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In a time of global change, having an understanding of the nature of biotic and abiotic factors that drive a species' range may be the sharpest tool in the toolbox of conservation and management of threatened species. However, such information are lacking for most tropical and epiphytic species due to the complexity of life history, the roles of stochastic events, and the diversity of habitat across the span of a distribution. In this study, we conducted repeated census across the core and peripheral range of Trichocentrum undulatum, a threatened orchid that is found throughout the island of Cuba (species core range) and southern Florida (the northern peripheral range). We used demographic matrix modeling and stochastic simulations to investigate the impacts of herbivory, hurricanes, and logging (in Cuba) on projected population growth rates (λ and λs) among sites. Our study indicates that the Florida population is under high extinction risk and most populations in the core range show less interannual variability, but, with the exception of one population, are also in decline. The peripheral population experienced higher herbivory damage than did the core populations, by a native inflorescence‐crippling fly, Melanagromyza miamensis, and an invasive, mortality‐triggered scale, Diaspis boisduvalii. The latter was found in the Florida population only. Hurricanes increased levels of mortality and had a negative effect on λ. However, λ increased following hurricane events due to increased recruitment and decreased herbivory. Life table response experiments suggest that higher adult survival was the largest contributor to the higher λ observed in the growing Cuba populations, as compared with the population in Florida. Logging simulations in Cuba indicate that populations can maintain stability only if selective logging of host trees occurs at low frequency. Reintroduction of the species in its northern peripheral habitat is needed to ameliorate the threats from sea‐level rise and invasive herbivorous insects to secure the current species' northern, continental range margin. Our study exhibits how vital rates and ecological interactions vary across a species distribution and respond under differing stochastic events. [ABSTRACT FROM AUTHOR] more...

Trees in the Garden Route National Park ( GRNP) indigenous forests in South Africa are selectively harvested for timber based on criteria that include signs and symptoms induced by wood-rotting fungi. However, virtually nothing is known regarding the identity and host associations of these macro-fungi in this natural ecosystem. Surveys were conducted in three harvesting compartments in the GRNP to investigate the taxonomic affiliation and species richness of these fungi on standing and recently harvested trees. Samples were collected from basidiomes on infected trees and tree stumps, and from diseased tissues on symptomatic trees. Phylogenetic analyses using ITS sequences characterized the isolates obtained into 26 Operational Taxonomic Units ( OTUs) belonging to 17 genera after clustering the sequences at a 97% identity threshold. Ganoderma (Ganodermataceae) and Inonotus (Hymenochaetaceae) were the most species-rich genera and the Bloukrans compartment, with 22 OTUs, showed the highest species richness. A fungus ( OTU1) affiliated with Ganoderma pfeifferi was the most abundant in the surveyed areas. Its predominance was also evidenced on host trees since it occurred on 15 of the 20 tree species sampled, with Olea capensis subsp. macrocarpa (Oleaceae) being the most colonized host. Given the wide variety of wood-rotting basidiomycetes revealed by this study and particularly the preponderance of species with pathogenic potential, more attention should be given to better understand their ecological role in this natural ecosystem as well as the effects of logging that may enhance their dissemination or negatively affect their diversity and the health of trees in the region. [ABSTRACT FROM AUTHOR] more...

The article presents a study on the impact of logging to aboveground live biomass in rainforests lowland areas at the Makapa concession in Papua New Guinea. It applied modified Bitterlich plotless technique to quantify aboveground live biomass of logged and unlogged regions. Results show that the regions have a mean aboveground carbon loss of 35 ± 2.8 Megagram per hectare. It adds that the plotless technique was efficient in estimating the logging damage and mean aboveground biomass. more...

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