Resreach On Ancient And Famous Trees Species Resource And Landscape Evaluation In Dongguan City

Ancient and Famous Tree Species in Dongguan City are green heritage from Dongguan ancestors,contains rich change marks of natural,climate,geography and humanities.The rapid development of the city and renewal of the old city,make the living environment of these tree species in Dongguan get worse and worse every day,the survival of these old tree species which are full of historical,economic,landscape value is facing the unprecedented threat.How to explore and utilize the resources of ancient and famous tree species reasonably and effectively,has very important practical significance and far-reaching strategic significance.This paper is based on the scientific,systematic and detailed investigation of the resources of ancient tree species in Dongguan City,analyzes the quantity,distribution,age structure,growth performance,health status,the related influencing factors and so on,analysis features of resource structure and surrounding environment landscape in Dongguan City,establish the evaluation model for ancient tree landscape,provide the basic data for protecting ancient trees and the species diversity in Dongguan city,provide data basis for development and ecological construction of Dongguan city.The results of the study show that:(1)The species and quantity of the surviving ancient and famous trees in Dongguan are all rich,there are 2827 plants and 63 species,belonging to 52 genera of 33 families.The main species are Ficus microcarpa,Bombax ceiba,Mangifera indica,Cleistocalyx operculatus,Ficus altissima,Litchi chinensis,Cinnamomum camphora,Celtis sinensis,Dimocarpus longana and so on,the quantity of Ficus microcarpa is the most abundant,which is up to1864 plants.And the Cycas pectinata,Aquilaria sinensis,Scolopia saevat,Phyllanthus emblica,Ziziphus mauritiana and other 23 species,the quantity of each is only 1 plant,the quantity is extremly uneven.(2)There is large difference in quantity of ancient and famous tree species between different town streets:The number of ancient and famous trees species from the largest to thesmallest:Houjie Town(214 plants),Shijie Town(190 plants),Liaobu Town(189 plants),Shipai Town(183 plants),Humen Town(1172 plants),Wangjiang Street(169 plants),Zhongtang Town(154 plants),Chashan Town(149 plants),Qishi Town(138 plants),Daojiao Town(124 plants),Dongcheng Street(120 plants),Gaobu Town(100 plants),Wangniudun Town(87 plants),Qingxi Town(73 plants),Dongkeng Town(69 plants),Machong Town(62plants),Tangxia Town(54 plants),Changping Town(52 plants),Guancheng Street(50 plants),Dalingshan Town(49 plants),Qiaotou Town(48 plants),Hengli Town(45 plants),Changan Town(45 plants),Dalang Town(44 plants),Xiegang Town(41 plants),Shilong Town(41plants),Zhangmutou Town(34 plants),Hongmei Town(29 plants),Nancheng Street(27plants),Shatian Town(25 plants),Fenggang Town(16 plants).There was no significant correlation between the quantity of Ancient and Famous Tree Species in Dongguan City and the area,population density,population density and total GDP of every town street in Dongguan City.(3)There is 84 plants at the age of 500 years old in Dongguan City,which is 2.9% of total species,there is 234 plants at the age between 300 and 499 years old,which is 8.27% of total species,there is 2496 plants under the age of 300 years old,which is 88.29% of total species,there is 13 plants having the special significance,which is 0.46% of total species.Ancient and famous tree species in Dongguan City are relatively low age and their age grade is not complete.There is no remarkable correlation between age and towns Street area,population density,economic gross,Famous Trees have correlation with population density,but the correlation is very small.(4)The growth of plants is influenced by regional environment and site conditions.The ancient and famous tree species due to the large tree age and low viability,from the state of the growth,there are 2151 plants growing normally,which is 76.09% of total species,591 plants showing signs of weakness,which is 20.91% of total species,85 plants growing weakly and being in danger state,which is 3.01% of total species.Ancient and famous tree species with higher height,the DBH and crown width is larger,with reasonable biological characteristics,growths of DBH and crown are close,and the overall growth performance is good.(5)Taking ancient and famous tree species in Dongguan and the surrounding environment of the landscape as the research object,collect 65 photos of representative samples of ancient landscape type,with scenic beauty evaluation(SBE method)to evaluate the landscape,as an independent landscape,the landscape forest canoe SBE value is high,the SBE with growth space restricted by building value is low.Taking the ancient landscapeSBE value as the dependent variable,using the semantic differentia method(SD method)to quantify the ancient landscape elements,taking quantitative values as independent variables,using Gradual elimination of variable method to carry out operation,I used multiple linear regression analysis to establish the evaluation model of landscape trees.The main influence factors of landscape trees in Dongguan city are sight width,crown fullness and sense of hierarchy.