Determinant(s)	Taxa/ecosystem	Region	Spatial scale	Main finding	Reference
Palm species distributions
Topography, drainage, vegetation	All 23 palm species in a 50 ha plot	South America	Local	Palm species distributions were related to microhabitat variables, mainly topography, but also drainage and canopy height.	Svenning (1999)
Soil, human influence	Seven species of canopy and sub-canopy palms	Central America	Local–landscape	Distribution and abundance of five palm species is related to edaphic variation. The distribution of one species is influenced by human harvesting.	Clark et al. (1995)
Temperature, topography	Euterpe edulis	South America	Landscape	The distribution of E. edulis is constrained by low temperatures and possibly dew formation (especially occurring in valleys).	Gatti et al. (2008)
Climate	Trachycarpus fortunei	Europe, Asia	Regional–continental	There is a strong relationship between minimum winter temperatures (influenced by growing season length) and the native and invasive distribution of this palm.	Walther et al. (2007)
Climate, soil, habitat, human impact, space	29 palm species	Africa	Continental	Climate (especially water availability) and space (possibly reflecting dispersal limitation) are the most important distributional determinants for most palm species. Soil type is only relevant for a few dry-climate species, possibly reflecting hydrology.	Blach-Overgaard et al. (2010)
Topography, species traits	62 palm species	South America	Local/landscape–continental	Palm species abundance at the landscape scale was related to topographic niche breadth, while continental range size correlated with stem height (possibly reflecting species' dispersal potential).	Kristiansen et al. (2009)
Palm community composition
Soil fertility and texture, topography, spatial distance	All palms; non-inundated lowland rainforest	South America	Local	Palm community composition is related to soil fertility (cations), texture (sand content), elevation and spatial distance. The environmental predictors remain important when spatial distance is taken into account, but not vice versa.	Poulsen et al. (2006)
Hydrology, topography, canopy openness, spatial distance	All palms; forest on palaeo-riverine terraces	South America	Local–landscape	At local scale, most variation (approx. 85 %) remains unexplained, with soil moisture being the strongest predictor. At the landscape scale, geographic distance explains most variation (88 %), and composition exhibits links to larger-scale biogeographic patterns (e.g. species with sub-Andean affinities in western local assemblages).	Normand et al. (2006)
Soil, precipitation, vegetation, spatial distance	Understorey palms; lower montane forest	Central America	Landscape	Variation in palm community similarity is related to soil properties (especially inorganic nitrogen availability and cation concentration), but also climate and geographic distance.	Andersen et al. (2010)
Soil fertility and texture, hydrology, topography, spatial distance	All palms; non-inundated lowland rainforest	South America	Landscape	Palm community composition is strongly related to soil clay content and for a sub-set (understorey palms in bottomlands) also to distance to watercourses. Soil fertility, topography (slope) and spatial distance were not relevant predictors.	Costa et al. (2009)
Topography, space	All palms; montane rainforest	South America	Local–landscape	Both topography and spatial location imposed strong controls on palm community composition.	Svenning et al. (2009)
Soil, topography, spatial distance	All palms; non-inundated lowland rainforest	South America	Landscape–regional	Palm community composition is more strongly related to geographic distance than to environmental variables. Soil fertility and texture are the only relevant environmental factors.	Vormisto et al. (2004a)
Geographic distance, climate, topography, vegetation, soil	All New World palms	Americas	Continental	Geographic distance decay in palm community similarity depends more on geographic distance than on environmental distance. Environmentally complex or geographically fragmented sub-regions exhibit stronger distance decays than more homogenous sub-regions.	Bjorholm et al. (2008)
Palm species richness
Area, mid-domain effect	All palms in New Guinea	Australasia	Regional	Area and a mid-domain effect explain the majority of variation in palm species richness along an elevational gradient.	Bachman et al. (2004)
Climate, topography, vegetation, space	All New World palms	Americas	Continental	Water-related variables (annual rainfall, number of wet days) are the most important environmental predictors for palm species richness, followed by soil fertility. Space (latitude squared) is the dominant spatial variable.	Bjorholm et al. (2005, 2006)
Climate, topography	All New World palms	Americas	Continental	Climatic factors related to energy and water availability and productivity determine the species richness of widespread palms, but the species richness of range-restricted palms is to some extent determined by topographical complexity, too.	Kreft et al. (2006)
Climate	All Brazilian palms	South America	Continental	Water availability and temperature seasonality are most important in determining palm species richness.	Salm et al. (2007)
Climate, topography, net diversification rate	All New World palms	Americas	Continental	Palm species richness increases with net diversification at both deep and shallow phylogenetic levels, and all increase with decreasing (absolute) latitude and increasing energy/temperature and water availability. An increase of species richness with topographic range is linked to recent diversification.	Svenning et al. (2008)