| KOIPOND | Backyard ecosystem of a sort |
| BIODOME | Closed ecosystem of a 1996 Pauly Shore film |
| SERENGETI | Ecosystem of Tanzania famous for the land migration of wildlife |
| WILDFLOWERS | Plants growing naturally and forming an intrinsic part of the ecosystem of woodlands, meadows and country lanes such as bluebells, cowslips, ramsons, wood anemones or violets (4,7) |
| TAIGA | Northern ecosystem of coniferous forests |
| NEWTS | Forming the aquatic ecosystem of many ponds, salamander-like amphibians with three species in the UK - common, palmate and great crested (5) |
| REEF | Coral -; inhabited by invertebrates that spawn during a full moon, a type of ecosystem likened to a tropical rainforest of the sea (4) |
| ROCKPOOL | Inhabited by limpets, crabs, starfish and other sea life, a shoreline ecosystem in the form of a natural aquarium left behind by the tide (4,4) |
| DANUBE | A cyanide spill in 2000 left parts of which European river's ecosystem barren of life? (6) |
| SEAGRASS | Fundamental component of a healthy marine ecosystem |
| ZOOPLANKTON | Low member of a marine ecosystem |
| CORALREEF | Type of underwater ecosystem home to some 4,000 species of fish, seahorses, sponges, anemones, jellyfish, sea turtles, snappers and starfish (5,4) |
| BEE | The pollination of crops provided by ___ species and other organisms contributes to food production and is considered an example of an ecosystem service (3) |
| PLANKTON | Microscopic organisms floating in the sea that are a vital part of the marine ecosystem (8) |
| CORALMINDERS | Protectors of the reef ecosystem? |
| FOREST | Type of ecosystem formed by trees (6) |
| COS | Variety of lettuce found in ecosystem |
| EMMER | Ecosystem mercifully preserving old kind of wheat |
| KELPFOREST | Underwater ecosystem made up of brown algae |
| ICE | Essential part of Arctic ecosystem (3) |
