Soil-related variations in the population dynamics of six dipterocarp tree species with strong habitat preferences

Abstract

Differences in the density of conspecific tree individuals in response to environmental gradients are well documented for many tree species, but how such density differences are generated and maintained is poorly understood. We examined the segregation of six dipterocarp species among three soil types in the Pasoh tropical forest, Malaysia. We examined how individual performance and population dynamics changed across the soil types using 10-year demographic data to compare tree performance across soil types, and constructed population matrix models to analyze the population dynamics. Species showed only minor changes in mortality and juvenile growth across soil types, although recruitment differed greatly. Clear, interspecific demographic trade-offs between growth and mortality were found in all soil types. The relative trade-offs by a species did not differ substantially among the soil types. Population sizes were projected to remain stable in all soil types for all species with one exception. Our life-table response experiment demonstrated that the population dynamics of a species differed only subtly among soil types. Therefore, species with strong density differences across soil types do not necessarily differ greatly in their population dynamics across the soil types. In contrast, interspecific differences in population dynamics were large. The trade-off between mortality and growth led to a negative correlation between the contributions of mortality and growth to variations in the population growth rate (λ) and thus reduced their net contributions. Recruitment had little impact on the variation in λ. The combination of these factors resulted in little variation in λ among species.

Long-term effects of selective logging on dipterocarp populations in the Pasoh Forest Reserve, Malaysia

“…To describe the size dependency of diameter growth, we used the mean annual dbh growth rate of the three tree size categories used here (small, medium and large) for the parameterisation. The parameterisation of σ followed Yamada et al (2013b). Briefly, survival of trees usually showed a size-dependent pattern; survival of small trees is lower than that of larger trees (Zuidema and Boot 2002;Potts 2003).…”

“…The study populations were divided into 14 dbh classes following Yamada et al (2013b) for every species. Briefly, the first six classes had a width of 5 cm dbh, except for the first class (1-5 cm dbh).…”

Choosing native tree species for establishing man-made forest: A new perspective for sustainable forest management in changing world

“…AA, its increment also did not show an extreme difference to that of GDRF. In spite of intensive and frequent maintenances, the result seemed to indicate that several species do better in certain soil types and site conditions (Shono et al 2007;Yamada et al 2012;Scheneider et al 2013;Dong et al 2014); however swampy area might need more intensive nurturing than those of mineral soil for a dipterocarp lowland dry species to reach the similar growth performance and so as the vice versa.…”

Spatiotemporal changes in biomass after selective logging in a lowland tropical rainforest in Peninsular Malaysia

“…Nevertheless, AGB and its regeneration processes differed between the upland and swampy areas. This can be attributed largely to the species composition, which is probably associated with factors such as the topography and soil types (Davies et al 2003, Manokaran et al 2004) and the flooding and soil permeability (Yamada et al 2010(Yamada et al , 2013. For example, merchantable timber species (e.g., dip-Fig.…”