Environmental correlates for tropical tree diversity and distribution patterns in Borneo

Abstract

Aim Identify environmental correlates for tropical tree diversity and composition. Location Borneo, Southeast Asia. Methods A GIS‐environmental database with 5 arc minute (c. 10 × 10 km) resolution was combined with tree inventory data. Tree diversity, phylogenetic diversity (PD) and the two main compositional gradients were determined for 46 tree inventories. Akaike's information criterion and a data jackknifing procedure were used to select 50 explanatory models for diversity and composition gradients. The average of these models was used as our final diversity and compositional model. We applied Moran's I to detect spatial autocorrelation of residuals. Results Tree diversity, PD and the two main compositional gradients in Borneo were all significantly correlated with the environment. Tree diversity correlated negatively with elevation, soil depth, soil coarseness (texture) and organic carbon content, whereas it correlated positively with soil C:N ratio, soil pH, moisture storage capacity and annual rainfall. Tree PD was correlated positively with elevation and temperature seasonality and was largely determined by gymnosperms. However, angiosperm PD also correlated positive with elevation. Compositional patterns were strongly correlated with elevation but soil texture, cation‐exchange‐capacity, C:N ratio, C and N content and drainage were also important next to rainfall seasonality and El Niño Southern Oscillation drought impact. Main conclusions Although elevation is the most important correlate for diversity and compositional gradients in Borneo, significant additional variability is explained by soil characteristics (texture, carbon content, pH, depth, drainage and nutrient status) and climate (annual rainfall, rainfall seasonality and droughts). The identified environmental correlates for diversity and composition gradients correspond to those found in other tropical regions of the world. Differences between the regions are mainly formed by differences in the relative importance of the environmental variables in explaining diversity and compositional gradients.

Soils on exposed Sunda Shelf shaped biogeographic patterns in the equatorial forests of Southeast Asia

“…Indeed, current heath and swamp forests are characterized by a limited mix of tree species of the surrounding forests, resulting in much reduced diversity and productivity compared with lowland forests on finetextured and richer soils (22,29).…”

Patrones de diversidad y distribución de helechos y licopodios en un bosque mesófilo de montaña de México

“…In the present study, the total richness along the elevational gradient was 78 species of ferns and lycophytes; however, the richness and diversity values of both taxonomic groups showed no significant relationship (P < 0.05) with respect to elevation (Figure 2). This contrasts with the results of other investigations that refer to a unimodal response (Rahbek, 2005;Sánchez-González & López-Mata, 2005;Sang, 2008;Zhu, Jiang, Liu, Xiong, & Kang, 2007) or, less commonly, positive or negative responses between elevation and species richness, for different groups of plants and ecosystems (Rahbek, 2005;Slik et al, 2009). It is important to note that elevation is an environmental mes más frío (TMMF), rango anual de la temperatura (RAT = BIO5-BIO6), temperatura media del trimestre más húmedo (TMTH), temperatura media del trimestre más seco (TMTS), temperatura media del trimestre más cálido (TMTC), temperatura media del trimestre más frío (TMTF), precipitación anual (PA), precipitación del mes más húmedo (PMH), precipitación del mes más seco (PMS), estacionalidad de la precipitación (EP), precipitación del trimestre más húmedo (PTH), precipitación del trimestre más seco (PTS), precipitación del trimestre más cálido (PTC), precipitación del trimestre más frío (PTF).…”

“…Los cambios más conspicuos en la composición y diversidad de especies vegetales en regiones montañosas están relacionados con diferencias en altitud (Rahbek, 2005;Slik et al, 2009). En el presente estudio, la riqueza total a lo largo del gradiente altitudinal fue de 78 especies de helechos y licopodios; no obstante, los valores de riqueza y diversidad de ambos grupos taxonómicos no mostraron relación significativa (P < 0.05) con respecto a la altitud (Figura variable that affects the composition and structure of communities in an indirect and complex way, as species respond to an intricate combination of climatic (temperature, precipitation), soil and topographic variables (Pinokiyo, Singh, & Singh, 2008;Sang, 2008;Slik et al, 2009).…”

“…En el presente estudio, la riqueza total a lo largo del gradiente altitudinal fue de 78 especies de helechos y licopodios; no obstante, los valores de riqueza y diversidad de ambos grupos taxonómicos no mostraron relación significativa (P < 0.05) con respecto a la altitud (Figura variable that affects the composition and structure of communities in an indirect and complex way, as species respond to an intricate combination of climatic (temperature, precipitation), soil and topographic variables (Pinokiyo, Singh, & Singh, 2008;Sang, 2008;Slik et al, 2009). In the case of ferns and lycophytes, it is common for richness and diversity to increase at intermediate elevations where humidity is suitable for reproduction and development (Kluge et al, 2006;Watkins et al, 2006), and to decrease at both low elevations, due to water shortages resulting from the increase in temperature, and at high altitudes due to low temperatures (Cuevas et al, 2013;Kluge et al, 2006;Sánchez-González et al, 2010).…”

“…The most conspicuous changes in the composition and diversity of plant species in mountainous regions are related to differences in elevation (Rahbek, 2005;Slik et al, 2009). In the present study, the total richness along the elevational gradient was 78 species of ferns and lycophytes; however, the richness and diversity values of both taxonomic groups showed no significant relationship (P < 0.05) with respect to elevation (Figure 2).…”