Environmental controls on dominance and diversity of woody plant species in a Madrean, Sky Island ecosystem, Arizona, USA

Abstract

The Sky Island archipelagos of the Sierra Madre Occidental contain diverse, highly endemic, and topographically complex ecosystems, yet the local and landscape-scale controls on woody plant dominance and diversity patterns are poorly understood. This study examines variation in woody plant species composition in relation to a suite of environmental variables (i.e., elevation, potential soil moisture, soil type, geologic substrate, and heat load) in the Chiricahua National Monument, Arizona (CHIR). Nine vegetation types were identified using cluster analysis that varied by species composition and plant life form. Non-metric multidimensional scaling and correlation analyses identified significant relationships between vegetation composition and elevation, potential soil moisture, and heat load. Rarefied species richness varied among vegetation types, and in relation to topography, with higher species richness occurring on more topographically complex sites. b (species turnover) and c (landscape) diversity were also high in CHIR compared to other temperate forests. This study highlights the importance of local-and landscape-scale environmental controls on species diversity and vegetation patterns in Madrean evergreen woodlands.

Tree species diversity driven by environmental and anthropogenic factors in tropical dry forest fragments of central Veracruz, Mexico

“…Elevation has been identified in several studies of tropical and temperate forest communities as the most important environmental feature influencing woody plant composition and structure. For instance, for the Chiricahua National Monument, Sierra Madre Occidental, in Arizona, elevation was the single most important factor, though the independent effects of heat load, soil moisture, and soil type also play important roles in species' sorting patterns (Poulos et al 2007). In a chaparral, Santa Ynez, California, shrub species diversity increased at higher elevations, on steep slopes, in rocky conditions, where potential soil moisture was low, where local topographic variability was high, and where total canopy cover was low (Moody and Meentemeyer 2001).…”

“…Many authors have noted the importance of topographic variation, elevation, slope, aspect, and the distribution of plant communities (e.g., Moody and Meentemeyer 2001;Pausas and Austin 2001;Balvanera et al 2002;Poulos et al 2007;Mwaura and Kaburu 2009). The timing of solar radiation is an important factor in the topographic distribution of vegetation in drylands (Walton et al 2005).…”

Leaf‐level trade‐offs between drought avoidance and desiccation recovery drive elevation stratification in arid oaks

“…The elevational stratification of the species has been historically documented (Blumer , Shreve , Whittaker and Niering , Wentworth ), and both climatic and fire regime‐related reasons for the range differences have been proposed (Barton , Poulos et al. , Poulos , Poulos and Camp , Schwilk et al. ).…”

Topography-associated thermal gradient predicts warming effects on woody plant structural diversity in a subtropical forest

“…As a result, plant diversity patterns show considerable spatial heterogeneity in response to topography-associated energy distribution. Furthermore, variations in plant structural diversity patterns increase with a higher complexity of topographic conditions58.…”