飞播年限对浑善达克沙地植物群落特征的影响

于2013~2017年对浑善达克沙地的11个飞播区和1个未飞播的流动沙地(对照)进行植物群落调查,采用固定样地观测和空间差异代替时间变化相结合的方法,对飞播后浑善达克沙地的植被恢复状况及乔木、灌木半灌木和草本植物的稳定状况进行了分析。结果表明:飞播后,随着恢复年限的延长,沙地植物群落的物种数明显增加,且在恢复第9年时物种数达到最高值;飞播提高了浑善达克沙地植物群落的高度、盖度和密度,但随着恢复年限的延长,沙地植物群落的频度呈先升高后下降的趋势;在浑善达克沙地植被恢复过程中,乔木和灌木半灌木的综合指数波动较小,草本植物波动较大,综合指数变动幅度分别为0.0750、0.0714和0.1617;浑善达克沙地飞播区的乔木、灌木半灌木和草本植物主要呈竞争关系,其稳定指数分别为5.07、6.78、16.74,表现为乔木<灌木半灌木<草本植物。浑善达克沙地飞播区草本植物的稳定性高于乔木和灌木半灌木,且飞播有利于浑善达克沙地退化植被的恢复与重建。

The Effect of Aerial-Seeding Years on Plant Community Characteristics in Otindag Sandy Land

The restoration status of plant community in different restoration years were studied, and the stability status of tree, shrubs and semi-shrubs, and herbaceous plants in aerial-seeding plant community were studied too. From 2013 to 2017, the methods, the fixed sample plots and spatial difference instead of time variation, were used in the study. The plant community in a non-aerial seeding area(CK) and 11 aerial-seeding areas in Otindag sandy land was investigated. The vegetation restoration status and the stability status of trees, shrubs and semi-shrubs, and herbaceous plants in Otindag sandy land after aerial seeding were also analyzed. After the aerial sowing, the number of species in the sandy land increased obviously with the extension of restoration period, and it reached the highest value in the ninth year after restoration. With the aerial seeding, the height,coverage,and density of the vegetation community were increased in Otindag sandy land, but with the extension of restoration period, the vegetation community frequency increased first and then decreased. In the process of vegetation restoration in Otindag sandy land, the composite index of trees, shrubs and semi-shrubs fluctuated slightly, while that of herbaceous plants fluctuated greatly, its change range was 0.0750,0.0714,and 0.1617 respectively. In the aerial seeding area of Otindag sandy land, there was a major competition between tree, shrubs and semi-shrubs,and herbaceous plants, and their stability index was 5.07,6.78,16.74 respectively, which showed that tree was smaller than shrubs and semi-shrubs, and herbaceous plants. Herbaceous plants stability is higher than shrubs and semi-shrubs, and tree in the aerial seeding areas. Furthermore, aerial seeding is beneficial to the restoration and reconstruction of degraded vegetation in Otindag sandy land.