TABLE 1.

Comparison of the four implementation strategies in terms of compatibility with current standards, backward and forward compatibility, performance, biodiversity coverage, generalization potential and ease of standardization

Implementation strategy	Subcategory	Compatibility with current standards	Backward and forward compatibility	Performance for monitoring programme	Potential biodiversity coveragea	Potential for spatiotemporal generalization	Ease of standardization
(A) Taxonomy‐based	Screening species	+++	++	+++	++	+	+
(A) Taxonomy‐based	Screening bioindicators (for BIs)	+++	++	++	+	+	+
(B) De novo	Bioindicators discovery	—	—	—	+++	++	+
(B) De novo	Supervised learning and predictions	+++	+++	+++	+++	++	+
(C) Structural community metrics	Alpha and phylogeny‐aware metrics	+ (alpha diversity)	—	+	+++	+	+
(C) Structural community metrics	Co‐occurrence networks metrics	—	—	—	+++	+++	+
(D) Functional community metrics	Functional genes/ transcripts	—	—	—	+++	+++	++

^a Depends on molecular methodology, i.e., amplicon versus shotgun. If amplicon, it will depends on PCR primers targets, e.g., universal eukaryotes and prokaryptes versus group specific primers.