Influence of spatial and environmental variables on rattan palm (Arecaceae) assemblage composition in Central Sulawesi, Indonesia

Rattan palms are dominant elements of Southeast Asian rainforests and of high economic importance, yet little is known about the ecological factors determining the spatial distribution of species and assemblages. We studied rattan palm assemblages at two sites at different elevations in Lore Lindu National Park, Sulawesi, Indonesia (Pono: 958–1,266 m; Bariri: 1,390–1,507 m). At each site, we established a transect of 1.29 km consisting of 65 study plots of 10 × 10 m2 each, regularly spaced 20 m from each other. In total, we recorded 5,081 rattan individuals belonging to 22 species, with 1,367 individuals of 16 species at Pono and 3,714 individuals of 8 species at Bariri. Variance partitioning explained 29–49 % of community variation at Pono and 40–72 % at Bariri, with most variation jointly explained by spatial and environmental variables. Within the environmental influence, soil factors dominated over local topographical ones. RDA ordination allowed the discrimination of four species groups at Pono and three groups at Bariri. These groups were related to soil and less clearly to topographic variables. Our study is the first documentation of the importance of soil parameters in determining the spatial distribution of rattan palms. Interestingly, juvenile palms (1 m tall), calling for further studies on the demography of rattan palms

Influence of spatial and environmental variables on rattan palm (Arecaceae) assemblage composition in Central Sulawesi, Indonesia

Rattan palms are dominant elements of Southeast Asian rainforests and of high economic importance, yet little is known about the ecological factors determining the spatial distribution of species and assemblages. We studied rattan palm assemblages at two sites at different elevations in Lore Lindu National Park, Sulawesi, Indonesia (Pono: 958-1,266m; Bariri: 1,390-1,507m). At each site, we established a transect of 1.29km consisting of 65 study plots of 10×10m2 each, regularly spaced 20m from each other. In total, we recorded 5,081 rattan individuals belonging to 22 species, with 1,367 individuals of 16 species at Pono and 3,714 individuals of 8 species at Bariri. Variance partitioning explained 29-49% of community variation at Pono and 40-72% at Bariri, with most variation jointly explained by spatial and environmental variables. Within the environmental influence, soil factors dominated over local topographical ones. RDA ordination allowed the discrimination of four species groups at Pono and three groups at Bariri. These groups were related to soil and less clearly to topographic variables. Our study is the first documentation of the importance of soil parameters in determining the spatial distribution of rattan palms. Interestingly, juvenile palms (1m tall), calling for further studies on the demography of rattan palms

Elevational patterns of species richness and density of rattan palms (Arecaceae: Calamoideae) in Central Sulawesi, Indonesia

We studied species richness and density of rattan palms in 50 plots of 10 × 100 m2 each between 250 m and 2420 m in eight sites in Lore Lindu National Park (LLNP), Central Sulawesi. Rattans were observed in all sample sites, representing three genera and 34 species. The elevational patterns for species richness and density were humped-shaped with maxima around 1000 m. Polynomial models of second order explained 59 and 32% of species richness and density with the factor elevation, respectively. A majority of rattan species (65%) overlapped between 1000 and 1100 m elevation, while a pronounced change in the rattan flora occurred above 1100 m. Commercially important rattan species (Calamus zollingeri, C. ornatus var. celebicus, Daemonorops macroptera) were not observed above 1250 m. The change of species assemblage was significantly related to elevation (56%), followed by geographical distance (47%) and precipitation (40%). Less than 10% of LLNP is lowland forests, much of which is threatened by agricultural intensification. In contrast, montane forests are well represented in the park and high elevation forests are not subject to agricultural conversion or intensive harvesting of rattan and other forest products

Influence of spatial and environmental variables on rattan palm (Arecaceae) assemblage composition in Central Sulawesi, Indonesia

Rattan palms are dominant elements of Southeast Asian rainforests and of high economic importance, yet little is known about the ecological factors determining the spatial distribution of species and assemblages. We studied rattan palm assemblages at two sites at different elevations in Lore Lindu National Park, Sulawesi, Indonesia (Pono: 958–1,266 m; Bariri: 1,390–1,507 m). At each site, we established a transect of 1.29 km consisting of 65 study plots of 10 × 10 m2 each, regularly spaced 20 m from each other. In total, we recorded 5,081 rattan individuals belonging to 22 species, with 1,367 individuals of 16 species at Pono and 3,714 individuals of 8 species at Bariri. Variance partitioning explained 29–49 % of community variation at Pono and 40–72 % at Bariri, with most variation jointly explained by spatial and environmental variables. Within the environmental influence, soil factors dominated over local topographical ones. RDA ordination allowed the discrimination of four species groups at Pono and three groups at Bariri. These groups were related to soil and less clearly to topographic variables. Our study is the first documentation of the importance of soil parameters in determining the spatial distribution of rattan palms. Interestingly, juvenile palms (1 m tall), calling for further studies on the demography of rattan palms