The Mackenzie Basin – facts, fallacies and fabulous features!
Photo Chris Woolmore Nicholas Head Dept Conservation Technical Advisor – Terrestrial Ecology Background
Largest inter-montane basin in NZ
Characterised by: • climatic extremes = ecologically distinctive (‘desert character’)
• comprises ‘intact sequences’ of nationally rare glacial derived ecosystems
• rich biodiversity and strongholds for many threatened species ~ 24% Canty’s rare plants (>60 spp)
• internationally regarded glacial geomorphology Photo G. Denton
Intact sequences of glacial landforms. High environmental variation at macro and micro scale. Pre–human Vegetation
12,000 ybp – rock, gravel, bare ground, colonising herbaceous vegetation
5,000 ybp complex woody mosaic: • open conifer forest and scrub on humid hill slopes and moraines
• scrub, red and fescue tussock on driest and youngest surfaces
• rich biodiversity adapted to open naturally disturbed habitats (climate and fauna)
• natural fire rare Arrival of Maori ~900 ybp
• extensive fire
• loss of hill slope forest and basin floor conifer forest/scrub
• down slope migration of snow tussock
• expansion of fescue tussock, red tussock and scrub across basin floor
• extinction of large birds Arrival of Europeans ~ 1840
European arrival • extensive fescue tussock, red tussock and scrub
• dune lands
“rivers of sand” (surveyor general 1850s)
“great tawny expanse of low tussock grassland” (von Haast 1862)
• continued depletion – weeds, pests overgrazing
• post 2000 - irrigation development and complete loss
(refs: von Haast. 1870; Cockayne, L. 1919; Zotov, V.1938; Molloy et al 1963; Connor, H. 1964; O’Connor, K. 1982; Burrows, C. 1996; McGlone et al. 1998; 2001; Walker et al. 2003) Water colour by surveyor Thompson (1857) Despite long history of disturbance and ecosystem depletion by humans, much of the Mackenzie retains its natural character and biological values. Mackenzie Basin: - National Stronghold for Naturally Rare Ecosystems
• Especially: - inland alluvial surfaces, inland dunes, moraines, kettleholes, braided rivers, wetlands
• Unparalleled for their extent and diversity
• Occur in contiguous sequences
• Provide habitats for numerous rare and threatened species
• The protection of naturally rare ecosystems and habitats for threatened species are national priorities (MfE 2007) ...inland alluvial surfaces and associated nationally threatened plants…
Leptinella conjuncta
Myosurus minimus Ceratocephala pungens ...inland dunes and threatened plants…
Lepidium solandri
Pimelea sericeo-villosa subsp pulvinaris
Carmichaelia vexillata
...moraines, kettleholes and threatened plants …
Isolepis basilaris
Iphigenia novae-zelandiae Cardamine ‘Tarn’
...threatened and rare birds
black-fronted tern
banded dotterel
wrybill
black-billed gull
oystercatcher ...threatened and rare freshwater fish
Lowland longjaw galaxias koaro
Upland alpine galaxias ‘Bignose’ galaxias Brachaspis robustus Sigaus minutus
Hemiandrus sp Hexathele aff. petriei 10% of NZ lizard fauna – 10 species
Southern Alps gecko McCann’s skink
Jewelled gecko
Spotted skink Scree skink Strong Rational for Protection - Relevant Legislative and Policy Framework
• CPLA = ‘protect inherent natural values’ • RMA (1991) = must provide for significant ecological values • Tenure Review = ‘protection’ of significant inherent values (biodiversity and landscape) • New Zealand Biodiversity Strategy (MfE 2000); National Priorities (MfE 2007) •Draft NPS (2011?) , RPS (2012) •ENV Crt (2012); Mackenzie forum (2013); Upper Waitaki Water Zone Plan (2013) …but…Increasing Threats and Diminishing Opportunities • Extensive loss and fragmentation occurring in the Mackenzie
- nationally rare and threatened ecosystems and spp rapidly being lost
- significant natural landscapes lost
• e.g. Twizel to Omarama road corridor was an ecosystem of national significance!
• Much more planned! 2001 2003 2004 2006 2008 2012
Canterbury Plains The upper Waitaki Basin! Other threats = Weeds and pests Management and Sustainability of Dryland Ecosystems
The Tekapo Scientific Reserve 1992 2011
Monitoring Plots Tekapo Scientific Reserve 1992 - 2011 The Dryland Park Concept
• In recognition of the national importance of the Mackenzie’s rare and threatened dryland biodiversity.
• No other opportunities remain in NZ to protect similar ecosystems along contiguous ecological sequences.
• Threatened by false perceptions, intensive agriculture, weed invasion.
• Key concepts = landscape scale protection of connected glacial ecosystems: range of protection mechanisms: public amenity. … opportunities for ‘Tourism and to grow the Conservation Economy’
• Outstanding recreation opportunities: mountain biking, tramping, cycling, hunting, fishing etc - much greater potential for increased use.
• Potential protected corridor from to the basin floor to Aoraki National Park.
• Synergies with the Mackenzie sky Park incl. A way forward …
Clarity over bottom lines
Ecological input throughout process
Engagement with LINZ on common goals
Collaborative management and increased funding for weed and pest control
Appropriate protection mechanisms over and above Tenure Review
Recognising the importance of landscape scale connectivity and public amenity Summary
• The Mackenzie Basin comprises nationally rare ecosystems that provide habitats for many threatened species. • Its ecosystems are a national priority to protect but ongoing losses continue. • A Mackenzie ‘Drylands Park’ should be a legacy that protects nationally important conservation values, facilitating tourism and growing the conservation economy.
Photo Chris Woolmore Acknowledgements
Derek Brown, Warren Chinn, Joy Comrie, Di Lucas, Brian Patrick, Geoff Rogers, Susan Walker, Chris Woolmore