CLIMATE change could be affecting the quality of acorn crops from the UK's oak trees, the Woodland Trust has said.

Research using data recorded by members of the public for the trust's Nature's Calendar survey of the changing seasons has found that warmer years tend to lead to less synchronised flowering of oak trees, and as a result smaller crops.

Professor Tim Sparks, from Coventry University, analysed more than 160,000 pieces of data and found that the more first flowering dates varied, the poorer the acorn crop was.

There was a 20 per cent drop in average scores for the abundance of the acorn crop recorded in the Nature's Calendar survey for every four days' increase in the variation of first flowering.

With eight of the ten warmest years on record occurring since 2002, the trend is likely to continue in coming years, the Woodland Trust said.

Prof Sparks said: "This is a preliminary result which requires further study, but there is a significant correlation for both species of native oak.

"Synchronised years tend to be those with a later mean flowering date, suggesting warmer years are associated with smaller acorn crops."