| fragile ecosystem | 2.83 | Fragile ecosystems destroyed. | ||
| marine ecosystem | 2.11 | They say the platforms also interfere with delicate marine ecosystems. | ||
| natural ecosystem | 1.51 | It is especially difficult to measure the value of natural ecosystems. | ||
| delicate ecosystem | 1.25 | They say the platforms also interfere with delicate marine ecosystems. | ||
| entire ecosystem | 0.99 | We have taken this entire ecosystem for granted. | ||
| local ecosystem | 0.86 | So, how do they fit into the big picture in the local ecosystem? | ||
| coastal ecosystem | 0.53 | The otters are the keystone species of a coastal ecosystem called kelp forests. | ||
| whole ecosystem | 0.53 | Mercury poisoning will upset the whole ecosystem. | ||
| antarctic ecosystem | 0.46 | He said the illegal fishing threatened the fragile Antarctic ecosystem. | ||
| aquatic ecosystem | 0.46 | Both consume oxygen when they get into aquatic ecosystems. | ||
| complex ecosystem | 0.46 | Neopets.com is a constantly evolving alternative world with a complex ecosystem. | ||
| endangered ecosystem | 0.33 | Scientists consider the Black Sea one of the most endangered ecosystems. | ||
| healthy ecosystem | 0.33 | Its presence is a sign of a healthy ecosystem. | ||
| unique ecosystem | 0.33 | Second, the hemlocks are the keystone of a unique ecosystem. |