The conclusion that can be drawn is that plant protection involves processes and interactions that occur between “natural” and “human use” systems.


The previous case studies have shown that changes in natural systems and in human use systems can both affect pest problems, food production, and cause further natural system (ns) – human use system (hus) interactions.
  • Example 1: High levels of pesticide use (hus) can cause the development of resistance to insecticides in insect populations (ns) resulting in greater crop loss (hus).

  • Example 2: Changes in cropping practices (hus) or burning fossil fuels (hus) – that emit green-house gasses that cause global warming (ns), can both have an impact on pest development (ns) and cause crop losses (hus).

  • Importantly, plant protection scientists, agronomists, policy makers and farmers need to be aware of these interactions.