美国North Dakota州土地利用研究及对我国草地利用的启示

Studies on land use of North Dakota state and its instruction to China

草地退化不仅仅是今天中国才发生的事情。历史上曾经发生"黑尘暴"的美国Nort hDakota州,现仍有62.7%土地被用作耕作,林地所占面积仅为1%。私有制以及种植业较高的利润率,是该州种植业比重高于畜牧业的重要原因。草原保护项目(CRP)得到了美国政府财政的大力支持,在North Dakota州采用了以草地恢复为主的措施。美国发达的教育体系带来的高流动率,使得North Dakota州自30年代后居住人口稳定在60～70万成为可能,从而避免了中国出现的草原地区不断增加的人口压力。由此可见:草地作为重要的自然资源,不可能完全保护起来;没有其它配套措施,私有制可能会带来新一轮垦殖;草地畜牧业仍然是畜牧业的重要组成部分,畜牧业发展需要结合种植业尤其需要与饲料生产相结合。

The grassland degradation did not just happen in current China.Historically,the＂Dust Bowl＂took place in the Great Plains,including the North Dakota state.Nowadays in North Dakota,62.7% of land is used for cropland,and 1% is forest land.There are two important reasons,private property and higher profit rate of crops,for the bigger proportion of crops to livestock.The Conservation Reserve Program is supported by the United States finance,and in North Dakota,the major of practice surrounds grass.The developed education system in USA takes a higher flow rate,and makes the population in North Dakota stabilize the range of 600 000 to 700 000 after 1930s.Thus it prevents the result of the increasing population press on the grassland in China.From the studies,we can conclude that：（1）the grassland is an important nature resource,and can’t be protected completely;（2）private property maybe take reclamation again without other measures;（3）the grassland livestock is also an important component of the whole livestock,and the development of livestock production need cooperate with crops production especially the feed.