University of Tasmania
Browse
Pracejus_whole_thesis.pdf (4.9 MB)

Improving study designs for assessing forestry impacts on the giant freshwater crayfish, Astacopsis gouldi

Download (4.9 MB)
thesis
posted on 2023-05-27, 11:03 authored by Pracejus, AM
This survey aimed at correlating the abundance of Astacopsis gouldi, the world's largest freshwater crayfish, with two different plantation types in Northern Tasmania. After a pilot study revealed inherent difficulties in relying on conventional methods to select suitable sampling sites, selection criteria were refined and ultimately improved through the use of species distribution modelling (MaxEnt). Accumulated mean annual run-off and mean annual rainfall stood out as important in the model and helped to reduce the proportion of intermittent streams in the data set. Analyses conclude that there is no observable plantation effect that correlates with crayfish abundance; however, this should be taken with caution because the sample size was too small to detect a potential effect on crayfish abundance. As a result, approximately 15-18 sites are recommended to be used per tested group. A classification tree further suggests that the presence of undercut banks, log jams and submerged logs might constitute important mesa-habitat features that should require further analysis in the future. The study is thus more recommendative in nature and should assist future researchers to develop effective sampling strategies to address the difficulties inherent in assessing crayfish abundance in plantation streams.

History

Publication status

  • Unpublished

Rights statement

Copyright 2016 the author

Repository Status

  • Open

Usage metrics

    Thesis collection

    Categories

    No categories selected

    Exports

    RefWorks
    BibTeX
    Ref. manager
    Endnote
    DataCite
    NLM
    DC