Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Relationship between above‐ground net primary productivity (ANPP) and species richness in three different land‐use types in a semi‐arid steppe ecosystem of northern China. GE, grazing exclusion without biomass removal; MW, grazing exclusion with biomass removal by mowing in August; FG, free grazing.
