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BiodiversityRerenga rauropi

Biodiversity is one of the four key focus areas for Hawke's Bay Regional Council. We are working towards halting biodiversity decline and envisioning a new hope for biodiversity in Hawke’s Bay.

We’re passionate about protecting Hawke’s Bays’ unique biodiversity so it can thrive.

What is Biodiversity?

Biodiversity is the huge variety of living things and how they are all connected, including plants, animals, and micro-organisms as well as the ecosystems where they live.

Biodiversity can be of any scale – it could be a patch in your backyard or a whole continent. It’s everything from algae in our ponds and lakes, to the huge whales that travel out in Hawke Bay. Our indigenous biodiversity, made up of our native species, their genetic diversity, and the habitats and ecosystems that support them, is of huge value to New Zealanders, our economy, our quality of life, and our sense of identity as a nation.

Sadly biodiversity is in decline across New Zealand, and it’s one of Hawke’s Bay Regional Council’s focus areas.

Watch the Biodiversity Hawke's Bay video to find out more about Biodiversity here in our region. 

We're under threat

  • In New Zealand 75 animal and plant species have become extinct since human settlement. 90% of seabirds and 80% of shorebirds are threatened with or at risk of extinction.
  • Almost two-thirds of New Zealand’s rare ecosystems are under threat of collapse, and over the last 15 years 86 species became at risk of extinction, compared with the conservation status of just 26 species improving in the past 10 years.
  • Approximately 75% of indigenous forest cover has been lost.
  • New Zealand is losing species and ecosystems faster than nearly any other country with four thousand of our native species in trouble.

HB Biodiversity threat chart

What we do

We use an ecosystem-based conservation approach to protect indigenous biodiversity. This involves securing, maintaining, and restoring a full range of remaining natural habitats and ecosystems. The approach focuses on habitats and ecosystems as a means of conserving the biodiversity that relies on them. By focusing on natural ecosystems we’re aiming to maintain viable populations of native species. 

Our current focus is to ‘secure from extinction’ 900 sites we’ve selected across the region that are really special. For each site, we work with landowners and groups to create a plan on how to best protect this site, which can include deer fencing, pest control, and replanting.

If you have a natural site on your property that you would like to protect then please contact the Biodiversity Team for further information.

One site we’re working with the community on is Little Bush, a site managed by Forest and Bird with a 45 minute walk which passes through a regenerating forest of ferns, climbers, and native orchids. The reserve contains a mix of native plant species, including kahikatea, mātai, rimu, hīnau, lemonwood, and pōkākā, with a number of threes over 500 years old. Forest and Bird actively manage weeds and predators, but deer have been able to access the site causing damage to the native forest by feeding on forest plants, trees and seedlings, potentially changing the composition of the forest understorey. Working with them, we have started to build a fence to keep deer out which will be completed during winter 2019/20.

The region was mapped for potential ecosystem types (i.e. pre-human inhabitation) using the latest ecosystem classification system developed by the Department of Conservation. Classification is based on climate and geology (including substrates and susceptibility to waterlogging), but also takes into account a known influence of volcanic (and glacial, if present) activities. A range of other existing documentations were deployed to create a comprehensive spatial layer of the ecosystem pattern.

The resulting map shows the pattern of terrestrial ecosystems that should occur under certain environmental conditions. 61 potential ecosystems types are mapped.

This base layer was intersected with the Land Cover Database (LCDB 4.0) and indigenous land cover types were extracted to estimate the remaining areas of each ecosystem type.

There are 4970,000 ha of indigenous terrestrial areas left in the region, which includes 59 ecosystems types. 22 of these ecosystems are threatened (less than 30% of original area left), mostly of lowland forest types, coastal and dune vegetation types, braided riverbed vegetation, and wetlands. Two ecosystem types were presumed extinct (one lowland forest type and one wetland type) whose historic extents were very small.

Ecosystem Prioritisation is undertaken using Zonation, a tool (software) that prioritises ecosystem or habitat sites based on their representation (i.e. ecosystem types for terrestrial and rivers, and geomorphic types for lakes), connectivity (with other terrestrial sites and/or aquatic ecosystems) and conditions.

Zonation-based prioritisation has been adopted by a number of regional councils and Department of Conservation. It requires ‘a cap’ in which it produces the best set of sites to achieve full representation. It is generally an area-based cap which is set by asking ‘of the remaining indigenous ecosystems, how much area can we manage within a given timeframe?’

For the Hawke’s Bay, we have set the cap of 30% (of the 497,000 ha of indigenous areas remaining) by 2050. The principle behind the 30% is the species-area curve, i.e. when habitat (or a population) is reduced to 20% of the original extent (or a population), the rate of species loss is exponentially accelerated. Therefore 30% was chosen as a reasonable target that balances species response with achievability and affordability.

The scope of the Zonation-driven prioritisation included terrestrial ecosystems (including wetlands and braided riverbeds), lakes and streams. Although ranking was done separately for the three ecosystem domains, ranking of terrestrial ecosystems reflects the connectivity with lakes and/or streams. For example, if there are two sites representing the same ecosystem type, but one intersects with high ranked streams and the other doesn’t, Zonation will rank the former higher as it would account for the connectivity of the terrestrial ecosystem with the river ecosystem.

Zonation identified 900 terrestrial sties (150,000 ha), 10,034 segments of streams (6,700 km), and 77 lakes (1,700 ha) as the top 30% priority. These sites/segments represent a full range of ecosystem types that are present in the region.

529 of the 900 priority terrestrial sites are less than 10 ha in size. Many of these small sites represent threatened ecosystem types whose remnants are becoming scarce, smaller, more fragmented and isolated. The majority of these sites are on private land.
Interpretation of the Zonation output has been done in collaboration with local experts with ecological and site knowledge, and involved verification of the ecosystem types and reviewing the boundaries indicated by the Zonation.

As mentioned earlier, the ranking of terrestrial ecosystem sites takes into account the connectivity to streams and lakes. Many of the top 30% terrestrial sites adjoin to, or contain highly ranked river segments and lakes. Given the very large volume of river segment and lake sites which are ranked top 30%, staff propose that they do not review river/lake sites individually. If significant values associated with river/lake sites that are not currently associated with the top 30% terrestrial ecosystem sites, they will be added.

As with any modelling tool, Zonation has limitations which need to be considered in the decision making process.

Ecosystem-based site prioritisation is a critical first step to achieving the Biodiversity Strategy objectives and outcomes of sustaining, protecting, and improving the full representation of native species and habitats. It is intended that the Ecosystem Prioritisation will form part of the conversation and decision making by groups and organisations across Hawke’s Bay.

The Ecosystem Prioritisation framework will become an integral part of integrated catchment management. Priority sites that are identified in catchments of interest could also be part of the solution to address issues such as soil/wind erosion and water quality. This is because these remnants are providing ecosystem services such as soil conservation and water retention at a varying degree depending on the their condition. These remnants are also proof that the ecosystem is resilient to the ecosystem is resilient to the condition of the site, and could be capitalised upon by afforestation as part of integrated catchment management. 

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