Date: 12th September 2022
To NSW Scientific Committee
Proposed delisting of Boronia hapalophylla as endangered
Dear Scientific Committee
Thank you for advising us of the above preliminary delisting.
In your letter that accompanied the document, you thank me for “providing advice” on the subject. However, it appears that little or no attention has been given to that advice.
An important component of my advice was, specifically: “I did express some doubts as to whether or not nearby sub-populations of Boronia at Sherwood and Flaggy Creek Nature Reserve etc, were indeed B. hapalophylla. It has been our observation (Pat and I), that those other populations contain plants that are not strongly aromatic, do not flower year-round, have a persistent calyx, i/e/ adhering to the branchlets for a period after flowering, and are a shorter species, <1m tall.”
The only part of my advice that is noted was that the seemingly smaller plants in those other sub-populations could be, “the result of too frequent fire that does kill all the plant above ground, so we never get to see a mature specimen. I have recorded Shannon Creek specimens of well over 2 metres, but who knows how large they will become if fire is excluded from the landscape”.
That latter comment was purely speculation on my part, but has seemingly been taken as scientifically based, as your Preliminary Determination then quotes me as follows: “A number of subpopulations are subject to high fire frequencies shorter than the recommended fire free thresholds (NSW NPWS 2019; NSW BioNet 2022) and demographic shifts toward smaller plants (J. Edwards in litt. April 2022)
In that respect, I have no idea what the fire-free thresholds for those sandstone communities are, and wonder if anyone does. I note that a study of fire impacts on sandstone communities was a recommendation of the Northern Rivers Regional Biodiversity Strategy (2010) (4.2.7. Undertake research into the fire ecology of threatened plants in the Glenreagh–Coaldale sandstone area), but whether that has been done, I don’t know. Therefore, I’d like my comments to be accurately reflected in your final determination.
Something I can say is that all those reserves are subjected to extreme levels of far-too-frequent fire, 2 to 5 years on average, to the point where they are fast losing tree cover.
In conclusion it seems that, given the modern genetic testing that is available, perhaps some effort could have been made to determine if those other populations are in fact B. hapalophylla, or possibly even an undescribed species, before proceeding with the delisting.
Thanks for the opportunity to comment.