Map of study area in the Tabu River Basin, Inner Mongolia Autonomous Region, northern China. (a) Location of the 130 survey sites in the study area. (b) Examples of four survey sites with varying levels of habitat loss and fragmentation per se shown with a 500-m radius buffer.

Hypothetical model of habitat fragmentation that alters the relationship between grassland plant diversity and above-ground biomass by affecting the percentage of grassland specialists in the community in the Tabu River Basin, a typical agro-pastoral ecotone of northern China. Arrows represent the hypothesized paths among variables. See the main text for a description of arrow directions.

Relationship between habitat fragmentation and grassland plant richness in the Tabu River Basin, a typical agro-pastoral ecotone of northern China. The R2 values in the figure are from linear regression models. The n in the figure is the number of surveying sites used in the linear regression models. * and ** represent significance at the 0.05 and 0.01 levels, respectively.

Standardized parameter estimates and 95% confidence intervals for habitat fragmentation and plant richness affecting above-ground biomass in the Tabu River Basin, a typical agro-pastoral ecotone of northern China. Standardized estimates and 95% confidence intervals are calculated by the multi-model averaging method. * and ** represent significance at the 0.05 and 0.01 levels, respectively.

Results from piecewise structural equation model with hypothesized paths showing how habitat fragmentation alters the relationship between grassland plant richness and above-ground biomass in the Tabu River Basin, a typical agro-pastoral ecotone of northern China. The widths of arrows are proportional to the standardized path coefficients. Black and red solid arrows represent the positive and negative effects, respectively. Black solid and grey dashed arrows represent the significant and nonsignificant effects at the 0.05 level, respectively. The Fisher’s C and P-values are from the piecewise structural equation model.

Relationships between grassland plant richness and above-ground biomass at low, moderate, and high levels of habitat loss from 130 landscapes in the Tabu River Basin, a typical agro-pastoral ecotone of northern China. The R2 values in the figure are from linear regression models. ** represent significance at the 0.01 level.