Long-term snow alters the sensitivity of nonstructural carbohydrates of Syntrichia caninervis to snow cover: Based on a 7-year experiment

Abstract

The dynamics of nonstructural carbohydrates (NSC) profoundly affect productivity and ecological adaptability to adversity in plants. Global warming induced the frequent occurrence of extreme precipitation events that altered the winter snow pattern in deserts. However, there is a lack of understanding of how desert mosses respond to long-term snow cover change at the NSC level. Therefore, in this study, long-term (7-years) winter snow removal (-S), ambient snow (CK), and double snow (+S) experiments were set in the field to investigate the content of NSC and its component in Syntrichia Caninervis. Our results showed that changes in snow depth, snow years, and their interaction significantly affected NSC and its component of Syntrichia caninervis. Compared to snow removal, NSC, soluble sugar, and starch significantly decreased with the increasing snow depth. The ratio of soluble sugar to starch significantly increased, while NSC and soluble sugar gradually returned to the normal level with an increase in snow years. It is worth mentioning that snow removal significantly reduced the soluble sugar to starch ratio compared to ambient snow depth, whereas the double snow experiment significantly increased the ratio of soluble sugar to starch during winter. This indicated an obvious trade-off between carbon utilization and carbon storage in Syntrichia caninervis. Snow removal stimulated Syntrichia caninervis to store sufficient carbon sources by starch accumulation for its future growth, while double snow promoted its current growth by soluble sugar accumulation. The variance in decomposition showed that soil physical and chemical properties, snow cover, and their interaction explained 83% of the variation in NSC and its components, with soil and plant water content, pH, and electrical conductivity (P-WC, S-WC, S-pH, and S-EC) as significant predictors. This highlights that snow indirectly affected NSC and its component contents by changing soil physical and chemical properties; however, long-term changes in snow cover could slow down its sensitivity to snow.

Differentiate responses of soil nutrient levels and enzymatic activities to freeze-thawing cycles in different layers of moss-dominated biocrusts in a temperate desert

“…The insulating effect of moss crust regulates several ecosystem processes and functions, such as water evaporation, microbial activity, nutrient cycling efficiency, and plant nutrient availability ( Belnap, 2003a ). In addition, the resistance of moss crusts to weathering erosion and their physiological-ecological adaptations during FTC complicates the multifunctional changes in soil nutrients ( Zhang et al., 2010 ; Yin et al., 2021 ; Zhang et al., 2022 ).…”

Snow-cover loss attenuates the effects of N addition on desert nutrient cycling and microbial community

“…The desert flora of central Asia is dominant in the western and central parts of the desert, and ephemeral plants are widely distributed. Snow-cover (6–16 cm) is during winter ( Hui et al., 2022 ), mainly from November to March (Stable snow period: 100-150 days) ( Zhang et al., 2022b ). The vegetation in China’s largest fixed and semi-fixed desert is dominated by Haloxylon ammolondren , Haloxylon persicum , Ephedra distachya and Ceratoides latens , with well-developed BSCs widely dispersed, moss crusts distributed under the plant canopy and in plant gaps, some algal crusts distributed on the bare ground, and only a few lichens distributed ( Huang et al., 2021 ).…”