André Vézina, ITA, La Pocatière Campus
Benefits of Installing Shelterbelts
April 2006
André Vézina, ITA, La Pocatière Campus
Reasons for planting shelterbelts around livestock buildings
Odour mitigation Reduction of heating costs Control of snow accumulation Reduction of air-conditioning costs Reduction of dust volume Protection for livestock Aesthetic enhancements to surroundings Enhanced biodiversity Secondary productions Reduction of greenhouse gas emissions
André Vézina, ITA, La Pocatière Campus
How shelterbelts help mitigate odours(Tyndall and Coletti, 2000)
Dilution of gas concentrations
Dust and aerosol deposition
Interception of dust and aerosols
Absorption of chemical constituents of odours
André Vézina, ITA, La Pocatière Campus
Dilution of gas concentrations
André Vézina, ITA, La Pocatière Campus
If temperatures are favourable, and if the site topography is flat and free of obstacles, air circulation close to the ground will cause objectionable odours to be less noticeable.
André Vézina, ITA, La Pocatière Campus
Shelterbelt Quiet zone
Turbulent zone (plume dilution)
Distance from shelterbelt (H)
(Adapted from Raine, 1974, as used in McNaughton, 1988)
André Vézina, ITA, La Pocatière Campus
Artificial windbreaks used to deflect ventilated air upward, so that foul air flows higher above the ground, can noticeably reduce odours downwind (OCTF, 1998; Bottcher et al., 1999).
André Vézina, ITA, La Pocatière Campus
Dust and aerosol deposition
André Vézina, ITA, La Pocatière Campus
Air containing dust particles can carry a greater amount of odour-producing molecules than the same volume of dust-free air (OCTF, 1998).
In average, a windbreak with a porosity of 40% will reduce wind velocity by 50% over 10 H, and by 25% over 10-20 H (Vézina, 1985).
This reduction will cause wind-borne particles to be deposited.
André Vézina, ITA, La Pocatière Campus
Wind tunnel modeling of a three-row shelterbelt system has quantified reductions of 35-56% in the downwind mass transport of odorous particles (dust and aerosols) (Laird, 1997; Thernelius,1997).
Other studies have shown a 70-90% reduction in pesticide concentrations on the lee side of shelterbelts made of hardwoods (Porskamp et al., 1994).
André Vézina, ITA, La Pocatière Campus
Interception of dust and aerosols
André Vézina, ITA, La Pocatière Campus
Absorption of chemical constituents of odours
André Vézina, ITA, La Pocatière Campus
Significant quantities of volatile organic compounds have been measured on the surface of plants and within plant tissues (Reischl et al., 1989; Gaggi et al., 1985).
Micro-organisms that dominate the surface of plants absorb volatile organic compounds, thus providing additional surface area for pollution collection. These organisms also have the ability to metabolize and breakdown volatile organic compounds (Screiber and Schonherr, 1992; Mueller, 1992).
André Vézina, ITA, La Pocatière Campus
Choinière Project (2004): Evaluating the performance of mature shelterbelts in mitigating odours
André Vézina, ITA, La Pocatière Campus
F factor (odor limits)
Reduction in length of odour plumes by 19%, 23% and 25% compared to control
Distance
Source/wb
Odor plume length Length reduction
No windbreak
André Vézina, ITA, La Pocatière Campus
Reduction in surface area of odour plumes by 30%, 33% and 37% compared to control
Distance Source/wb
No windbreak
Odor plume area Length reduction
André Vézina, ITA, La Pocatière Campus
Odour dilution is enhanced by a ratio of 1.9, 3.2 and 5.1, respectively at distances of 60 m, 30 m and 15 m.
Hardwoods
Conifers
Average (Hdw-Cnf)
Average dilution ratio vs. distance between odour source and hedge
André Vézina, ITA, La Pocatière Campus
10-15% in NE USA (Heisler and De Walle, 1988) 27% in Western Canada (PFRA)
(1.2% per km/h in wind speed in unprotected areas)
Reduction in heating costs
André Vézina, ITA, La Pocatière Campus
Shading created by trees and shrubs can lower temperatures by 10-14°C, thus reducing air-conditioning costs by 50-70% (Gaudet, 1985). The trees should be planted on the western side of the buildings to ensure optimal protection during the summer without significantly reducing solar radiation during the winter (USDA, 1985).
André Vézina, ITA, La Pocatière Campus
Control of snow accumulation
André Vézina, ITA, La Pocatière Campus
Improved weight gain and reduced death rate in livestock.
André Vézina, ITA, La Pocatière Campus
Shading is beneficial to animals. For example, milk production starts to decline when temperatures exceed 20°C (Hintz, 1983).
André Vézina, ITA, La Pocatière Campus
A dense hedge of trees and shrubs has been shown to reduce by one-third the volume of decibels generated by normal road traffic in a peri-urban area in Nebraska (Cook and Van Haverbeke, 1976).
André Vézina, ITA, La Pocatière Campus
Shelterbelts have the ability to collect a portion of air-borne dust particles. According to Dochinger (1980), dust fall can be reduced by 38% with the use of coniferous shelterbelts and by 27% with hardwoods, compared to an area that contains no trees.
André Vézina, ITA, La Pocatière Campus
Aesthetic enhancements to surroundings
André Vézina, ITA, La Pocatière Campus
Enhanced Biodiversity
Presence of trees and shrubs is of considerable help in enhancing biodiversity (Boutin et al., 2003; Deschênes et al., 2003; Maisonneuve and Rioux, 2001).Their study included six types of buffer strips: grasslands, grass-like strips, low-growing scrublands, high-growing scrublands and wooded hedgerows. It is in these wooded hedgerows that the highest population and greatest diversity of birds was found as well as the highest populations of amphibians and reptiles. The total number of small mammals captured increases from grasslands to scrublands to wooded hedgerows.
André Vézina, ITA, La Pocatière Campus
Secondary productions
Wood
Berries
Nuts
Branches
André Vézina, ITA, La Pocatière Campus
Hybrid poplars
110 clones
Lapotika Farm,
La Pocatière
André Vézina, ITA, La Pocatière Campus
Planted en 1981, harvested in 2005
André Vézina, ITA, La Pocatière Campus
Yield
1 m3/tree 90% lumber 7 trees/cord
André Vézina, ITA, La Pocatière Campus
We expect better results from some selected clones
André Vézina, ITA, La Pocatière Campus
Study conducted on 10 shrub species (La Pocatière, 2004-2006)
André Vézina, ITA, La Pocatière Campus
Preliminary results (www.cepaf.ca)
Sambucus canadensis, aronia melanocarpa, viburnum trilobum and rosa rugosa gave the best yields among the shrubs under investigation.
Sambucus canadensis show the best yields (1,25 kg per plant), but we expect the plants to give more as they reach their full production potential.
André Vézina, ITA, La Pocatière Campus
Branches
Trends in floral design have increased the demand for branches from a number of shrubs with decorative flowers and fruits, as well as branch form and color. A study is underway under the leadership of Bruno Moser, head of Purdue's Department of Horticulture, to develop a sustainable system to produce economic shoots of a number of plant species including the Salix caprea (pussy willow) and S. matsujdana tortuosa (corkscrew willow).
André Vézina, ITA, La Pocatière Campus
Reduction of greenhouse gases
Evolution of carbon emissions in Canada with and without Kyoto Protocol application
(Rochette, 2000)
André Vézina, ITA, La Pocatière Campus
This 3 row model is capable of sequestering 300 tons of carbon per kilometre of windbreak within a 40-year timeframe (PFRA (1997).By planting annually 100 km of hedgerows by 2010 in eastern Canada , it would be possible to mobilize, in 40 years, a total of 0,2Mt of CO2, which
represents 0,03% of the forecasted annual production in Canada in 2010. A small step in the right direction…
André Vézina, ITA, La Pocatière Campus
Inconveniences
Rodents (negligible)
Birds (negligible)
Higher odour concentrations in the area between the
shelterbelt and the source of the odour
Increase (3°C) in air temperature within protected area