Natural Resource Management and Environmental Conservation
Natural resource management and environmental conservation covers soil, water, rangeland, forests, biodiversity and climate. The exam tests carrying capacity, erosion control, water harvesting and the effects of farming on the environment.
Core rules
Carrying capacity is the number of animals a pasture can support without degradation. Stocking rate is the number actually kept per unit area. Rotational grazing rests camps and allows recovery. Contour banks, grass strips and mulching reduce erosion. Water harvesting captures runoff for crops or livestock. Biodiversity supports pollinators, predators and soil life. Pollution from fertiliser, manure and pesticides must be managed.
Worked example
A 500 ha ranch has a recommended carrying capacity of 10 ha per large stock unit (LSU). The farmer currently keeps 70 LSU. Calculate the sustainable number and the excess. Reasoning: sustainable LSU = 500 ÷ 10 = 50 LSU. Excess = 70 − 50 = 20 LSU. The farmer should reduce stock or lease extra land. Keeping 70 LSU is a stocking rate above carrying capacity and will cause overgrazing, bush encroachment and erosion.
Traps that cost marks
Do not confuse stocking rate with carrying capacity. Do not assume rain immediately restores degraded range. Do not ignore the difference between short-term drought and long-term degradation.