Effect Of Seasonal Snow Cover On Litter Decomposition Of Schrenk Spruce In Tianshan

Litter decomposition is an integral part of the ecological behavior of forest ecosystems and is an indispensable part of biological processes and abiotic processes.The seasonal snow formed by forest heterogeneous environment is an important factor in controlling the structure and function of mountain forests in middle and high latitudes.It may have a significant effect on the decomposition process of litter,and how the snow factor is involved and affect the drought The decomposition of litter in the semi-arid area of mountain ecosystem is not clear.Based on the gaps,slope and wind direction of the Picea schrenkiana coniferous forest in the arid and semi arid mountainous areas,this paper is divided into four snow gradients(Freezing and thawing period,deep freezing period,thawing period)and the growing season(the early growth season and the late growth season)in the winter snowfall covered by the winter snow in the winter of 2015-2016,The decomposition dynamics of leaf litter and the response of carbon,nitrogen and phosphorus elements to the snow factor in winter forest were analyzed systematically.With a view to a more comprehensive understanding of the response of key ecological processes such as litter decomposition in arid and semi-arid mountainous areas to global climate change.The results show:(1)The decomposition rate of litter was 14.6%-13.6% during the winter period,and the decomposition rate was 11.6%-13.6%.The loss of litter is 46.6%-48.0% of the total annual loss.The difference of snow thickness in winter has a significant difference in the decomposition rate of litter in the snow gradient,which has an important effect on the decomposition of litter.The decomposition rate of litterfall and the decomposition rate of snow-covered spruce litter were significantly different from those of snow-covered spruce litter,and the decomposition rate of litter was decreased,the decomposition coefficient of Olson litter decreases,and the fitting equation is as follows: y = 98.009e-0.310 x,and the fitting equation is: y = 98.592e-0.296 x.The fitting equation is: y = 98.556e-0.277 x,snowless gradient is fitted under the equation: y = 99.251e-0.273x;different snow gradient snow spruce litter The contribution rate of litter decomposition loss during the winter snow cover was 46%-48.5%.In the early stage of the growing season,the degradation of litter was the most.(2)The carbon,nitrogen and phosphorus elements and the stoichiometric ratio of the litter of the Picea schrenkiana had a great response to the change of the snow thickness.The carbon content of litter was released and released in the process of litterfall decomposition of Picea schrenkiana,and the carbon content of litter was released after the end of the year.The release rate of litter carbon was And decreased with the decrease of the height of the snow layer.The nitrogen content of the litter was in the enrichment-release-enrichment state during the decomposition of litter of the Picea schrenkiana,and after the decomposition of the litter And the decrease of the height of the snow layer caused the release of nitrogen from the litter to a certain extent.The phosphorus elements in the litterfall were in the order of enrichment-release,And the decrease of the thickness of the snow layer causes the release of phosphorus from litter to a certain extent.(3)The carbon,nitrogen and phosphorus contents of litter were closely related to soil carbon,nitrogen and phosphorus,and soil organic carbon was positively correlated with litterfall(P <0.05)There was a significant positive correlation between soil total nitrogen and litter nitrogen,and soil total phosphorus was negatively correlated with litter nitrogen.Soil nutrient elements were closely related to litter nutrient elements and had the same trend,and soil nutrient content was at a certain level On the decision of the litter nutrient content of the size.