Natural distribution and community ecological characteristics of Taxus fuana

Taxus fuana is a national Category Ⅰ protective species in China, which is seldom distributed in other regions of the world due to its strict requirements for the growing environment. In this research, the natural distribution, the community composition, structural characteristics, and species competition of T. fuana in Jilong were investigated. The cluster analysis results according to the important value(P_i), showed that T. fuana mainly formed four community types, including the community of Tsuga chinensis + T. fuana(C1), Quercus semicarpifolia + T. fuana + Celtis sinensis + Corylus chinensis(C2), T. fuana + Quercus spinosa(C3), and Tsuga chinensis + T. fuana + Corylus chinensis(C4), which were mostly scattered in Rema village, Langjiu village, and Jipu village of Jilong town. By sorting out the data of all kinds of trees′ height(H) and diameter at breast height(DBH), the vertical structure of the four communities was obvious. Tsuga chinensis was the highest with the average height of 25 meters, while T. fuana and other trees were lower with the average height of 7 meters. The arborous layerproportion of all communities were greater than 50% except that the proportion of C3 community was 17.8%. The proportion of regeneration layer of T. fuana in the four communities was zero, so there were serious regeneration problems. The tree structures of T. fuana were different in different communities. The diameter-level distribution of C1 and C2 communities were relatively good, C3 communities were mostly middle or small grade, while C4 communities had serious dating problems. The vertical structure and tree structure indicated that T. fuana had serious insufficient regeneration problem. The index showed that the species diversity and richness were better, but the evenness was worse. T. fauna in the study area was sparsely distributed, with only 1.34 plant per 100 m~2 on average. Because of the sparse distribution, the inter-species competition of T. fuana was greater than the intra-species competition, and the main competitive pressure was from Tsuga chinensis and Quercus semicarpifolia. A series of problems of T. fuana might result in the declination of this species, therefore, the regeneration and competition of T. fuana must be concerned.