The most common and most likely answer to this crossword clue is the 5 letter word BIOME
B
I
O
M
E
Buddy explains!
The straight part
We know that "an ecological community" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case an ecological community = biome.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does BIOME mean?
BIOME noun- Any major regional biological community such as that of forest or desert
- All the genomes of such a community