Evaluation of big scale agriculture in grassland ecosystems in Eurasian Continent

2003年至2006年，我们在乌克兰、哈萨克、蒙古和内蒙古的中国四个国家进行了欧亚草原的生态调查。本次调查由1)植物区系调查、2)植被调查、3)生物量调查和4)土壤剖面调查组成，取得了以下一些新的认识：1)欧亚草原东部和西部在哈萨克斯坦和蒙古交界处的植物区系差异很大。那里有阿尔泰山和滕山。植物不能自由越过高山。2)欧亚草原东部与日本的植物区系在草地上差异较大，但在湿地上相似。3)位于哈萨克斯坦和蒙古交界处的欧亚草原东部和西部的植物群落在物种组成上也存在差异。4)可以估计弃耕后的演替程度。由于样方调查的结果，生物多样性在弃耕后10年左右增长最大，蒙古草原积累了450-1000g/ha的碳。5)欧亚草原东部和西部的土壤也不同。东部土壤为赤潮土，西部为黑钙土。6)东部草原主要是放牧，西部草原主要是耕地。7)因此，欧亚草原东半部和西部草原的许多性质是不同的。

From 2003 to 2006, we conducted ecological survey of the Eurasian steppe in four countries, Ukraine, Kaza-khstan, Mongolia and China (Inner Mongolia). Our survey was made up by 1) flora survey, 2) vegetation survey, 3) biomass survey and 4) soil profile survey.We could gain, as a result, some new knowledge as follows;1) The floras between eastern part and western part of Eurasian steppe differed much at the border of Kazakhstan and Mongolia. There are Altay Mountains and Tenshan Mountains there. Plants can't exceed high mountains, freely.2) The floras between eastern part of Eurasian steppe and Japan quite differ each other in grassland, but are similar in wetland.3) Plant communities based on species composition also differed between eastern and western part of Eurasian steppe at the border of Kazakhstan and Mongolia.4) We could estimate a sere of succession after abandon plowing. It became clear that the biodiversity grew maximum at about ten years after abandon plowing and that 450-1000g/ha of carbon accumulated in Mongolian grassland, as a result of quadrat method of survey.5) Soils of eastern and western part of Eurasian steppe are also different. Eastern soil is Kastanozem, while western one is Chernozem.6) Main human impact in eastern steppe is grazing, while that of western steppe is plowing.and7) Consequently, many properties are different between eastern half of Eurasian steppe and western one.