Dung and carrion beetle diversity in small forest patches versus large continuous forest in the southern Cape, South Africa

This paper analyzes the diversity of dung and carrion beetles (Scarabaeinae and Silphidae) in four human-induced habitats of a disturbed tropical montane cloud forest: polyspecific shade coffee plantations, monospecific shade coffee plantations, tropical montane cloud forest fragments, and clear cuts. The four habitats had similar richness, species composition, and assemblage structure of dung and carrion beetles. Differences were found in abundance and biomass levels for the four dominant species in the landscape. Dung beetles were more abundant than carrion beetles, but the biomass was higher for the latter. Carrion beetles were seasonal, while dung beetles were clearly not. When forest fragments and shade coffee plantations were compared to other similar habitats in the region, the same general pattern was observed. However, forests with high disturbance and monospecific shade coffee plantations had lower species richness than forests with low and medium disturbance and polyspecific shade coffee plantations. Thus shade coffee plantations maintain connectivity between patches of cloud forest in a landscape that is strongly affected by human activities. Protecting landscape diversity appears to ensure high species richness.

Abstract:Fragmented populations are usually exposed to the negative effects of reduced gene flow, genetic drift and population differentiation. These effects result in the collective loss of genetic variation, thereby reducing the probability of population adaptation to new environmental conditions and increasing the risk of extinction. Forest fragments commonly exhibit suboptimal site conditions, which can result in enhanced clonal reproduction, and a potential reduction in clonal diversity due to increased selfing and inbreeding depression. The clonal diversity, genetic diversity and structure ofHeliconia angusta(Heliconiaceae) were assessed using AFLP-markers. We analysed six patches in the continuous forest (Atlantic rain forest, State of Rio de Janeiro) and eight patches (155 leaf samples in total) in five nearby forest fragments (age of oldest fragment:c. 50 y; size range: < 5–100 ha). Clonal diversity (Pd) of patches was slightly, yet significantly, lower in forest fragments compared with continuous forest. Measures of genetic diversity of patches in forest fragments did not differ from those in the continuous forest. A STRUCTURE analysis did not show any clear clustering of patches in the continuous forest and forest fragments. Our results suggest thatH. angustahas not yet suffered from the anticipated negative effects of fragmentation.

<p>The conservation of tree communities in forest ecosystems across the world is challenged by various anthropogenic pressures such as deforestation and fragmentation. In many areas in West Africa, fragmentation has reduced the original continuous forest ecosystems to small and isolated forest patches, mostly managed by local communities. While the importance of such small patches in biodiversity conservation is recognized in literature, evidence from tropical forest ecosystems and plant-based studies are still limited. In our study, we (i) assessed the contribution of small, unprotected forest patches to tree species conservation; (ii) determined the variation of seed dispersal syndromes in tree stands between a continuous forest and small forest patches; and (iii) identified the drivers of tree species colonization among forest patches. We sampled 69 plots in the Lama forest reserve (continuous forest) and the surrounding small isolated forest patches within 20-km radius. Trees and natural regenerations were recorded in two vegetation types including the degraded dense forest and old fallow. For each species, the IUCN conservation status and functional traits including dispersal syndrome, seed weight and maximum height were recorded. We used Generalized Linear Models to identify the determinants of immigrant regeneration densities in isolated forest patches. In total, 103 woody species were recorded and the species richness was higher in the forest patches than in the continuous forest for all vegetation types. In the dense vegetation, a similar trend was found and the number of threatened species was higher in the forest patches. Tree assemblages differed between the continuous forest and the forest patches. Tree density was higher in the continuous forest than in small forest patches. Defaunation somewhat affected the regeneration of disturbed forest patches as germination and seedling were dominated by abiotic-dispersed species and local species. Taller or heavier seed species were more likely to colonize forest patches and the density of tree species in a forest patch increased with abundance of immigrant regeneration in the nearest neighbor. We recommend the implementation of sustainable management in form of participative restoration of low-regenerated species in forest remnants  for enhanced biodiversity conservation.</p><p><strong>Keywords</strong>: Species richness, dispersal syndrome, functional traits, fragmentation, forest patches, continuous forest</p>

Vertical distributions of scarabaeids dung beetles (Coleoptera: Scarabaeidae) were studied in a tropical mountaineous rainforest of Gede-Pangrango National Park using human dung traps. Samples were collected at four different altitudes of 500-1000m, 1001-1500, 1501-2000 and 2001-2500m of five different collection sites (Cibodas, Selabintana, Situ Gunung, Bodogol, and Gunung Putri). As many as 1052 individuals of 28 species of scarabaeid dung beetles that belonging to five genera were collected.Onthophagus was the most diverse group, which consists of 21 species (75% of collected species) and followed by Copris with 3 species (10.7%), Paragymnopleurus with 2 species (7.1%), Catharsius with 1 species (3.6%), and Phacosoma with 1 species (3.6%). The Shanon-Winner index of diversity and evenness gradually declined with the increase of altitudes. The different of environment conditions on each altitude might affect to the diversity, abundance, and distribution of dung beetles. The diversity of dung beetles at the interval of 1001-1500m and 1501-2000m were not so high but abundance and similarity were high. Diversity index, evenness, abundance, and species similarity of dung beetles at the interval of 2001-2500m was low because of unfavorable habitat. Although the diversity of dung beetles at the interval 500-1000m was the highest, however abundance and similarity index were relatively low. Analyze of diversity, abundance, evenness, and similarity indexes of dung beetles on each of the different altitudes and environment conditions were discussed in this paper.

Assessing the species diversity, richness, and abundance of dung beetles in wildlife and wildlife-livestock systems is crucial in understanding the effects of anthropogenic processes on the community structures of dung beetles to improve conservation strategies in Namibia. We tested the hypothesis that the species diversity, richness, and abundance of dung beetles in wildlife systems will be better than in wildlife-livestock systems. Sampling of dung beetles was carried out using baited pitfall traps for a period of 12 months. Linear transects of 1.1 km in length were installed with 12 pitfall traps separated by a distance of 100 m from each other. An independent samples test was used to compare the abundance, richness, and diversity of dung beetles in two ecosystems. A total of 47,818 individuals were collected from both wildlife and wildlife-livestock systems belonging to 44 species, 25 genera, and 8 tribes. Dung beetle abundance, richness, and diversity were significantly higher in the wildlife system than in the wildlife-livestock system (T = 4.676, df = 59.04, p < 0.05; T = 1.825, df = 35, p < 0.05; T = 4.676, df = 59.04, p < 0.05). The wildlife system was more species-rich (n = 43) when compared to the wildlife-livestock system (n = 34). A higher Shannon-Wiener Index was reported in wildlife systems (H’ = 2.561) than in wildlife-livestock systems (H’ = 2.289). The results from the non-metric multidimensional scaling ordination demonstrated a dissimilarity (stress = 0.155) in species composition and abundance of dung beetles between the two systems. Different land-use systems have proven to have an impact on species assemblage of dung beetles. We concluded that wildlife systems in Namibia have a richer ecological and functional dung beetle community as compared to a wildlife-livestock system, most likely influenced by anthropogenic activities.

Conversion of forest habitat to different land uses will change the environmental quality of the altered land. Since the relationship between anthropogenic disturbance and animal diversity and ecosystem services emerged, much scientific research has been conducted on this aspect. The present study focuses on comparing dung beetles, a known biological indicator, on examining five diverse environs (large forests, forest patches, Pinus plantations (Pinus caribaea), home gardens, and tea plantations) Coprophagous beetles of the subfamily Scarabaeinae (Coleoptera: Scarabaeidae). This study examined whether dung beetles' diversity, species richness, functional groups, and ecosystem services (dung removal) vary with the habitat types. We also assumed that the intensity of anthropogenic activities varies in these habitats. The experiment was conducted for 48 hours each in five habitat types with three selected replicates per each habitat type. The Shannon-Weiner Diversity Index shows that the highest dung beetle diversity is recorded in large forest areas (2.1719). The highest species abundance (186) and richness (22) were recorded in the large forest. The lowest species abundance was recorded in tea plantations (109). The lowest species richness was recorded in pinus plantations (10). Moreover, functional group diversity is high in habitats with fewer human activities. The dominant species in large forests is Onthophagus favrei (dominancy index-2.9%). In forest patches and pinus plantations, Onthophagus amphinasus (19%) and Paracopris signatus (36.30%) appeared consecutively. In home gardens and tea plantations, the most dominant species is Onthophagus unifasiatus (26.50% and 28.40%). Habitats with anthropogenic activities have less species richness and a high dominancy index. Furthermore, dung beetle resource relocation efficiency was skewed toward forest areas. The highest dung removal percentage was recorded in forest areas (large forest-9.58% and forest patches-7.33%). The dung removal in the anthropogenic activities related to land uses was decreased as a home garden (7.17%), Pinus plantation (6.58%), and tea plantation (5.42%). Moreover, large dung beetles (body mass≥0.5 g) were only recorded in large forests and forest patches. Low diversity in tea plantations could be attributed to pesticide and fertilizer usage, as beetles are highly sensitive to these chemicals. Pinus plantations showed low rates of dung removal because resource availability in those habitats is less due to the fewer mammals. These findings indicate that replacing forests and forest areas with simplified human residential areas and agricultural systems can result in shifts towards less specialized dung beetle communities with altered proportions to other animal groups. 
 Keywords: Scarabaeinae, Dung removal, Species richness, Species abundance, Dominance index

The relative effects of two components of mountain environmental heterogeneity, altitude (1500, 1700 and 2000 m a.s.l.) and habitat (pastures, coniferous forests, wet meadows, scrub and anthropogenic woods) on the diversity of dung beetles in an Italian alpine valley were determined. The additive gamma diversity analysis indicated that differences among habitats (sH) were always smaller than those among altitudes (sA), irrespective of the measures used; it also showed that the contribution of sA to γ-diversity was higher than expected by chance for all the measures of species diversity used, whereas the contribution of sH was significantly higher in the case of one measure only. Generalized linear models confirmed that altitude was the most important factor associated with local diversity, with all the diversity parameters considered progressively and significantly increasing with increasing altitude. Indicator species analyses revealed that dung beetle altitudinal and habitat diversity patterns depended on local choice of species, with preferences for altitudinal levels being more numerous and apparent than those for habitats. Despite the minor effect of habitat differences, comparing a three-habitat with a single-habitat scenario it was possible to demonstrate that greater habitat heterogeneity is associated with a significantly greater diversity of dung beetles. This study suggests that preservation of local environmental heterogeneity by means of traditional pastoral activities should be encouraged as a means of conserving the diversity of dung beetle species in the Alps.

Tropical landscape structures have been transformed into mosaic structures consisting of small patches of primary and secondary forests, and areas of other land use. Diversity of insect assemblages is often higher in primary forests than in surrounding secondary forests. However, little is known about how the primary forests affect diversity in surrounding secondary forests in a landscape. In Sarawak, Malaysia, the typical landscape in areas from which lowland tropical rainforests had originally spread consists mainly of primary and secondary forests, with small areas of cultivation. In this study, we examined how the proportion of remnant primary forests in a landscape affects species diversity and species composition of ants and dung beetles in Macaranga-dominated secondary forests. The proportions were quantified based on remote-sensing data at various spatial scales, ranging from 100- to 5,000-m radius from each of the target forests. We found that the proportions of remnant primary forests within a 100-m radius had a significant positive effect on ant species diversity, and those within 100-, 300-, and 500-m radii significantly affected species compositions. However, the proportions of remnant primary forests had no significant relationship with dung beetle diversity, while those within 100- and 1,000-m radii had significant effects on species composition. The different responses to the remnant primary forests are likely to be related to differences in the movement and dispersal traits between the two taxa.

Dung beetles are important to ecosystems as they aid in nutrient recycling and waste removal. In North Florida, there is a high diversity of dung beetles due to the intentional and accidental introduction of non-native species. Understanding patterns and processes on local scales is important for conservational planning. The aim of this study was to evaluate how dung beetle communities respond to different dung sources, forage composition, and habitat types. We surveyed for the presence and distribution of dung beetles in an open field and forest as well as in three types of pasture forage designs. In the first experiment, four transects with pitfall traps from forest to open field were established with either horse, pig, or cow feces bait. In the second experiment, three cattle grazing systems with different forage species were tested with only cow feces. In the first experiment, 16 species were identified between the field and forest sites including native and exotic species. Although the dung type had little effect on beetle distribution, a significantly different distribution of dung beetles between the field and forest was observed. Only one species, Onthophagus hecate Panzer (Coleoptera: Scarabaeidae) showed no preference between open field and forest habitat. During this second experiment, no difference in dung beetle distribution was found between the three types of pasture assemblages. This study supports habitat type as a driver of interspecies distribution and diversity of dung beetles in North Florida.

Cattle grazing on oil palm plantation (agropastoral) has the potential to increase biodiversity by providing new habitats and providing foods for invertebrates. Dung beetles use the cattle’s dung for food and to lay eggs. The aim of this research is to study the effect of cattle grazing on oil palm plantation toward the diversity, abundance and ecosystem services of dung beetles. The research was conducted in the oil palm plantation of PT. Astra Agro Lestari Tbk. Central Kalimantan Province. Samplings were done on 6 oil palm blocks (4 plots on each block) consisting of 3 blocks that have been grazed by cattle (agropastoral) and 3 blocks that were not grazed (non-agropastoral). Samplings were done using baited pitfall traps and dung removal test. The treatments were replicated 4 times (0, 4, 8 and 12 wk). In total 24 species belonging to 5 genera and 11 019 individuals dung beetle have been collected. The most diverse group were genera from Onthophagus (16 species; 66.7% of collected species) and follow by Aphodius (4 species; 16.6%), Catharsius (2 species; 8.3%), Panelus (1 species; 4.2%) and Oniticellus (1 species; 4.2%). The result showed that the diversity of dung beetle was the same in agropastoral and non-agropastoral, but the abundance was 4 times higher in agropastoral habitat. Dung removal in non-agropastoral was 16% higher than agropastoral. Overall the result showed that cattle grazing has increased dung beetle population, although it has no effect on the diversity and ecosystem service of dung beetle.

Traditional agro-pastoral practices are in decline over much of the Alps, resulting in the complete elimination of livestock grazing in some areas. Natural reforestation following pastoral abandonment may represent a significant threat to alpine biodiversity, especially that associated with open habitats. This study presents the first assessment of the potential effects of natural reforestation on dung beetles by exploring the relationships between the beetle community (abundance, diversity, species turnover and assemblage structure) and the vegetation stages of ecological succession following pastoral abandonment. A hierarchical sampling design was used in the montane belt of the Sessera Valley (north-western Italian Alps). Dung beetles were sampled across 16 sampling sites set in four habitat types corresponding to four different successional stages (pasture, shrub, pioneer forest and beech forest) at two altitudinal levels. The two habitats at the extremes of the ecological succession, i.e. pasture and beech forest, had the greatest effect on the structure of local dung beetle assemblages. Overall, dung beetle abundance was greater in beech forest, whereas species richness, Shannon diversity and taxonomic diversity were significantly higher in pasture, hence suggesting this latter habitat can be considered as a key conservation habitat. Forests and pastures shared a lower number of species than the other pairs of habitats (i.e. species turnover between these two habitats was the highest). The two intermediate seral stages, i.e. shrub and pioneer forest, showed low dung beetle abundance and diversity values. Local dung beetle assemblages were also dependent on season and altitude; early-arriving species were typical of pastures of high elevation, whereas late-arriving species were typical of beech forests. It is likely that grazing in the Alps will continue to decrease in the future leading to replacement of open habitats by forest. This study suggests therefore that, at least in the montane belt, reforestation may have potentially profound and negative effects on dung beetle diversity. Maintaining traditional pastoral activities appears to be the most promising approach to preserve open habitats and adjacent beech forests, resulting in the conservation of species of both habitats.

Landscape effects on taxonomic and functional diversity of dung beetle assemblages in a highly fragmented tropical forest

Context. Remnant forest patches in rural landscapes may be important sites for maintaining viable populations of restricted forest species, especially when these remnant habitats maintain some connectivity, for instance through riparian vegetation strips and other forest patches. Aims. We assessed the use of remnant forest habitats in a rural landscape of southern Chile (40°S) by the ‘near threatened’ arboreal marsupial Dromiciops gliroides (Microbiotheria), in relation to habitat type (riparian strips, forest fragments and continuous forests), width of the riparian forests, and the presence and abundance of the hemiparasite Tristerix corymbosus, whose fruits are readily eaten by D. gliroides. Methods. In two summers, 2004 and 2008, we set up grids of 96 live traps for three consecutive nights at each of 16 sites along two riparian forest strips, four additional sites in remnant, non-riparian forest patches, and four more within continuous pre-Andean forest. We counted hemiparasites on trees in the trapping grid area, and estimated their individual volumes. Key results . In total, 48 individuals of D. gliroides were captured at all sites during the 2 years. We documented a significant positive relationship between the width of riparian vegetation and the number of individuals captured (r s = 0.78, P = 0.02, n = 8) for one riparian strip, but not for the second one. Neither habitat type nor the frequency of hemiparasites related statistically to D. gliroides abundance. Key conclusions. We conclude that in the rural landscape of the Chilean Lake District, narrow riparian forest strips, in a highly inter-connected mosaic of remnant forest patches may be as important as large patches and continuous Andean forests to sustain viable populations of this threatened, strictly arboreal, marsupial. Implications. The present study reports, for the first time, the presence in narrow riparian forests immersed in a pasture-dominated agricultural matrix of this forest-specialist marsupial, which was previously known only from continuous pre-Andean forests.

Niche shift in three foraging insectivorous birds in lowland Malaysian forest patches

ABSTRACTAims We have compared local (alpha) and regional (beta) species diversities of dung beetles in wet forests in the main tropical regions including Madagascar. Madagascar is exceptional in lacking native large herbivorous mammals which produce the key resource for dung beetles elsewhere.Location Central and South America, mainland Africa, Madagascar and Southeast Asia.Methods Trapping data on dung beetles and data on mammalian faunas were obtained from published and unpublished studies. We used our original data for Madagascar.Results Species richness of dung beetles and that of large‐bodied (> 15 mm length) species in particular were highly significantly explained by the regional number of large‐bodied (> 10 kg) mammals (R2 from 50 to 80%). For a given pairwise spatial distance between two communities, beta diversity was significantly higher in Madagascar than elsewhere, explaining the very high total species richness in Madagascar in spite of low local diversity.Main conclusion The presence and numbers of large herbivorous mammals greatly influence the species richness of dung beetles in tropical wet forests. The lack of native large herbivores rather than a limited species pool explains the low local diversity in Madagascar. Exceptionally high beta diversity in Madagascar suggests a pattern of old radiation involving extensive allopatric speciation.