Which species concept would be most useful to a team of biologists conducting a survey of bird diversity in forest plots?

The correct answer is - morphospecies concept.

Explanation:

The morphospecies concept is a species concept that is based on the differences and similarities in their structural or morphological features and characters to distinguish different species. The morphospecies concept is presented by Charles Darwin in his book "On the Origin of Species by Means of Natural Selection".

For a survey of bird diversity in forest plots, the morphospecies concept would be best as it is practically tough to study the phylogeny or other characters than morphology.

Thus, the correct answer is - morphospecies concept.