Saturday, 20 October 2012
Habitats often grade into each other so it's difficult to tell where one starts and another ends. Sometimes the mix becomes a habitat on its own, with elements from each but also some that are unique to itself. I remember visiting some oak savannah near Chicago where scientists were having a stand up fight to decide if this was really a habitat or just trees invading tall grass prairie. It was an important argument because the accepted way to manage prairie was to set light to it! One faction wanted to remove all the trees but another wanted to save them.
How did they decide? By making an inventory of all the plants to see which ones came from the prairie and which came from the forest. In fact they found several plants that only occur in oak savannah. A detailed survey of invertebrates was to make the point even more strongly. Oak savannah is now a recognised habitat that is worth conserving.
Back at Paxton Pits we have scrub which we recognise as an important habitat but some visitors might think of as neglected pasture. It's more than just brambles and thorns invading grassland and it holds species that do not occur in pasture or in woodland. In the margins of Cloudy and Hayling Pits we have willow and birch carr which is what you get when reed-beds are invaded by trees.
We could just let nature take its course, but without the presence of big browsing animals such as beavers, deer, elk or mammoths we would eventually lose all the open areas on the reserve and all the scrub, and all the wet woodland too.
Instead, we try to keep a decent amount of each habitat and this means removing some scrub from grassland and some trees from our reed-beds. That's just what we have been doing for the last few weeks by the Hayling pit where a Sunday work party, organised by the Friends of Paxton Pits Nature Reserve, made a start on cleaning out an old pond area and the mid-week volunteers began clearing willows from the reed-bed.
I was delighted to see a lot of young frogs in the mossy hollows between the trees and a fine adult toad with beautiful golden eyes.
I took photos of the profusion of fungi to be found in the damp woodland and listened to the frequent rattles of a Cetti's warbler. Every few minutes a jay flew overhead, carrying an acorn in its crop. We are going to find a lot of new turkey oak seedlings next year, all planted by the jays that have invaded us this month from the continent.