Manmade marshes poorer in plant-life than natural ones 20
September 2012, by Tom Marshall Artificially-created salt
marshes are no substitute for natural ones, hosting fewer kinds
of plant and often ending up overrun by just a few species,
scientists have shown. Sea lavender is conspicuous on a natural
salt marsh at Holkham, Norfolk. That's a problem, because the EU
Habitats Directive obliges the UK to replace salt marsh that's
lost to coastal development or erosion with new, 'biologically
equivalent' habitat elsewhere. Until now we've thought we were
complying, but the new study shows that making artificial salt
marsh that's an adequate substitute for the real thing is a lot
harder than we thought. Natural salt marsh is a precious habitat
that supports a very wide range of living things. It's home to
plants, insects and birds that live nowhere else, and is greatly
valued by naturalists and local people. The traditional
assumption has been that if we let coastal land that was once
salt marsh flood again – a p