Spatial distribution characteristics of biomass in four main types of rangeland in Shanxi

This research mainly investigated 70 sample plots in the rangelands in Shanxi Province, which comprises of four types of rangelands, namely, warm-temperate tussock, warm-temperate shrub tussock, temperate steppe and temperate montane meadow. We measured the above-ground biomass and underground biomass of rangelands, and analyzed the changes in biomass extracted from four altitude gradients, six latitude gradients and five longitudinal gradients. From this regard, it is possible to understand the spatial distribution characteristics of biomass in Shanxi Province, lay a rational foundation for managing and protecting the Shanxi Province rangeland ecosystem. The results revealed an overall trend that the spatial distribution of biomass of rangelands enhanced at first, but then decreased with the increasing altitude, especially for the altitude range of 1 200-1 600 m, which incidentally recorded the highest underground biomass (1 412.86 g·m-2) and total biomass (2 037.87 g·m-2). Shoot biomass (301.5 g·m-2) and litter biomass (105.97 g·m-2) were highest at altitudes below 800 m. With the latitude from south to north, the underground biomass and total biomass increased and then gradually decreased, while the south appeared to be slightly higher than the north (P>0.05). Underground biomass and total biomass in the southern and northern areas were significantly lower than that in the central region (P<0.05). However, with the longitude from west to east, the total underground biomass and total biomass first decreased, and then increased. Biomass in four types of rangeland varied significantly. Underground biomass in the warm-temperate tussock and other three rangelands were significantly (P<0.05) different. Litter biomass in warm-temperate tussock and temperate montane meadow were significantly different than the two other rangeland types.