Tundra ecosystems are fragile because they are extremely sensitive to changes in climate. The average temperature in the Arctic has increased by 2 degrees Celsius (3.6 degrees Fahrenheit) since the late 19th century, which is more than twice the global average. This warming is causing the tundra to thaw, which is releasing large amounts of carbon dioxide and methane into the atmosphere. These gases are greenhouse gases, which contribute to climate change. In addition, the melting permafrost is disrupting plant communities and animal habitats.
Other reasons why tundra ecosystems are considered to be fragile include:
* Low productivity: Tundra ecosystems are low-productivity systems, meaning that they produce a relatively small amount of biomass per unit area. This is due to the cold climate and short growing season.
* Simple food webs: Tundra ecosystems have simple food webs, with few species at each trophic level. This makes them vulnerable to disturbances that affect even a single species.
* Harsh conditions: Tundra ecosystems are exposed to harsh environmental conditions, such as cold temperatures, high winds, and limited sunlight. This can stress plants and animals and make them more susceptible to disease and predation.