茂兰洞庭华南五针松群落特征
Characteristics of Pinus Kwangtungensis Community at Dongting, Maolan

华南五针松Pinus kwangtungensis是贵州喀斯特石山山顶、山脊的主要先锋种和建群种，生境恶劣，群落天然更新缓慢，数量极少，被列为国家II级保护植物。2022年9~11月，在贵州茂兰保护区甲良五针松保护点开展样地调查，研究该区域内华南五针松群落的种类组成、植物区系以及群落稳定性。结果表明：在3600 m2的样方中，共有植物102种，隶属于47科66属，群落数量优势科为兰科，有4属13种，群落建群种为华南五针松，亚优势种为化香，伴生种为乌冈栎、荔波鹅耳枥、青冈栎、角叶槭。群落具有明显的亚热带植被特征，科属的分布以热带为主，温带次之，热带成分21科、40属，各占44.68%和60.61%，温带成分11科、9属，占23.4%和13.6%，乔木层以温带分布为主，温带成分科的植物有926株，占乔木总株数的86.62%，重要值为79.25%。群落稳定性较差，乔木层5个频度级的关系为A < B > C > D < E，群落不稳定；群落的Simpson指数(0.8886)和Shannon-Wiener指数(2.7795)均小于南亚热带常绿阔叶林和南亚热带雨林的Shannon-Wiener指数，群落物种数较少；群落物种丰富度及稳定性高于湖南莽山低于广东，符合纬度梯度分布格局；华南五针松年龄结构呈衰退趋势，随时间推移，有被化香、荔波鹅耳枥等增长型树种取代的可能。
Pinus kwangtungensis is the pioneer and constructive species on the peaks and ridges of the Gui-zhou karst mountain forest, the habitat is harsh and natural renewal of the community is slow, the number is small, and classified as a class II national protected plant. We conducted a sample survey at the Pinus kwangtungensis Protection Point in Maolan Nature Reserve, from September to No-vember 2022, and analyzed the plant species composition, floristic geographical composition and community stability of the community of Pinus kwangtungensis. The results showed there were 102 species of 66 genera in 47 families in an area of 3600 m2. The dominant family is Orchidaceae, with 4 genera and 13 species. The community-building species are Pinus kwangtungensis, the subdomi-nant species were Platycarya strobilacea, and the associated species were Quercusphillyreoides, Carpinus lipoensis, Cyclobalanopsis glauca, and Acer sycopseoides. The community has obvious sub-tropical vegetation characteristics, both in family and in genus; tropical elements were first, and temperate elements were second. The tropical elements were 21 families and 40 genera (44.68% and 60.61%), the temperate elements were 11 families and 9 genera (23.4% and 13.6%). The ar-bor layer was mainly temperate element. The number of individuals in temperate element was 926 (86.62%), and the important value was 79.25%. The stability of the community is poor. The arbor layer frequency grade was A < B > C > D < E, and the community of arbor layer was unstable. The Simpson index (0.8886) and Shannon-Wiener index (2.7795) of the community were smaller than Shannon-wiener index of south subtropical evergreen broad- leaved forest and south subtropical rain forest. The number of species in the community is small. The richness and stability of commu-nity species are higher than those in Mangshan, Hunan, and lower than those in Guangdong, con-sistent with the distribution pattern of latitude gradient. In