Floods and conservation: best not to over-reach

“Nature has a way of dealing with high rainfall events and storms: in rainfall-prone areas, she covers the soils with thick, deeply-rooted plants, providing a network of vegetation that absorbs the water and hold the soils in place. Biodiverse ecosystems have a complexity and resilience that can take on more of the knocks that nature throws at us than eroded, heavily utilised or human-altered environments can.

Rich, dense vegetation in a landscape can dull the impact of a downpour, diluting, absorbing, channelling, holding and then slowly releasing water. Mangroves and salt marshes buffer coastal landscapes from storms, reducing the force of the onslaught by softening its power and slowing the erosive energy of wind and wave action. These systems are designed by nature to take on nature.

If you mess about with these systems, what happens? The services provided by ecosystems erode and things start to go wrong. If you remove vegetation from the land, soils are laid bare and are washed away. If you carve up a landscape, alter natural features, damage the soil structure, pave it, or build all over it, nature will battle to function.”

That is Pippa Howard from FFI on how poor landscape management in Britain has contributed to the current floods severely impacting parts of southern England. I agree with the main thrust of her piece, but I was nonetheless alarmed by a couple of important points.

Firstly nature never designs anything. It might seem a nice turn of phrase but it is sloppy language and a little bit of thought could have removed the anthromorphism without diminishing the power of the argument.

This has a bearing on the second point, which is that on their own nature’s flood defences are often not sufficient. Nature is as red in tooth and claw as she ever is nurturing and maternal, and certainly won’t hold back from the odd catastrophic flood just because we go all eco-activist. Indeed the occasional catastrophic occurrence is very much a part of how nature goes about refreshing herself.* How else do you think we got big wide flood plains around just about every major river in the world? Ecosystems have both short term cycles and longer term, often more abrupt and less predictable dynamics, that interact in complex ways. Some species even rely on once in a decade type events to reproduce (desert flowers are a classic case in point).

All of which is little comfort to flooded farmers in the Somerset Levels and elsewhere. Yes the focus may well have swung too far one way, and more sensible approaches to landscape management could undoubtedly help mitigate future floods. But I’d keep the man-made defences too.

* Ok I admit it: this anthromorphism can be hard to avoid!

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