WHAT IS SPECIAL ABOUT WHAT IS SPECIAL ABOUT NELSON S BIODIVERSITY - - PowerPoint PPT Presentation

WHAT IS SPECIAL ABOUT WHAT IS SPECIAL ABOUT NELSON NELSON’ ’S BIODIVERSITY S BIODIVERSITY

and where is it going?

by Shannel Courtney Department of Conservation, Nelson

Nelson City Nelson City

Nelson’s Coastal Ecosystems Nelson’s Coastal Ecosystems

• extensive coastline
• wide variety of coastal systems

– very sheltered to very exposed – range of substrates, landforms, array of coastal processes

• parts of which are nationally and regionally

important for biodiverstiy

Nelson Boulder Bank Nelson Boulder Bank

Boulder Bank Community Boulder Bank Community

spotted skink porcupine shrub

• sponge beds
• horse-mussel beds

Boulder Bank underwater Boulder Bank underwater communities communities

Estuarine Ecosystem Estuarine Ecosystem

back beach beetle bar-tailed godwit native musk

Dunelands Ecosystem Dunelands Ecosystem

katipo pingao

Mineral Belt Ecosystem Mineral Belt Ecosystem

mini gecko mineral belt forget-me-not

Limestone belt Ecosystem Limestone belt Ecosystem Limestone belt Ecosystem Limestone belt Ecosystem

Limestone belt Ecosystem Limestone belt Ecosystem

limestone kowhai limestone three finger

River Ecosystems River Ecosystems

– relatively big rivers

• cf. those of NZs

largest cities – still have tracts of native riparian vegetation – drain hard rock substrates and headwaters are vegetated: good water quality in upper reaches – collectively retained most of their native fish fauna – important habitat for several threatened species

Freshwater wetland Ecosystems Freshwater wetland Ecosystems

• naturally few freshwater wetlands in Nelson
• most are coastal and associated with river

mouths, estuaries, dunes and boulder beaches

• provide important refuges for wetland species

Forest Ecosystems Forest Ecosystems

• Nelson still retains some significant tracts of coastal and

lowland forest (unlike many cities)

• special vegetation types

– matai – black beech forest – tanekaha – southern rata forest

• 17 species of nationally threatened plants
• national stronghold for several species

– shovel mint, mineral belt endemics

• species limits and northern elements

– southern limits for NI species (tanekaha, pukatea, kohekohe, tawa, black maire) – western limits for Sounds species (ramarama, leafless bushlawyer)

Where is our native Where is our native biodiversity going? biodiversity going?

• Need to know:
• what Nelson’s past biodiversity was like,
• how it differs from today’s,
• the factors that contributed to how it got to

what we have today

What did Nelson City originally What did Nelson City originally look like? look like?

• Most of the Nelson region below 1200m

(treeline) was covered in tall forest.

• Open areas were uncommon and confined

to river beds and deltas, wetlands, estuaries, dunes, bluffs, and the Nelson mineral belt.

• The Region was teaming with wildlife –

birds, lizards, bats, insects and seals.

Nelson Haven – 1200 AD?

Pepin Island, 1200 AD? Pepin Island, 1200 AD?

Rocks Road, 1200 AD? Rocks Road, 1200 AD?

Maitai River mouth Maitai River mouth – – 1200 AD? 1200 AD?

hamilton’s frog giant weta tuatara striped gecko

Nelson City 1842 Nelson City 1842

John Saxton sketch

Forest loss in Nelson Region Forest loss in Nelson Region -

• 2005

2005

Cleared lowland forest Remaining lowland forest Cleared upland forest Remaining upland forest Non-forest ecosystems (alpine, dunes, mineral belt, estuaries, bluffs, boulder bank, river beds)

Native Vegetation Loss in Nelson Native Vegetation Loss in Nelson City City -

• 2005

2005

Nelson City boundary Cleared lowland forest Remaining lowland forest Cleared upland forest Remaining upland forest Non-forest ecosystems (mineral belt, estuaries, boulder bank, bluffs)

Natural Areas protected for Natural Areas protected for biodiversity in Nelson City biodiversity in Nelson City

Nelson City boundary Cleared lowland forest Protected lowland forest Cleared upland forest Protected upland forest Non-forest ecosystems (mineral belt, estuaries, boulder bank, bluffs)

Native Vegetation Loss in Nelson Native Vegetation Loss in Nelson City City

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

coastal & lowland (<600m) upland (>600m) total

native vegetation lost native vegetation remaining

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

coastal & lowland (<600m) upland (>600m) total

Native Vegetation Loss in Nelson Native Vegetation Loss in Nelson City City

native vegetation lost native vegetation remaining - unprotected native vegetation remaining - protected

Native Lowland Vegetation Loss in Native Lowland Vegetation Loss in Nelson City Nelson City

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

estuaries coastal flats coastal hill country lowland flats lowland hill country

native vegetation lost native vegetation remaining

Underwater communities Underwater communities

• lost bryozoan and fingersponge reefs
• depletion of top predators: blue cod,

crayfish, terakihi, snapper

• Ecklonia kelp beds almost gone

Estuarine communities Estuarine communities

Seabird turf community Seabird turf community

Native dune community Native dune community

Riverine & wetland communities Riverine & wetland communities

Alluvial forest communities Alluvial forest communities

Lowland hill country forest Lowland hill country forest communities communities

• fragmentated
• small
• not regenerating
• weedy
• vulnerable to stock and

animal pests

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% native birds (99) native reptiles & frogs (15) native fish (17) native plants (545)

extinct gone from Nelson City loss from Nelson City imminent populations stable

Conservation status of animals & Conservation status of animals & plants native to Nelson City plants native to Nelson City

Fernbird ONE POPULATION LEFT IN NELSON CITY Blue duck EXTINCT IN NELSON CITY

Australasian bittern NO BREEDING POPULATIONS IN NELSON CITY Banded rail LOW NUMBERS & DECLINING IN NELSON CITY

NZ falcon LOW NUMBERS & DECLINING IN NELSON CITY South Island kaka NO BREEDING POPULATIONS IN NELSON CITY

NZ Grayling Brown mudfish EXTINCT EXTINCT IN NELSON CITY Giant kokopu ONE KNOWN POPULATION IN NELSON CITY

Nelson green gecko

LOW NUMBERS & DECLINING IN NELSON CITY

Giant flax weevil

GONE FROM NELSON CITY

Swamp maire Swamp maire

shovel mint shovel mint (Scutellaria novae

(Scutellaria novae-

• zelandiae)

zelandiae)

• nationally endangered
• known only from 12 sites

in Nelson & N. Marlborough

• confined to alluvial forest
• 1 site left in Nelson City

Future A Future A -

• based on past and present trends

based on past and present trends

continued:

• regional exinctions of native species
• increased number of nationally and regionally endangered

species and communities

• attrition and loss of natural and semi-natural areas
• increase in natural area fragmentation
• decrease in natural area buffering from the working

landscape

• decrease in natural area structural diversity and species

diversity, eg lowland old growth forest gone

• increase in extent and no. of weed & animal pest species
• decrease in natural area quality and integrity due to weeds

and animal pests

• decrease in the rate of natural area loss
• increase in no. of restoration initiatives
• increase in legal protection for biodiversity,

including marine reserves

Future A Future A -

• based on past and present trends

based on past and present trends

Future B Future B – – encouraged by a encouraged by a biodiversity strategy biodiversity strategy

Active restoration initiatives:

• The Brook, Whakapuaka, Paramata Flats, and Maitai-

Roding Water Reserve as sanctuaries

• Connecting and enlarging fragmented natural areas
• Creating and enhancing riparian corridors along streams

and rivers

• Increasing water quality and restoring the structural

quality of our waterways

• Connecting coastal and inland ecosystems
• Creating new natural areas (especially of extinct or rare

ecosystems)

• Creating marine reserves, taiapure, mataitai

Future B Future B – – provided for by a provided for by a biodiversity strategy biodiversity strategy

• For species and habitats:
• improving biosecurity and border control measures
• getting serious about weed and animal pest control
• restoring habitats for threatened species
• re-introducing native species
• adopting the principle of eco-sourcing to maintain

the distinctiveness and genetic integrity of Nelson’s native plants and animals