Trees ready for the future climate: how to select without guessing

Selecting trees for the future climate is not about guessing which species will survive in 2050. It is about combining climate scenarios, microclimate, functional traits, regional experience, diversity and monitoring. Uncertainty should be managed with alternatives and pilot batches, not hidden behind lists of resistant trees.

A city contains hot courtyards, windy avenues, damp low-lying areas and exposed slopes. The climate scenario sets the trend, but the microclimate decides part of the daily stress.

Mapping reflected heat, water, soil and wind is still the first step.

A species’ climatic distribution gives context, but on its own it does not reveal tolerance of heatwaves or urban drought. Functional traits and field results help to compare survival strategies.

The ability to recover after stress also matters, not just staying alive with a degraded crown.

A diverse palette reduces exposure to a single pest or climatic response, but it should include functional diversity, not just different names. On large projects, avoid excessive percentages of one species or cultivar.

Monitoring growth, mortality, dieback and watering needs makes it possible to update choices. Adaptation is a process, not a closed list.

An adaptation plan should include alternative species for each function and identify the stretches or areas where they can be trialled. When a tree fails, the replacement does not have to repeat the same species automatically if the site has shown a structural limitation.

Setting aside continuous soil space and improving the planting usually adds more to the safety margin than looking for a tree described as indestructible. How the site is built is part of climate adaptation.

The most common mistakes are using climate maps as the only evidence; choosing only species from warmer regions; repeating one cultivar on a large scale; and failing to set aside capacity for replacement.

At Diaplant, selection for the future climate combines climate data, functional attributes, diversity and local observation. Wherever possible, new options are trialled in pilot batches before being scaled up.

Preparing for the future climate means deciding under uncertainty. The best defence is a selection that is well founded, diverse and observed after planting.

• Forest Research. Urban Tree Manual. (2018).
• Relating the climate envelopes of urban tree species to their drought and thermal tolerance. (2021).
• Functional traits are better than climate niche approach at predicting the vital growth and mortality rates of urban tree species. (2026).
• Crown dieback and mortality of urban trees linked to heatwaves during extreme drought. (2023).