Spatial and temporal shifts in functional and taxonomic diversity of dung beetles in a human-modified tropical forest landscape

Beiroz, Wallace; Sayer, Emma J.; Slade, Eleanor M.; Audino, Lívia Dorneles; Braga, Rodrigo Fagundes; Louzada, Júlio; Barlow, Jos

doi:10.1016/j.ecolind.2018.07.062

Cited by 53 publications

(29 citation statements)

References 69 publications

(83 reference statements)

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“…Although our results were obtained in the southern Atlantic forest, a similar mechanism is probably occurring in other Neotropical forests since most studies have shown a similar reduction in dung beetle diversity after forest conversion (e.g. Audino et al 78 , Beiroz et al 79 ). Also, previous studies showed the importance of other factors, such as soil type and vegetation structure 2,7,80 , influencing patterns of dung beetles diversity; however, these studies were not able to explain the ability (or inability) of species to exploit open human created habitats.…”

Section: Discussionsupporting

confidence: 63%

Thermal niche helps to explain the ability of dung beetles to exploit disturbed habitats

Gómez

Verdú

Zurita

2020

Sci Rep

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in terrestrial ecosystems, insects face a wide range of temperatures among habitats and time; consequently, the thermal niche is one of the main determinants of habitat selection and temporal patterns of activity. the replacement of native forests changes micro-climatic conditions and reduces the diversity of dung beetles; however, the physiological mechanisms behind these changes are not clear. We explore the role of the thermal niche in dung beetles to explain the ability of native species to exploit human-created habitats. Using infrared thermography, we measured variables associated with the thermal niche in 17 native species and used linear mixed-effects model and ANOVAs to compare disturbed habitats and the native forest. endothermy and body mass explained the ability of dung beetles to exploit human-created open habitats. Small and diurnal species with very low endothermy were able to exploit deforested open habitats; evening/nocturnal/crepuscular species showed similar body mass and high endothermy in all habitats. Regarding thermoregulation mechanisms, none of the species (except one) showed defined or efficient mechanisms of physiological thermoregulation. in view of the accelerated process of forest replacement and climate change, a more profound understanding of the physiological requirements of species is essential to predict and mitigate future extinctions. At local scales, anthropogenic habitat disturbance usually modifies microclimatic conditions (e.g. forest canopy loss), resulting in novel thermal challenges for organisms (e.g. open habitats) 1,2. In tropical and subtropical forests, recent studies have shown a marked reduction in the abundance and taxonomic and functional diversity of dung beetles in land uses with complete loss of canopy cover, such as pastures devoted to cattle raising 2-4. In contrast, land uses preserving canopy cover (such as tree plantations and silvopastoral systems) can partially preserve the structure of the dung beetle assemblages of the native forest 2,5-7. Differences in dung beetle diversity among land uses differing in canopy cover have been associated mainly with a marked increase in ground level temperature 2,8-10 and with the low tolerance of forest dung beetles to high temperatures (typical of open habitats during the day) 3,11-13. Although previous studies have suggested that the physiological intolerance of forest dung beetles to high temperatures is a potential constraint to exploit disturbed habitats 2,3,14 , this hypothesis has never been tested. This knowledge gap on dung beetle thermal biology led us to ask the following question: can the thermal niche of dung beetles explain the occupation of disturbed habitats, and taxonomic and functional changes reported in previous studies? We tested this central question in the southern Atlantic forest of South America, one of the most diverse and threatened ecosystems worldwide 15-17. The physiological responses of insects, especially those associated with temperature (endothermy, thermoregulation, thermal tolera...

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Section: Discussionsupporting

confidence: 63%

Thermal niche helps to explain the ability of dung beetles to exploit disturbed habitats

Gómez

Verdú

Zurita

2020

Sci Rep

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“…It has been proposed that dung beetle assemblages in tropical forests are structured by their niche space (environmental filtering), while the influence of limited dispersal and random colonization are discarded 29 . This suggests that the arrival and establishment of species depends on environmental factors 29,53 , and could result in ecological redundancy in dung beetle assemblages 28, 54,55 . Also, in tropical forest the degradation and loss of natural habitats decreases the functional diversity of dung beetles 26,27,56 , which has consequences on their ecosystem functions 57 .…”

Section: Discussionmentioning

confidence: 99%

Assembly mechanisms of dung beetles in temperate forests and grazing pastures

Ortega-Martínez

Moreno

Rios-Díaz

et al. 2020

Sci Rep

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the role of deterministic and stochastic mechanisms in community assembly is a key question in ecology, but little is known about their relative contribution in dung beetle assemblages. Moreover, in human modified landscapes these mechanisms are crucial to understand how biodiversity can be maintained in productive agroecosystems. We explored the assembly mechanisms driving dung beetle assemblages in forests and grazed grassland patches, and assessed the role of dung availability, soil hardness and moisture, elevation and land use heterogeneity as environmental predictors of functional diversity. to determine the underlying assembly mechanisms, we estimated functional diversity metrics (functional richness, evenness and divergence) and their departure from the predicted values by null models. We also used GLMs to assess the influence of environmental variables on functional diversity. in most cases, stochastic processes prevailed in structuring dung beetle assemblages and, consequently, environmental variables were not good predictors of dung beetle functional diversity. However, limiting similarity was found as a secondary mechanism with an effect on dung beetle assemblages in grasslands. Our results highlight the importance of stochastic processes that may reflect a metacommunity dynamic. therefore, restoring landscape connectivity might be more important than habitat quality for the conservation of these functionally diverse beetle assemblages. Community assembly theory provides a conceptual foundation about the mechanisms that determine species composition of local assemblages 1,2 , and this background becomes especially relevant for studies concerning the ecological consequences of environmental contemporary changes. For example, results from a recent study have made it possible to improve our understanding of biological invasions, a global issue that is critical in ecology and conservation 3. However, an important remaining issue is to unravel how current anthropogenic changes to the environment, such as land use change and agricultural production can modify the assembly mechanisms that shape the structure and composition of local communities 4. Human activities have contributed substantially to the loss of species and degradation of ecosystems 5,6 , generating impacts on ecological communities 7. Therefore, identifying the drivers of community assembly in human modified landscapes is an urgent challenge. Both deterministic and stochastic mechanisms are important in assembling biological communities. The main deterministic mechanisms driving community assembly are limiting similarity and environmental filtering 8-10. If the local community is formed by non-redundant species, its trait diversity will be high (trait overdispersion) as a result of strong ecological interactions, and community assembly is considered to be driven by a limiting similarity mechanism due to competition 8. On the contrary, the environmental filtering mechanism (the abiotic filter) structures local communities through environmental r...

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“…Both these findings suggest that previous forest disturbance could have acted as an environmental filter or selective force (Balmford, ; Nunes et al, ): Microclimatic changes relating to previous logging or fires (e.g., Hardwick et al, ; Lindenmayer, Hunter, Burton, & Gibbons, ) may have extirpated the most disturbance‐sensitive species—as previously observed for dung beetle communities in primary forests converted to oil palm plantations in Southeast Asia (Edwards et al, )—and favored the species that are more tolerant to drought and fires. This conjecture is supported by evidence showing that dung beetle species are highly susceptible to environmental modification (Beiroz et al, ), including changes in forest structure (Salomão et al, ) and microclimatic conditions (Birkett, Blackburn, & Menéndez, ). Perhaps more importantly, our results support that local human‐driven disturbance and climate‐associated stressors can act together and influence tropical forest biodiversity and functioning.…”

Section: Discussionmentioning

confidence: 84%

El Niño impacts on human‐modified tropical forests: Consequences for dung beetle diversity and associated ecological processes

et al. 2020

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Our knowledge of how tropical forest biodiversity and functioning respond to anthropogenic and climate‐associated stressors is limited. Research exploring El Niño impacts are scarce or based on single post‐disturbance assessments, and few studies assess forests previously affected by anthropogenic disturbance. Focusing on dung beetles and associated ecological functions, we assessed (a) the ecological effects of a strong El Niño, (b) if post‐El Niño beetle responses were influenced by previous forest disturbance, and (c) how these responses compare between forests impacted only by drought and those affected by both drought and fires. We sampled 30 Amazonian forest plots distributed across a gradient of human disturbance in 2010, 2016, and 2017—approximately 5 years before, and 3–6 and 15–18 months after the 2015–16 El Niño. We found 14,451 beetles from 98 species and quantified the beetle‐mediated dispersal of >8,600 seed mimics and the removal of c. 30 kg of dung. All dung beetle responses (species richness, abundance, biomass, compositional similarity to pre‐El Niño condition, and rates of dung removal and seed dispersal) declined after the 2015–16 El Niño, but the greatest immediate losses (i.e., in 2016) were observed within fire‐affected forests. Previous forest disturbance also influenced post‐El Niño dung beetle species richness, abundance, and species composition. We demonstrate that dung beetles and their ecological functions are negatively affected by climate‐associated disturbances in human‐modified Amazonian forests and suggest that the interaction between local anthropogenic and climate‐related stressors merits further investigation. Abstract in Portuguese is available with online material.

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Spatial and temporal shifts in functional and taxonomic diversity of dung beetles in a human-modified tropical forest landscape

Cited by 53 publications

References 69 publications

Thermal niche helps to explain the ability of dung beetles to exploit disturbed habitats

Thermal niche helps to explain the ability of dung beetles to exploit disturbed habitats

Assembly mechanisms of dung beetles in temperate forests and grazing pastures

El Niño impacts on human‐modified tropical forests: Consequences for dung beetle diversity and associated ecological processes

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