
Publication title -
journal of vegetation science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.1
H-Index - 115
eISSN - 1654-1103
pISSN - 1100-9233
DOI - 10.1111/jvs.12121
Subject(s) - ephemeral key , snow , seedling , snowmelt , habitat , growing season , biomass (ecology) , agronomy , environmental science , ecology , biology , geography , meteorology
Question The ephemeral layer is an important component of the plant community in cold deserts. Conventional wisdom has it that the ephemeral layer primarily depends on early spring snowmelt water for germination and development. However, this hypothesis has never been subjected to rigorous testing. Location Southern edge of the G urbantunggut D esert, a cold desert and a natural habitat of ephemeral plants (the inter‐sand dune lowland), in the far northwest of C hina and around the geographical centre of the E urasian continent. Methods At the end of the snow cover season between 2009 and 2011, four different snow treatments (0, 50, 100 and 200% snow cover, with 100% representing the natural amount of snow) were applied, using five replicates. Seedling establishment, species diversity and plant growth, population, cover and productivity were monitored throughout or sampled at the end of the growing season. Results The ephemeral plant germination and seedling density were significantly influenced by changes in snow cover. Germination, density of mature ephemeral plants and plant coverage rose as snow cover depth increased. However, the height, rooting depth, numbers of lateral roots and above‐ground biomass of individual plants decreased as snow cover increased, and plant size was negatively correlated with plant density. At the ephemeral layer level, above‐ground biomass showed no significant variation between snow treatments. There was also no significant difference in species richness among the snow treatments. Conclusions Increased snow resulted in higher plant density of ephemerals. However, this high density induced strong competition, reducing the body size of individual plants. By the end of the growing season, snow treatments did not induce significant changes in primary productivity of the ephemeral layer. Primary productivity or growth after seedling establishment depended mainly on rainfall that occurred after the snow had melted, not on snowmelt water itself. Thus conventional wisdom was shown to be only partially true. Snow was important to these ephemeral plants, but its role was limited to seedling establishment.