Artificial ecosystems and stability
Answers are for parents and teachers.
1
Field A has 60 plant species, B has 12. If a pest eliminates 3 species, by what percent does richness fall in each?
A – 5 %, B – 25 %
2
Harvest energy is 90 GJ, extra energy used 30 GJ. Find the energy return.
3
3
Write two ecological advantages of drip irrigation.
Water is saved; soil salinisation and erosion decrease.
4
Write the stages of vegetation recovery in an abandoned field (secondary succession).
Annual weeds → perennial grasses → shrubs → trees.
5
Write three ecological benefits of urban greening.
Traps dust and gases, cools and humidifies air, reduces noise and creates habitat for animals.