Study on recovering of vegetation and improvement of livestock production in desertificated/degraded grassland of Inner Mongolia, China.

将内蒙古划分为6个带，将草原划分为5种类型。测定了近20年来草地面积和草地生产力的变化。草甸草原、典型草原和草原荒漠的草地面积显著减少，草地生产力下降。3区和4区、典型草原和草原荒漠的生产力下降幅度较大。另一方面，20 a间家畜数量的显著增加仅发生在草甸草原和典型草原。结果表明，不同的草地类型和不同的地带具有不同的草地生产力，土壤全氮、全磷浓度可能与不同草地类型和地带间的生产力差异有关。另一方面，在本研究的20年间，各草原类型的生产力下降率与牲畜增加率之间没有相关性。气温变化与降雨的相互作用被认为是草地退化的备选因素，但由于每个地区都没有气象站，需要对此问题进行详细的研究。

Inner Mongolia was classified in to 6 zones and grasslands were classified in 5 types. The changes of grassland areas and grass productivities during past 20 years were determined in the present research. The grassland areas remarkably decreased in Meadow steppe, Typical steppe and Steppe desert, and the productivity decreased in all grassland. The decrease rates of the productivities were higher in zone 3 and 4, and in Typical steppe and Steppe desert. On the other hand, the remarkable increases of the livestock were recorded only in Meadow steppe and Typical steppe during 20 years. It was demonstrated that the different grassland types and zones have different grass productivities and the possibility that total nitrogen and phosphorus concentrations in soil were related to the difference of the productivity among grassland types and zones. On the other hand, no correlation was found between decrease rate of the productivity and the increase rate of livestock in each grassland type during 20 years in the present study. The interaction of the change of temperature and the rainfall was considered as alternative factor of the grassland degradation, but detail research is needed for this problem because each area did not have a weather station.