Molluscs and ecosystem functioning
We undertake research on the role of molluscs in ecosystem functioning, both in projects that specifically focus on molluscan communities and species, and as components of multidisciplinary (multitaxa) projects.
Current research projects include:
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Litter decomposition
Microcosm studies are being used to study the role of land snails in decomposition processes in New Zealand forests. The study focuses on partitioning the effects of plant litter and snail diversity, the relative effects of mucus and faeces in stimulating microbial activity, and the interactions of land snails with other detritivores such as millipedes and isopods.
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Tree fall and seral development of forest tree and land snail communities
Disturbances such as cyclones are important in the temporal and spatial dynamics of New Zealand forest ecosystems. One of the most damaging cyclones to hit New Zealand in recent times was Cyclone Bola, which struck the North Island in March 1988. Over the past 20 years Gary Barker has been following the seral development of forest vegetation and associated land snail communities in tree-fall gaps in forests severely affected by Cyclone Bola in the Bay of Plenty region.
Suggested reading
Barker GM 2002. Gastropods as pests in New Zealand pastoral agriculture, with emphasis on Agriolimacidae, Arionidae and Milacidae. In: Barker GM ed. Molluscs as crop pests. Wallingford, UK, CAB International. Pp. 361–423.
Barker GM 2005. The character of the New Zealand land snail fauna and communities: some evolutionary and ecological perspectives. Records of the Western Australian Museum, Supplement 68: 53–102.
Barker GM, Mayhill PC 1999. Patterns of diversity and habitat relationships in terrestrial mollusc communities of the Pukeamaru Ecological District, northeastern New Zealand. Journal of Biogeography 25: 215–238.
Wardle DA, Barker GM. 1997. Competition and herbivory in establishing grassland communities: implications for plant biomass, species diversity, and soil microbial activity. Oikos 80: 470–480.
Wardle DA, Barker GM, Bonner KI, Nicholson KS 1998. Can comparative approaches based on plant ecophysiological traits predict the nature of biotic interactions and individual plant species effects in ecosystems? Journal of Ecology 86: 405–420.
Wardle DA, Barker GM, Yeates GW, Bonner KI, Ghani A. 2001. Introduced browsing mammals in New Zealand natural forests: aboveground and belowground consequences. Ecological Monographs 71: 587–614.
Key personnel:
Gary Barker (Landcare Research, Hamilton)