Silvopasture Design Calculator

This calculator sizes a silvopasture planting — trees integrated into working pasture — and estimates the tradeoffs between shade, forage, and cost. Total trees comes straight from your planned density times acreage; canopy coverage at maturity is derived geometrically from each tree's expected crown diameter (treated as a circle) multiplied by tree count, divided by total pasture area. It also back-solves the maximum tree density that keeps canopy under your target percentage, since silvopasture systems generally need to stay below 40-50% canopy for grass to persist. Forage impact is modeled as a simple tradeoff: canopy coverage reduces grass yield (roughly 0.8% yield loss per 1% canopy, capped at 60%) but also improves forage quality (about 0.5% quality gain per 1% canopy, capped at 30%), reflecting how shaded, cooler pasture often grows less bulk but more digestible forage. The livestock benefit side estimates heat-stress days above cattle's roughly 80°F comfort threshold from your average summer high, then scales an assumed weight-gain improvement (up to 15% in practice — full shade coverage across a full 120-day hot season) by how much shade canopy coverage actually provides and how many heat-stress days there are to offset.

Carbon sequestration combines a flat per-tree annual estimate (0.05 tCO2e/tree) with a flat per-acre pasture-improvement estimate (0.3 tCO2e/acre) — both fixed averages, not species- or soil-specific. Establishment cost totals seedling purchase, a flat $7/tree protection allowance (tubes or cages to keep livestock from browsing young trees), and $3/tree planting labor. Treat the heat-stress and carbon figures as directional planning numbers rather than site-verified projections. Herd size (AU) is collected but doesn't currently factor into any of the calculations above.