Abstract:

Desertification has been widely treated as one of the major environmental hazards in the world by scientific communities and the public. Fortunately, local governments have recognized the harm of desertification and paid more attention to controlling desertification in degraded sandy grassland area. Artificial planting and fencing are usually the effective approaches used for desertification prevention, which will elevate vegetation coverage and prevent vegetation degradation. In this paper, soil and vegetation characteristics and their relationship were evaluated under 4 revegetation management modes (unenclosed natural management, enclosed natural management, unenclosed artificial management and enclosed artificial management), which have restoration about 15 years in the southern edge of Mu Us desert degraded sandy land area in Leilongwan Town, Hengshan County, Shaanxi province. The results indicated that the vegetation and soil characteristics of all tested management modes were improved after revegetation for 15 years compared with the mobile dune. Vegetation height, coverage and biomass significantly increased by 0.12~1.03 m, 12.70%~53.18% and 7.27~29.08 g·m^-2, respectively, soil bulk density decreased 0.12~0.27 g·cm^-3 and soil total property increased 6.80%~17.01%, meanwhile soil organic matter, cation exchange capacity (CEC), total N, and available N, P and K improved significantly. The better qualities of vegetation and soil characteristics were observed in enclosed management mode compared to unenclosed mode, meanwhile the better ones were also found in artificial management mode compared to natural mode. Therefore, enclosed artificial revegetation is the optimal mode to obtain the best vegetation and soil effects. By the enclosed and artificial revegetation measures, the plant and soil gradually have formed an interaction system, in which plant height, coverage and biomass have significantly correlation with the soil organic, CEC and soil nutrients of the degraded sandy grassland. In order to improve vegetation restoration and accumulate soil nutrients, enclosure combined with artificial vegetation restoration is an appropriate revegatation management mode of degraded sandy grassland in the agro-pastoral transitional zone.

Key words: Vegetation restoration, Enclosure, Degraded sandy grassland, Management mode, Soil characteristics, Plant characteristics

摘要：

以陕北横山县雷龙湾乡恢复15年的退化沙质草地为研究对象,对未封育自然恢复、封育自然恢复、未封育人工恢复和封育人工恢复4种管理方式对植被和土壤性质的影响及二者的相关性进行了研究,以期为退化沙质草地筛选科学的植被恢复模式选择提供科学依据.结果表明:与流动沙地对照组相比较,经过15年的植被恢复4种管理方式均可不同程度的改善退化草地土壤及植被性质,地表植被高度、盖度和生物量分别提高0.12~1.03 m,12.70%~53.18%和7.27~29.08 g·m^-2,土壤容重降低0.12~0.27 g·cm^-3,土壤总孔隙度提高6.80%~17.01%,有机质、阳离子交换量、全氮及速效养分含量也显著提高.封育管理方式下植被与土壤的恢复效果优于未封育方式,人工植被恢复优于自然植被恢复,采取封育与人工植被恢复相结合的管理方式,严重退化沙质草地在植被恢复过程中植被与土壤特征形成了相互作用、相互影响的协调关系.为了促进农牧交错带退化沙质草地生态恢复,研究区应该采取封育与人工恢复相结合的植被恢复管理方式.

关键词: 植被恢复, 封育, 退化沙质草地, 管理方式, 土壤性质, 植被性质