Biodiversity in Canterbury (with an emphasis on flora) state, pressures, issues, and needs Susan Walker Landcare Research, Dunedin ECan Land Workshop 22 April 2008 Council Chambers, Environment Canterbury

Large variation from upland to lowland indigenous habitats retained, and protected, are “non representative” State

Canterbury habitats - habitat loss to 2001/02 Elevation zones Remaining indigenous cover <400 m 400 – 800 m m m >1600 m

Elevation zones <400 m 400 – 800 m m m >1600 m Protected lands Private covenant or public conservation land Canterbury habitats - protection against loss

Large variation from upland to lowland indigenous habitats retained, and protected, are “non representative” Remaining lowland ecosystems much reduced, highly modified and poorly protected State

) The relationship between area and proportion of species remaining is not linear 2) The relationship is a curve 3) As area decreases, at some point the proportion of species decreases rapidly Habitat loss : some science Area effects Proportion of species remaining Proportion habitat area remaining

An intact environment Proportion of species remaining Proportion habitat area remaining

An intact environment 3.9% 10% HABITAT LOSS PREDICTED SPECIES LOSS Proportion of species remaining Proportion habitat area remaining

A modified environment Proportion of species remaining Proportion habitat area remaining

A modified environment % HABITAT LOSS PREDICTED SPECIES LOSS 12% Proportion of species remaining Proportion habitat area remaining

Canterbury habitats - habitat loss to 2001/02 Elevation zones Remaining indigenous cover <400 m 400 – 800 m m m >1600 m

m Below 400 m (7.5%) m (37%) >1200 m Canterbury habitats - habitat loss to 2001/02 Proportion of species remaining Proportion habitat area remaining

Elevation zones <400 m 400 – 800 m m m >1600 m Protected lands Private covenant or public conservation land Canterbury habitats - protection against loss

Percent (%) of zone protected (Private Covenants or DOC) m (11.5%) Below 400 m (1%) m Canterbury habitats - protection against loss >1600 m m Proportion of species remaining

m Below 400 m (7.5%) m (37%) >1200 m Canterbury habitats - habitat loss to 2001/02 Proportion of species remaining Proportion habitat area remaining

Percent (%) of zone protected (Private Covenants or DOC) m (11.5%) Below 400 m (1%) m Canterbury habitats - protection against loss >1600 m Proportion of species remaining m

Below about 30% area remaining, patch isolation increases exponentially (simulation, supported by review of field study results) (1) (12) (75) (255) (739) (1089) (1297) (1242) (802) (443) (193) Proportion of original habitat in the landscape (%) Simulated distance to nearest neighbour (Andrén 1994) Average distance Maximum distance Std dev. (n)(n) No. habitat patches Habitat remaining Habitat loss Isolation effects Fragmentation

Canterbury Proportion of NZ Threatened plants (2005) (Acutely and Chronically Threatened) Proportion of NZ land area Canterbury (47%) 103 species Nationally threatened plants in Canterbury

Distribution of threatened plants in Canterbury (2005) By elevation zone No. Acutely and Chronically Threatened plants “Lowland”“Montane”“Subalpine & Alpine” By ecosystem type No. Acutely and Chronically Threatened plants

Also locally or regionally threatened: ‘common’ palatable or fire sensitive trees and shrubs Hebe cupressoides Tekapo military camp

In other places, more rugged secondary woody species and communities are expanding

Large variation from upland to lowland indigenous habitats retained, and protected, are “non representative” Remaining lowland ecosystems much reduced, highly modified and poorly protected High numbers of threatened plant species, particularly in the lowland and montane zones (which are poorly protected) in highly modified, non-forest ecosystems Woody vegetation in flux: some winners, some losers State – to sum up

Threatened Environment Classification For each LENZ Level IV environment, the classification shows how much indigenous cover remains & how much is protected

% Indigenous cover left + LENZ % Protected + = Threatened Environment Classification Canterbury

Habitat loss and poor protection: indicators of threatened plant distribution in Canterbury % protected (Private covenants or DOC) % indigenous cover left Percenatge area Distribution of Canterbury threatened plants (2005) No. Acutely and Chronically Threatened plants “Lowland”“Montane”“Subalpine & Alpine”

Threatened Species in South Island QEII covenants Number of threatened plant species geographically widespread covenants (Nelson, Marlborough, Canterbury, Otago & Southland) Threatened environments: Correlated with threatened plants in covenants Thanks to Wildlands, esp. Kelvin Lloyd

Environment Threat Categories (Proportion Land Area) Canterbury New Zealand Canterbury’s Threatened Environments 23% <10% indigenous cover left (24%) 1.3 million ha (31%)

Categories 1, 2 & 3 Environments with much reduced indigenous vegetation Loss of habitats for native species has been greatest Communities are often highly modified and depleted Often provide critical habitat for threatened species NOTE: Categories 1 & 2 are National Priority 1 in the government’s National priorities for protecting rare & threatened native biodiversity on private land 1<10% indigenous cover leftAcutely Threatened 210–20% leftChronically Threatened 320–30% leftAt Risk

Birdlings Flat, Canterbury <10% indigenous cover left (Acutely Threatened)

Rakaia Island kanuka forest & <10% indigenous cover left (Acutely Threatened)

River engineering work to protect kanuka forest and dry shrubland at Rakaia Island

Relict kowhai/Plagianthus woodland, South Canterbury <10% indigenous cover left (Acutely Threatened)

Mcleans Island <10% indigenous cover left (Acutely Threatened)

Weka Pass area North Canterbury <10% indigenous cover left (Acutely Threatened)

Limestone Valley South Canterbury <10% indigenous cover left (Acutely Threatened) Gentianella calcis subsp. taiko

Olearia hectori Aciphylla subflabellata Pseudopanax ferox South Canterbury <10% indigenous cover left (Acutely Threatened)

Kowhai Bush, Kaikoura 10-20% indigenous cover left (Chronically Threatened)

Banks Peninsula Crater Rim 20-30% indigenous cover left (At Risk)

Ashburton Basin 20-30% indigenous cover left (At Risk)

Categories 4 & 5 Environments with poorly protected indigenous biodiversity Loss of habitats for native sp has been less extreme (>30% indigenous cover left), BUT Poorly protected (<20% of land area) Often highly modified and depleted Poorly protected indigenous vegetation may be vulnerable to development, and may receive little conservation management (pest, weed control) Species are more likely to be in decline or at risk of extinction than in better protected environments 4>30% left and 10% protectedCritically Underprotected 5>30% left and 10–20% protectedUnderprotected

Mackenzie Basin >30% left and <10% protected Critically Underprotected

Mackenzie Basin >30% left and <10% protected Critically Underprotected

Category 6 Environments with less reduced and better protected indigenous biodiversity In past these environments have been less suitable for development, therefore more secure to clearance Particularly important for species that require extensive habitats to survive Many threatened animals (birds, bats, fish, frogs) now survive only here BUT Still vulnerable to pest, weeds, other extractive land-use (mining, logging, hydro development) 6>30% left and >20% protectedLess Reduced and Better Protected

Shrubland Lake Coleridge >30% left and >20% protected (Less Reduced Better Protected)

Forest and scree, Arthurs Pass >30% left and >20% protected (Less Reduced Better Protected)

Herbivory Pressures on native flora

Not only stock…

Ubiquitous feral grazers and browsers

Herbivory Weeds Pressures on native flora

Light-demanding, grazing tolerant weeds

Persistent tall woody weeds

But some seral woody “weeds” are 1) natives and/or 2) may provide nurses for native plants and/or shelter and food for native animals Removing them could do biodiversity more harm than good

Herbivory Weeds Incompatible activities Pressures on native flora

Irrigation

Use of spray (and fire) to clear ‘scrub’

Herbivory Weeds Incompatible activities Rapid habitat loss to land use intensification Pressures on native flora

Mackenzie Basin

Ashburton Basin

The regional council has a major role Community awareness and support is critical BUT : Economics tells us voluntary approaches cannot solve the problem! Much to do on many fronts, few tools to help prioritise Issues (my thoughts)

Biodiversity persistence = Conservation of pattern + process (The desired outcome) 1. Leave it there Biodiversity protection in Canterbury (Councils, DOC, LINZ, landowners, community groups, etc) 2. Legal protection 3. Intervene 4. Restore

Much more difficult, but some emerging tools (e.g. Pestspread) Some prioritisation and reporting tools ready to use now Biodiversity persistence = Conservation of pattern + process Biodiversity protection in Canterbury (Councils, DOC, LINZ, landowners, community groups, etc)

The regional council has a major role Community awareness and support is critical BUT : Economics tells us voluntary approaches cannot solve the problem! Much to do on many fronts, few tools to help prioritise Good-news-only reporting is unlikely to help (Cullen, Hughey et al.) Capability and funding issues, esp. for smaller, poorer councils Issues (my thoughts)

A bottom line Need to cap indigenous vegetation loss Indigenous vegetation needs to be defined broadly Invest in an aware constituency -Work with willing landowners -Inform, advise, educate, incentivise, participate in activities Monitor and report losses as well as gains Build in-house biodiversity capability, and relationships with district council biodiversity staff Needs (if you want to sustain biodiversity)