Ponderosa Pine Die-Off in Horse Pasture: Soil Compaction + Beetles

**Horse pasture = double stress** on ponderosa pines:

1. **Soil compaction** from hoof traffic → root suffocation.
2. **Manure buildup** → excess nitrogen/urea → nutrient imbalance, root burn.
3. **Stressed pines emit volatiles** → attract **mountain pine beetle (*Dendroctonus ponderosae*)**.

Signs of Beetle Attack

• Pitch tubes (popcorn-like resin) on bark.
• Boring dust (frass) in bark crevices.
• Needles fading green → yellow → red → gray.

Immediate Actions

• **Contact MT DNRC Forester:** dnrc.mt.gov for on-site diagnosis.
• **Remove & destroy** beetle-infested trees (burn, chip, debark) **before spring flight**.
• **Reduce pasture pressure:** Rotate horses, aerate soil, manage manure.
• **Thin stand** to reduce competition if overstocked.

Resources

MT Pine Beetle Info: beetles.mt.gov