Conserving the plants of eastern South Island limestone, Nga tipu o te pakeho

Just released Conserving the plants of eastern South Island limestone, Nga tipu o te pakeho, by Peter Heenan and Geoffrey Rogers is a free to download publication on the conservation of specialised limestone flora of the eastern South Island (Marlborough, Canterbury and Otago), also available as a stunning wee A5 field book. The first 50 pages outline the geology, evolution/history of these calcicole (limestone loving) plants, the challenges they face and the threats which are bringing many to the brink of extinction.  This is followed by 74 fact sheets (2 pages each) for each of the specialist limestone plants known from the eastern South Island.  27 of these plants are yet to be described and formally named, for now they have intriguing tagnames like Craspedia “Awahokomo” (a woollyhead) and Myosotis “Waipara” (a forget-me-not).  A nice touch is the inclusion of a couple of paintings by Nelson artist and former South Marlborough Threatened Plant Botanist, Cathy Jones, one being Limestone violet and Limestone angelica instantly recognisable for the few in the know of this special place.

Here are a few sample pages of personal favourites, click on the photo to see it at a readable scale.

 

Click this link to download Nga tipu o to pakeho and then ‘Download full-text pdf’.  For a hard copy contact peter.botanist@outlook.com , there’s a cost for P&P of $5.50 within NZ

Nga tipu o te pakeho, was preceded in 2018 by a relatively technical document written for the Department of Conservation, also by Geoff and Peter along with Shannel Courtney, providing an overview of the situation for limestone plants at a national level.  ‘Science for Conservation 331. The calcicolous vascular flora of New Zealand Life forms, taxonomy, biogeography and conservation status‘.  Which is available for download from the Dept’s publications page here, and for the fact conscious, I’ve included the abstract.

Abstract

This report describes the life forms, taxonomic status, geological biogeography and conservation status of 152 calcicolous taxa in New Zealand, 91 (60%) of which have been formally named. Of the remaining 61 unnamed taxa, 26 are raised in this study with supporting voucher specimens. This is the first endeavour to describe the calcicolous vascular flora of New Zealand which, at 5.6% of the estimated total New Zealand vascular flora, is substantially greater than previously thought. Most calcicoles (91%) are confined to the South Island, with only 13 taxa occurring in the North Island, and 95% of the calcicoles are endemic to regionally-confined geological units, with a richness bias towards units located in West Nelson, Marlborough and Canterbury. In addition, 73% have total habitat areas of < ̄10 ha, likely as a result of adaptation to persistent, isolated, differentiated terrains that provided non-forest habitat throughout the numerous climatic cycles of the Pleistocene. In total, 71 (47%) of the calcicolous taxa are ranked as Data Deficient or Threatened (cf. 14% of the entire flora), 43 (29%) of which are ranked as Nationally Critical. However, 33 (46%) currently receive no form of conservation management. Together, our measures of taxonomic resolution and extinction risk argue for this being a particularly under recognised and threatened flora and ecosystem.

Click to access Conserving-the-plants-of-eastern-South-Island-limestone-Nga-tipu-o-te-pakeho.pdf

On a personal level, I’ve had the good fortune to work with some of these plants and in these outstanding landscapes, which I would hope everyone can appreciate for their sheer awesomeness.

Nga tipu o to pakeho author Geoff Rogers walks through the Sawcut Gorge in Marlborough

Here’s a few pics and observations from working with ‘the plants belonging to limestone’ in the last 20 years.

Surveying the Chalk Range

On a southern part of the Chalk Range with the Chalk Range speargrass p56

for the Chalk Range cress (Pachycladon fasciarum, p160)

Pachycladon fasciarum, Chalk Range cress

Dave Barker and I, carried a roll of weldmesh onto the crest of the range to install some experimental cages.

OLYMPUS DIGITAL CAMERA

Because the numerous goats

OLYMPUS DIGITAL CAMERA

are probably the biggest, immediate, threat facing this plant at the current time.

goat browsed Chalk Range cress

More recently I was privileged to join Nelson botanists and one of the authors, (Geoff) onto Ben More  and into Isolation Creek.

 

Ben More is a prominent (1200m) hill cloaked in native tussock

OLYMPUS DIGITAL CAMERA

that crests onto an escarpment

Artist and botanist Cathy Jones inspects the Ben More escarpment

home to the forget-me-not (Myosotis arnoldii, p150),

OLYMPUS DIGITAL CAMERA

amongst other cool plants

OLYMPUS DIGITAL CAMERA

Down in Isolation Creek

OLYMPUS DIGITAL CAMERA

The stunning canyon is decorated by the equally stunning Mathew’s harebell (Wahlenbergia mathewsii, p206)  along with a host of other calcicolous plants.

Botanist Shannel Courtney inspects Wahlenbergia mathewsii in Isolation Creek

OLYMPUS DIGITAL CAMERA

Tengawai escarpment, crevices, the habitat of two endemic and other rare plants have been taken over by exotic plants following nutrient enrichment.

Altitude, scale and isolation do a lot to protect the flora of places like Isolation Creek but the bulk of the special species are found in small, fragmented landscapes such as the Tengawai escarpment.

Here the future for the plants is gloomy at best.  Farming pressures have seen the covering shrubby vegetation sprayed off and the escarpment fertilised and oversown.  Whether deliberate or accidental doesn’t really matter, the deed is done, and the calcicoles over much of the escarpment are dead and gone displaced by a thin scurf of  ryegrass, clover and weeds, it will take radical changes in management to turn the tide on habitat loss here. On at least one section goats are farmed, they in turn camp on the escarpment resulting in additional nutrients that filter down the crevices boosting the weeds that dislocate the unique calcicoles like the endemic Tengawai buttercup (Ranunculus callianthus, p178)

Limestone angelica (Gingidia enysii, p142)

Limestone geranium (Geranium socolatum, p140)

and the endemic Manahune gentian (Gentianella calcis ssp. manahune, p134) not pictured in this post.

The Tengawai story is repeated to some degree at most of the sites where limestone outcrops across both islands. Economic pressures, ignorance of the values present in farmed sites and the general encroachment of exotic plants, with grazing by exotic animals, combine to create a unique flora under pressure of extinction.

This entry was posted in Canterbury, Ecology, Environment, South Marlborough, Uncategorized and tagged , , , , , , , , , , , , . Bookmark the permalink.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s