If there is one good thing about human beings it’s our ability to
get a lot done in a short time. Unfortunately this also applies to altering and
changing the natural environment (mostly for the worst). The scale of human
based impacts on ecosystems is huge particularly when it comes to damaging and
changing the habitats present to suit our own needs. To make it worse the funds
to try to fix (or at least limit) the damage are often frustratingly limited.
The Tree Sparrow took advantage of agricultural expansion, but has since declined markedly. |
Thankfully for us
nature can be flexible. Species can adapt to take advantage of altered land and
the new niches and opportunities it presents. Whether this is Pied Wagtails
roosting near vents on rooftops, Blue Tits using a nest box or Carabid beetles
colonizing conifer plantations; life does its best to succeed. These examples
are all of species that have exploited a new niches or opportunity in the short
term. But given long enough whole communities can adapt to exploit a new
habitat that has been created by man. I mentioned Farmland birds in my last blog post and I will talk a bit more about them now as they are a
fascinating example of such a 'cultural community'.
These birds have shown
remarkably adaptability to human alteration of the landscape. All of the
species we today associate with farmland (Yellowhammers, Linnets, Tree Sparrows
etc) are primarily seed eaters. So naturally they would occur in open grassland
habitats.
Brief history
lesson: the farmland in the U.K didn't just spring up by itself; it came about
as a result of mass deforestation beginning sometime between 5000 - 4500 BC.
This was for some species a death knell; but not these little pioneers.
Populations moved and grew to exploit these new niches that had been created
and it was a boom time for them. Fast forward 7000 years and these species are
in serious decline: Yellowhammers by 54%, Linnets by 60% and Tree Sparrow by
90%. As a result huge efforts are being put into helping these species, with
65% of U.K farmland now under some sort of stewardship scheme. And rightly so
it’s important to protect the species we have; they are all we have got
left.
As good as nature
is at adapting and species amazing ability to colonise new habitats is; it’s a
simple fact that the ecosystems that form around man-made habitats are often
drastically different and sometimes a lot less diverse than there natural
counterpart. So it could be argued that working to conserve and improve the
population of species present is not enough to fully repair an ecosystem.
Beavers bring massive benefits to wetland ecosystems. |
Step-up rewilding. This relativity new idea is gaining favour
amongst conservationists. Advocated by people such as George Monbiot, rewilding aims to conserve on a large scale, protecting whole ecosystems and
natural processes by returning them to their natural state (i.e pre-human
impacts). Such projects often involve conversion of habitats to their natural
state, such as re-forestation, and many include re-introductions of species and
top predators to help bring ecosystems back into balance, by linking up habitat
fragments and improving the overall ecosystem quality species populations tend
to increase and become more stable. Re-introducing the right species can have huge benefits for the ecosystem as a whole, such as Beavers. Additionally, restoring ecosystem functions
bring benefits such as minimising flood risk (reforestation) and water cleaning
(reed beds).
So whose land is
it anyway? Which option is better, conserving the species we have or
undertaking large and expensive rewilding projects to restore the species and
habitats that should occur in an area? The truth is there is no clean cut answer.
For some areas and habitats it makes sense to rewild; for example the reforesting
of Scottish uplands to expand Caledonian Forest. However often some areas can’t
be rewilded; maybe they are two small or the land use is too important to be
changed. In these cases it makes sense to do our best to conserve the species
already present.
So I guess it
boils down to this. Humans have changed ecosystem and habitats so much that
much of the land doesn’t really 'belong' to any species now. So the question of
'Whose land is it anyway?' becomes irrelevant. We need to do our best to
conserve as much biodiversity as possible. The best way to do this is to be
pragmatic….
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