A new method for monitoring macrophyte communities in small shallow lakes and ponds

Macrophytes are key to the functioning of small shallow lakes (SSLs) because they maintain a clear water state through numerous positive feedbacks. The composition macrophyte communities changes under anthropogenic pressures; as result, tools designed easily and rapidly assess their structure increasingly requested. We tested three sampling methods (the S3m method, stratified mapped inventory) monitor macrophytes in 26 SSLs. effect each method was evaluated on seven descriptors communities, including median conservation value. results were comparable for methods, but failed accurately value number species present at low frequency, exotic patrimonial species, hence serious consequences management decisions. applied 262 SSLs ranging from 1 m2 43 ha surface area. Generalised additive models used investigate environmental factors correlated with four or ecosystem descriptors. showed that area, distance source, elevation, bank verticality determinants richness. Invasive crayfish impacted richness coverage submerged macrophytes, whereas fish presence increased percentage reduced interest. successfully wide diversity France. It proved be rapid, reproducible, representative monitoring Therefore, it should SSL management.