Living trees as fence posts

Drive around Costa Rica’s windy mountainous roads and you will see numerous trees, from those bearing colourful fruits to others sporting thick spines, planted about 1 to 3 meters apart. Connected by long lines of barbed wire, these rudimentary-looking arrangements, known as living fences, have both economic and environmental benefits over their dead wood counterparts.

Farmers across Central America plant living fences because these green barriers are a more economically feasible and readily accessible method for containing livestock and protecting crops. For one, the main materials of living fences are the branches of tree species that root from sticks and grow into larger trees. Shared among neighbors or sold at local markets, these sticks are much cheaper and more common than manufactured posts. Without the need for paint or preservatives, which can add toxins into the environment, maintenance costs also remain low. Additionally, animals graze on living fences, saving farmers costs in livestock feed.

By providing some shade and serving as windbreaks, living fences can significantly decrease the amount of energy farm animals need to regulate their body temperatures. As livestock allot this extra energy to growth and, in dairy cows, producing milk, farmers experience higher yields, whether in meat or milk, for planting living fences.

saving money & materials

These tree posts also offer farmers the additional benefits of firewood, timber, fruits, tanning astringents, and dyes. In Costa Rica, the federal government even provides payment for ecosystem services (PES) to farmers with living fences. A study on a region where a 2002 to 2007 World Bank project funded and monitored the building of living fences throughout Costa Rica, Nicaragua, and Colombia, reports that small landholding producers rank the conversion of conventional fences into their living alternatives as a high priority.

But living fences are not only beneficial to farmers. Because living fences stabilize soils through their roots system, they can decrease erosion and protect watersheds from excess particulate matter. The roots of living fences also “pump” nutrients, a term used to describe roots that take up mineral nutrients from deep in the ground. These nutrients are later incorporated in the topsoil.

Above ground, living fences increase biodiversity in an area by providing many animals with food and shelter. Pollinators such as butterflies, bees, and birds are frequent visitors of living fences and, when living fences exist between two forests, animals can use them as passageways to easily move from one area to the next.

As pastures are abandoned, living fences also assist in quicker forest recovery than conventional fences because, with their greater tree cover protection and possibility for a meal, they more readily host a variety of birds and other seed disperses.

By using living trees instead of their dead wood counterparts, farmers can also ease pressure off of the forests that supply manufactured posts. Whole trees do not need to be cut for living posts because they grow from the trimmed branches of rooted posts. Living fence posts are also less-frequently replaced than dead wood posts, because they are less susceptible to rot and decay. In addition to slowing down deforestation, living fences posts, like any other living trees, uptake and store carbon. These benefits together can help mitigate climate change by decreasing the amount of carbon dioxide in the atmosphere.

Offering farmers, wildlife, and plants numerous advantages, living fences are certainly a sustainable and beautiful alternative to conventional construction.

By Molly Redfield

Molly is a research intern with the Nourishing the Planet project.

Source: Nourishing The Planet