Bee and butterfly numbers have slumped after a tenth year of unsettled weather, National Trust experts have said.
Mild winter and spring weather led to extremely high grass growth, leading to a good year for farmers with livestock and for making silage or hay, but the grass growth meant a difficult year for warmth-loving insects, including common meadowland butterflies.
The assessment comes as the National Trust marks ten years of its annual weather and wildlife review, which is aimed at understanding how changing weather patterns is affecting wildlife at its places.
The conservation charity is working with its tenants and partners to reverse the alarming decline in UK wildlife, with 56 per cent of species seeing their numbers fall in the last 50 years.
Matthew Oates, nature and wildlife specialist at the National Trust, said: “Another year of unsettled weather has seen extraordinary grass growth – good for livestock and hay making, but bad for many plants and insects which like short turf grassland, like the common blue butterfly.
“Our rangers have had to work closely with farmers and graziers to get grazing levels right for these plants and insects. In many places it’s been a struggle, but at a handful of places like Somerset’s Collard Hill – home to the large blue butterfly – graziers have triumphed.
“2016 comes on top of an unsettled decade, with many species struggling in the face of climate change and more intensive farming practices.”
A mild winter, cold spring and mild, wet weather in May and June led to very high grass growth in early summer. Grass grew at a rate almost a third faster than in previous years, according to Agriculture and Horticulture Development Board figures.
An unsettled decade
In the past decade, National Trust nature experts have noticed that winters are becoming milder and summers wetter, which could have a devastating effect on warmth-loving insects, their bird and bat predators, and many low-growing plants. Over the last 50 years more than half of UK species have declined.
National Trust nature expert Matthew Oates said: “In the ten years we’ve been reviewing wildlife at our places we’ve noticed pulses of unsettled weather become the norm. We last enjoyed a good summer in 2006.
“Mild winters and periodically wet summers have seen common wasp numbers apparently slump in many parts of the country, along with common ‘meadowland’ insects like the common blue butterfly. This could have a knock on effect on the invertebrates, birds and bats that eat them. And what affects insects today could well affect us tomorrow.”
Climate change has had a clear effect on weather and wildlife in the last decade:
- In ten years the growing season has extended by almost a month, the Met Office announced earlier this year . Both the Met Office and the World Meteorological Organization have predicted that 2016 will be the hottest year on record – the third year in a row of record-breaking surface global temperatures .
- Warmer temperatures, higher levels of carbon dioxide in the atmosphere and a longer growing season are leading to vegetation growing more quickly. According to a study published in November, this increase in vegetation growth is also leading to a drop in the amount of CO2 in the atmosphere .
- Common wasp numbers appear to have crashed in many districts in recent years, perhaps suffering during milder winters and wet springs.
Matthew Oates added: “Long term, changes in how we manage land has also led to wildlife declines – with more than half of species experiencing a drop in numbers in the last 50 years.
“But one of the great successes of the last decade have been the ways farmers and conservationists have worked together to reverse wildlife declines in many of our places.”