Wind is a significant part of any climatic system. It interacts with other weather elements and can impact upon a permaculture site in a variety of ways, from modifying temperatures to affecting livestock. When you conduct a site survey and sector analysis of your permaculture garden, documenting the pattern of the wind is an important inclusion. On a larger scale winds follow fairly regular patterns, with air moving from cooler areas to warmer ones (such as from the ocean to the land) and from areas of high pressure to low.
At the level of the individual site, other factors can influence wind patterns, such as obstacles and topography. Fortunately, wind can also be deliberately directed and its movement altered. One of the primary ways to do this is by planting a windbreak.
Windbreaks can contribute to the tree cover on your property and be permeable to a degree to avoid too much of an abrupt disturbance in the wind pattern (which can create different problems). Choose species that are suited to your climate and site conditions, and that have deep anchoring root systems and, ideally, grow quickly so that the windbreak can get established. Nitrogen-fixing trees with good leaf fall are also beneficial as the windbreak can then become self-mulching, minimising the effort required to maintain it.
With the right design and plant species a windbreak can have many beneficial effects on your site. Here are some of them.
Cool Hot Microclimates
A windbreak can not only be designed to divert cold winds away from specific areas, but also to channel them to hot spots on a site that need cooling. You may have locations within your site, where plants and animals are affected by heat. Diverting cool winds towards those locations can help lower the temperature and make the conditions more bearable for animal or plant life. The shade from a windbreak can also prove to be effective at cooling a microclimate
Reduce Plant Damage
Windbreaks can protect plants from damage. If plants and trees are exposed to string winds they can experience stress, breaking of branches and stems, increased leaf and fruit loss, and even uprooting. By protecting the plants, you not only prevent plant damage, but you are also likely to get better yields (a happier plant will produce more) and more pollination by insects.
Wind moving across soil can deplete the soil in different ways. Wind can blow away loose topsoil and it can cause the soil to lose moisture more quickly than protected areas. A windbreak helps to minimise these effects. The planting of a windbreak also serves to help retain the integrity of the soil via the plant roots, and offer protection against erosion by rain.
Decrease Evaporation From Water
It’s not just from the land that wind can cause moisture to evaporate at a quicker rate; it also affects bodies of water. The wind quickens the uptake of water into the air from ponds, swales and other open water bodies. Windbreaks can divert the wind away from passing over water bodies.
Reduce Energy Loss From Buildings
Wind can also carry energy away from buildings. Instituting a windbreak to protect a house from a strong wind can have a significant effect on preventing heat loss – sometimes up to 60 percent in the colder winter months. This reduces your energy bills. Windbreaks can also shade buildings to cool them when the weather is warm.
A windbreak can also serve as a source of timber for use in the garden. Because a windbreak should have a degree of permeability (to avoid too radical a movement in the wind, which can create its own problems), they should be pruned regularly. Pruning offers material for compost or mulch, while more established windbreaks could also provide timber for garden beds and other projects.
Species suitable for a windbreak may not suit any other parts of your permaculture site, so planting a windbreak can increase the biodiversity of your site. As with other plantings, there are possibilities for companion and guild planting around a windbreak to incorporate more species. This also helps to give the soil ground cover to keep its cohesion and preserve its moisture and nutrient content.
Those species in the windbreak can also serve to attract different forms of wildlife. The sheltered side of the windbreak can attract insects and birds. The plants in a windbreak can also serve as nutrient traps for nutrients borne by the wind and rain. This helps the plants thrive which, in turn, will attract more wildlife. A windbreak can also be a useful device for preventing damage by wildlife. The right sort of plantings on the exterior side could, for example, help keep deer from getting into your vegetable patch.
Direct Wind to a Turbine
Wind contains energy. Being able to harness and utilise that energy is a great strategy to reduce reliance on outside (and often polluting) energy sources. Indeed, electricity production from wind farms is likely to become more and more important as the world needs to find more renewable means of producing energy. On the local scale, this can occur as well. A windbreak could, besides providing the benefits outlined above, direct wind to a generating turbine. Even a small wind turbine can generate enough energy to power other functions within your garden, such as a pump to move water.
Animals need protection from harsh winds, in both warm and hot conditions.
Being too hot or too cold will affect the animals’ behaviour, which will have the knock-on effect of making them less productive. A windbreak helps prevent animals suffering in cold conditions, and provides shade for them to cool down when the weather is hot.
Animals will also benefit from the fact that windbreaks can provide a filter to catch airborne dust, as well as, possibly, bacteria that could be detrimental to health. Filtering out dust also makes for a better environment for the people living on the site.