A Study of Selection and Evaluation of Excellent Native Tree Species in Chongqing

On the basis of investigation and analysis of the natural conditions and socio-economic status,an evaluation was made of 60 excellent native tree species in Chongqing determined by field surveys and literature review in order to select certain superior species.Different evaluation and selection criteria were established according to different uses of the species.For timber species,eight indexes were selected.They were fast-growing ability,fertility,barren resistance,cold resistance,drought resistance,pest resistance,wood quality and market price.For biomass energy species,eight indexes were selected.They were fast-growing ability,fertility,barren resistance,cold resistance,drought resistance,pest resistance,versatility and market price.For ornamental species,11 indexes were selected.They were ornamental characteristics of leaves,ornamental characteristics of flowers,ornamental characteristics of fruits,ornamental characteristics of trees,cold resistance,drought resistance,pest resistance,pollution resistance,SO2-absorption ability,dust-absorption ability and noise-reduction ability.The three-score grade standard was adopted for each evaluation index,analytic hierarchy process(AHP) was used to determine the weight of each index,and the 60 target species were comprchensively evaluated according to each index score and weight.The main results and conclusions are as follows.(1) According to the comprehensive evaluation of 20 timber species,Liriodendron chinense,Toona sinensis,Alnus cremastogyne,Sassafras tzumu,Cinnamomum appelianum and Cinnamomum camphora are excellent native timber species,and Melia azedarach,Melia toosendan,Magnolia officinalis and Elaeocarpus sylvestris come second.(2) According to the comprehensive evaluation of 20 biomass energy species,it is recommended to choose Eucommia ulmoides,Alnus cremastogyne,Melia azedarach,Robinia pseudoacacia,Swida wilsoniana and Idesia polycarpa as main source species of biomass energy forest,and to choose Bothrocaryum controversum,Litsea cubeba,Xanthoceras sorbifolia,Quercus acutissima and Quercus variabilis as alternative trees.(3) According to the comprehensive evaluation of 20 ornamental species,Michelia maudiae,Dendrobenthamia japonica,Davidia involucrata,Koelreuteria paniculata,Liquidambar formosana and Magnolia officinalis are excellent ornamental trees and can be used as backbone species in the landscape project.In addition,Pterocarya stenoptera,Idesia polycarpa,Ormosia hosiei and Bretschneidera sinensis can be keynote trees.