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Ōsaka, Japan

Ueda A.,Japan Forestry and Forest Products Research Institute | Dwibadra D.,Indonesian Institute of Sciences | Noerdjito W.A.,Indonesian Institute of Sciences | Sugiarto,Kutai Timur Agricultural High School | And 4 more authors.
Journal of Insect Conservation

Clean Development Mechanism afforestation often involves the creation of fast growing tree plantations on non-forest lands. To estimate the possible impacts of afforestation on the biodiversity of local species, we compared the diversity of dung beetles collected using baited pitfall traps placed in grasslands, plantations of Acacia mangium, and intact natural forests in East Kalimantan, Indonesia. The species richness in plantations was higher than that on grasslands but lower than that in intact natural forests. Ordination analysis revealed that the structures of beetle assemblages in plantations were intermediate between intact natural forests and grasslands. However, the indicator species for the intact natural forests were never or rarely seen in the plantations. These results suggest that afforestation increases the local native diversity of dung beetles but that plantations are not readily colonized by the indicators of intact natural forests. Conversely, it is suggested that afforestation decreases the abundances of two grassland specialists. © 2015, Springer International Publishing Switzerland. Source

Hosaka T.,Hiroshima University | Hosaka T.,Tokyo Metroplitan University | Niino M.,Hiroshima University | Kon M.,Nishida cho | And 4 more authors.
Forest Ecology and Management

The loss of forest biodiversity via anthropogenic disturbance is severe in tropical countries and its consequences to ecological functions are of global concern. Selective logging is one of the main causes of tropical forest degradation, and its ecological impacts often result from the construction of road networks such as skid trails, logging roads and log yards. However, the effects of such narrow road clearings on forest-dependent species and associated ecological functions have rarely been studied. The present study therefore aimed to assess the impacts of such clearings on dung burial and secondary seed dispersal by dung beetles. The abundance of all functional guilds and the total biomass of dung beetles were drastically low at road clearings, but guild composition was only significantly different between the forest interior and log yards. Dung burial rates decreased with canopy openness, where 40% of dung remained unburied at logging roads and log yards. However, beads (seed mimics) in the dung piles were buried deeper and more frequently in log yards than the forest interior. In contrast, horizontal seed-removal distance was longer in the forest interior than at all road clearing sites. Reduced dung burial rates, and deeper but shorter, seed removal in clearings implies a negative effect of road clearings on the efficiency of secondary seed dispersal and other ecological functions of dung beetles. The imposition of limits on the number and size of logging road networks would be effective for retaining the ecological functions performed by the diverse forest-dependent species after logging. © 2014 Elsevier B.V. Source

Niino M.,Hiroshima University | Hosaka T.,Hiroshima University | Hosaka T.,Tokyo Metroplitan University | Kon M.,Nishida cho | And 3 more authors.
Raffles Bulletin of Zoology

Diel activity and habitat preferences are thought to be important for resource partitioning among species sharing food resources. Dung beetles in tropical forests provide a good example for testing this hypothesis, as they utilise a patchily distributed and ephemeral resource, i.e., mammalian dung, with strong inter- and intra-specific competition. However, information on diel activity patterns and habitat preferences of dung beetles remains limited in Southeast Asia. Our study demonstrates distinct diel activity and habitat preference of dung beetles in Peninsular Malaysia. Only a few small-sized diurnal species preferred open-land habitats, whereas the remainder favoured forest habitats. Large-sized species (>50 mg) were primarily nocturnal, while small-sized species (<50 mg) were diurnal. Therefore, although the numbers of individuals and species were higher during daytime, the biomass of dung beetles was 10 times higher at night than during the day in the forest, implying higher dung availability at night. Our review of diel activity in dung beetles in Southeast Asia suggests that activity patterns largely overlapped among species in the same genera or tribe; e.g., species in the Coprini tribe are almost all nocturnal, whereas those in Onthophagini, Oniticellini and Sisyphini are mostly diurnal. Therefore, diel flight activity might be largely determined by phylogenetic or physical constraints such as body size. Diel activity patterns may also facilitate the co-existence of dung beetles in different genera or tribes but may be less important for closely related species, except for some with diel activity patterns that differ from their congeners. © National University of Singapore. Source

Hosaka T.,Hiroshima University | Hosaka T.,Tokyo Metroplitan University | Niino M.,Hiroshima University | Kon M.,Nishida cho | And 4 more authors.

Conservation of biodiversity in production forests is crucial for mitigating biodiversity loss in the tropics. The major ecological impacts of selective logging are often the result of small clearings for skid trails, logging roads, log yards, and logging camps; however, their impacts on forest biodiversity have rarely been examined. The purpose of this study was to assess the impacts of these clearings on a forest-dependent faunal group, dung beetles, and to identify the environmental factors responsible. Abundance and species richness of dung beetles decreased drastically in clearings, but directly increased in forests with the distance from roads/trails; abundance and species richness at 10 m from roads/trails were almost comparable with those detected in further interior forests. Similarly, species composition was significantly different between forests and clearings (except skid trails) but recovered within a short distance from roads/trails. Canopy openness was the most important environmental factor affecting the abundance, and species richness and composition of dung beetles; most dung beetle species were concentrated under closed forest canopy with less than 10 percent of canopy openness, whereas canopy openness ranged from 16 to 53 percent in clearings. Our study demonstrates that even small-scale, unpaved clearings affect dung beetle communities through increased canopy openness. Although the effective distance was not very large, a considerable portion of logged areas can be affected when road networks are dense therefore minimizing the density of road networks and enhancing canopy recovery after logging are important for retaining biodiversity in tropical production forests. © 2014 The Association for Tropical Biology and Conservation. Source

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