… and so does Stephen

The natural environment and wildlife, part 2

In the first blog in this current series, which I posted on 20 Jul, I said that I was a great fan of Simon Barnes, but I also have a second environmental hero who is not so well known. He is Stephen Trotter, Chief Executive of Warwickshire Wildlife Trust. You may remember that Stephen was kind enough to lead one of our bluebell walks in South Cubbington Wood, which I reported on in my blog of 29 May.

Stephen has produced a paper What ecological effects might HS2 have on wildlife and wild places? (which may be found here).

Stephen’s analysis, in contrast to Simon Barnes’ emotional and evocative article, is written in cold scientific terms, but the message is no less stark. The paper spans nine pages and is crammed with detail so, even though I plan to devote both this and the next blog to it, I can’t possibly attempt to summarise it completely. All I propose to do is select a small number of Stephen’s points that I found particularly interesting, but I do strongly recommend that you read the original paper.

Stephen reports that a preliminary analysis by The Wildlife Trusts has identified 160 designated wildlife sites which appear to be at risk from HS2, on the basis that indirect impacts on sites were assumed to be likely at up to 500 metres each side of the line. The list includes 12 Sites of Special Scientific Interest, 84 Local Wildlife Sites, 61 Ancient Woodlands, 25 river corridors of interest for wildlife, 3 nature reserves managed by the Wildlife Trusts and 2 local nature reserves.

Stephen summarises the importance of these sites as follows:

Each of these sites makes a valuable contribution to the landscapes and biodiversity which surround the proposed HS2 route. Some of the identified sites have national or regional value but all have significant value for local wildlife. They provide ecosystem services and an important recreational and amenity resource where people from local communities can access and enjoy wildlife and wild places on their doorstep. There is also concern for the countless hedgerows, trees and unrecognised habitat patches – which though they may not register on the scale of designations are still important elements of a living, connected and functioning landscape.

Like Simon Barnes, Stephen is concerned with the fragmentation of the natural environment that the HS2 track will cause:

The linear nature of the route will present an almost complete physical barrier to the movement of a large number of species across the line. Large terrestrial species will presumably be actively excluded from the line by fencing, cutting and application of herbicides. This can be a particular issue for animal species with regular movements across different habitats irrespective of whether these involve a daily commute, infrequent visits or seasonal migrations. For example, many amphibians follow regular movements between breeding, feeding and overwintering sites; using relatively fixed routes across their landscape at different times of year.

Stephen stresses how important naturally connected habitat features, such as trees, hedges, woods and water features are to some bats, enabling them to navigate around and exploit the landscape; allowing them to commute between roosts and feeding areas. He says:

Gaps or barriers in this connectivity can prevent movement and have impacts on populations. For example, a study on the rare barbastelle bat, which may occur near the HS2 route, has shown how dependent these animals are on a fine level of landscape connectivity. Barbastelles commute large distances each night to exploit suitable patches of habitat and a ‘gap’ or barrier can prevent their use of important habitats which might have consequences for important populations which roost many miles from the route.

He also notes in association with connected habitat that:

The HS2 route passes through at least 5 areas which have been identified as important areas in which to promote ‘living landscape’ initiatives. These are areas where immediate and substantial benefits could be achieved by restoring damaged land and reconnecting previously fragmented habitats to improve the sustainability and resilience of the landscape increasing its ability to adapt to climate change and other pressures.

He also considers the point that Simon Barnes makes that the dissection of habitats into smaller patches that HS2 will cause can have fundamental consequences for wildlife. He lists the likely impacts as: a reduction in species diversity (100 ha of habitat could be expected to keep only 70% of the species that would have survived in 1000 ha); loss of characteristic species (woodlands of less than 2 – 3 ha have been found not to support characteristic woodland species that should be present); changes in community composition, isolation, edge effects, changed rates of species extinction and colonisation, reproductive success, population dynamics and predator-prey relationships; and increasing isolation and ‘insularization’ (which may lead to the loss of species, inbreeding, invasion by invasive species, edge effects, etc.).

So we have two environmentalists expressing themselves in very different ways, but both are conveying the same essential message about the dangers that the fragmentation of the natural environment that HS2 will cause pose to biodiversity and the health of our wildlife habitat.

In the next blog I will cover some of the other likely impacts of HS2 that have been identified by Stephen Trotter.

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2 responses to this post.

  1. Posted by Bill Adam on July 25, 2011 at 2:33 am

    :Let’s have some postive thinking on “increasing isolation and ‘insularization’ (which may lead to the loss of species, inbreeding,”.Think Galapagos islands and Darwin’s discovery of new finch species, a direct result of “increasing isolation and ‘insularization’ “(which may lead to the creation of species, due to inbreeding,)

    Reply

  2. Posted by Roseg on August 1, 2011 at 11:27 am

    Bit of a difference in scale, wouldn’t you say, Bill, between the Galapagos Islands, 3,040 square miles of land, spread over 17,000 square miles of ocean (Wikipedia) and the proposed landtake for HS2, which could isolate comparatively tiny pockets of land?

    Reply

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