Variation In Leaf Non-structural Carbohydrates Along Elevational Gradients In Taibai Mountain

The non-structural carbohydrates(NSC)of plant leaves cannot only reflect the carbon supply of plants,but also reflect the adaptation strategies of plants to the external environment.In this study,the northern slope of Taibai Mountain was selected as the study area,and the soluble sugar,starch and NSC concentrations of 269 plants(belonging to 68 families and 155 genera)were investigated.Based on the community survey data,we used the scaling-up method to examine the variation in leaf NSC data along different altitudinal gradients from species to plant functional growth form(PGF)and community levels,respectively.These main results are as follows:(1)At the species level,leaf soluble sugar,starch and NSC showed similar patterns,i.e.increased first and then decreased last increased along the elevational gradient.The total effects of climate,soil and PGF explained the difference of 20.94%-30.87% of NSC.Moreover,climatic variables had the greatest impact on NSC,which could explain 15.41% variation in NSC.(2)At the PGF level,different growth types of NSC varied with altitudes.Leaf soluble sugar,starch and NSC in the tree layer increased first and then decreased with the increased elevation.Climate and soil variables explained 58.11%-77.12% variation in NSC in the tree layer.Moreover,climatic variables were the main factor influencing the NSC of tree leaves,with climate explaining 58.74% variation;in the shrub layer,leaf soluble sugar,starch and NSC in the shrub layer increased first and then decreased with the increased elevation.Climate and soil variables explained a total of 45.78%-53.93% variation,with climate explaining 43.40% variation;in the herb layer,leaf soluble sugar,starch and NSC decreased first and then increased with the elevation.Climate and soil variables explained a total of 79.44%-89.20% variation,and soil variables accounted for the largest variation in NSC(44.22%).(3)At the community level,leaf sugar,starch and NSC concentrations exhibited obvious patterns along the altitudinal gradients characteristics.The NSC showed a trend of increasing first and then decreasing along the altitudinal gradients.Both climate and soil explained the 66.71%-78.19% of total variation.Moreover,the independent effects of climate explained a substantial portion of variation in the NSC variation(47.76%).(4)NSC varied largely among different levels.Compared with the species level,the community level showed a more obvious altitudinal trends.In addition,climatic variables explained the larger variation in trait variation than soil variables,which are true at the species,plant growth form and community levels.