低覆盖度行带式固沙林带间植被修复过程及其促进沙地逆转效果分析

Vegetation Restoration Process and Sand-reversal Effect of Low Coverage Sand-fixing Forest Belts

针对内蒙古自治区相同配置模式的低覆盖度杨树行带式造林带,对不同恢复时间梯度上带间植被特征和土壤化学性质进行了初步研究。结果表明,随着恢复年限的延长植物多样性呈明显增加的趋势,在16～20a间增加趋势变缓;从生活型和水分生态型来看,恢复初期带间植被组成及生长状况较差,主要以一年生草本且旱生的植物为主,在恢复16a后,主要以多年生草本和中生植物为主,说明半干旱风沙区杨树行带式造林带间植被在经过16a左右的修复,其群落结构趋于稳定,生态功能增强。经过长期的防护效应,有效地改善带间植被的生长环境,土壤有机质的含量造林20a比造林2a时增加2.5倍,土壤逐渐肥沃,生态系统相对稳定。

Selecting the poplar forest belts with same arrangement mode in Inner Monglia as study objects, the characteristics of vegetation and soil chemistry in the afforestation areas with different enclosure dura- tion were studied. Results showed that with the increase of enclosure duration, the species diversity signifi- cantly increased and the increment became slow in a period hetween 16 to 20 years after afforestation. In as- pects of the life form and water ecotype, the vegetation growth condition and composition were poor at early stage of enclosure. The vegetation was mainly comprised of annual herbs and xerophytic plants at the early stage. After enclosure for 16 years, the vegetation was mainly comprised of perennial herbs and meso- phytes. All of these indicated that the community structure became stable and the ecological function was enhanced at the poplar afforestation areas of semi-arid sandy area after enclosure for 16 years. After 20 years of afforestation, the soil organic matter content increased by 2.5 times compared with 2 years after af- forestation. Soil fertility and the stability of ecosystem also relatively increased.