Funded MSc topic: Native invertebrate biodiversity in Hawke’s Bay orchards

14 April 2013

Plant & Food Research is offering a $10,000 MSc scholarship to answer the following research question:

What is the role of apple orchards in providing habitat for native (non-pest) arthropods in the Hawke’s Bay region and how might they complement efforts to build native biodiversity in riverside restoration projects?

Recent invertebrate biodiversity surveys of commercial apple orchards in the Heretaunga Plains region of Hawke’s Bay have revealed both exotic and endemic species representing most major orders. Little is known of the native, non-pest arthropod species in these managed habitats; it has often been assumed that since the predominant plant species (apple) is exotic, then the invertebrate fauna will also be predominantly exotic. Even at the landscape level, NZ native plant diversity is very low in this region, with no remnants of lowland native forest or scrub and only recent plantings of natives as part of a riverside re-vegetation project.

Read more about the re-vegetation project

 

The project will involve some Hawke’s Bay-based field work (collections, observations), analysis of and comparison with existing datasets, and laboratory-based experimentation with field-collected specimens at Plant & Food Research’s Mt Albert Research Centre in Auckland. Some day-to-day support during the field phase of the project will also be available from Plant & Food Research’s Hawke’s Bay research centre.

The design of the project is not fixed but possible approaches might include:

  • Study site selection – survey of vegetation types alongside the Karamu stream and selection of sites for field collection of arthropods; discussions with Hawke’s Bay Regional Council staff would be helpful for this
  • Field collection of arthropods using pitfall and sticky traps and branch-beating over one summer season in Hawke’s Bay in areas next to the Karamu stream that have been replanted with native vegetation and also areas which have not yet been restored, as well as commercial apple orchards at varying distances from the streamside sites.
  • Assessment of plant diversity at collection sites (including understorey and shelterbelt plants in orchards)
  • Analysis of GIS data to determine the landscape context for each collection site (e.g. adjacent land uses, aspect, altitude)
  • Identification and counting of specimens collected. Choose focal species on basis of abundance, ease of field collection, ease of identification, ability to maintain in the lab and ecological function (perhaps predators, pollinators and/or detritivores, i.e. potential providers of ecosystem services but not likely to be apple pests). Perhaps include both native and exotic species from a single family for comparison (e.g. carabids such as Mecodema occiputale or M. sulcatum and Laemostenus complanatus, or ants such as Monomorium antarcticum and Nylanderia spp.).
  • Analysis of field collection data to answer the following: Which native invertebrate species occur adjacent to the Karamu stream in Hawke’s Bay? Are the invertebrates found in areas replanted with natives different from those found in parts of the riverside which have not yet been replanted? Which native species can be found in both apple orchards and the riverside? How do landscape features affect the distributions of species?
  • Feeding ecology of focal species: determine feeding preferences in controlled laboratory-based experiments using field-collected prey or detritus; if predators, check for intraguild predation; assess competitive success of native v. exotic species in feeding arena experiments.
  • Assess the relative mobility of different focal species: what is their predominant mode of dispersal? How far can they travel? How far do they move in ‘real-world’ situations? How likely are they to move from apple orchards to streamside sites?
  • Are there other resources (egg-laying sites, overwintering sites, etc.) that these species need and how might these be provided in the apple orchard and streamside sites?

Interested students should apply directly to Assoc. Prof. Louise Malone (louise.malone@plantandfood.co.nz). Please include a copy of your academic transcript, an indication of when you are available to start and a covering letter explaining why you are interested in this topic.