It is not uncommon to find an apple tree deep in the woods, a reminder that the forest-dominated landscape we know today is relatively recent. In the 1800s, farmers cleared much of the region for agriculture, and in those clearings, built wood-framed houses and planted apple trees. When, often for economic reasons, people later abandoned those farms, many of the houses fell down, but the apple trees remained.
And so today the trees stand, along sunlit woods roads, behind stone walls, and fruiting in clearings shaded by tall evergreens. But how many are there? And how are they doing, after all this time?
Researchers with the USDA Forest Service Northern Research Station and the Maine Forest Service collaborated with apple experts from the Maine Heritage Orchard and Washington State University to study the population of apple trees (Malus domestica) in U.S. forests. As described in a March 2023 article in Biodiversity and Conservation, they used data from the Forest Service’s Forest Inventory and Analysis network of plots – one for every 9.4 square miles of forest – to estimate a total national population of more than 250 million forest apple trees. The vast majority were in the eastern half of the country, where apples ranked 96 out of 223 tree species in terms of abundance.
Apple trees are widely dispersed in eastern U.S. forests, but most abundant in New York (more than 150 million), followed by Pennsylvania, Wisconsin, Illinois, and Michigan. The largest size apple trees are concentrated in New York, Pennsylvania, and Maine.
There are signs that all is not well among the apples. Populations are down by 24 percent compared to the 1998–2012 period, likely due to a combination of trees aging and dying, reduced fruiting due to lack of management or pruning, and a more robust canopy shading out the sun-loving apples.
This decline in wild populations is a concern, both for habitat and agricultural reasons. Although apple trees aren’t native – they originated in central Asia – they aren’t invasive, and their fragrant blossoms are beacons for bees and buffets for caterpillar-eating birds. The 259 million apple trees in eastern U.S. forests represent a reserve of genetic diversity, including many heritage strains that are absent from modern orchards. According to the researchers, conserving and evaluating forest apple trees could be key to enhancing the resilience of apple production in the region, while offering opportunities to rediscover and revive long-lost cultivars.