Designing & Planning Sustainable Habitat Configurations in New Zealand’s Cultural Landscapes Colin Meurk & Graeme Hall Meurkc@landcareresearch.co.nz NZ landscape at a crossroads – which way the countryside? • Similar development of cultural landscape to England … • But 5000 years crammed into <1000! … & • No equivalent latterday integration of nature, culture & production in NZ – or not yet! • We may carry on along the present trajectory … • or redirect landscape evolution towards preserving NZ’s special identity thru biodiversity & natural character Worse than europe because … • Shade-tolerant invaders take over … • Little native regen. after pressure removed • Small native herbs swamped by exotic grass • Seedbanks dominated by exotic spp. Visibility of nature •Human memory banks dominated by exotics Sustainable Management & Use of natural resources Identification with regional biodiversity & landscape Protectiveness towards natural values Landscape & Ecological Sustainability & Integrity Feedback System Learning from natural processes Enculturation of natural values Quality of Life definition Familiarity with nature Love it or Lose it! • Habitat loss accelerated Post-RMA – nonsense! • Insulting - community restoration efforts overwhelmed by govt & corporate destruction • Diversionary tactics – huge numbers of strategies, policies & rules gathering dust! • Is it to be a Knowledge Economy or a Dark Ages of trivia, waste, sterility, lost identity, life denial? If Serious … Need to know … • What is likely to happen? • What innovative intervention is possible/necessary to achieve goals of natural character in the NZ landscape? • No longer are we divorced from our role as ‘intelligent’ conductors of landscape form & direction • If we don’t provide leadership then someone else will prescribe our landscape & culture for us! • In this presentation we provide some positive options & guidelines for overcoming the gloomy prognosis for NZ’s biodiversity & landscapes Start with Forest succession model adapted from US Linkages (Pastor & Post 1985) • Reformulated & generalised as LINKNZ (Hall & Hollinger 2000) • Empirically based & tested models (Fiordland, SE NZ pollen, Lake Thompson, Pisa Range, NZ Biomes) • Operates on autecological, physiological & growth properties of trees in relation to climate & soil conditions of a site Bringing in the Spatial Component Successful Propagule Dispersal Linking succession & dispersal Composite scenarios • In fullness of time – distance makes little difference … • Provided there are receptive habitats & … • Pest control … • Kauri or podocarps come to dominate in lowlands – regardless of starting line up (native or exotic). • In contrast, the montane zone, where native beech forests predominate, is in trouble from exotic shade-tolerant invaders Native Plant Colonisation of Receptive Habitats in Cultural Landscapes Applying models to green space planning • Link with island biogeographic approach to reserve design • Bigger is always better, but … • In constrained environments (urban & rural) .. • Have to make compromises … • In general, large iconic bush birds – kiwi, kokako need remnants >> 6 ha • But, most NZ wildlife is either small (1-6 ha adequate for viable populations) or vagile, so can … • Use stepping stones in a patchy landscape Combining reserve design, dispersal data, stepping stones & visibility/accessibility • 6.25, 1.6 & 0.01 ha forest patches with 50 m buffer have … • 2.25, 0.06 & 0.0 ha core respectively • These should be maximally 5, 2 & 0.02 km apart from patches of their own or larger size • Such an optimum configuration for forest patches in a cultural landscape – allows … • Propagule saturation across whole landscape • Bird habitat virtual continuity • Gene flow between plant & animal populations Optimising Patch Shape – Linear forest patch 625 m 50 m buffer zone 100 m core area = zero ha Street/playground Noble Tree Grove total area = 6.25 ha Neighbourhood Habitat Patch 125 m 10 m District/Suburb Core Sanctuary 250 m 150 m 10 m 25 m 0.01 ha 125 m 25 m core 2.25 ha Core 0.06 ha Total area 1.56 ha Buffer zone Total area 6.25 ha skin 150 m 250 m Optimal Forest Patch Pattern & Percentage Patch Area Calculation 60° 1/6 of 6.25 ha patch 4.33 km 60° 60° 5 km Percentage Patch Area Calculation Thus 3/6 of patch size in whole triangular area for 6.25 ha at 5 km spacings – Area = ½ x 5 x 4.33 km2 x 100 ha = 1082.5 ha % area occupied by large patches = 6.25 x 3/6 x 100% 1082.5 = 0.29% Total patch area = ca. 4.4% 6.25 ha 1 km 0.2 km 0.01 ha Urban matrix 1.56 ha 5 km Frequent dispersal Integrating People Nature & Landscape 100 m 100 m Clusters of big trees every 200 m 1 km 1 km 500 m 5-10 min walk 1 ha reserve every km; 5 minutes walk from every home Observed max. dispersal 2.5 km 10 mins cycling 4-10 ha reserve every 5 km; 30 minutes walk/ 10 minutes cycling from every home The real world of green space planning in SW Christchurch Opportunities … • Plight of NZ biota & Biodiversity Strategy cries out for drastic measures – at a broad landscape level • Positive signs in spontaneous regen. of some native elements • Can manipulate & redirect this dynamic – so long as we stop throwing around time bombs (weeds) • Models test novel ideas about where the biosecurity threats lie in the long term …& how to … • transform exotic plantations into native production systems (for utility & biodiversity) Exotic to Podocarp Plantation - Auckland Biodiverse Landscapes Are Us! • The following visualisations are backed by the data & models presented here • We have to be very patient tho … • may take centuries to restore the landscape - equivalent to the idyll of the english countryside • But if we don’t start now (by preserving the primary habitats or building blocks) the potential will be lost & the goal will be out of reach. Contemporary Dysfunctional Rural Landscape Prospective Integrated Functional Landscape Contemporary utilitarian high country landscape remnant native veg in far distance exotic plantation retirement fence lake winter wet paddock protected natural area Moraine with wilding birch, briar, etc drain Biodiverse high country futures remnant native veg, regenerating grazed matagouri woodland retirement fence boundary obscured exotic plantation surrounded by nz trees beech Homestead (opportunity for native rockeries) native hedgerows shelter belt with native border of shrubs short tussock lake protected natural area wetland highway hay bales behind native hedgerows Moraine with native shrubs & woodland Stream with riparian vegetation Urban Bio-sterility? Traditional urban conservation of remnants or islands The Native Bush Garden ‘Gardening’ for vulnerable herbaceous biodiversity & wildlife Recommendations – simple really • No more rotations of Douglas fir in high country (estimate 200-250 years for saturation of entire montane beech forest biome) • Research & implement use of sterile pines or hybrids (e.g. Leyland cypress) for forestry • Promote new indigenous forestry by planting & manipulating succession • Get serious about weed control • Promote/facilitate native regeneration in range of semiproduction & border habitats (hedgerows, woodlots, road verges, riparian zones, homestead woods) • Restore habitats – as last resort after protection of primary habitat & land surfaces • Integrate biodiversity into urban habitats • Work at landscape/visible level (visibility is key to nature sustainability) • Generate scenarios as goals - incorporating traditional structural elements & indigenous composition Visibility is a key to sustainability – don’t subjugate the Kiwi Identity to …