Blog - Ecology

Ecology

Andrew , 1 July 2008

Ecology is looking to be one of the key issues for this wind farm. Our view is that the site clearly has important ecological values but the wind farm will have a very small impact and there is in fact potential for improvement through measures like re-planting, destocking and pest control.

The important values are (in brief):

The site is reputed to be the most extensive forest on limestone in Canterbury
It is home to two endangered plants (from the latest classifications); Nationally Endangered Maccaskill's hebe and Nationally Vulnerable Limestone Wheatgrass.
There are another 8 plant species with ‘rare’ classifications
It is home to a strong population of the threatened Canterbury Gecko

The site meets the criteria for a priority for protection in the national biodiversity strategy and this is reflected in Ecan's regional biodiversity strategy released earlier this year. However, the site needed for the wind farm has no particular legal status (eg district plan designation) giving it any protection. It is a working farm and it has been since 1850 and it will continue to be if this windfarm does not go ahead.

We have spent a great deal of time and effort carefully designing the windfarm to minimise any impact. But we do need a road to get the turbines to the top of and along the ridge. The result is that out of a 21 ha construction footprint around 16 ha is on pasture grass. There are a few difficult areas where we can't avoid the vegetation hence we need to clear about 2.2 ha of forest and 3 ha of shrubland. On the hillside in general there is 180 ha of forest and a similar amount of shrubland – which means the total foot print in percentage terms is 1.2% of forest and 1.6% of shrubland. If it helps to visualise things you could say that there more than 500 rugby fields worth of forest and shrub in the area but only 7 rugby fields will be removed.

Of the rare species many are located entirely on the steep northern escarpment and we have avoided this entirely with our design. The limestone wheatgrass is mostly to the south of the windfarm and more than 95% of it will be left completely alone. There are estimated to be about 20 plants within the immediate construction zone but it may be possible to avoid some of these during detailed design. Many of the other rarities are scattered throughout the bush so we will miss most of them.

Earthworks will necessarily impact on some of the rock outcrops that provide gecko habitat and it is unlikely that this can be replaced (and certainly not in the exact form and location from which they came).

So, what will we do about the impacts that we can't avoid?

Firstly we will replant shrubland and some forest species using local seed sources. Some plants will be propagated off-site and brought back to site when needed, others may be planted by direct seeding.

We will also allow some areas to regenerate by reducing or eliminating grazing. Regeneration potential is huge with an observed 100% increase in shrubland and a 30% increase in forest since 1950. On site it is easy to see places where young vegetation is waiting to take off but is being regularly trimmed by browsing animals.

We will target some of our planting to improve connectivity between existing forest patches.

Of course, we will be fencing off our planting areas and initiating pest control programmes.

For the lizards we will set up trapping programmes for the likely predators. Our survey noted a lot of potential habitat but relatively few lizards suggesting the numbers are being kept in check by either carnivorous predators or clumsy stock. With both stock and predators under control we expect the lizard population to expand into the new habitat.

Best of all we will create covenants over key parts of the ridge so that the biodiversity values are protected in perpetuity, thus meeting the primary goals of the national and regional biodiversity strategies.

Overall we believe the local impacts of the windfarm can easily be compensated for on site and with long term good management of the ecology we will end up with a much improved site, more extensive forest and shrubland vegetation and a valuable asset for the people of Canterbury. Furthermore there is a wider environmental argument that is also important and that relates to the green-house gas offsetting benefits of the windfarm. This site can truly be a win-win for the local and global environments as well as for local generation.