Major factors affecting the distribution of Viscum articulatum Burm in an ancient cultivated tea plantation.

The aims of this study were to explore the distribution of Viscun articulatum in tea comunity and carry out a regression analysis of the factors affecting the distribution of V. articulatum based on the data of individual tea trees at the quadrat level. The results showed that 1) the mean rate of V. articulatum parasitism on tea trees was about 40%, and the frequency distribution of height for V. articulatum followed the ecological distribution while the number of branches was in the left skewed normal distribution, with most of them preferring to grow at 1/3--3/4 of the tree height. The distribution of V. articulatum depended more on tea tree characteristics than on environmental factors. 2) At single tea tree level, tea tree characteristics may have effect on the distribution of V. articulatum in the order of canopy ground diameter tree height height under branch mosses/lichen coverage. The tea trees with a high mosses/lichen coverage, large canopy, ground diameter ≥11 cm, height ≥3.1 m and HUD of 23--55 cm were found to be the most likely hosts of V. articulatum. 3) At the quadrat level, environmental factors affecting the distribution of V. articulatum were ranked as elevation slope aspect canopy density slope degree. V. articulatum is mainly distributed in the study area at elevations higher than 1 420 m, scarcely at mountain top or valleys. It was found to be more abundant in northwest and southeast slopes as well as in the areas with high canopy density. The greater the slope degree is, the better it grows. 4) Light and water were the dominant environmental factors affecting the distribution of V. articulatum, and the host community factors led to the reallocation of light and moisture, thus affecting the distribution position of V. articulatum in tea trees.