樟子松固沙林更新迹地草本植物多样性及其对土壤理化性质的影响

以科尔沁沙地南缘的彰武县章古台万亩林为研究对象,野外取样调查和实验室检测分析相结合,以樟子松固沙林采伐迹地为对照,研究不同植被恢复类型下樟子松固沙林更新迹地生境的改良效果,探讨植被重建后植物多样性及土壤理化性质的响应。结果表明:1)樟子松(Pinus sylvestris)固沙林更新迹地植被重建后,草本植物物种多样性增加,林下植物偶见种数目增多,13种草本植物在8个样地中未重复出现;2)与采伐迹地相比,不同植被重建类型土壤理化性质均有所改善,土壤容重、田间持水量、有机质、全氮、碱解氮、速效钾在彰武小钻杨(Populus xiaozhuanica)、五角枫(Acer mono)林地改良效果较好,全钾在红刺榆林(Hemiptelea davidii)地含量明显提高、山杏(Armeniaca sibirica)林地的有效磷相比采伐迹地明显提高,且均表现为上层改良效果优于下层;3)不同植被恢复类型土壤理化性质间存在显著差异,随着物种多样性的增加,土壤理化性质逐渐改善,土壤容重、田间持水量、有机质、全磷与植物多样性具有显著的相关性,土壤理化性质的与植物多样性相互作用,共同促进生态系统正向演替。研究结果为控制科尔沁沙地土壤沙化,加速该区生态系统的恢复与重建提供理论依据。

Herbaceous plant diversity and soil physicochemical properties on the regeneration slash of Pinus sylvestris var. mongolica

This study used field sampling and laboratory tests to determine plant diversity and soil physical and chemical characteristics and their correlation in regeneration slash of Pinus sylvestris on Horqin sandy land. The results showed that after vegetation reconstruction in the regeneration slash of P. sylvestris, herbaceous species diversity changed dramatically and the number of species in the forest increased. Compared with the logged area of P. sylvestris, the soil physical and chemical characteristics were all improved after vegetation reconstruction. In areas with Populus xiaozhuanica and Acer mono, soil bulk density decreased and field capacity, organic matter, total nitrogen, and available potassium increased. In addition, total potassium in areas with Hemiptelea davidii and available phosphorus in areas with Prunus sibirica were substantially improved, and all variables were better in the upper than in the lower layer. There were significant differences in soil physical and chemical properties between different vegetation restoration types. With the increase in herbaceous species diversity, soil physical and chemical properties improved and herbaceous plant diversity and soil bulk density, field capacity, organic matter, and total phosphorus were significantly correlated. The results showed that soil physical and chemical properties and the recovery of herbaceous plant diversity interacted to promote the positive succession of the ecosystem. Based on these results, we elaborated on the changes in plant diversity and soil physical and chemical properties during the process of vegetation reconstruction in sandy land. The results have theoretical significance, and will provide practical guidance in the restoration and reconstruction of ecological systems in Horqin Sandy lands.