Sav­ing an ex­tremely rare na­tive plant

The Dominion Post - - Front Page -

The patch­work ef­fort to pre­serve New Zealand’s most threat­ened plants is il­lus­trated by an ex­tremely rare daisy that grows nat­u­rally only in Can­ter­bury and has been raised and stud­ied in Welling­ton.

The crit­i­cally en­dan­gered ‘‘dry plains shrub daisy’’ (Olearia ade­no­carpa) is fail­ing to re­gen­er­ate in the wild, says pri­mary re­searcher Dr De­bra Wot­ton.

There are fewer than 700 adult plants left and it is ranked among the 50 most threat­ened New Zealand plants.

The daisy is one of 150 an­i­mals and plants that will get ‘‘en­hanced’’ pro­tec­tion un­der the Draft Threat­ened Species Strat­egy that Min­is­ter of Con­ser­va­tion Mag­gie Barry re­leased last week.

Work­ing from Welling­ton’s Otari Na­tive Botanic Gar­den and Wil­ton’s Bush Re­serve – the only pub­lic botanic gar­den ded­i­cated solely to na­tive plants – Wot­ton ger­mi­nated the daisy and Otari staff raised the plants over the last 18 months.

Si­mul­ta­ne­ously, Wot­ton was con­duct­ing field tri­als to de­ter­mine how best to re­turn the plant to the wild in Can­ter­bury. The daisy only oc­curs nat­u­rally in the Waimakarir­i and Rakaia river flood plains in Can­ter­bury, where it oc­cu­pies stony, sandy ar­eas in for­mer river chan­nels, Wot­ton says. It likely colonised these sites af­ter floods de­posited fresh sed­i­ments.

But flood pro­tec­tion works have re­duced flood­ing and stopped cre­ation of the daisy’s pre­ferred habi­tat.

Mean­while, his­tor­i­cal burn­ing and graz­ing by stock have re­placed na­tive shrub lands with non­na­tive grass­lands. The daisy can­not com­pete with non-na­tive grasses. In short, al­most all of the ecosys­tem needed by the daisy is miss­ing. Ef­forts to pre­serve the daisy in the wild have in­cluded fenc­ing – es­pe­cially to stop brows­ing by hares and rab­bits – and spray­ing her­bi­cide on non­na­tive grasses.

But these pro­grammes are ex­pen­sive, in­ten­sive and cover rel­a­tively small ar­eas. Wot­ton’s work has two as­pects. First, she has ger­mi­nated the dry plains shrub daisy at Otari, a suc­cess­ful ef­fort that will see 70 sub-adult in­di­vid­u­als sent to Christchur­ch City Coun­cil.

The plan is for Depart­ment of Cor­rec­tions crews to plant them out later this year. (Otari will keep about a half dozen daisies for its own col­lec­tion and as in­sur­ance in case the species fails in Can­ter­bury.)

In­ci­den­tally, ger­mi­nat­ing na­tives is not nec­es­sar­ily straight­for­ward. Ef­forts at Otari to raise other rare na­tives have some­times failed, says Rewi El­liot, act­ing man­ager of Welling­ton Gar­dens. In one case, the plants were dead within weeks of plant­ing in the ground.

A se­cond as­pect of Wot­ton’s re­search is get­ting the daisy to thrive in wild con­di­tions in Can­ter­bury. Sim­ply plonk­ing the plants into suit­able ground isn’t worth­while be­cause they can’t com­pete. An an­swer is habi­tat restora­tion, a much more am­bi­tious project.

Work­ing with En­vi­ron­ment Can­ter­bury and the Univer­sity of Can­ter­bury, Wot­ton is con­duct­ing field tri­als test­ing whether shade and shel­ter, in­clud­ing from other na­tive shrubs but also con­structed wooden shel­ters with shade cloth, can help the daisy sur­vive in the wild.

Wot­ton and col­leagues are also test­ing ‘‘nat­u­ral dis­tur­bance regimes’’ by adding grav­els to grow­ing sites. These repli­cate in some mea­sure the daisy’s pre­ferred habi­tat. Wot­ton said ger­mi­nat­ing the daisy and the habi­tat re­search were ini­tially sep­a­rate projects. But hav­ing raised the plants, it would have been a waste to not send them to Can­ter­bury.

Otari was keen and she worked her con­nec­tions in the south­ern city to bring the var­i­ous agen­cies, and the Depart­ment of Cor­rec­tions, to­gether. ‘‘For a lot of species, we don’t know why they are de­clin­ing or how to re­verse that de­cline,’’ says Wot­ton. ‘‘My re­search helps us a get a han­dle on that and helps us re­verse the de­cline.’’

Wot­ton got her PhD in Ecol­ogy from Univer­sity of Can­ter­bury, worked as a sci­en­tist at Depart­ment of Con­ser­va­tion and Land­care Re­search. In 2013, she founded Moa’s Ark Re­search, a con­sul­tancy firm pro­vid­ing eco­log­i­cal ser­vices on na­tive bio­di­ver­sity. She is also a re­search as­so­ciate at the Univer­sity of Can­ter­bury and works from Otari.

Her daisy re­search is funded by sci­ence grants, plus as­sis­tance from Otari, ECan, city coun­cil, Can­ter­bury Univer­sity and doses of her vol­un­teer time.

The draft Threat­ened Species Strat­egy re­leased last week will – if it sur­vives pub­lic con­sul­ta­tion in­tact – ‘‘man­age 500 [New Zealand] species for pro­tec­tion by 2025 ... and 600 species for pro­tec­tion by 2030’’.

In ad­di­tion, it iden­ti­fies 150 species for en­hanced pro­tec­tion, ‘‘en­sur­ing that the long-term health of 150 threat­ened and at-risk species will be im­proved’’. The top 50 of these are ‘‘notable to New Zealan­ders and cur­rently re­ceiv­ing man­age­ment’’.

Think kiwi, kakapo, Maui’s dol­phins, tu­atara and the like. Just five plants make the top 50, in­clud­ing Bartlett’s rata. The next 100 con­tains 34 plants, in­clud­ing the dry plains shrub daisy.

It’s not clear from the draft doc­u­ment what ‘‘en­hanced pro­tec­tion’’ means for the daisy or Wot­ton’s re­search.

The daisy re­search pro­gramme il­lus­trates – de­pend­ing on point of view – how many or­gan­i­sa­tions and in­di­vid­u­als are al­ready work­ing to­gether to pre­serve rare plants and shows ex­actly where the draft strat­egy can help.

Al­ter­na­tively, it shows how patch­work cur­rent ef­forts are. Otari, for ex­am­ple, is funded en­tirely by Welling­ton City Coun­cil but as­sists with rare plants and trees from around the coun­try, in­clud­ing North­land, Whanganui, Otago and Can­ter­bury.

The daisy re­search is driven by a pri­vate con­sul­tant vol­un­teer­ing some of her time and work­ing con­nec­tions with, among oth­ers, the Depart­ment of Cor­rec­tions. They could use some help.


From Welling­ton, Dr De­bra Wot­ton is prop­a­gat­ing a crit­i­cally en­dan­gered New Zealand na­tive plant called dry plains shrub daisy.

The daisy, seen here in the wild, can’t com­pete against non-na­tive grasses.

There are only about 700 adult plants of the crit­i­cally en­dan­gered daisy left.

The olearia ade­no­carpa in flower.


Dry plains shrub daisy seedlings at Otari Wil­ton’s Bush in Welling­ton.

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