Impact of decreased summer rainfall and mild, wet winters
Aspects of the historic landscape such as ancient woodland and veteran trees are likely to be affected by decreased summer rainfall. Drought tolerance of trees will vary both between different species and individuals. However, hotter, drier summers will inevitably increase the stress of many ancient trees. This stress will be exacerbated where near-surface roots are damaged through soil disturbing activities such as ploughing within close proximity to the tree.
The mild, wet winters have the potential to promote the occurrence and spread of pests and disease.
Impact on veteran trees
For veteran trees that are currently struggling to survive, climate change may hasten their demise. Of all historic environment features, these may be the most sensitive to change and the most difficult to protect or replace.
The creation of new veteran trees is a long-term project and species should be considered on both their ability to grow now and in the environment several hundred years hence.
If summers do become drier and hotter, veteran trees currently growing in southern England will be most at risk. However, where such trees currently exist at the northernmost limits of their natural range, a warmer climate may be beneficial, allowing increased growth through a longer growing season.
Options for replacing at-risk species
Where an individual species in the landscape is at risk from climate change, one option would be to plant an alternative species in anticipation of climate change whilst maintaining the feature in the landscape. One example would be replacing a former beech avenue with the more drought tolerant hornbeam.
Where species change is less desirable, obtaining new plants from the current extremes of the species natural geographical range would increase the genetic diversity and the adaptability of the species at the given location.