黄土残塬沟壑区刺槐林枯落物水源涵养功能综合评价

为了对黄土残塬沟壑区刺槐林枯落物水源涵养功能综合评价,并提供以功能导向型的林分改造理论依据。于2017年7—8月在山西省吉县蔡家川流域选取475,900,1 575,1 850,2 525株/hm~2不同密度的刺槐林为研究对象,采用坐标综合评定法对不同密度刺槐林分枯落物层水源涵养功能进行综合评价。结果表明,5种林分密度梯度中,当林分密度为1 575株/hm~2时,刺槐林枯落物层能充分发挥其水源涵养功能,而林分密度过高(2 525株/hm~2)或者过低(475株/hm~2)枯落物发挥水源涵养功能的能力均急剧减弱。为了使刺槐林枯落物水源涵养功能正常发挥,其林分密度应控制为1 500株/hm~2。建议现有林分改造中,宜将刺槐林向该密度进行调控。

Comprehensive Evaluation of Water Conservation Function of Litters of Robinia Pseudoacacia Forest Lands in Gully Region on Loess Plateau

In order to comprehensively evaluate the function of water conservation of litters in Robinia pseudoacacia forests and provide the theoretical basis for the function-oriented stand improvement in Gully Region on Loess Plateau, five stand densities (475, 900, 1 575, 1 850, 2 525 plants/hm²) were chosen as subjects in this study at Caijiachuan watershed in Ji County of Shanxi province from July to August, 2017. The comprehensive coordinate method was applied to evaluate the function of water conservation of litters in R. pseudoacacia forests. Results showed that the litters of R. pseudoacacia forests could become effective fully on water conservation when the stand density was 1 575 plants/hm². However, the ability of the litter to play the function of water conservation was significantly reduced when the forest density was too high (2 525 plants/hm²) or too low (475 plants/hm²). The forest density should be controlled at 1 500 plants/hm² so that its litters could play fully the function of water conservation in R. pseudoacacia forests. Therefore, it was advised that the existing forest of R. pseudoacacia should be improved accordance to this forest density.