摘要
通过对黄土丘陵沟壑区陕西延安羊圈沟小流域坡面上退耕还林还草后形成的林地(单一种植刺槐人工林)、草地(单一的撂荒草地)、草地-林地-草地(上坡位和下坡位撂荒草地,中坡位种植刺槐人工林)及林地-草地-林地(上坡位和下坡位种植刺槐人工林,中坡位为撂荒草地)四种不同的植被格局下植物物种多样性及土壤理化性质变化的研究,旨在揭示植被恢复过程中,坡面上植被不同的空间配置模式对植物物种的组成及土壤环境变化的影响。研究发现,4种植被格局下植物物种的多样性以单一的撂荒草地坡面最高,人工林的种植一定程度上影响了林下植物物种多样性的恢复,但整个灌木和草本的群落结构4种植被格局之间均未达到极不相似水平。土壤有机碳及总氮含量均以坡面上草地-林地-草地的空间配置格局最高且有机碳存在显著差异,而撂荒草地则在土壤水分的保持及改善土壤pH值上优于其他3种植被格局。
Variation of plant community and soil property are a key index for vegetation restoration assessment. However, in the hilly area of the Loess Plateau, studies about variation of plant community and soil properties on slope scale under different vegetation patterns are limited. Therefore, in order to understand the effects of different vegetation patterns on plant community and soil properties during vegetation restoration, a case study was conducted in the hilly area of the Loess Plateau, located at the Yangjuangou catchment, Yan'an City, Shaanxi Province. In 2007, variation of plant community and soil physicochemical properties were measured under four types of slopes, each with different vegetation pattern, including Forest ( forest planted by human), Grass, Grass - Forest - Grass ( grass on the upper and lower slopes and forest on the middle slope), and Forest - Grass - Forest ( forest on the upper and lower slopes and grass on the middle slope). On each of the four slopes, three transects were established from the hill tops to the hill toes. Sampling sites were spaced every 35 -45 m along the transects. Each sampling site includes tree sample plots (one along each of the transects). In each sample site, one 10 m ~ 10 m plot was used for tree survey; six 1 m x 1 m plots were used for shrubbery and herbage survey. Soil samples (0 - 10 cm and 10 -20 cm) from each sample plot for each of the four slopes were analyzed for their physicochemical properties. The results indicate that the plant species under four vegetation patterns mostly belong to Compositae, Gramineae, Leguminosae and herbage species is much more than shrub. Jaccard similarity index which indicates similar degree between two plant community compositions shows the plant community composition under Forest and Grass was sim- ilar and the value was 0.56, and the Jaccard similarity index value between Grass - Forest - Grass and Forest - Grass - Forest was 0.44. The Shannon Wiener diversity index of Grass was higher than the other three vegetation patterns. However, there were no significant differences among different vegetation patterns for Evenness and Simp- son dominant indices. For soil properties, soil organic carbon and total nitrogen were significantly higher under Grass - Forest - Grass than under the other vegetation patterns and Grass had highest soil bulk density and soil wa- ter content compared to other vegetation patterns in 0 - 10 cm soil layer. In 10 -20 cm soil layer, the soil proper- ties variation was similar to 0 - 10 cm, soil organic carbon and total nitrogen was higher under Grass - Forest - Grass, Grass had higher soil water content and lower pH value than the other vegetation patterns. In conclusion, compared to the plantation forest, the abandoned grass was better for plant diversity restoration, soil water reserva- tion and soil pH melioration. Therefore, in the Loess Plateau whose water is a limited factor, land being abandoned was a better choice for vegetation restoration. However, if soil nutrients accumulation was considered in this area where the soil erosion is serious problem on the slope, Grass - Forest - Grass restoration pattern on the slope was better for soil carbon and nitrogen accumulation. Although significant difference was existed between different vege- tation patterns, no significant relationship between plant diversity and soil nutrients variation.
出处
《干旱区地理》
CSCD
北大核心
2012年第5期787-794,共8页
Arid Land Geography
基金
国家"十一五"支撑计划重大项目(2006BAC01A01)
关键词
黄土高原
植被恢复
土壤性质
多样性
Loess Plateau
vegetation restoration
soil property
diversity