Managing forests for water supply to help offset climate change

Scientists from the US Forest Service at a 5,600 acre research facility experimental forest have been assessing the feasibility of managing forests for water supply in the changing climate of the future.

Using some of the longest continuous records of climate and hydrology, the team coupled it with data from experiments on forest management to determine whether forest management could sustain water supply.

The results seemed to show precipitation patterns are becoming more extreme, as expected in climate models, as well as increases in temperature. Management approaches were applied to determine their effect, including thinning strategies and converting hardwood stands to pine. The later, due to the tendency of pines to keep their needles year round, decreases streamflow.

SRS Research Ecologist and lead author Chelcy Ford said of the results, “From a streamflow perspective, the extreme case of converting hardwood forest to pine produced the largest effect on available surface water. Though it might be a good option for mitigating climate change under future scenarios of increased precipitation, species conversion from hardwood forest to pine would be a poor choice under drier scenarios where it could worsen water shortages by reducing the amount of available water in streams."

As the policy makers and land managers look to solutions to some of the effects of climate change, experiments like this are essential in determining the impacts of different policies. However, they should be careful when looking at the risks and benefits of each strategy. "Managers need to carefully weigh the risks of adopting one strategy over another," says Ford. "They also need to realize that any strategies they consider will have to address these risks at the regional or even more fine-scaled level, taking into account possible changes to local precipitation patterns."