Threatened Vascular Plants of New Zealand - Where Are We At?
NZPCN maintains a policy of updating (on a provisional basis) threatened plant conservation assessments. Partly to fulfil our IUCN responsibilities but also because many new taxa, most of which are threatened are being recognised, and these are not catered for by the March 2004 publication. Hopefully a formal re-listing will happen soon.Currently the NZPCN fact sheets for Acutely Threatened list 127 taxa (57 Nationally Critical, 51 Nationally Endangered and 19 Nationally Vulnerable). In 2004 122 taxa were listed (47 as Nationally Critical, 54 as Nationally Endangered, 21 as Nationally Vulnerable). The overall numbers suggest a gain of 5 taxa, however, within the subcategories there have been 10 gains in Nationally Critical, three losses in Nationally Endangered and two in Nationally Vulnerable). What has happened?
Firstly, since 2004 there has been an impressive increase in taxonomic literature dealing with new indigenous species, since 2004, 11 taxa have been described, all of which provisionally qualify as Acutely Threatened, indeed seven as Nationally Critical. Examples include Myrsine umbricola, Prasophyllum hectorii and Pseudowintera insperata. Thus these increases are not due to poor conservation management but in fact reflect an impressive improvement on the countries vascular plant biosystematic knowledge.
NZPCN has also chosen to list Botrychium lunaria, Calochilus herbaceus and Hibiscus trionum – taxa for which there is still some doubt as to the correct application of these names to some or all New Zealand examples. However, as these taxa are so severely at risk of extinction to continue to await formal revision seems a risky conservation venture (especially for globally distributed species such as Botrychium lunaria and Hibiscus trionum), therefore NZPCN had elected to list these species under currently accepted and available names. The caveat is that for these three species the NZPCN fact sheet clearly notes the taxonomic issue.
Less pleasant has been the gain to “Acutely Threatened” of eight taxa some of which had been regarded as “Chronically Threatened” or even as “At Risk”. The serious plight of kakabeak (Clianthus maximus) has been described in a previous Trilepidea issue. The other seven taxa to move up in category are: Hebe barkeri, Juncus holoschoenus var. holoschoenus, Senecio kermadecensis, S. lautus var. esperensis, Aciphylla dieffenbachii, Epilobium hirtigerum, and Utricularia australis. On the positive, one of these, Epilobium hirtigerum has long been regarded as “Data Deficient”, its new provisional status reflects improved knowledge resulting at long last from numerous listings prompting field survey and interest.
On the flip side conservation management coupled with informed survey has bought good news for Cortaderia turbaria (was Nationally Critical now Nationally Endangered), Wahlenbergia pygmaea subsp. tararua (was Nationally Critical now Data Deficient), Aciphylla traversii (was Nationally Endangered now Chronically Threatened/Gradual Decline), Astelia chathamica (was Nationally Endangered now Chronically Threatened/Gradual Decline), Bulbinella modesta (was Nationally Endangered now At Risk/Sparse), Carex inopinata (was Nationally Endangered now Data Deficient), Embergeria grandifolia (Nationally Endangered now Chronically Threatened/Serious Decline), Boehmeria australis subsp. dealbata (Nationally Endangered now At Risk/Range Restricted), Dracophyllum longifolium var. septentrionale (Nationally Vulnerable now Data Deficient), and Leptinella featherstonii (Nationally Vulnerable now Chronically Threatened/Gradual Decline). It should be noted that the situation for Cortaderia turbaria, once New Zealand’s most threatened native grass, is still far from stable.
Posted: 07/04/2006