Structural characteristics and species diversity of the endangered plant Ardisia violacea

Key words: 
• forest ecology /
• rare and endangered plant /
• Ardisia violacea /
• community structural characteristics /
• species diversity

Abstract: To understand the Ardisia violacea plant community's structural characteristics so as to protect this rare and endangered plant，a survey of community structure and species diversity was conducted through quadrat sampling in Lhetang Forest Park，Jiande City，Zhejiang Province. Using permanent plots and examining every individual within，all trees were identified and measured. To describe community population characteristics，importance values of tree populations were calculated，Raunkiaer's life-form spectrum was used，and species diversity of tree and shrub layers were analyzed using Shannon-Weiner，Simpson，and Pielou evenness indexes. The population age structure of the different tree layer species were categorized into three regeneration types：unimodal，sporadic，and inverse-J. Results showed 47 families，79 genera，and 116 species of vascular plants. Raunkiaer's life-form spectrum revealed that micro-phanerophytes and nano-phanerophytes characterized the forest. Structural features of the community for the woody layer included two evergreen conifers species，48 evergreen broadleaved trees species，and 33 deciduous broadleaved trees species. Using habitat，community structure，and species composition，communities with Ardisia violacea were found in three forest community types：Castanopsis eyrei-Castanopsis fargesii，mixed Cunninghamia lanceolata-broadleaf，and Cunninghamia lanceolata. Vertical structure was composed of four layers：tree，shrub，herb and interlayer with the height structure being similar （P＞0.05）. Species richness in the three communities was greatest for the shrub layer（45，30，29，P＜0.05）. For the Shannon-Weiner index，the mixed Cunninghamia lanceolata-broadleaved community herb layer was biggest （2.42，P＜0.01）；whereas the Castanopsis eyrei-Castanopsis fargesii and Cunninghamia lanceolata community shrub layers were largest （2.61，2.37，P＜0.01）. For the Simpson index，the Castanopsis eyrei-Castanopsis fargesii and the Cunninghamia lanceolata community tree layers were hugest（5.130，6.957，P＜0.01）；whereas the mixed Cunninghamia lanceolata-broadleaved community shrub layer was largest （6.097，P＜0.01）. Unimodal type species included Liquidambar formosana，Alniphyllum fortunei，and Pinus massoniana；sporadic type species included Cyclobalanopsis glauca，Schima superba，and Lindera aggregata；and inverse-J type species were Cunninghamia lanceolata，Castanopsis eyrei，Castanopsis fargesii，and Symplocos caudate. In allusion to the biological characteristics of Ardisia violacea，means of in situ conservation was supposed to be taken as the most important management countermeasure for the forest in the future. In addition，it should be done that intermediate selective cutting of the subordinate species in the tree and shrub layer so as to create a good condition for Ardisia violacea populations regeneration and development.［Ch，2 fig. 7 tab. 29 ref.］