Windbreaks (shelterbelts, vegetative environmental buffers) placed around livestock production facilities as Working Trees can help mitigate the movement of odors and dust generated by these operations. Four primary factors are thought to contribute to these odor issues: Urban expansion has placed many more people into closer contact with agricultural operations. Large scale livestock confinement production has led to increased concentrations of manure. Heavy concentrations of odor emissions travel across highly modified landscapes relatively devoid of natural barriers. Market economics and regulatory policies create limited producer incentives to control activities beyond minimum regulatory requirements.