山西4类主要天然草地的生物量空间分布特征

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

通过对山西省暖性草丛类、暖性灌草丛类、温性草原类、温性山地草甸类4类主要天然草地的70个大样地进行调查,测定草地地上、地下生物量,分析4个海拔梯度,6个纬度梯度和5个经度梯度的生物量变化规律,旨在掌握山西天然草地生物量的空间分布特征,为充分了解山西草地生态系统及合理利用奠定基础。结果表明,山西省主要类型天然草地生物量随海拔的升高呈现出先升高后降低的趋势,海拔1 200-1 600 m的地下生物量和总生物量最高,分别为1 412.86和2 037.87g·m^(-2);而地上活体生物量和凋落物生物量则是在<800m的海拔处最高,分别为301.5和105.97g·m^(-2)。随纬度从南向北地下生物量和总生物量呈先增加后降低的趋势,且南边略高于北边(P>0.05)。随经度从西向东地下生物量和总生物量呈先增加后降低再增加的趋势。不同草地类型地上生物量存在较大差异,暖性草丛类草地的地上活体生物量显著高于其余3类草地类型(P<0.05)。暖性草丛类和温性山地草甸类草地的凋落物生物量显著高于暖性灌草丛类和温性草原类草地(P<0.05)。

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.