Research On The Vegetation Patterns Of Riparian Buffer Strips In Upstream Regions Of Suzhou Creek

Riparian vegetation buffer strips have significant ecological functions. The original conditions of riparian vegetation along Suzhou Creek have been seriously undermined since 1920s. In recent several decades, the ways and modes to reserve and restore riparian vegetation belts have aroused tremendous concerns with lots of work being implemented.On the basis of potential ways in constructing and restoring the riparian buffer strips along upstream suburban regions of Suzhou Creek, some specific experiments are being conducted at Dongfenggang, Huaxin Town, Qingpu District, including the vegetation selection and planting, pattern design as well as index testing and some important first-hand data and achievements have so far been obtained. However, it still remains unproved whether these vegetation patterns could be recommended to all other upstream regions of Suzhou Creek, or whether there were alternative vegetation modes and structures in buffer strips that would have better ecological functions and landscape application.Therefore based on pre-analysis to aerial photographs and relevant materials, the master's thesis (Hereinafter referred to as "Thesis") selectively focused on eight sampling points in upstream regions along Suzhou Creek, namely Zhaotun, Baihe, Anting Automobile Town (AAT), Upriver Dongfenggang, Huangdu, Huajiang Road, Jianglinxin Road and Fenghua Road, to investigate and research on the category and number of plants for floristic analysis (Hereinafter referred to as "the Investigation"). Subsequently, necessary sample plots were designed and surveyed to assess plant community structure according to the statistics of vegetation abundance, coverage, frequency, average heights, etc. By introducing various diversity indices such as Shannon-Wiener, Margalef and Pielou, Thesis analyzed and evaluated the vegetation diversification at different sampling points and also valued, on a comprehensive scale, the landscape suitability of each point with respect to many landscape indices (ie. constitution, structure, diversity, fragment, and aesthetics).Meanwhile, Thesis established an integrated index system by combining vegetation, landscape and other indices, to score each sampling point and evaluate their level, respectively. The indications can be summarized as follows:(1) Level I riparian strips include Jianglinxin Road and Fenghua Road, man-made landscape greenbelts, which have stable community structures, diversified species and extraordinary landscape effects, hence fairly good comprehensive vegetative functions for buffer strips; (2) Level II riparian strips include Zhaotun, Baihe, Upstream Dongfenggang, and Huajiang Road, which have basically steady community structure and comparatively affluent species; and(3) Level III riparian strips include AAT and Huangdu, of which the former pertains to natural strips with randomly growing ruderals due to lack of maintenance, while the latter is a "Green Corrider" with comparatively low amounts of vegetation species and narrow strip bandwidth. However, AAT provides advice on selection of local species and vegetation patterns and Huangdu, the only artificial sampling point with abundant grass covering land, suggests reasonable community structure for the reference. Besides, Thesis analyzed and delineated the land use types in the upstream regions of Suzhou Creek in terms of the Investigation and aerial photographs, and evaluated the grassland research and vegetation pattern experiments undertaken in the experimental area at Dongfenggang.According to research findings, Thesis finally put forward suggestions applicable for establishing and restoring riparian buffer strips, including the species selection, collocation, the bandwidth determination as well as the maintenance and management for the riparian buffer strips. Altogether with first-hand data and results obtained in the Investigation, and the fruits and experience summarized in Dongfenggang experiments, Thesis raised the comprehensive proposal and possible planning for building vegetation along the suburban river banks of upstream regions of Suzhou Creek, such as the advice on introducing arbor, shrub, grass and hydrophyte to form complicated community structures and the requirements on judging and choosing appropriate plant species, specifically discussed the design principles and species selection for three distinctive types of riparian strips, namely natural riparian buffer strips close to farmland, man-made riparian buffer strips close to roads, and man-made riparian buffer stirps for landscape usage.