One man went to mow

It was going to be a cooler, showery day, so I went to Fulford Ings to continue with some Himalayan balsam pulling. I spent most of the morning amongst two metre high nettles, getting stung continuously and rained upon intermittently. Would a monoculture of balsam be any worse than a monoculture of nettles? Neither is very attractive from a human perspective, but nettle is the food plant of the caterpillars of several of our most common butterflies, whereas the balsam is an alien which is displacing our wild flowers and damaging our river banks.

The meadow in mid-June

There's a bend in the river on the stretch I was working on and it wasn't until I stopped for lunch that I realised that the main meadow area, around the bend, had just been mown. I was shocked to see it so bare, as two weeks ago it had been a mass of wild flowers, just waiting for some insects to emerge. Now that we'd had some warmer weather, I was expecting it to be buzzing. Last year, when I met the landowner, he'd said he would get professional advice about a mowing regime for the meadow.

Where did all the insects go?

So when should it have been cut? I've looked up several sources on the internet and found the answer is not as straightforward as I expected. It depends on the age of the meadow, the weather, and on who is giving the advice! The farmer wants the best hay, the ornithologist wants to protect ground nesting birds, the botanist is solely interested in plant diversity, and the entomologist favours those plants that support the greater variety of insects.

This meadow was resown three years ago, following the installation of a new main sewer pipe for York. A young meadow needs to be cut earlier so that the maximum amount of nutrient is removed. Greater diversity is created on nutrient poor soils. Many of the plants are perennials, so they don't need to go to seed before being cut - they'll come up again next year anyway. The annuals and biennials however, do need to be allowed to go to seed before they are cut and the cuttings left to dry out and drop their seed before the hay is collected up. Exactly when they are ready for cutting is dependent on the weather.

I'd like to have seen the tansy left uncut, so that tansy beetle pupae that are currently underground have a food supply when they emerge as beetles in August. On the next meadow downstream, that's exactly what happens - they mow round the tansy clumps. It's possible there because the clumps are bigger and there are fewer of them. Here it would have been impractical as there are too many small clumps of tansy. However, all is not lost. There is an uncut strip between the footpath and the riverbank, with several larger clumps of tansy, which will remain the best place for tansy beetles along this stretch of the river.

References:
http://www.floodplainmeadows.org.uk/files/floodplain/Cutting%20Article.pdf
http://wildseed.co.uk/page/management-of-meadows-and-grassland
http://www.bbowt.org.uk/wildlife/wildlife-advice/wild-info-wildflower-meadows/creating-and-managing-wildflower-meadow

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