干热河谷不同恢复群落对林下物种多样性和土壤理化性质的影响

Effects of different restoration communities on understory species diversity and soil physical and chemical properties in dry-hot valley

【目的】揭示红河干热河谷不同恢复群落对林下物种多样性和土壤理化性质的影响。【方法】以红河干热河谷人工恢复15 a的久树Schleichera oleosa群落、车桑子Dodonaea viscosa群落、铁刀木Cassia siamea群落、清香木Pistacia weinmannifolia群落等植物群落和天然次生稀树灌草丛为对象,采用典型样地和随机取样的方法,对林下草本层植物的物种组成、多样性特征以及土壤理化性质进行比较研究。【结果】①不同恢复群落内,共发现维管植物60种,隶属于20科49属,其中优势科为豆科Leguminosae、菊科Asteraceae、禾本科Poaceae和大戟科Euphorbiaceae。②4种人工恢复群落中,清香木群落的丰富度指数、Shannon-Wiener多样性指数、优势度指数均显著高于天然次生稀树灌草丛(P<0.05)。③4种人工恢复群落在物种组成上均与天然次生稀树灌草丛处于中等不相似水平。④4种人工恢复群落的土壤有机质、全氮、有效磷、速效钾均显著低于天然次生稀树灌草丛(P<0.05)。【结论】红河干热河谷不同人工恢复群落中,林下物种多样性和土壤理化性质均存在显著差异。与天然次生稀树灌草丛相比,人工恢复群落可以在相对较短的时间内增加林下物种多样性,但不能快速恢复土壤养分。

[Objective]This study aims to reveal the effects of different restoration communities on understory species diversity and soil physical and chemical properties in the dry-hot valley of the Red River.[Method]The plant communities of Schleichera oleosa,Dodonaea viscosa,Cassia siamea,Pistacia weinmannifolia and natural secondary sparse shrub and grass artificially restored for 15 years in the dry-hot valley of the Red River were taken as the objects,the species composition,diversity characteristics and soil physical and chemical properties of understory herbaceous plants were studied by using typical plots and random sampling methods.[Result](1)A total of 60 species of vascular plants were found in different restoration communities,belonging to 20 families and 49 genera,of which the dominant families were Leguminosae,Compositae,Gramineae,and Euphorbiaceae.(2)Among the four artificial restoration communities,the Richness index,Shannon-Wiener diversity index and dominance index of P.weinmannifolia were significantly higher than those of natural secondary sparse shrub and grass(P<0.05).(3)The similarity degree of species composition between the four artificial restoration communities and the sparse shrub and grass was at a moderate dissimilarity level.(4)The soil organic matter,total nitrogen,available phosphorus and available potassium of the four artificially restored plant communities were significantly lower than those of sparse shrub and grass(P<0.05).[Conclusion]There are significant differences in understory species diversity and soil physical and chemical properties among different restoration communities in the dry-hot valley of the Red River.Compared with the natural secondary sparse shrub and grass,the artificial restoration community can increase the species diversity in a relatively short period of time,but cannot quickly restore soil nutrients.