Philosophical Transactions of the Royal Society B: Biological Sciences
Current policy is driving renewed impetus to restore forests to return ecological function, prote... more Current policy is driving renewed impetus to restore forests to return ecological function, protect species, sequester carbon and secure livelihoods. Here we assess the contribution of tree planting to ecosystem restoration in tropical and sub-tropical Asia; we synthesize evidence on mortality and growth of planted trees at 176 sites and assess structural and biodiversity recovery of co-located actively restored and naturally regenerating forest plots. Mean mortality of planted trees was 18% 1 year after planting, increasing to 44% after 5 years. Mortality varied strongly by site and was typically ca 20% higher in open areas than degraded forest, with height at planting positively affecting survival. Size-standardized growth rates were negatively related to species-level wood density in degraded forest and plantations enrichment settings. Based on community-level data from 11 landscapes, active restoration resulted in faster accumulation of tree basal area and structural properties ...
Of the dung beetles collected in Singapore, Catharsius molossus (Linnaeus) is the largest and onl... more Of the dung beetles collected in Singapore, Catharsius molossus (Linnaeus) is the largest and only large nocturnal tunnelling species, last recorded there in the late 1970s. To determine if the species is still extant in Singapore, we conducted dung beetle surveys at six study sites. Both cattle- and pig-dung baited pitfall traps were used to determine the species’ dung preferences. In total, 52 individuals were captured, with 49 individuals from cattle-dung baited traps. Most of them were captured within the contiguous northern patch of forests in the Central Catchment Nature Reserve. Catharsius molossus appears to be a specialist of herbivores’ dung. Established populations of both the Sambar deer (Rusa unicolor) and Eurasian wild pig (Sus scrofa) are likely sources of dung for this species.
∗ Department of Integrative Biology, University of California Berkeley, Berkeley, CA 94720, USA ... more ∗ Department of Integrative Biology, University of California Berkeley, Berkeley, CA 94720, USA National Center for Ecological Analysis and Synthesis, 735 State St., Suite 300, Santa Barbara, CA 93101, USA Smithsonian Tropical Research Institute, Apartado 0843-03092 ...
Questions What processes govern the long-term recovery of tropical secondary forests? Specificall... more Questions What processes govern the long-term recovery of tropical secondary forests? Specifically, how are seedling species density, stem density and functional groups in older regenerating forests affected by existing trees, the regeneration environment and distance to seed sources? Location Central Catchment Nature Reserve, Singapore. Methods We investigated three primary forest plots and nine 60-yr-old secondary forest plots varying in their degree of recovery. We analysed seedling parameters as a function of the abiotic and biotic regeneration environment as well as distance to primary and mature secondary forests. Results The secondary forest plots had functional composition distinct from, and Chao-estimated species richness and stem density lower than the primary forest plots. Seedling communities were most strongly associated with the mature tree communities within each plot; associations with other intra-plot variables and distance to potential seed sources were lower but still highly significant. Overall, aside from the mature tree community, the most significant predictors of seedling species composition were fern cover, VPD, soil Al, available P and C:N ratio. Primary forest species were associated with low light environments, low macronutrients and low Al saturation. Secondary forest species were associated with high P, low soil pH and low total exchangeable bases. Long-lived pioneers differed from short-lived pioneers in their association with high soil C:N ratio, low Al saturation, low P and tolerance of a wider light range. Overall, improved seedling recruitment was associated with decreasing fern cover, thinner layer of leaf litter and higher light. At the landscape level, species density was inversely related to distance to potential seed sources. Conclusions Our findings suggest that historical soil degradation and subsequent feedback processes among the adult trees, seedling communities and the regeneration environment strongly affect forest succession. Nutrient-efficient and Al-tolerant pioneers, such as the fern Dicranopteris linearis, were probably initial colonizers. Chance dispersal and recovery of the regeneration environment subsequently affected the establishment of long-lived or short-lived pioneers. Persistence of D. linearis and long-lived pioneers slowed forest recovery, while short-lived pioneers improved nutrient recovery and ameliorated the above-ground conditions to facilitate subsequent succession, provided that seeds of primary forest species were present.
Philosophical Transactions of the Royal Society B: Biological Sciences
Current policy is driving renewed impetus to restore forests to return ecological function, prote... more Current policy is driving renewed impetus to restore forests to return ecological function, protect species, sequester carbon and secure livelihoods. Here we assess the contribution of tree planting to ecosystem restoration in tropical and sub-tropical Asia; we synthesize evidence on mortality and growth of planted trees at 176 sites and assess structural and biodiversity recovery of co-located actively restored and naturally regenerating forest plots. Mean mortality of planted trees was 18% 1 year after planting, increasing to 44% after 5 years. Mortality varied strongly by site and was typically ca 20% higher in open areas than degraded forest, with height at planting positively affecting survival. Size-standardized growth rates were negatively related to species-level wood density in degraded forest and plantations enrichment settings. Based on community-level data from 11 landscapes, active restoration resulted in faster accumulation of tree basal area and structural properties ...
Of the dung beetles collected in Singapore, Catharsius molossus (Linnaeus) is the largest and onl... more Of the dung beetles collected in Singapore, Catharsius molossus (Linnaeus) is the largest and only large nocturnal tunnelling species, last recorded there in the late 1970s. To determine if the species is still extant in Singapore, we conducted dung beetle surveys at six study sites. Both cattle- and pig-dung baited pitfall traps were used to determine the species’ dung preferences. In total, 52 individuals were captured, with 49 individuals from cattle-dung baited traps. Most of them were captured within the contiguous northern patch of forests in the Central Catchment Nature Reserve. Catharsius molossus appears to be a specialist of herbivores’ dung. Established populations of both the Sambar deer (Rusa unicolor) and Eurasian wild pig (Sus scrofa) are likely sources of dung for this species.
∗ Department of Integrative Biology, University of California Berkeley, Berkeley, CA 94720, USA ... more ∗ Department of Integrative Biology, University of California Berkeley, Berkeley, CA 94720, USA National Center for Ecological Analysis and Synthesis, 735 State St., Suite 300, Santa Barbara, CA 93101, USA Smithsonian Tropical Research Institute, Apartado 0843-03092 ...
Questions What processes govern the long-term recovery of tropical secondary forests? Specificall... more Questions What processes govern the long-term recovery of tropical secondary forests? Specifically, how are seedling species density, stem density and functional groups in older regenerating forests affected by existing trees, the regeneration environment and distance to seed sources? Location Central Catchment Nature Reserve, Singapore. Methods We investigated three primary forest plots and nine 60-yr-old secondary forest plots varying in their degree of recovery. We analysed seedling parameters as a function of the abiotic and biotic regeneration environment as well as distance to primary and mature secondary forests. Results The secondary forest plots had functional composition distinct from, and Chao-estimated species richness and stem density lower than the primary forest plots. Seedling communities were most strongly associated with the mature tree communities within each plot; associations with other intra-plot variables and distance to potential seed sources were lower but still highly significant. Overall, aside from the mature tree community, the most significant predictors of seedling species composition were fern cover, VPD, soil Al, available P and C:N ratio. Primary forest species were associated with low light environments, low macronutrients and low Al saturation. Secondary forest species were associated with high P, low soil pH and low total exchangeable bases. Long-lived pioneers differed from short-lived pioneers in their association with high soil C:N ratio, low Al saturation, low P and tolerance of a wider light range. Overall, improved seedling recruitment was associated with decreasing fern cover, thinner layer of leaf litter and higher light. At the landscape level, species density was inversely related to distance to potential seed sources. Conclusions Our findings suggest that historical soil degradation and subsequent feedback processes among the adult trees, seedling communities and the regeneration environment strongly affect forest succession. Nutrient-efficient and Al-tolerant pioneers, such as the fern Dicranopteris linearis, were probably initial colonizers. Chance dispersal and recovery of the regeneration environment subsequently affected the establishment of long-lived or short-lived pioneers. Persistence of D. linearis and long-lived pioneers slowed forest recovery, while short-lived pioneers improved nutrient recovery and ameliorated the above-ground conditions to facilitate subsequent succession, provided that seeds of primary forest species were present.
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