Lecture_6_Silvopasture_Fall 2017

Allowing livestock to graze in an existing woodlot is NOT a Best Management Practice. Forest grazing often results in excessive damage to existing trees and reduces natural regeneration. This can have a significant effect on the future value of the woodlot.

All trees sequester carbon from the atmosphere. Individual fast-growing hybrid poplars can remove approximately 25 kg of CO 2 per year from the atmosphere. If trees are planted in a 10m x 10m grid there would be 100 trees per hectare which, in combination with the pasture production, can remove 2.5 tonnes of carbon di oxide per hectare per year. Pasture alone can remove approximately 1 tonne of carbon per hectare per year.

Forage Production Introducing trees into your pasture will have an effect on the amount of forage (browse) produced. As the trees grow the amount of available light needed to grow the understory forages decreases. Carefully consider the impacts on forage production before you plant your pasture land. Young trees will have no immediate effect on the amount of forage produced Forage production declines with the increasing shade from growing trees and more shade tolerant pasture species will start to dominate If your farm has more pasture than is required to feed the entire herd then the impacts on forage production may not affect your operation

O N D J F M A kg DM ha -1 d -1 0 2 4 6 8 10 12 14 SS 20% SS 70% Open Forage production and shade interaction

@OMAFRA Innovates Climate Change Knowledge Exchange 2017 Plastic wind barrier

@OMAFRA Innovates Climate Change Knowledge Exchange 2017

Bioenergy options Planting fast growing, short rotation trees for energy production can reduce the cost of silvopasture while still providing some of the benefits. Hybrid Willows and Poplars are most commonly used for biomass plantations Many cultivars exist – you will have to carefully research which are most suitable for the specific conditions of the planting site Trees are harvested on a 3 – 5 year cycle

short rotation harvests results in regular and predictable revenue trees never reach a height where shade significantly reduces forage crop production there is also less shade benefits for animals planting stock is relatively inexpensive when compared to more valuable hardwood species trees can be grown on-farm by establishing a small nursery require a local market to be economically successful if no local market exists much of the woody biomass can be used on the farm as fuel for crop driers, heating buildings or as bedding material

A poplar-based silvopasture system in Chile. Poplar trees are harvested on the 16th year for revenue and they re-plant it again. For the first 3 years they even grow corn or wheat and then pasture is seeded.

Short Rotation Woody Crops (SRWCs) Shrub Willow Hybrid Poplar

September 2007 Short Rotation Willow Control Plots

Fruit and nut production It is possible to grow fruit and nut producing trees in a silvopastoral system although there are a number of precautions that may make it incompatible under most circumstances. Requirements for pesticides and fungicides may be incompatible with livestock In a pesticide free or organic cultural system this may not be an issue Fruits or nuts that fall to the ground should not be collected and marketed for human consumption Special precautions are needed to minimize livestock damage of new and established orchards

livestock should be excluded from the plantation until the trees crowns are above the reach of the animals egg-based repellents may be used to deter livestock from rubbing or grazing

Carbon models for silvopastoral and monoculture pasture systems

Atmospheric CO 2 Trees Net annual above and below Ground carbon = 1.1 t ha -1 y -1 Grass Roots Annual input = 2.48 t ha -1 y -1 Grass Net annual above ground Carbon = 5.41 t ha -1 y -1 Leaves + Fine roots Annual inputs = 1.92 t ha -1 y -1 Leached carbon = 1.4 t ha -1 y -1 Annual carbon input to soil = 4.94 t ha -1 y -1 Animal Respiration Carbon = 1.62 t ha -1 y -1 Animal Grazing = 5.41 t ha -1 y -1 Soil Respiration Carbon = 1.97 t ha -1 y -1 Animal CH 4 Emissions (CO 2 -e C) = 3.24 t ha -1 y -1 Faeces carbon = 0.54 t ha -1 y -1 NET CARBON SEQUESTRATION = 2.67 t ha -1 y -1 Hypothesized carbon budget for poplar-based silvopastoral system (all fluxes are expressed as t C ha -1 y -1 )

Atmospheric CO 2 Grass Roots Annual input = 2.49 t ha -1 y -1 Grass Net annual above ground Carbon = 5.45 t ha -1 y -1 Leached carbon = 0.95 t ha -1 y -1 Annual carbon input to soil = 3.04 t ha -1 y -1 Animal Respiration Carbon = 1.63 t ha -1 y -1 Animal Grazing = 5.45 t ha -1 y -1 Soil Respiration Carbon = 1.1 t ha -1 y -1 Animal CH 4 Emissions (CO 2 -e C) = 3.27 t ha -1 y -1 Faeces carbon = 0.55 t ha -1 y -1 NET CARBON SEQUESTRATION = 0.99 t ha -1 y -1 Hypothesized carbon budget for monoculture pasture system (all fluxes are expressed as t C ha -1 y -1 )

Carbon sequestration and Methane Emissions: • Silvopastoral system with hybrid poplars = 2.67 t C ha -1 y -1 Methane emission from a sheep = 25 g day -1 (Hegarty, 2002) …. Total CO 2 equivalent emission from a sheep = 0.19 t CO 2 y -1 Number of sheep that could potentially be grazed (C neutral) = 9.9 t CO 2 y -1 0.19 t CO 2 y -1 = 52 sheep

Carbon sequestration and Methane Emissions: • Monoculture pasture system = 0.99 t C ha -1 y -1 Methane emission from a sheep = 25 g day -1 (Hegarty, 2002) …. Total CO 2 equivalent emission from a sheep = 0.19 t CO 2 y -1 Number of sheep that could potentially be grazed (C neutral) = 3.7 t CO 2 y -1 0.19 t CO 2 y -1 = 19 sheep

Tree density of 111 trees per hectare can potentially enhance the C neutral carrying capacity by: 52 – 19 = 33 sheep

Silvopasture • Designed and managed for the production of trees, forage and livestock. • Blends agriculture, silviculture and conservation practices. • Considerations: objective; tree spp; density and pattern; forage spp; livestock type; animal management; silviculture considerations; wildlife interactions; economics. Silverhills Ranch, Lumby BC Jay Springs Lamb, Pinantan BC

BC Context – Area: 95 million ha; 94% Crown land; 60 million ha forested. – Grazing resource - mix of private land, grazing leases, licences and permits. – Animals are wintered at lower elevations near the ranch, move to higher elevation, forested Crown range in spring and summer. – Crown range - 30 to 40% of beef cattle total annual needs; integral to beef sector agribusinesses. – Overlapping land uses: timber, grazing, mining, recreation, guiding, community watersheds, wildlife use, etc. – Silvopasture an additional tool complementary or supplementary to existing management practices. – Case by case - evaluate utility along with other approaches.

Forest Grazing & Silvopasture Opportunistic Forest Grazing Compatible Management Silvopasture No/Minimal management, No integration Managed to minimize conflict, mitigate problems Designed and managed for synergies, Full integration - courtesy G. Powell

Field Pilot Development • Information synthesis: review; planning framework; existing research installations and demonstrations. • Operational field pilots - develop beneficial management practices, management recommendations which support regional and site- specific needs, and knowledge transfer. • Technical committee formed – Silvopasture structured through harvest from mature/ingrown sites in the Southern Interior

Southern Interior Pilot

• Vernon Creek Watershed – Community Watersheds on Crown land in B.C. - managed for a diversity of activities e.g., domestic water supply, recreation, forestry, livestock grazing, environmental protection. • Partnerships – BC Ministry of Agriculture; BC Ministry of Forests, Lands and Natural Resource Operations; Agriculture and Agri-Food Canada; the Regional District of Central Okanagan; the District of Lake Country; Okanagan Basin Water Board; Coldstream Ranch; Tolko Industries Ltd.; BC Cattlemen’s Farmland Riparian Interface Stewardship Program; BC Institute of Technology; private sector. • Support – Growing Forward , a federal-provincial-territorial initiative; Growing Forward 2 , a federal-provincial-territorial initiative; Agricultural Greenhouse Gases Program; OBWB Water Conservation and Quality Improvement Grant Program.

Objectives • Assess above-ground carbon storage potential; integrated timber and forage production potential; economic costs and benefits; livestock distribution and use. • Demonstrate silvopasture as a management option; technology transfer - producers and resource managers; business analyses.

Project Description • Crown land • Two forested rangeland sites (20 and 50 ha) • 1300 to 1400 m elevation • BEC: dry, mild Montane Spruce (MSdm1) • Douglas-fir, lodgepole pine, spruce, subalpine fir • Treatments: – forage control – forestry control – silvopasture (600 sph) – silvopasture (1200 sph)

Implementation • Partnership - ongoing • Site selection; pre-treatment - 2011 • Harvest – 2012 • Mechanical site prep – 2012 • Incremental riparian protection • Forage seeding – 2013, 2014 • Tree Planting - 2013 • Fd beetle sanitation harvest - 2013 • Grazing – spring, fall • Monitoring – annual, periodic • Reporting; outreach

Monitoring • Capacity for carbon storage - compare among silvopasture, conventional forest stands and forage sites • Forage production and utilization • Species composition, % cover • Potential production and utilization (caged and uncaged plots) – biomass • Seedlings • Height, diameter, damage; natural regeneration • Riparian health • Livestock use – GPS collar data - use of riparian areas relative to other habitats. – Pellet plots – relative habitat use