Environmental Science
Lesson 3 of 4 9 min +60 XP

Biodiversity & Ecosystem Services

Why variety keeps ecosystems working.

What you'll learn

  • Define biodiversity
  • Give examples of ecosystem services
  • Link biodiversity loss to human wellbeing
The many-legged safety net

A meadow with dozens of plant and insect species shrugs off a drought or pest that would wipe out a single-crop field. Biodiversity is that safety net — variety keeps pollination, clean water, and food supplies from collapsing when one thread snaps.

Variety is not a luxury

Biodiversity is the variety of life at every level — genes, species, and ecosystems. It underpins ecosystem services: the benefits people get from nature, such as pollination of crops, water purification, climate regulation, and soil formation. More diverse systems tend to be more resilient to shocks.

Redundancy is resilience

When many species perform similar roles, the loss of one is buffered by others. Low-diversity systems are brittle — a single pest or disease can collapse them.

Roughly three-quarters of leading food crops depend on animal pollinators; declines in bees and other pollinators directly threaten food supply.
Lab · Trace a service
  1. Pick the ecosystem service of crop pollination.
  2. Identify which organisms provide it.
  3. Explain what happens to the service if their diversity collapses.

What you should see: Pollination is provided by bees, birds, and other animals; losing their diversity reduces and destabilizes pollination, cutting crop yields.

Knowledge Check

+18 XP / correct

1. 'Ecosystem services' are…

2. Higher biodiversity tends to make an ecosystem more…