通过对北京市永定河流域气候、地质条件及人为活动的调查，分析了永定河流域风沙化土地的成因。
Through the investigation on climate, geological condition and human activity of Yongding River Basin, the origin of wind-sandy land in Yongding River Basin was analyzed.
通过对天然红松林下的更新进行调查，阐明了天然红松林下的更新好坏和林分类型及土地条件有着密切的关系，对今后天然红松林经营起到借鉴作用。
According to the renovation investigation under natural Korean pine forest, this paper states that there are con - sanguineous relationship among renovation, forest type and site conditions.
通过对天然红松林下的更新进行调查，阐明了天然红松林下的更新好坏和林分类型及土地条件有着密切的关系，对今后天然红松林经营起到借鉴作用。
According to the renovation investigation under natural Korean pine forest, this paper states that there are con - sanguineous relationship among renovation, forest type and site conditions.
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