DURHAM, N.H. – University of New Hampshire scientists have received $1.25 million in funding from the National Science Foundation (NSF) to explore more closely the role that forests play in regulating the Earth’s climate.

Scott Ollinger from UNH’s Institute for the Study of Earth, Oceans, and Space (EOS) and the Earth Systems Research Center will use the five-year grant to understand how the biodiversity of forests — the number of tree species represented as well as the differences in their sizes and shapes and how they absorb and reflect light — affects their ability to soak up CO2 and mitigate the impacts of climate change.

“We are trying to answer questions like does the biodiversity of forests matter to the things that humans need, like clean air, clean water and buffering the effects of climate variability?” said Ollinger. “Would North America’s climate be different if we only had half the number of tree species?”

In general, forests can play a major role in regulating the Earth’s climate. An acre of forest can absorb twice the CO2 produced by an average car each year. They are the largest form of carbon storage, or “sinks,” in the U.S. and the way trees use water and reflect sunlight has a large effect on temperature. “Forests often dampen climate extremes. They can make heat waves less hot and cold spells less cold,” said Ollinger.

Ollinger explains that information on the effects of forest biodiversity on climate has been difficult to obtain. Most studies on the effects of plant diversity on ecosystems have been done in grasslands, where small plots can be used to manipulate biodiversity by planting and weeding. “In a forest, you’d need to plant different combinations of tree species over an enormous area then wait a hundred years for them to mature,” said Ollinger.

In this study, Ollinger and his team, research associate professor Bobby Braswell, associate professor of Earth and geospatial science Michael Palace and research associate professor Jingfeng Xiao, will take a “big-data” approach by using data from a vast network of sensors on towers above 40 different forests throughout North America.

The research will bring together unique sources of data, like AmeriFlux and the National Ecological Observatory Network (NEON), that have not previously been used to address these questions. Measurements will be collected with high-tech tools like drones, aircraft spectrometers and laser imaging systems as well as on-the-ground fieldwork. The study will focus on a more complete picture of how the number of tree species in different forests affects the uptake of CO2, the transfer of water from soils to the atmosphere, and on the sensitivity of these processes to climate variability.

This issue is increasingly relevant as North America loses tree diversity, primarily due to invasive pests and pathogens like chestnut blight, Emerald ash borer and Hemlock wooly adelgid. New Hampshire alone hosts 40 invasive species that could weaken or even eradicate an entire tree species.

The grant is part of a $15.9 million award from the National Science Foundation Directorate for Biological Sciences that will fund 12 new MacroSystems Biology and Early NEON (National Ecological Observatory Network) Science projects. Early NEON Science grants go to projects that don't fit into the macrosystems biology focus on regional- to continental-scale questions, but use or leverage NEON data and/or samples to address innovative ecological or biological questions, or develop analytic or computational tools that enhance the use and value of NEON data.