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GEOSTATS: Spatial analysis of coarse woody debris?

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  • Lisa Cuthbertson
    QUESTION: HOW TO DO SPATIAL ANALYSIS OF LINE INTERCEPT DATA Hi, I have nine 40 x 40m plots in which I have mapped all the trees, snags and stumps, and sampled
    Message 1 of 1 , Oct 11, 2000
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      QUESTION: HOW TO DO SPATIAL ANALYSIS OF LINE INTERCEPT DATA
       
      Hi,
       
      I have nine 40 x 40m plots in which I have mapped all the trees, snags and stumps, and sampled for the presence of the Armillaria root rot fungus infecting these woody substrates. So far, for these plots, I have used the univariate Ripley's K function to examine the overall tree pattern and I have used the bivariate Ripley's K function to see if there is a spatial association between infected and uninfected trees.
       
      In addition to sampling the trees, I sampled the soil for the presence of the fungus. I am going to use kriging to get an overall idea of 'hot' and 'cold' spots for the presence of this fungus in the soil in my plots. I want to overlay the tree and soil data to see if areas where the fungus is prevalent in the soil is it also more likely to be infecting the trees.
       
      Finally, I have used a line intercept method to sample coarse woody debris for the presence of Armillaria root rot colonising logs on my plots. My sampling design was five, 40 meter (west to east) transects spaced 10m (N-S) apart within each 40x40m plot. My problem is that the logs are a discontinuous substrate. I thought about using point pattern analysis but I can't guarantee that I haven't missed logs on the plot because I only sampled the logs I bumped into on the transect.
       
      My questions are:
       
      1) Can I do spatial analysis with my coarse woody debris dataset (sampled using line intercept)? If so, what are the best method and program to use to do this?
       
      2) Is kriging the best method to use for the soil samples (I also have environmental variables measured at each sample point)? If so, what program is best to use?
       
      3) How do I blend the three data sets together? Apart from making a map of the three substrate types and showing visually where the fungus is and where it isn't. Is it possible?
       
      Thanks in advance for any suggestions, references, or advice.
       
      Lisa
       
      Graduate student
      Department of Renewable Resources
      University of Alberta
      Edmonton, AB
      Canada
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