Study On Tree Species Selection Of Suburban Forest Eco-network System Construction In Harbin

Based on the status of suburban forest of Harbin, 49 well-grown afforesting tree species including 32 species arbor, 16 species shrub and only 1 species vine which are mainly Pinus sylvestris var. mongolica, Betula platyphylla, Syringa oblata and Acer negundo et al, were selected in this study. An information system concerning tree species was established by sorting qualitative index, testing quantitative index as well as referring to other study results.The paper, accorded to the basis of tree species selection, and aims at environmental character and functional demand et al, three main influencing factors, tree characteristics, ecological habit and function, including ecological function, landscape function and economic function, comprise 31 single indexes, were included in this study as follows. Tree characteristics index comprise growth type, maximum height, maximum diameter, root, growth rate, longevity and disease and pest resistance. Tree ecological habit index comprise pollution-resistance, light, soil, water and temperature. Tree function index have following aspects, ecological function comprise leaf area index, carbon fixation and oxygen-releasing capacity, water-releasing humidity-increasing capacity, kill bacterium capacity, dust-absorbing capacity, heavy metal absorption capacity, sulfur dioxide absorption capacity and wind-resistance; landscape function comprise tree shape, branch color, foliage shape, foliage growth time, foliage fall color, flower color, fruit shape and fruit color, economic function comprise annual growth quantum, wood price, fruit output of every trunk and fruit unit price. Especially ecological function indexes were studied and mensurated by experiment. Proportion of every index in different trees was got by expert questionnaire; then matrixes by analytic hierarchy process were established and justified; then test for every matrix was identified and every index in different trees was calculated; finally, Visual Basic and Microsoft Access were used for foregrounding developed language and background database respectively. An inquiring system of tree species was set up according to grade distinction of every index and demand of different trees. Therefore, information concerning tree species, weight values, sequence and others were obtained by inputting one or more indexes into computer.In accordance with various functions of Harbin forest types, the expert system presented expectation value of every index in different trees as follows. Salix matsudana, Ulmus pumila, Quermus mongolica, Populus alba×P.beroliensis and Betula platyphlla are frontal 5 tree species with weight value 90.37, 90.12, 88.12, 87.55 and 86.2 respectively, were used for farmland protection forest; Acer negundo, Salix matsudana, Juniperus rigida, Fraxinus mandshurica and Ulmus pumila are frontal 5 tree species with weight value 78.14, 76.92, 75.96, 74.72 and 74.56 respectively, were used for urban protection forest; Ulmus pumila, Salix matsudana, Populus alba×P.beroliensis, Acer negundo and Larix gemelinii are frontal 5 arbor tree species with weight value 80.07, 79.07, 77.5, 72.42 and 71.67 respectively, were used for road protection forest; Salix matsudana, Populus alba×P.beroliensis, Ulmus pumila, Larixgemelinii and Betula platyphlla are frontal 5 tree species with weight value 92.37, 88.72, 86.62, 85.82 and 85.7 respectively, were used for river protection forest; Fraxinus mandshurica, Larix gemelinii, Populus alba*P.beroliensis, Ulmus pumila and Salix matsudana are frontal 5 tree species with weight value 89.61, 8.35, 87.12, 85.56 and 80.15 respectively, were used for wood forest; Cornus alba, Prunus tomentosa, Primus triloba, Syringa obalata and Sambucus williamsii are frontal 5 shrubs with weight value 82.93, 81.23, 80.85, 78.38 and 77.78 respectively, were used for landscape forest; and Acer negundo,Malus baccata, Sorbus pohuashanensis, Prunus maackii and Prunus padus are frontal 5 arbors with weight value 82, 81.52, 80.3, 79.62 and 78.9 respectively, were used for landscape forest; Prunus salicina, Prunus armeniaca, Xanthoceras sorbifolia, Crataegus pinnatifida and Pyrus ussuriensis are frontal 5 tree species with weight value 88.85, 80.88, 73.25, 69.35 and 63.77 respectively, were used for economic forest.