Typical Plant Disposition Types On Urban Ecological Effects In Suzhou

Landscape aesthetics was the main consideration and less consider its ecological effects in plant disposition. In this paper, typical landscape plants and plant dispositions were selected to analyze and evaluate, understand their ecological effects, such as, cooling and humidification effects, photosynthesis characteristics and the dust-capturing capacity unit area in Suzhou. These results maybe provide a theoretical basis or reference for the urban ecological landscape construction.The results are showed as follows.1. The rank of the effects of the different space types on the temperature-decreasing and humidity-increasing was square and park﹥street﹥classic garden and residential district﹥hotel﹥campus.2. In selected four types of plant disposition, temperature change trend and humidity change trend of micro-environment were on the contrary. The rank of the effects of the plant disposition types on the daily temperature-decreasing and humidity-increasing was small trees communities﹥trees-shrubs-grass﹥trees-grass﹥trees-hard road. The highest temperature-decreasing effects were observated in the trees-shrubs-grass, trees-grass, trees-hard road and small trees community at 10:00 and 11:00, 10:00 and 11:00, 15:00 and 17:00 with the temperature dropping 2.3℃, 2.1℃, 1.8℃ and 1.9℃, respectively. The highest humidity-increasing effectcs were observated in the trees-shrubs-grass, trees-grass, trees-hard road and small trees community at 10:00 with 13.5%, 13.3%, 11.7% and 11.8%.3. With the increasing of PAR in the range of 0-200μmol.m-2·s-1, the Pn of plants increased rapidly, with the PAR increasing in the range of larger than 0-200μmol.m-2·s-1, Pn of plants continued to increase, than the Pn no longer to increase instead of maintaining a certain level with the PAR increasing continually. The order of the Amax of plants was Euonymus japonicus Thunb. var. Ovatus Aureus>Prunus lannesiana Wils.>Loropetalum chinense(R.Br.) Oliv. var. rubrum Yieh>Osmanthus fragrans(Thunb.) Lour. >Photinia serrulata Lindl. >Cinnamomum camphora(L.) Presl. >Magnolia grandiflora L.>Camellia japonica L.. The order of the AQE was Osmanthus fragrans(Thunb.) Lour.>Prunus lannesiana Wils.>Photinia serrulata Lindl.>Loropetalum chinense(R.Br.) Oliv. var. rubrum Yieh>Camellia japonica L.>Euonymus japonicus Thunb. var. Ovatus Aureus>Magnolia grandiflora L.>Cinnamomum camphora(L.) Presl.. The order of the LSP was Euonymus japonicus Thunb. var. Ovatus Aureus>Osmanthus fragrans(Thunb.) Lour.>Loropetalum chinense(R.Br.) Oliv. Var. rubrum Yieh > Cinnamomum camphora(L.) Presl. > Magnolia grandiflora L. > Prunus lannesiana Wils.>Camellia japonica L.>Photinia serrulata Lindl.. The order of the LCP was Camellia japonica L.>Euonymus japonicus Thunb. var. Ovatus Aureus>Loropetalum chinense(R.Br.) Oliv. var. rubrum Yieh>Osmanthus fragrans(Thunb.) Lour. > Prunus lannesiana Wils. > Cinnamomum camphora(L.) Presl. > Photinia serrulata Lindl.>Magnolia grandiflora L.. The order of the Tr was Loropetalum chinense(R.Br.) Oliv. Var. rubrum Yieh>Euonymus japonicus Thunb. var. Ovatus Aureus>Prunus lannesiana Wils.>Photinia serrulata Lindl.>Osmanthus fragrans(Thunb.) Lour. > Magnolia grandiflora L. > Camellia japonica L. > Cinnamomum camphora(L.) Presl.. The results of cluster analysis showed that the rank of the effects of different plants on photosynthetic ecological was Loropetalum chinense(R.Br.) Oliv. var. rubrum Yieh, Euonymus japonicus Thunb. var. Ovatus Aureus and Prunus lannesiana Wils. > Osmanthus fragrans(Thunb.) Lour. > Camellia japonica L., Photinia serrulata Lindl., Cinnamomum camphora(L.) Presl. and Magnolia grandiflora L..4. The order of plant dust-capturing capacities in different seasons was May﹥August ﹥ November. The order of mean dust-capturing capacities of plants was Loropetalum chinense(R.Br.) Oliv. Var. rubrum Yieh>Magnolia grandiflora L.>Photinia serrulata Lindl.>Osmanthus fragrans(Thunb.) Lour.>Prunus lannesiana Wils. > Camellia japonica L> Euonymus japonicus Thunb. var. Ovatus Aureus >Cinnamomum camphora(L.) Presl. Blade structure greatly affects leaf dust-capturing capacity. Observations under scanning electron microscope showed that leaves of plants, higher dust-capturing capacity, have cilia, surface with ridge-like structure folds or grooves, and leaves of plants, weaker dust-capturing capacity, have surface smooth,non-ciliated, surface with wax or warty skin projections. In addition, correlation analysis showed that the relationship between Cond of plant leaf and dust-capturing capacity was significant positive and the relationship between the WUE and total area of leaf was very significant negative.5. Comprehensive ecological effects of plants were in descending order of Loropetalum chinense(R.Br.) Oliv. Var. rubrum Yieh>Euonymus japonicus Thunb. var. Ovatus Aureus>Photinia serrulata Lindl. >Prunus lannesiana Wils. >Osmanthus fragrans(Thunb.) Lour. >Magnolia grandiflora L. >Cinnamomum camphora(L.) Presl. > Camellia japonica L.. Based on the integrated ecological effects, the recommended plant dispositions were showed that the first layer was ground cover plants, the second layer was Photinia serrulata Lindl., and the third layer was Osmanthus fragrans(Thunb.) Lour. or Magnolia grandiflora L. in “triple-layer-greening” mode; the first layer was ground cover plants, the second layer was Loropetalum chinense(R.Br.) Oliv. var. rubrum Yieh, the third layer was Photinia serrulata Lindl., and the fourth layer was Osmanthus fragrans(Thunb.) Lour. or Magnolia grandiflora L.in "quadruple-layer-greening" mode and the first layer was ground cover plants, the second layer was Loropetalum chinense(R.Br.) Oliv. Var. rubrum Yieh, the third layer was Photinia serrulata Lindl., the fourth layer was Osmanthus fragrans(Thunb.) Lour., and the fifth layer was Magnolia grandiflora L. in “five-layer-greening”mode.