Analysis of soil carbon, nitrogen and phosphorus in degraded alpine wetland, Zoige, Southwest China.

Abstract

Based on their vegetation characteristics,5degraded alpine wetland plots were selected to investigate grassland degradation processes in the Huahu Scenic Area,Zoige County,in Southwest China.Pika(Ochotona curzoniae)burrow densities,soil carbon(C),nitrogen(N)and phosphorus(P)were measured(0-10 cm depth).The mean soil C and soil N content ranged from 3.7%-4.9% and 0.38%-0.56% respectively,but there were no differences among the plots.However,soil P was significantly higher in plots on the flat areas compared with plots on sloping ground.The soil C/N,C/P and N/P ratios were 11.0,62.3and 5.7,respectively.Carbon,N and P all decreased with increasing soil depth as did the C/N and N/P ratio.The C/P ratio was positively correlated with pika burrow density.The study was helpful for understanding the grassland nutrient cycling processes and for identifying pika control and wetland management strategies.