植物群落和物种多样性动态过程及物种丧失机制放牧试验

在长期严格的沙地草场放牧试验的基础上,通过调查及多种计算和分析,揭示了在放牧条件下植物群落和物种多样性的动态演变规律及物种丧失的机制,主要结论是:(1)在不同稳定的牧压下群落外貌特征及组分发生明显的分异。(2)持续强度放牧使物种消失,α多样性下降,为理解现代物种消亡和灭绝机制提供了部分依据,现代物种的消亡和灭绝正是由于人们对于生境的破坏引起的,生境破坏引起局部地区物种的消失,这种局部消失的不断累加就可能引起物种的消亡和绝灭。(3)放牧试验对物种组成和β多样性的影响表现在时空两个方面。

Dynamic process of plant community and species diversity and mechanism of species extinction under grazing test

Based on the strict and long-term grazing test and quadrate investigation, we revealed the dynamic succession of plant community and species diversity as well as mechanism of species losses under the grazing condition. The main results are (1) The community appearance characteristics and composition become dividing obviously under stable different grazing pressure. (2) The continued intensive grazing causes the species losses and decrease in a diversity, this provides partly basis for understanding the modern species disappearance and extinction. The species extinction was due to destruction of habitat by human being. Destruction of habitat leads to species disappearance in local istrict. Accumulation of the species losses in local district may lead to the species true extinction. (3) The grazing influence the species composition and (3 diversity in both the temporal and spatial dimensions.