Invertebrates constitute the majority of multi-cellular species on Earth, and have a critical role in the functioning of ecosystems. Despite their abundance, diversity and ecological importance, most studies of biodiversity focus on birds, large mammals and plants.
Invertebrates are included in this experiment because of:
- their abundance
- the diversity of functional groups
- their role in ecosystem processes
- their relatively small scale of operation – which was appropriate for some treatments
- their short generation time and rapid response to to woodland manipulations
- their importance as a food source for other fauna (e.g. Common Dunnart, Sminthopsis murina).
Invertebrate research in the experiment has so far concentrated on arthropod assemblages, with a special focus on beetles. Beetles are an abundant and functionally diverse component of the fauna of grassy woodlands, and are an ideal insect group to show responses to the experimental treatments.
Beetles and Logs
Research published in Biological Conservation has shown that logs in box-gum grassy woodlands support highly diverse assemblages of native beetles. The research found that logs contributed to the diversity of beetles in two different ways by increasing species richness and variability of species across the landscape. Find out more:
Beetles and Eucalyptus Trees
Recently published research in Journal of Biogeography has shown that beetle assemblages under the two tree species, Yellow box (Eucalyptus melliodora) and Blakely's red gum (E. blakelyi) had distinctive differences in diversity and composition. This can be exploited for conservation purposes to maximise biodiversity at landscape scales, but also to maintain heterogeneity in species richness, trophic function and biomass at fine spatial scales. Find out more:
Beetles and Kangaroo Grazing
The overabundance of vertebrate herbivores can be a significant barrier to ecological restoration due to their impact on grass biomass. The response of beetle assemblages were examined over a period of 18 months as part of the experimental treatment that manipulated kangaroo (Macropus giganteus) grazing levels using exclosure fences, and addition of coarse woody debris. Grazing had a significant negative effect and coarse woody debris volume had a positive effect on overall beetle abundance and species richness. For ecological restoration, exclosure fences and coarse woody debris can be used to manage the impacts of overabundant vertebrate herbivores. This will assist the recovery of the grass-layer, with benefits for insect diversity and their associated ecological functions.
Beetles morphology and Ecology
Morphological traits provide a functional link to many aspects of an organism’s ecology, but few studies have explored how morphological traits can complement phylogenetic information to extend our predictions of the ecology of diverse insect assemblages. In this study, we demonstrated that body length, 'robustness' and appendage length are significantly related to microhabitat use when comparing members of the same family. Find out more:
Ongoing research will focus on:
- arthropod responses to changes in kangaroo grazing levels
- the role of arthropods in carrion decomposition
- changes in leaf litter arthropods in response to the reintroduction of Bettongs
- Barton, P.S, Weaver H.J. and Manning A.D. (2013) Contrasting diversity dynamics of phoretic mites and beetles associated with vertebrate carrion. Experimental and Applied Acarology 1-13.
- Barton, P.S., Cunningham, S.A., Macdonald, B.C.T., McIntyre, S., Lindenmayer, D.B., and Manning, A.D. (2013). Species traits predict biodiversity dynamics at ephemeral resource patches created by carrion. PLOS ONE. 8(1) Article: e53961
- Barton, Cunningham, Lindenmayer, Manning. (2012). The role of carrion in maintaining biodiversity and ecosystem processes in terrestrial ecosystems. Oecologia. in review.
- Barton, Cunningham, Manning, Gibb, Lindenmayer, Didham. (2012). The spatial scaling of beta diversity. Global Ecology and Biogeography. In review.
- Barton, P.S., Manning, A.D., Gibb, H., Wood, J.T., Lindenmayer, D.B. & Cunningham, S.A. (2011) Experimental reduction of native vertebrate grazing and addition of logs benefits beetle diversity at multiple scales. Journal of Applied Ecology. doi:10.1111/j.1365-2664.2011.01994.x Abstract
- Barton, P.S., Gibb, H., Manning, A.D., Lindenmayer, D.B. & Cunningham, S.A.(2011) Morphological traits as predictors of diet and microhabitat use in a diverse beetle assemblage. Biological Journal of the Linnean Society. 102: 301-310. Abstract
- Barton, P. S., Manning, A. D., Gibb, H., Lindenmayer, D. B. and Cunningham, S. A. (2010).
Fine-scale heterogeneity in beetle assemblages under co-occurring Eucalyptus in the same subgenus.Journal of Biogeography 37 (10), pp. 1927-1937. Abstract
- Barton, P. S., Manning, A. D., Gibb, H., Lindenmayer, D. B. and Cunningham, S. A. (2009). Conserving ground-dwelling beetles in an endangered woodland community: multi-scale habitat effects on assemblage diversity. Biological Conservation 142: 1701-1709. Abstract