Chamaecyparis montane cloud forest in Taiwan: ecology and vegetation classification

Montane cloud forest is one of the most endangered ecosystems. However, there are few comprehensive studies on the distribution of subtropical montane cloud forest (SMCF). Chamaecyparis forest is one type of SMCF in Taiwan, distributed across the whole island. This study describes eleven types of this forest in Taiwan based on the Braun-Blanquet approach. Plots were selected from the National Vegetation Database of Taiwan. Two alliances were defined, both of which belong to the order Fagetalia hayatae. Topography and altitude explain the contrasting habitat requirements of these two alliances, whereas seasonality of moisture, soil properties and altitude explain differences in floristic composition at the association level. The alliance of Chamaecyparidion formosanae on slopes and ridges includes coniferous or mixed coniferous and evergreen broad-leaved forests; it is found at higher altitudes and is more influenced by the summer monsoon than the other alliance. Five associations are defined within this alliance. The alliance of Pasanio kawakamii-Machilion japonicae growing on slopes and in valleys contains evergreen broad-leaved forests or forests with a mixture of coniferous and evergreen broad-leaved species. Six associations can be determined under the alliance of Pasanio kawakamii-Machilion japonicae. Classification of each syntaxon was formalized using Cocktail Determination Key.