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Understanding the effects of global change on biodiversity

band3The continued growth of human populations and of per capita consumption have resulted in unsustainable exploitation of Earth’s biological diversity, exacerbated by climate change, ocean acidification, and other anthropogenic environmental impacts. We have argued that effective conservation of biodiversity is essential for human survival and the maintenance of ecosystem processes1. Despite some conservation successes (especially at local scales) and increasing public and government interest in living sustainably, biodiversity continues to decline. Moving beyond 2010, successful conservation approaches need to be reinforced and adequately financed. In addition, however, more radical changes are required that recognize biodiversity as a global public good, that integrate biodiversity conservation into policies and decision frameworks for resource production and consumption, and that focus on wider institutional and societal changes to enable more effective implementation of policy1.

We have used landsat satellite imagery to reveal the devastating impacts of government subsidies on deforestation in lowland Chile, where native forests were rapidly replaced by plantations in the 1990s2. Proximity to roads and slope determined which forests were lost3. The remnant fragments were severely altered as a result of isolation4. In collaboration with Rob Ewers we have developed approaches to quantify the landscale-level effect of fragmentation5,6, scaling up from measure of biodiversity change made on the ground.

We have also explored the consequences of invasion of a hawkweed into New Zealand Nothofagus forests. The hawkweed has invaded ~80% of the study region within ~50 years of arrival, with invasion occurring mostly in sites with high plant diversity (i.e. so much for diverse communities repelling invaders!). We show that invasion is facilitated by diverse communities because the right kind of mycorrhizas for hawkweed are present in the soil 7. The herb is a particularly successful invader because it establishes well in treefall gaps then persists even after the forest closes over again8.

  1. Rands, M.R.W., Adams, W.M., Bennun, L., Butchart, S.H.M., Clements, A., Coomes, D.A., Entwistle, A., Hodge, I., Kapos, V., Scharlemann, J.P.W., Sutherland, W.J., Vira, B. (2010) Biodiversity Conservation: Challenges Beyond 2010. Science 329: 1298- 1303. DOI link
  2. Echeverría, C., Coomes, D.A., Salas, J., Rey-Benayas, J.M., Lara, A., & Newton, A. (2006) Rapid deforestation and fragmentation of Chilean Temperate Forests. Biological Conservation, 130, 481-494. DOI link
  3. Echeverría, E., Coomes, D.A., Hall M. and Newton, A.C. (2008) Spatially explicit models to analyze forest loss and fragmentation between 1976 and 2020 in southern Chile. Ecological Modelling DOI link pdf (password needed)
  4. Echeverría, C., Cayuela, L., Manson, R., Coomes, D.A., Lara, A. , Rey-Benayas, J.M. & Newton A.C. (2007) Spatial and temporal patterns of forest loss and fragmentation in Mexico and Chile. In: Biodiversity Loss and Conservation in Fragmented Forest Landscapes: The Forests of Montane Mexico and Temperate South America (ed A.C. Newton), pp 14-41. CABI, Wallingford, Oxford.
  5. Echeverría, C., Newton, A.C., Lara, A., Benayas, J.M.R., & Coomes, D.A. (2007) Impacts of forest fragmentation on species composition and forest structure in the temperate landscape of southern Chile. Global Ecology and Biogeography, 16, 426-439. DOI link
  6. Lafortezza, R., Coomes, D.A., Kapos, V., & Ewers, R.M. (2010) Assessing the impacts of fragmentation on plant communities in New Zealand: scaling from survey plots to landscapes. Global Ecology and Biogeography in press. DOI link
  7. Ewers, R.M., Kapos, V., & Coomes, D.A., Lafortezza, R., & Didham, R.K. (2009) Mapping community change in modified landscapes. Biological Conservation, 142, 2872-2880. DOI link
  8. Spence, L. A., Dickie, I. A., & Coomes, D.A. (2011). Arbuscular mycorrhizal inoculum potential: a mechanism promoting positive diversity-invasibility relationships in mountain beech forests in New Zealand?. Mycorrhiza, 21(4), 309-314. DOI link
  9. Spence, L.A., Ross, J.V., Wiser, S.K., Allen, R.B. & Coomes, D.A. (2010) Disturbance affects short-term facilitation, but not long-term saturation, of exotic plant invasion in New Zealand forest. Proceeding Royal Society - Biology DOI link