晋西黄土高原水土保持林适宜密度研究

黄土高原区水土流失严重,由于降水、温度等自然气候的限制因素,关于适宜的林分密度的研究至关重要.从林分生长状况,林下枯落物蓄水能力,林下草本植物多样性和林地土壤物理特性等方面,对山西省吉县蔡家川流域不同密度的人工林进行了研究.结果表明,从林分生长状况,恢复地表草本植物多样性,改良土壤物理性质的角度出发,该地区营造刺槐林时密度以1 325株/hm~2为宜,油松林的密度以1733株/hm~2为宜,侧柏刺槐混交林的密度以2 089株/hm~2为宜.从增加林地枯落物的蓄水能力考虑,该地区营造刺槐林时密度以2 133株/hm~2为宜,油松林的密度以2222株/hm~2为宜,侧柏刺槐混交林的密度以2 356株/hm~2为宜.刺槐、油松、侧柏刺槐混交林中,侧柏刺槐混交林地草本植物多样性指数和均匀度指数最高,刺槐林地土壤的非毛管孔隙度最大,土壤涵养水源能力最强.

Best Density of Soil and Water Conservati on Forest on Loess Plateau of Western Shanxi Province

Soil erosion on the Loess Plateau is serious due to precipitation,temperature,and other natural climate constraints and thus,determination of an appropriate stand density becomes very important. In this study,we conduct a systematic research on several aspects of the existing plantation in Caijiachuan,such as stand growth status,water storage capacity of forest litter, biodiversity,and physical properties of soils. Results show that,in order to improve the growth conditions,biodiversity,and soil physical properties,the best planting density of black locust,Panus,and the mixed forest should be 1 325,1 733,and 2 089 plant/hm²,respectively,whereas by considering the water storage capacity of the forest litter,the result turns out to be 2 133,2 222,and 2356 plant/hm²,respectively.Besides,the mixed forest has the highest biodiversity index and evenness index and the nor-capillary porosity and the capacity of the water conservation of forest soil in locust forest are also the host.