川西北沙化草地生态恢复工程对沙地植被群落的影响

Effect of ecological restoration project in northwestern Sichuan on the vegetation community of grassland under desertification

2007年7-8月在川西北若尔盖与红原的沙化草地区内,对生态恢复0、1、3、5、7、10和12年的样地植物群落指标进行调查。结果表明:生态恢复工程增加了样地内植物种类、多样性指数、群落总盖度以及地上部分生物量,而群落密度和高度变化表现出波动性,规律性不强。群落恢复演替中主要数量特征受优势种、次优势种、伴生种的控制,是群落演替较为典型的特征。该区生态恢复工程加快了沙化草地植被的恢复速度与群落正向演替的速度,但恢复演替需要较长的时间。因此,在对沙化草地采取围栏封育期间,禁止牲畜进入封育区;针对沙化草地的特点,采用合理的浇(保)水施肥措施,种植适宜植物及应用合理的种植技术和植被管理技术,才能使植被恢复的速度和效果达到一个理想的结果。

In the ecological restoration area in northwestern Sichuan, the survey on vegetation commu nity of grassland under desertification which was restored for 0, 1, 3, 5, 7, 10 and 12 years was con ducted. The results showed that the ecological restoration project increased the number of plant spe cies, biodiversity index, total coverage and aboveground biomass. The community density and height showed a fluctuation without regular pattern. The features of vegetation community under restoration depended on the dominant, subdominant and companion species. The ecological restoration project ac celerated the vegetation restoration. To achieve the satisfactory restoration, the grassland should be under enclosure without any grazing activities and the reasonable reseeding, irrigation and fertilization should be applied for promoting the restoration in this area.