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

自然生境与树种之间通过生境条件有着密切的关系。Chosenia arbutifolia，Toisus urubaniana和Poplus maximowiczii占主导地位的上，下河漫滩和沉积坝，因为这些自然生境，其特点是砾石土壤和土壤水分比其他地貌表面，建立环境有利于这三种杨柳科树木。水坝的水调节大大改变了河岸物种的再生生境，从而影响其招聘，组成和增长率。本文探讨了水坝对河岸林动态的影响。首先，主要河岸树种的分布进行了调查，在Rekifune河，那里没有建坝，其再生栖息地被分为5个地貌面洪水频率的基础上。C.arbutifolia和T.urubaniana出现在最容易发生洪水的地区，如砾石坝和较低的洪泛平原。P.maximowiczii也喜欢粗沉积物，但建立在上游洪泛平原。演替后期的物种，如榆树和水曲柳，出现在被称为阶地的稳定表面上，那里的土壤由沙子和细砾石组成。柳属主导次要渠道。第二，在1997年建成防洪大坝的Satsunai河中，研究了大坝对再生过程的影响。春季多雪地区的洪水使河床沉积物流动，创造出适合种子发芽的潮湿冲积基质。这些生境对于水杨科物种的补充至关重要。一般来说，水坝可以减少春季洪水和/或稳定夏季水流。这种流态限制了砾石坝的发育，降低了洪水频率。洪水频率和规模的减少可能会降低先锋物种的密度，并将物种分布从先锋物种转移到后期演替物种。

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.