Vegetation ofChamaecyparismontane cloud forest in Lalashan Forest Dynamics Plot

Abstract

AbstractTo understand the vegetation-environment relationships within theChamaecyparismontane mixed cloud forest in Taiwan, we established a 1-ha Lalashan Forest Dynamics Plot (LFDP) in northern Taiwan (24°42D N, 121°26D E). We established the plot in July 2019 and finished the first census of all woody species in August 2020. We collected environmental factors related to the topography and soil properties, measured microclimate and soil moisture within the plot, and collected further microclimatic data with a nearby weather station. In total, we recorded 5220 individuals belonging to 65 species, 42 genera and 29 families, with a basal area of 69.1 m2ha−1, dominated byChamaecyparis obtusavar.formosana,Rhododendron formosanumandQuercus sessilifolia. Modified TWINSPAN classified vegetation into three types (ridge, east-facing slope and valley). Unconstrained ordination showed that the main gradients behind compositional changes are related to windwardness and convexity. The prevailing wind direction in the area is from the northeast, linked to the winter monsoon. Both east-facing slope type and valley type have relatively lower temperatures than ridge type, especially during summer. Convexity is related to soil moisture gradient (from dryer convex to wet concave sites). Fog frequency is seasonal, with the highest values during autumn and winter months. From soil properties, pH is negatively and phosphorus is positively related to topographical convexity. Litter decomposition is linked to both topographical, soil and biotic variables. Collected data will serve as a baseline for future resurveys and monitoring changes within this montane cloud forest.