摘要
为探究微地形对草本植物物种多样性的影响,选择古尔班通古特沙漠垄状沙丘为研究区,从4—9月连续4次进行地上植被调查,研究了沙丘坡向和坡位对草本植物多样性时空变化的影响。结果表明:沙丘草本植物种以菊科为主,生活型多为短命植物;迎风坡植物密度显著少于背风坡,且随调查期的后延,两坡向植物密度变化均呈"V"字型,共有种以背风坡相对较多;α多样性指数在迎风坡及背风坡均为坡上部最大,坡底最小且有显著差异;从4—9月,各坡位α多样性指数呈减少和"V"字型2种变化趋势;随坡位升高,迎风坡和背风坡物种替代性指数降低,相似性指数增加,两者在背风坡均表现为显著变化;随调查时间后延,两坡向上物种替代指数增加,相似性指数降低,但替代性指数均无显著差异,沙丘坡向和坡位对草本植物α多样性和β多样性时空格局均产生显著影响。因此,保护和恢复沙漠植物多样性,应考虑沙丘坡向和坡位生境异质性,并结合植物多样性在时间上的变化特征以制定科学的沙漠管理措施。
Spatial-temporal pattern of vegetation is determined by a variety of environmental factors on different scales. The influence of slope aspect and terrain on vegetation pattern has been increasingly reported in recent years. This study investigated the influence of slope location and terrain on vegetation distribution and their temporal structure on typical longitude sand dune in Gurbantunggut desert to provide scientific evidence for vegetation utilization and management, biodiversity conservation and ecosystem restoration and reconstruction. On each of three selected typical sand dunes, five parallel transects （west eastern direction） were established at 20 m intervals. Each transect covered six terrains： The base, lowslope, and upslope of the windward and leeward slopes of the sand dune. In midApril 2015, the aboveground vegetation was sampled in three 1 m × 1 m quadrats randomly placed along the transects. All plant species within each quadrat were identified and recorded. Among windward slope and leeward slope of sand dune, the main herbaceous species were from Compositae, and life form of ephemeral plants had the highest proportion; herbaceous density on windward slope was significantly lower than that on leeward slope, but showed a same trend of “V” pattern from April to September. On both slope aspects, the highest α diversity （richness index, Shannon index, Simpson index and Pielou index） was observed at up-slope and the lowest at base of slope; there was a decreasing trend or a “V” pattern in each terrain over investigation time. Cody index decreased but Sorenson index increased with the terrain rising on windward slope and leeward slope. The results suggested that habitat heterogeneity of sand dune terrain and slope should be considered to preserve and restore the desert plant diversity. Meanwhile, the temporal variation of plant diversity should be also considered to make scientific measures for desert management.
出处
《生态学杂志》
CAS
CSCD
北大核心
2018年第1期26-34,共9页
Chinese Journal of Ecology
基金
新疆维吾尔自治区高校科研项目(XJEDU2016166)资助.
关键词
沙丘
坡位
Α多样性
β
多样性
时空格局
sand dune
terrain
a-diversity
β-diversity
spatial-temporal pattern.
