放牧和氮添加对半干旱沙质草地优势种糙隐子草及群落功能性状的影响

为探究氮沉降背景下放牧对半干旱沙质草地植物功能性状的影响,本试验探究了放牧和短期氮添加(20 g·m-2·a-1)对半干旱沙质草地优势种糙隐子草(Cleistogenes squarrosa)和群落功能性状的影响.结果表明:放牧和氮添加增加了糙隐子草的重要值,放牧降低了糙隐子草叶面积,氮添加显著降低了围封草地中糙隐子草...

Effects of Grazing and Nitrogen Addition on Functional Traits of Dominant Species Cleistogenes squarrosa and Community in Semi-arid Sandy Grassland

To explore the effects of grazing on plant functional traits of semi-arid sandy grassland under the background of nitrogen deposition,we studied the effects of grazing and short-term nitrogen addition (20 g·m^-2·a^-1) on functional traits of the dominant species Cleistogenes squarrosa and community in semi-arid sandy grassland. The results showed that grazing and nitrogen addition increased the important value of C. squarrosa,while grazing reduced leaf area of C. squarrosa,and nitrogen addition significantly reduced C. squarrosa leaf dry matter content in enclosed grassland and increased leaf nitrogen content in enclosed and grazing grassland (P<0.05). Grazing significantly reduced height of the plant community at the same nitrogen level. Nitrogen addition significantly increased leaf area and leaf nitrogen content of plant community in enclosed grassland,and nitrogen addition significantly increased specific leaf area and leaf nitrogen content and decreased leaf dry matter content in grazing grassland (P<0.05). Regression analysis showed that the leaf area and leaf nitrogen content of C. squarrosa could better explain the changes of leaf area and leaf nitrogen content of community. The plants in semi-arid sandy grassland respond to grazing disturbance and nitrogen deposition by changing plant size and main leaf traits,which is of great significance for predicting the structure and function of grassland ecosystems in the future.