Plants in the UK Flowering Earlier Due to Climate Change
Key Findings
- Plants in the United Kingdom are flowering an average of 26 days earlier than they did before 1987 due to climate change.
- Earlier flowering dates could disrupt relationships between wildlife and cause species to collapse if they can’t adapt quickly enough.
- Herbs have seen the most pronounced shift in their first flowering date, at 32 days.
- Southern sites in the UK have flowered six days earlier than northern sites.
- Urban areas in the UK have flowered five days earlier than rural ones.
- Lower elevations in the UK have flowered one day earlier than higher elevations.
Climate Change and Plant Flowering
Climate change is causing plants in the United Kingdom to flower earlier than usual. A new study published in the Proceedings of the Royal Society B finds that the average first flowering date has shifted from May 12 before 1987 to April 16 from 1987 to 2019. This means that plants are now flowering almost a month earlier than they did just a few decades ago.
The study examined over 400,000 records from Nature’s Calendar, a citizen science database with observations dating back to 1736. The researchers looked at first flowering dates for 406 flowering plant species and compared those to temperature measurements. They found that the earlier flowering dates are strongly correlated with rising temperatures.
Ecological Risks of Earlier Flowering
The earlier flowering dates pose a number of ecological risks. One risk is that late frosts can kill early flowers. Another risk is ecological mismatch, which occurs when a relationship between wildlife is interrupted by changes in the timing of life-cycle events like breeding or migrating.
For example, if a certain plant flowers earlier, it may attract a particular type of insect, which in turn attracts a particular type of bird. However, if the bird’s breeding cycle hasn’t yet begun, the bird may not be able to take advantage of the early food source. This could lead to a decline in the bird population.
Plant Height and Flowering Time
The study also found that plant height plays a role in flowering time. Herbs, which are short-lived plants with faster turnover rates, have seen the most pronounced shift in their first flowering date. This suggests that herbs may be able to adaptively evolve quicker than other types of plants.
Location and Flowering Time
The study also looked at the relationship between plant location and flowering time. The researchers found that southern sites in the UK have flowered six days earlier than northern sites. Urban areas have flowered five days earlier than rural ones. And lower elevations have flowered one day earlier than higher elevations.
Impact on Garden Plants
The study focused on native plants in the UK, so it’s not yet clear what the full impact of earlier flowering will be on garden plants. However, the Royal Horticultural Society (RHS) has noticed early blooming in its gardens.
“We would expect a similar pattern [of earlier flowering] in garden plants,” says John David, head of horticultural taxonomy for the RHS. “And we have seen indications of this in our own RHS gardens, such as the apple flowering times in our orchard at RHS Garden Wisley.”
Conclusion
The earlier flowering of plants in the UK is a clear sign of climate change. This change poses a number of ecological risks, including the disruption of relationships between wildlife and the decline of certain species. It’s important to continue to monitor this trend and to take steps to mitigate its effects.
