Time to be inventive on woodland climate threat - researcher

As climate change bites hard, animals are migrating away from increasing heat, drought and wildfire.

Species are travelling north at a median rate of 17km a decade, but what of plants, and especially trees? How do they move home?

The answer could be assisted migration, where humans intervene, and either translocate species, or introduce southern species to make woodlands more robust to heatwaves.

Dr Sarah Dalrymple, a reader in conservation ecology at Liverpool John Moores University, believes it is time for action and has told The Guardian that conservation efforts in the UK need to be “more inventive”.

Sarah, who sits on a national taskforce, set up by the environmental watchdog Natural England, says the narrative has changed: “It’s the first time we’ve been able to talk openly about moving things.

“Earlier in my career the narrative was all about restoring past baselines, and then, as I got more independent in my research, I realised that’s impossible – we can’t do that any more.

“We are changing the climate so much, we have to be a little more inventive.”

Assisted migration or assisted colonisation is divisive. Conservationists have long argued against introducing non-native species. To do so is to meddle with nature, they say – and risk accidentally bringing in invasive species which can harm native environments.

But others say those arguments fail to deal with speed or size of change caused by the heating climate.

Commercial foresters are already preparing for change. At a site in Kent called Pleasant Forest, they are bringing in small-leaved lime and hornbeam seeds from parent trees from France, and a Mediterranean species of alder from Italy. 

When we have got examples of assisted migration, it’s often with species we’re working with which are absolutely on the brink of extinction and have run out of other options,” Darymple says. In 2016, a captive-bred swamp tortoise from Western Australia was moved 200 miles south to wetlands where they had never lived before, after experts said it was the only way to ensure the species’ long-term survival.

Darymple wants to see assisted migration explored earlier, working with species before their populations become so small they become unhealthy, and putting more research into what may work.

“You can never get rid of all the risks, but there is also risk in inaction. We have to balance the risk of doing things against losing these species from the ecosystem,” she says. “The risk of inaction is increasing every day.”