Environmental Studies
- Precautionary principle
- precipitable water
- precipitation-efficiency index
- Predation
- predation analysis
- predation compensation
- predator
- preening
- preferential species
- pressure head
- pressure melting
- pressure potential
- pressure-gradient force
- prevailing climax
- prey
- primary succession
- principal components analysis
- Priscoan
- proboscis
- process-response system