First paragraphs:
Feral or wild fruit such as apple, pear, and plum, are the offspring of domestic varieties that have escaped cultivation (Cronin et al., 2020). Such fruit is commonly found on farms across northeastern North America (Eppig, 2012) where older farm infrastructure such as field boundaries defined decades ago are still in place (Cronin et al., 2020). These feral trees are the hybrid offspring of heritage variety ancestors (Cronin et al., 2020; Gross et al., 2018; Volk & Henk, 2016) deposited by wildlife as seeds on stone piles, along woodland edges, in clearings, and on wooden rail fences (Fritz & Merriam, 1996). Rail fences on these farms were commonly built in a manner that did not require post holes, and were constructed from 60 to 200 years ago out of split cedar rails and installed on rocky ground (Bowley, 2015; McIlwraith, 1984) and stone field borders composed of glacial till and glacial erratics (Chapman & Putnam, 1940; Putnam & Chapman, 1936).
On many farms, these stone field borders still define the field sizes set when farmers first tried to clear arable land of stones and stumps by carrying or dragging rocks to field edges (Gage, 2015; Ripley et al., 1946). This has created a landscape of small fields with almost permanent field boundaries that are characteristic of farms in regions of shallow topsoil, rocky ground, typical of many farms across northeastern North America, including central Ontario (McIlwraith, 1984). These small fields are bordered by hedges of mixed species of native and introduced plants, shrubs, and trees (Fritz & Merriam, 1996). The resulting adventive hedges (Figure 1) can be up to 20 feet (6 meters) wide and are effectively linear woodlands (Fritz & Merriam 1996; Rackham, 1994) where wildlife abound alongside cattle, sheep, crops, and hayfields (Mineau & McLaughlin, 1996). Characteristic fruit trees and shrubs of these field borders include both native and introduced species (Fritz & Merriam, 1996), such as feral apples (Figure 2), crab apples, feral and native plums, gooseberries, grapes, cherries, blackberries and raspberries, rowan berries, dogwoods, and viburnums, all of which provide food and habitat for birds, mammals, and insects (Mineau & McLaughlin, 1996). . . .
