Wednesday, 3 February 2010

UN International Year of Biodiversity - January in South Manchester

So, we’re one month and a bit into 2010, the UN International Year of Biodiversity – how are we doing in South Manchester?

Well, as I predicted last December it’s not going terribly well – but not quite as bad as I expected.

We didn’t lose Hardy Farm, as seemed fairly certain a month ago, but the plans were not actually rejected by the Planning Committee because the developer withdrew his application before they could do so. That probably means that he is going to come back at some point with a revised plan – so it’s not over yet.

Contractors acting for the Environment Agency (EA) have been working on that part of Chorlton Brook which flows through the Chorlton Ees and Ivy Green Local Nature Reserve from Brookburn Road to the Mersey. On the plus side they’re actually doing this work during the winter - which makes a change from the usual ‘blitz-everything-during-the spring-just-as-the-birds-are-nesting’ approach. Nevertheless, they’ve chopped down some of the old, multi-stemmed White Willows which lined the brook and were something of a feature of it. No doubt someone decided that these trees were ‘diseased’ or ‘dangerous’ (or even ‘untidy’) – spurious reasons which are usually taken to be of much greater importance than the fact that the older the tree, the more important it is in biodiversity terms. Nevertheless, this is not an acceptable attitude on a nature reserve, where old trees (no matter how ‘decrepit’) are some of the most valuable organisms present. I will start to believe that the authorities have more than a token regard for biodiversity when they start valuing old trees rather than automatically and thoughtlessly cutting them down. Mind you, by that time we probably won’t have any old trees left to value!

The old trees that we have lost were covered in mosses and lichens and would have been rich in insects and other invertebrates. They would also have provided nesting and roosting opportunities for birds and bats. What is more, old trees develop more of these associations as they grow older. I suspect that they were just reaching a stage where they were beginning to become really interesting. Sadly, at this particular stage, they begin to look ‘untidy’ and ‘dangerous’, with broken limbs and rot holes, and some officious, know-nothing busybody is likely to come along and condemn them as ‘diseased’. No doubt they can be ‘dangerous’ ... if you stand underneath one in the middle of the night in a high wind! But this is also true of ‘healthy’ (looking) planted trees - which often have weakened root systems (quite a few of these have blown down in winter gales over the last few years).

I’m prepared to bet that, at some point, if this article and the protest letter I’ve written to the EA have any effect at all, they will promise to plant new trees. But, as I’ve argued many times before, tree planting has very little to do with conservation. Conservation is about valuing, retaining and enhancing what is there already – it is not about introducing new things.

The fate of the trunks and branches of the felled willows is also causing me some concern. At the moment they are stacked by various paths through the reserve. Already some of this wood has been shredded (in an industrial ‘tree-mincer’) and the resulting chippings sprayed on to the ground. Not only is this an unsustainable method of disposing of biomass, it also smothers the native vegetation. I am constantly amazed at the way the ‘tree-mincer’ operators always manage to choose the most sensitive areas possible to smother with their chippings. For example, on the north side of the brook there’s a little patch of a plant called Barren Strawberry (Potentilla sterilis) – it’s the only place in the whole reserve where this plant grows but it’s been unerringly smothered in chippings. On the south side there are some patches of an interesting plant called Opposite-leaved Golden Saxifrage (Chrysosplenium oppositifolium) and the biggest and best of these patches has been singled out for the chippings treatment. We’re also at risk of losing our only specimens of Hard Fern (Blechnum spicant), Yellow Loosestrife (Lysimachia vulgaris), Wood Anenome (Anenome nemorosa) and Black Currant (Ribes nigrum) which all grow on or near the banks of the brook.

It’s important to bear in mind, of course, that the EA are doing this work in order to protect us from flooding, but I can’t help thinking that if there was regular maintenance on the brook, rather than a major ‘blitzing’ every few decades, the effects on wildlife might be less catastrophic.

So it would seem that our Local Nature Reserve has almost certainly had its net biodiversity reduced; and it certainly hasn’t had it enhanced!

Elsewhere in South Manchester contractors working for the Greater Manchester Passenger Transport Executive (GMPTE) have been working on the new Metrolink line which will eventually run from Old Trafford to Didsbury. You will recall that this service will follow the route of the old Midland Railway line – which was abandoned in the 1960s and had, in the intervening 50 years, transformed into a rich wildlife corridor. In spite of promises to conserve biodiversity along this route, not much of the embankments along the Old Trafford to Chorlton section seem to be left. This has caused so much concern among certain residents of properties adjoining the Chorlton to Didsbury section that they have attached “save our trees” notices to trackside trees and marked them off with yellow tape! GMPTE have promised to plant five trees for every one tree that they remove - but this is pure developers’ tokenism, and as the regions through which the line will run are heavily built up, it’s not at all clear where all these trees will be planted.

Anyone who has tried to walk along this route, in the last few years, will know that much of it is/was flooded. In an area where most of our historic ponds have disappeared these flooded areas formed an important local habitat for water plants, water-living invertebrates, amphibians etc. GMPTE have, rather belatedly, submitted some plans for some replacement ponds – but these are, surely, at least a couple of years too late?

So, where are we up to in South Manchester in this UN International Year of Biodiversity? Well: ‘quite a few losses, hardly any gains’, probably sums it up fairly well. There have been some concessions: like working in the winter rather than the spring (a big advance) - but there’s a general impression that engineering considerations come first and the obligations that organisations have towards biodiversity are still not taken as seriously as they should be, and tend to be seen as a bit of an afterthought, or even something to be avoided if possible.

I’m planning for this to be the first of a number of such articles on biodiversity in South Manchester during this important year. Although I shall have no hesitation in naming and shaming organisations which destroy our wildlife and their habitats this year, I will also be looking and reporting on any examples of good practise that I come across.

Dave Bishop, February 2010

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