我们可以因此得出结论，该地区的气候在40000到30000年前曾剧烈地变化，导致这一区域从林地变成了草原。
We can thus conclude that the climate of the area changed dramatically between 40, 000 and 30, 000 years ago, causing the terrain to change from woodland to grassland.
从空间分布变化来看，主要表现为耕地向林地、草地及园地转变。
The spatial distributing changes of land use showed that the farmland was mainly converted to forestland, grassland and orchard.
研究了桉树萌生林、桉树植苗林、灌草丛和马尾松林地土壤中过氧化氢酶、蔗糖转化酶及脲酶的活性变化。
Variations of peroxidase, sucrose invertase and urease activity in soil from Eucalyptus coppice forest, Eucalyptus newly planted forest, shrub grassland and masson pine forest have been investigated.
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