Hello, I hope you’re well and life’s dealing you a good hand
at the moment. My apologies for being so lax in providing you with your weekly
update of peatland factoids, but a combination of hurricane and Arctic swells,
kept me in the water a bit too much last week.
The topic for this post, as you can see from the title is;
CLIMATE CHANGE!!!!!!! Alterations to the climate and their causes are well
documented and presented far more concisely than I can hope to achieve in a few
sentences, so here’s a good link on the general context for this post:
Evidently this whole business is of huge importance for the future
of global biomes and ecosystems within them. The alteration to climate will
vary across the globe and so within an assessment of potential impacts on
ecosystems, key environmental variables must be identified along with their
value ranges which support certain vegetation assemblages.
Moore (2002) identifies that climate change threatens to
change Peatlands primarily through alterations to temperature and precipitation
(directly for bogs or indirectly through groundwater recharge for fens).
As discussed previously a key dynamic of peatland formation and
development is the unbalanced relationship between biomass deposition and
decomposition. The product of any biological process is produced though the
energy available to a system. Thus with an increase in temperature there is an
increase in the biomass grown, but also decomposed. Davidson and Janssesns (2006)
state that the understanding of feedbacks within soil substrates to discern the
role of intrinsic temperature sensitivity on decomposition from those obscured
by environmental constraints which themselves can be subject to climate, is a
tad difficult... to say the least.
Something that be assured is that with increased atmospheric
Carbon dioxide and nitrate deposition the biomass productivity will increase globally
and thus the fundamental control on the opposing factors of peat formation is
the future distribution of precipitation as this restricts oxygen
concentrations and thus decomposition.
The role of this relationship will dictate the future view
of peatlands within the climate system as either sinks or sources of greenhouse
gases. In Moore (2002) the danger of increases in decomposition are made plain
in that peatlands may become sources of Carbon dioxide as well as methane and
nitrous oxide. These gases would contribute to a positive feedback system in
which climate change would intensify thereby threatening the release of more of
the 455Gt store of carbon which constitutes 25% of the global soil carbon
store.
Below is a good summary video of the feedback systems:
So climate change will impact, but it largely depends on precipitation.
In the next instalment we’ll take a look at climate projections for the UK and
see how peatland cover will be looking up to the 2080’s.
Cheers
Matt
References:
Davidson, E.A., & I.A., Janssens., 2006. Temperature
sensitivity of soil carbon decomposition and feedbacks to climate change.
Nature, vol. 440, p165-173
Moore, P.D.,2002. The future of cool temperate bogs.
Environmental Conservation, vol.29, p3-20.
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