Droughts are threatening global wetlands

Date:
October 9, 2020
Source:
University of Adelaide
Summary:
Scientists have shown how droughts are threatening the health
of wetlands globally. Scientists highlight the many physical and
chemical changes occurring during droughts that lead to severe,
and sometimes irreversible, drying of wetland soils.



FULL STORY ========================================================================== University of Adelaide scientists have shown how droughts are threatening
the health of wetlands globally.


========================================================================== Published in the journal Earth-Science Reviews, the scientists highlight
the many physical and chemical changes occurring during droughts that
lead to severe, and sometimes irreversible, drying of wetland soils.

"Wetlands around the world are incredibly important for maintaining
our planet's biodiversity and they store vast amounts of carbon that
can help fight climate change," says project leader Associate Professor
Luke Mosley, from the University's Environment Institute and School of Biological Sciences.

"Globally, wetlands cover an area greater than 12.1 million square
kilometres and deliver at least A$37.8 trillion (Int$27 trillion)
in benefits per year, such as for flood mitigation, food production,
water quality improvement and carbon storage." Wetlands can suffer
"water droughts" both from the effects of a drier climate, and also
when excessive water is extracted or diverted that would normally flow
into them.

The review paper describes how drought often leads to severe cracking and compaction, acidification, loss of organic matter, and enhanced greenhouse
gas (for example methane) emissions. In some cases droughts can lead to
very long- term (>10 years) and irreversible soil changes, with major
impacts on water quality when soils are rewet after the drought ends.

"We have seen many examples of how drought in the Murray-Darling Basin has caused major issues including acidification of soil and water due to acid sulfate soils exposure in wetlands. This review highlights substantial
gaps in our global understanding of the effects of drought on wet soils
and how they will respond to increasing drought," says Associate Professor Mosley, who is also Deputy Director of the Acid Sulfate Soils Centre.

Effects can be different in different soil types and different regions of
the world. The spatial distribution of drought studies shows there has
been limited assessment in a large number of regions, including south
and central America, Africa, the Middle East, Asia and Oceania. Many of
these regions are predicted to be vulnerable to drought impacts due to
climate change.

Lead author Dr Erinne Stirling, from Zhejiang University (China) and
the University of Adelaide, says one of the most pressing findings from
this review is that there are huge swaths of the world where there is
no readily available published research on drought-affected wet soils.

And secondly, she says, there is effectively no applied research into
water management outcomes for wetlands and wetland soils.

"At a global level, wet soils are highly vulnerable to the effects of
climate change and need to be protected given the very high environmental
and socio- economic values they support. It is our sincere hope that
the information in this review contributes to protecting these valuable ecosystems," says Dr Stirling.


========================================================================== Story Source: Materials provided by University_of_Adelaide. Original
written by Robyn Mills.

Note: Content may be edited for style and length.


========================================================================== Journal Reference:
1. E. Stirling, R.W. Fitzpatrick, L.M. Mosley. Drought effects on
wet soils
in inland wetlands and peatlands. Earth-Science Reviews, 2020;
210: 103387 DOI: 10.1016/j.earscirev.2020.103387 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2020/10/201009093544.htm

--- up 6 weeks, 4 days, 6 hours, 50 minutes
* Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1337:3/111)