Silvopasture ( silva is forest in Latin) is the practice of integrating Tree, forage, and the grazing of domesticated animals in a mutually beneficial way. It utilizes the principles of managed grazing, and it is one of several distinct forms of agroforestry. If done correctly, silvopastures can count as nature-based solutions to climate change.
Properly managed silvopasture (grazed woodland) can increase overall productivity and long-term income due to the simultaneous production of tree crops, forage, and livestock. It can provide environmental benefits, and has been practiced in many parts of the world for centuries.
Silvopasture systems influence microclimatic conditions, offering advantages over open pastures and a suitable ‘middle ground’ solution compared to forests in the context of climate change adaptation. By retaining partial tree cover, silvopastures create a more moderated environment that helps mitigate temperature extremes and optimize soil conditions. This offers less stressful conditions for the grazers as compared to the open pastures improving its feed and water intake, reproductive health, milk yields, fitness, and longevity .
The integration of trees in silvopastures provide shade, which reduces the intensity of photosynthetically active radiation (PAR) compared to open pastures, while still allowing more light than dense forests. This balance supports diverse plant growth and improved forage quality. One study measured air temperatures near the soil surface (0.25 m) to be consistently cooler in silvopastures than in open pastures, with reductions of up to 7%, while soil temperatures at depths of 5–10 cm are also significantly lower in silvopastoral systems compared to open pastures.
Silvopastures moderate soil moisture levels, with trees contributing to better water retention in some seasons through shading, less wind and reduced evaporation. Studies found that during winter and spring, soil moisture levels in silvopastures are slightly lower than forests but higher than open pastures, while in summer, they provide a balance, preventing excessive drying as seen in open pastures.
These microclimatic adaptations—cooler temperatures, moderated light levels, and improved soil moisture—enhance the resilience of silvopastures to climate stressors such as heatwaves and droughts, which in turn leads to a more robust agricultural system.
Grazing controls understory vegetation and reduces the accumulation of fuel biomass, lowering the risk of forest fires. This leads to the maintenance of profitability and biodiversity and reduction / avoidance of carbon release due to fire when compared to an open pasture and forest. This problem is of particular importance in fire-prone regions like Southern Europe.Rois-Díaz, M., Mosquera-Losada, R., & Rigueiro-Rodríguez, A. (2006). Biodiversity indicators on silvopastoralism across Europe (Vol. 21). Joensuu, Finland: European Forest Institute.
A study with a focus on the US suggests that welfare of cows benefit from a Silvopasture ecosystem, as they are shown to have improvement in physiological response to heat stress, increased grazing time and decreased standing time (resting and Ruminant) when compared to cows in the conventional pasture grazing system. This means that a silvopasture system allows livestock to better adapt to climate change.
Besides providing better ecosystem services like water quality and wildlife habitat, silvopasture systems provide farmers and producers with diversified income streams from timber, forage, and livestock products. This enhances resilience to market fluctuations and climate variability - which is enhanced by climate change - making the system highly attractive to smaller or resource-limited producers.
Studies show that carbon uptake (negative emissions) is lowest in open pastures, intermediate in silvopastures, and highest in reference forests. This pattern is consistent across systems like tree alley-cropping and orchard-hay systems. Open pastures have higher CO2 fluxes due to factors like soil respiration and warmer temperatures. Removing canopy trees in open pastures further increases these fluxes by reducing evapotranspiration and increasing soil moisture.
Silvopastures also help retain more soil carbon than open pastures. While converting forests to pastures initially increases soil carbon, this gain is short-lived due to higher temperatures and faster decomposition. After a few years, soil carbon in open pastures matches that of forests. Silvopastures, with their mix of trees and pastures, may help maintain soil carbon over time, although significant changes often take decades to occur.
Additionally, converting forests to open pastures raises soil nitrogen levels and decreases the carbon-to-nitrogen ratio. While silvopastures show more balanced nitrogen levels, open pastures can increase nitrous oxide (N2O) emissions, a potent greenhouse gas. Overall, silvopastures provide dual climate benefits: they sequester more carbon and reduce harmful nitrogen emissions, making them an effective strategy for climate resilience.
Incorporating a mix of native tree species in silvopastures not only boosts economic viability but also increases biodiversity, ensuring the success and productivity of the system. Trees offer various benefits like providing forage, improving soil health, offering timber, aiding in erosion control, and supporting livestock health. When selecting trees, it's essential to choose species that complement grazing activities. Fast-growing species like black locust, willow, and mulberry are ideal as they integrate well with grazing. Additionally, indigenous tree species can attract plenty of insect species, which in turn will lead to more bird species, hence enhancing biodiversity and making the natural ecosystem more resilient. Livestock can also consume unharvested fruits, helping to control pests and diseases.
Silvopastoral systems can yield better forage during droughts due to the adapted microclimate. Forage species are carefully chosen based on soil type, climate, grazing tolerance, shade tolerance and attraction to certain species. Shade-tolerant grasses like bahiagrass, bermudagrass, tall fescue, orchardgrass, and ryegrass, along with legumes such as subterranean clover and Sericea lespedeza, are commonly used in silvopastures. These species ensure optimized productivity, livestock nutrition, and ecosystem resilience.
To overcome these challenges, well-structured education and extension programs are essential to provide farmers with the necessary knowledge and technical support. Training initiatives, demonstration farms, and knowledge-sharing networks could help bridge the gap, ensuring that farmers can confidently implement silvopasture systems in a way that maximizes productivity while mitigating risks.
While price fluctuations affect all agricultural systems, diversified revenue streams in silvopastures—such as timber, livestock, and forage—can provide greater resilience against market volatility. However, it remains unclear whether silvopastures consistently outperforms conventional monoculture farms in profitability.
Furthermore, some policies actively discourage the integration of trees on farmland. Additionally, zoning regulations may classify silvopasture land as agricultural or forestry, which can ultimately restrict eligibility for subsidies or land-use incentives.
In some regions, there are unclear or restrictive land ownerships laws. This uncertainty around land tenure discourages farmers from committing to silvopasture as the systems requires long-term management.
Their experience shows sheep use the trees for shelter from wind. This could provide significant animal-welfare benefits. However, 'sheep time' close to trees results in soil compaction, with the greatest compaction after trees are planted at very low densities. Some botanists recommend trees be planted at no less than 400 per hectare to ensure good establishment.
Evidence of old wood-pasture management is detectable in many of the Ancient woodland of Scotland, such as Rassal ashwood in Ross-shire, and at Glen Finglas in the Trossachs. The Dalkeith Old Wood, belonging to the Duke of Buccleuch, cattle grazing beneath ancient oak, is designated as a Site of Special Scientific Interest (SSSI) (ASSI).
Epping Forest is one of the principal remnants of wood pasture in England. Here, the grazing of cattle was combined with the pollarding of trees for fuel, both for domestic consumption and for sale. This system continued in the parish of Loughton until being banned in 1879. The town's public hall, built with compensation money for the ending of the custom, is called the Lopping Hall in memory of the practice. Controlled cattle grazing and limited pollarding are still carried out by the conservators.
|
|