Farming the Forest

On a bright October day as a chill breeze signals the coming of winter, Yale School of the Environment scientists are deep in the soil preparing field experiments for this spring’s growing season. They are at a linear gap in Yale-Myers Forest studying how light gradients and tree root competition are affecting crop germination, soil moisture, and nutrients. There are six microzones within this gap and each crop, including sunchokes, fiddleheads, and assorted herbs, is planted within each zone. In some areas, the trees that line the sides of the gap are providing shade, in other areas, full sun.

Nearby, at Hidden Blossom Farm in Union, Connecticut, forests are being thinned to create silvopastures, where trees, forage, and livestock are integrated, and fruit and nut trees are being planted in open fields.

New England is the most heavily forested region in the U.S., with more than 80% of the region covered by forests. It is also the most densely populated and agriculturally limited area in the country. While only 8% of farmland nationwide is wooded, half the farms in New England directly abut or contain forestlands. Yet less than 2% of farmers in the region practice agroforestry.

YSE’s Joseph Orefice (left) oversees field experiments in agroforestry on his farm demonstration site in Union, CT, which include integrating trees, forage, and cattle grazing as well as planting fruit trees to create orchard silvopastures. Half the farms in New England directly abut or contain forestlands.

A new research collaboration is seeking to change that. YSE is partnering with Dartmouth College and the University of New Hampshire on the ADAPT (Adaptive Agroforestry Principles and Teaching) project, a $15 million USDA-funded program that is blending practitioner knowledge with modern science to help promote sustainable forestry and agriculture in a region running out of land for farming.

The team, which includes research partners from the U.S. Forest Service, is exploring how agroforestry can increase soil health and biodiversity, enhance carbon sequestration, and provide income in new markets for farmers. The researchers are experimenting with three agroforestry systems: silvopasture, which integrates trees, forage, and grazing; forest farming, where native food crops are planted under existing forest canopies; and food forests, inspired by Indigenous practices, where fruit and nut trees, such as apple and Chinese chestnut, along with shrubs and perennials, are planted as a stratified mixture.

“We’re using current science and going back to more traditional systems to create more resilient and dynamic agricultural systems by incorporating them into forests,” says Mark Ashton ’85 MF, ’90 PhD, the Morris K. Jesup Professor of Silviculture and Forest Ecology and director of Yale Forests.

Shrinking farms, fragmented forests

Farmlands in New England have been contracting for more than a century. What farmlands are left are boxed in by residential and commercial subdivisions, wetlands, and regenerating forests. In Connecticut, almost every farm shares a border with a forest.

Agroforestry is one of the oldest forms of land management — and also an emerging management system in modern-day agriculture. It is an answer to New England’s unique marginal landscape, promoting sustainable forestry and crop expansion in a region that gets most of its food outside its borders.

“Farmland is not available here in New England. You can’t just expand. You can’t rent new pasture. Forests that you already own are what’s available, and this work will let farmers expand their pasture without getting rid of forests,” says Joseph Orefice ’09 MF, director of forest and agricultural operations at Yale Forests, who owns the farm in Union where the field experiments in agroforestry are being developed.

Orefice’s farmlands, which have served as a silvopasture demonstration site for several field research projects, reflect the agricultural history of Connecticut and New England. In the 1700s, forests were cut down for subsistence agriculture and livestock. By the 1900s, as farming shifted west and industrial jobs took hold, the forests quickly grew back, only to come under pressure from residential and commercial development from the 1980s onward. Selective timber harvesting removed the most commercially valuable trees, unmanaged livestock grazed in the woods, and invasive species took hold — a familiar story for land stewards in New England.

Living lab

Now, Orefice’s farm and others across the region are providing up-to-date data on agroforestry practices as the ADAPT team tracks yields, climate impacts, carbon storage, and costs. The project is also providing training programs for practitioners through the newly established New England Agroforestry Training Program (NEAT).

“Our goal is to raise awareness and provide practical skills adapted to the New England landscape,” says Heidi Asbjornsen ’93 MFS, ’99 PhD, professor of natural resources and the environment at the University of New Hampshire. UNH is leading the project and has 10 cooperative farms and university forestland experimental sites.

“We have had an overwhelming interest from farmers. There’s real excitement about learning how to use their land in new ways,” she notes.

Bernard Nyanzu ’24 MESc, a postgraduate fellow at YSE, has been immersed in establishing research plots at Yale-Myers Forest and collaborating farms. At the linear gap in Yale-Myers Forest, Nyanzu took measurements of soil moisture and fertility in the microzones to characterize germination and growth rates of the fledgling native crops.

“We’re incorporating food crops that people like, including chestnuts, black walnut, elderberry, persimmon, and pawpaw. Each crop is grown in every zone so we can see where it performs best,” he says.

This past year, he led a team of student researchers in conducting a census of all plants in control and treatment areas. The team also developed experimental linear gap trials in the forests, collected soil samples to monitor soil nutrients and carbon content, planted trees for food forests, and established silvopasture in former forests.

Orefice, who earned his doctorate from the University of New Hampshire and his bachelor’s in forestry from the University of Maine, says the sites across New England are setting a baseline for research that will continue for more than a decade.

“The intent is that we will better understand functional mechanisms of these systems, which will inform how agroforestry can be practiced in this region,” Orefice says. “We will have real numbers to share, including on carbon storage and costs of agroforestry, which is what farmers always want to see.”