不同退耕还林模式林木生长量及土壤养分的变化

Effects of Different Models Used in Land Conversion on Tree Growth and Soil Nutrients

研究结果表明,不同退耕还林模式地土壤理化性质均得到不同程度的提高,其变化的程度:封山育林>林草混交>刺槐纯林模式>阳向坡地。封山育林、林草混交、刺槐沙棘混交、刺槐纯林土壤含水量比荒地分别提高了13.44%、7.91%、2.77%、1.03%;封山育林与林草混交模式地有机质含量比纯林分别增加了23.88%、23.88%,全氮分别增加了23.86%、36.2%,刺槐的蓄积量分别增加了67.4%、56.9%。

Different models adopted in land conversion for reforestation have improved the physical and chemical properties. The degree of this enhancement by the adopted models follows the order of mountain closure for regeneration, mixed plantation of grass and trees, mixture of rohinia and hypophea and pure robinia plantation. The increase of soil water contents by the models of mountain closure for regeneration, mixed plantation of grass and trees, mixture plantation rbinia and hypophyea and pure plantation of rohinia are 13.44%, 7.91%, 2.77% and 1.03%, respectively. The organic increase by mountain closure and mixed plantation of grass and trees are respectively 23.88% and 20. 88% over the contrast, and total nitrogen increased by 23.86% and 36. 2%. Stock volume in pure rohinia were increased by 67.4% and 56.9%.