Dung Beetle Communities and Seed Dispersal in Primary Forest and Disturbed Land in Amazonia1

Abstract

Seeds from tropical fiuiting trees ingested and defecated on the soil surface by primary dispersers (such as primates) are vulnerable to destruction from rodents, insects, and Fungi. Burial by dung beetles as an incidental result of their feeding and nesting activities often provides these seeds with rehgia from attack. To examine the effect of habitat disturbance on the dung beetle communities involved in this process, I surveyed dung beetles at three sites in the Amazon basin, in the states of Par& Amazonas, and Ronddnia, Brazil. Through principal component analysis on measurements of size and behavioral characters of beetles, I determined the relative quality of beetle species as seed dispersers (dispersal defined as horizontal or vertical movement of seeds) and ranked them into seed dispersal guilds. I used correspondence analysis to examine in what habitats (priiary forest or varying degrees of disturbed habitat) these guilds were abundant. Most guilds decreased with increasing habitat disturbance, but one g d d made up of large nocturnal burrowers (primarily Dichotomius) became more abundant with increasing disturbance (up to the level of highest disturbance surveyed), at which point all dung beetle species became scarce. Clear-cuts had lower species richness, lower abundance, and lower biomass than forested areas. These results imply that dear-cutting is detrimental to all seed dispersal dynamics in tropical rain forests, but that some levels of disturbance allow enough disperser activity to preserve this ecosystem function. RESUMOAs sementes de &ores tropicais ingeridas por dispersores primirios (como primatas, por exemplo) e depois defecadas na superficie do solo 60 vulnedveis h desuuiGo por roedores, insetos e fimgos. Como resultado de seu Mbito alimentar e de assentamento, 0 s besoms copr6fagos enterram as sementes, provendo refigio a estes ataques. A fim de examinar o efeito da permrbaGo do habitat nas comunidades dos besouros copr6fagos envolvidas no prOcesso, besoms copr6fagos foram estudados em trh locais da bacia Amdnica: nos estados do Pad, Amazonas e Ronddnia, n6 Brasil. Pela a d i s e do componente principal nas mediG6es de tamanho e caracteristicas de comportamento, foi determinada a qualidade relativa das espkies de besouros como dispersores de sementes (dispereo send6 aqui definida como 6 movimento vertical ou horizontal das sementes). As espkies foram agrupadas de acordo com sua preferencia de entern das sementes e criouse um ranking para estes grupos. Andise de correspondhcia foi utiliida para exarninar em quais habitats (floresta primiria ou locais corn niveis d v e i s de permrbaGo no ambiente) estes grupos de besouros eram abundantes. A maioria dos grupos diminuiu com o aumento da perterubaGo no ambiente, porkm um grupo (compost0 de grandes besouros de galerias noturnos, principalmente Dichotomius) tornou-se mais abundante com o aumento da permrb@o, atk o dvel mais alto de permrbaGo avaliado, quando todas as espkies de besouros ficaram escassas. As dareiras exibiram menor riqueza de esp...

Changes of dung beetle communities from rainforests towards agroforestry systems and annual cultures in Sulawesi (Indonesia)

“…Nevertheless, the density of five (out of six) most abundant species decreased with land-use intensity, whereas only one species showed a higher abundance in young secondary forest and agroforest compared to the natural forest. Similarly, in Amazonia most but not all dung beetles were negatively affected by habitat disturbance (Vulinec 2002). Furthermore, Roslin and Koivunen (2001) found that different species show very dissimilar responses to changes in landscape structure.…”

“…Diversity of some groups, such as solitary bees and wasps, may even increase with land-use intensity (Klein et al 2002) and Bornean hawkmoths (Lepidoptera, Sphingidae) do not reflect the influence of habitat disturbance (e.g., Schulze and Fiedler in press). The diversity of carrion beetles may not be seriously affected by forest clearance and the establishment of plantations (Hanski 1989), although reduced abundance and diversity in clear cuts may occur (Vulinec 2002). Klein (1989) and Andresen (2002a) quantified the reduced diversity of decomposer organisms as a result of forest fragmentation (see also Didham et al 1996).…”

Assessing the diversity of dung beetle assemblages utilizing Japanese monkey feces in cool-temperate forests

“…Apart from being recognized as important decomposer organisms (involved with nutrient recycling) (Hanski and Krikken 1991), their ecological role as a secondary seed disperser has recently received increasing attention (Estrada and Coates-Estrada 1991;Vullnec 2002). It has been reported worldwide that the species diversity of dung beetles has been rapidly decreasing with fragmentation and isolation of their habitats arising directly or indirectly because of increasing human activity (Klein 1989;Davis et al 2001;Halffter and Arellano 2002;Feer and Hingrat 2004).…”

Dung beetle (Coleoptera: Scarabaeidae: Scarabaeinae) diversity in continuous forest, forest fragments and cattle pastures in a landscape of Chiapas, Mexico: the effects of anthropogenic changes

“…The Scarabaeinae have also been widely used as indicator groups (see Nichols et al 2007, including a meta-analysis and a synthesis of 33 publications; Howden and Nealis 1975;Klein 1989;Halffter et al 1992;Estrada et al 1998;Davis et al 2000;Vulinec 2000Vulinec , 2002Andresen 2003;Scheffler 2005;Quintero and Roslin 2005;Shahabuddin et al 2005;Chapman et al 2003;Avendaño-Mendoza et al 2005;Vulinec et al 2006, along with some other references included in our 'Introduction and discussion').…”