Nature Notes – May 2023 column by Natureboy:
Plant diversity supports our insects, birds, animals – and us!
Swallows, house and sand martins have all now been spotted by local birdwatchers, along with the occasional cuckoo and other summer arrivals (various warblers, whitethroat and wheatear). Keen eyes have also seen the first swifts – although as yet I haven’t been lucky enough.
However, the arrival of spring seems to have stuttered along so far – and the number of swallows and martins seems low. I hope they are just late because of the cool weather – rather than not coming at all. The reports of record high spring temperatures and ongoing drought in Spain and Portugal are a concern for our incoming migrants – as many of them will have to negotiate these difficult conditions.
A lot of birds are already feeding fledglings. We have a robin who decided to nest in one of our sheds – in a box of paint cans. Presumably the parents thought this would be away from the prying eyes of magpies and cats, but it was a surprise when my partner went looking for paint! So, if you are going into your garden shed for the first time this spring – check before your move things!
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Our summer visitors and parenting birds need plentiful supplies of caterpillars, flies and other invertebrates and two recent reports should make us all very concerned for them.
Last year a ‘citizen science’ study for conservation charity Buglife concluded that the UK’s flying insect population had fallen by 60% in the last 20 years.
Climate change and air pollution are two of the identified reasons for this but the big problem remains habitat loss – and in particular the loss of diversity in many habitats. Modern agricultural practice remains a principal culprit.
In March another worrying report was published by the Botanical Society of Britain and Ireland (BSBI), concluding that half of our native plants have also declined in the last 20 years. Again, climate change is a factor – particularly for plants that were perhaps living at the edge of their range in the UK.
Such examples cited include the mountain plants Alpine lady-fern, Alpine speedwell and snow pearlwort. But the sharp decline of many species once thought common is perhaps of greater concern – corn marigold, harebells, and devil’s bits scabious are named.
The declines are mainly attributed to farming practice – especially the use of nitrogen fertilisers, selective herbicides on pasture and continued ‘land improvement’ (such as damp meadows being drained).
It would seem that ‘Farm Stewardship’ schemes and the existence of charitable organisations such as the ‘Farming and Wildlife Advisory Group’ (FWAG – which has now existed for more than 50 years) have not managed to stem the excesses of an industrial farming mindset.
I wrote some months ago about how I hoped one benefit of Brexit might be a ‘re-set’ in land management policy in the UK. But the government seemingly remain diffident about rolling out the proposed Environmental Land Management scheme (ELM) to replace EU subsidies. As far as I can tell, landowners are not yet clear about how to proceed.
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In terms of evidence – you cannot draw a more linear diagram. Plant diversity and abundance directly supports insect diversity and abundance that directly supports our bird and animal population.
If you want to see more swallows (and toads and hedgehogs) – look after plant diversity. What is stopping the government setting decisive agricultural policy?