The effects of river regulations and land-use development on the regeneration of riparian tree species and ecological functions of riparian zone.

生境条件决定了植物与树种之间的密切关系。在上、下游洪泛平原和沉积坝中，主要分布着白杨、白杨和白杨，这是因为这些地貌的特点是砾石土，土壤水分较其他地貌少，具有水杨科三种树木生长的有利环境。用于水调节的水坝极大地改变了河岸物种的再生栖息地，从而影响了它们的补充、组成和生长速度。本文研究了水坝对河岸森林动态的影响。首先，对未建坝的雷基富尼河优势河岸树种的分布进行了调查，并根据洪水发生频率将其再生栖息地划分为5个地貌面。在最容易发生洪水的地区，如沙砾坝和较低的洪泛平原上，出现了c.b arbutifolia和t.u ubaniana。p.m axmowiczii也喜欢粗质沉积物，但在上游洪泛区生长。晚期演替物种，如榆木（Ulmus davidiana var.japonica）和水曲柳（Fraxinus mandshurica var.japonica），生长在沙地和细砾石构成土壤的稳定表面上。柳属支配次生通道。其次，在1997年建成防洪大坝的Satsunai河，研究了大坝对再生过程的影响。积雪地区的春季洪水调动了河床沉积物，形成了湿润的冲积基质，非常适合种子发芽。这些栖息地对于水螅类物种的补充是必不可少的。大坝，一般来说，减弱春季洪水和/或稳定夏季流量。这种流态限制了沙砾坝的发育，降低了洪水的发生频率。洪水频率和震级的降低会降低先锋种的密度，使物种分布由先锋种向后期演替种转移。

There is a close relationship between physiotopes and tree species through habitat conditions. Chosenia arbutifolia, Toisus urubaniana and Poplus maximowiczii dominate upper and lower floodplains and the depositional bar, because these physiotopes, characterized by gravel soil and less soil moisture than other geomorphic surfaces, have establishment environments favored by these three species of Salicaceae trees. Dams for water regulation substantially alter the regeneration habitats of riparian species, thereby affecting their recruitment, composition and growth rate. This paper examines the effects of dams on the dynamics of riparian forests. First, the distribution of dominant riparian tree species was investigated in the Rekifune River, where no dams have been built, and their regeneration habitats were classified into five geomorphic surfaces based upon flooding frequency. C.arbutifolia and T.urubaniana appear on the most flood prone areas such as gravel bars and lower floodplains. P.maximowiczii also prefers coarse sediment, but establishes on upper floodplains. The late successional species, such as Ulmus davidiana var.japonica and Fraxinus mandshurica var.japonica, occur on stable surfaces referred to as terraces where sand and fine gravel make up the soil. Salix spp. dominates secondary channels. Second, the effects of dams on the regeneration process were examined in the Satsunai River where a flood control dam was completed in 1997. Spring floods in snowy regions mobilize riverbed sediment and create the moist, alluvial substrate ideal for seed germination. These habitats are essential for the recruitment of salicaceous species. Dams, in general, attenuate spring flooding and/or stabilize summer flows. This flow regime limits the development of gravel bars and reduces flood frequency. A decrease in flood frequency and magnitude may reduce the densities of pioneer species and shift species distribution from pioneer to late successional species.