Preliminary Studies On Community Characteristics And Vegetation Classification Of Huangshan Pine And Masson Pine Forests

Huangshan pine(Pinus hwangshanensis)and masson pine(P.massoniana)are important needleleaf tree species in southern China.The horizontal distribution of two pine trees overlaps in the same domain,while the vertical distribution differs significantly.Masson pine develops into subtropical evergreen needleleaf forest at a low altitude,while huangshan pine forms temperate evergreen needleleaf forest at middle and high mountains.Masson pine and huangshan pine forests have always been topics of interest to forestry scientistsand have been widely reported.However,relevant vegetation research has been reported earlier,with a narrow scope and scale,and inconsistent survey standards.It is necessary to systematically explore the vegetation classification of masson pine and huangshan pine forests,which is of great significance for vegetation restoration and forest management in southern China.This thesis selected masson pine and huangshan pine forests in the subtropical region as the research object,and conducted field survey of typical communities of two pine forests in the region based on the research and compilation standards of the Vegegraphy of China.The author obtained 54 plot datasets with a plot size of 20 × 50 m,analyzed the floristic characteristics of the community and the size structure of the dominant population using classical methods in plant community science and population ecology,and implemented the vegetation classification of two pine forests by means of two-way indicator species analysis(TWINSPAN).The main findings are as follows.(1)The huangshan pine and masson pine communities accommodated rich species and clearly dominant families.156 species of vascular plants belonging to 107 genera and 60 families occurred in huangshan pine communities with the dominant families of Rosaceae,Fagaceae,Ericaceae,Poaceae and Lauraceae.In masson pine communities there were 112 species of vascular plants in 78 genera of 47 families,with the dominant families of Fagaceae,Lauraceae,Ericaceae,Asteraceae,Pentaphylacaceae and Rosaceae.(2)Complex geographical elements of seed plants existed in the communities of huangshan pine and masson pine.In huangshan pine communities,8 areal types and 6 subtypes were recorded at the family level,and 13 distribution types and 2 subtypes at the genus level.In masson pinecommunities,7 area types and 5 subtypeswere documented at the family level,and 12 distribution types and 2 subtypes at the genus level.(3)The analysis of size-class structure indicated that population structure of huangshan pine and masson pine forests is unstable,the final succession direction were evergreen broadleaf forests or evergreen deciduous broadleaf mixed forest.In huangshan pine communitis,the sizeclass structure represented a single-peaked distribution for dominant tree species in the tree layes,indicating a declining trend.In masson pine communities,the size-class structure characterized an inverted "J" type for dominant tree species in the tree layes,indicating an overall increasing trend.(4)Based on the analysismethods of TWINSPAN,vegetation classification was conducted for the 54 sample plots.The Pinus hwangshanensis Forest Alliance was divided into 8associations,such as Pinus hwangshanensis-Rhododendron simsii-Polystichum makinoi Evergreen Needleleaf Forest,Pinus hwangshanensis-Quercus serrata-Carex chinensis Evergreen Needleleaf Forest,and Pinus hwangshanensis-Lindera aggregate-Lophatherum gracile Evergreen Needleleaf Forest.The Pinus massoniana Forest Alliance was divided into 9 associations,such as Pinus massoniana-Machilus thunbergia-Dicranopteris pedata Evergreen Needleleaf Forest,Pinus massoniana – Castanopsis carlesii-Diplopterygium glaucum Evergreen Needleleaf Forest,and Pinus massoniana-Rhododendron latoucheae-Heteropogon contortus Evergreen Needleleaf Forest.(5)The succession of huangshan pine and masson pine communities was explored.The huangshan pine community as a pioneer or transitional community,the succession result of huangshan pineforests may be an evergreen broadleaf forest or a deciduous broadleaf forest,while as a topographic top community,they tend to be stable.Generally,masson pine communities belong to the pioneer community.Through the transitional types of ’Pinus massoniana+evergreen broadleaf trees mixed forest’ or ’ Pinus massoniana+ deciduous broadleaf trees mixed forest’,they eventually develop into an evergreen broadleaf forest.In this thesis,the community characteristics of huangshan pine and masson pine forests in the subtropical area were investigated on a large spatial scale.For the first time,Pinus hwangshanensis Forest Alliance and Pinus massoniana Forest Alliance were systematically divided into associations,and a total of 17 associations were named and documented.The inadequacy of this thesis is that the survey data are limited,and the scope of the survey in future research needs to be expanded to obtain more scientific data.This study provides scientific data and technical support for the classification of pine forest vegetation and sustainable forest management.