Review
Tony Beauchamp
Threats section - Shared Services – DOC
16 December 2016
Kauri Dieback disease
Investigation into its distribution within the Waitakere Ranges Regional Park 2016
Overall
The report covers more than an investigation of distribution of PA. If that was the aim, then the
report needs to be modified to reflect that aim or the title changed to reflect the reports contents
which coverer likely ongoing adaptive management.
The report is informative but could be improved with some additional and more specific assessment
of the special distribution of Pa symptomatic trees in the Waitakeres. The methods and the
assessment of the data are difficult to follow and need to be made clearer. I currently cannot follow
how the data were assessed and how robust the results are as I cannot understand coverage. The
recommendations do not appear to offer clarity about how an adaptive management approach
could be implemented.
Methods
It is unclear as to what the survey in any one part of the Waitakere ranges was. It appears to have
comprised random assessment of 304 symptomatic trees (not mapped) and some track classification
system for kauri areas on tracks. However, it is unclear how further work outside of these 304
selected sites this is translated into the mapping and how areas of kauri were assessed as selected
for survey.
There is no indication of how bait lines were assessed.
There is no definition of what a waterway is.
Section 6.2 The 30 m and 15 m buffer section is not able to be understood. Was this is applied
irrespective of vegetation or were the issues in 6.3 taken into account at that time?
Section 6.4 I cannot follow what has been done here. This makes it very difficult to assess what the
results mean (are they an assessment or a sample approach within ArcView). More detail or better
figures are needed to explain what was done within ArcView.
Results
It is not possible to assess how the method of the two survey types are translated into the results, or
the actual coverage of kauri within the surveys.
Section 7.1 and 7.2 The presentation of the results could be improved with better figures and maps.
The 101 zones could be mapped and histograms produced to show the size distribution of
symptomatic and non-systematic areas.
The pink and red in Figures 1 and 2 do not stand out well. This is also a problem in Appendix 5. The
colour of one of them could be changed. The Legends on the maps in Appendix 5 and 7 are too
small.
If the assessment of waterways and bait lines is robust then I suggest you look at using statistically
robust methods like Analysis of Variance to assess the data around the proximity to human vectors
and waterway transfer routes. The current report does not adequately deal with the relationships
between these factors. There is no assessment of the distribution and risks to the remaining non-
symptomatic areas of kauri forest or their distance from vectors and how that could be changed by
management of vector risk. In other words there is no results that can be translated into an adaptive
management approach.
There appears to be no use of the track classification system in the methods. It would potentially be
more informative to have each track broken down into the classification, length of kauri, number of
contamination zones infected and not infected and the proportion of each. It may be useful to have
an assessment of track condition, and pig sign presence tabulated as well. It appears from the map
that entire track systems are contaminated and needing recommendations for upgrade or closure? It
is not evident where track maintenance will have the greatest benefit and that may be needed to
make sure that the recommendations can be translated into actions.
I would expect that some assessment of the data you hold on pigs could be done. It appears that the
question is some form of correlation between pig sign and dieback zone. Maybe the question could
be changed to where pig sign is. Is sign significantly more frequently encountered within dieback
zones as opposed to non-dieback zones. Is sign in the protection zones? What types of pig sign are in
dieback zones? The way it is written in this report I question if there should be any comments about
pigs in the results section.
Conclusion and Evaluation
No comments at this time given my comments about my ability to understand the results section.
Recommendations.
The recommendations are broad but it appears from what is presented in Appendix 5, and
potentially from what you hold on track networks, they can be made a lot more specific and hard
hitting. The current recommendations do not appear to represent the serious nature of the
comments in the first paragraph of the conclusions. There is no hierarchy within the list of
recommendations. I am unsure what the adaptive management approach is and how these
recommendations relate to what the authors are considering. I would expect that this could be
specified more clearly and with some preliminary work (examples) bringing in the existing list of
holistic recommendations. That depends on how you want to relate the track information you have
collected to the kauri dieback symptomatic areas.
As an example of what I am getting at:
A Waitakere Ranges Regional Park access management plan needs to be prepared to plan how to
respond in the short and long-term to the presence of PA or all kauri will be lost. The data from this
report could be used to define implement immediate access and adaptive monitoring objectives like
those listed below, and ultimately provide public access with significantly reduced risk of the transfer
of PA within and from the Waitakeres.
•
XXXXX tracks that are contaminated need to be closed until upgrades and new sanitary
stations reduce the potential for users to spread PA transfer.
•
XXXXX should remain open but need to be upgraded to a year-round dry surface.
•
XXXXX tracks require sanitary station upgrades
•
Areas that are defendable due to their proximity to human and animal vectoring need to be
identified, assessed and then protected. (i.e. identified by mapping, assessed by soil sampling
and protected by track closures and pig hunting or fencing etc).
