Environment & Energy
Related: About this forumClimate change is killing off soil organisms critical for some of Earth's ecosystems
This article is in the current issue of Science. It's a news item and I believe it's open sourced.
Climate change is killing off soil organisms critical for some of Earths ecosystems
Subtitle:
Science News 11 APR 2022 BY ELIZABETH PENNISI
Excerpts:
Such biocrusts cover 12% of all land on Earth, so keeping them healthy is essential for the health of the planet. As they disappear, deserts may expand, says Bettina Weber, an ecologist at the University of Graz who was not involved with the work.
Until the 1980s, few scientists paid much mind to the crunching underfoot while traipsing through grasslands, deserts, and other drylands. The crackling, it turns out, comes from centuries-old conglomerations of life that help retain what little water there is and produce life-sustaining nutrients such as nitrogen and carbon. Biocrusts play critical roles in arid ecosystems, says Trent Northen, a biochemist studying microbial communities at Lawrence Berkeley National Laboratory.
Researchers had assumed anything in a biocrust could take the heat, given that they thrive where its dry and hot. But in 2013, scientists discovered climate change is changing the microbial composition of biocrusts. A new survey of these organisms in a pristine grassland in Canyonlands National Park in Utah has uncovered a hidden vulnerability of some of the lichens in these crusts.
Twice a year since 1996, researchers from the U.S. Geological Survey (USGS) have headed to 12 soccer fieldsize plots in the parks grasslands to take stock of the kinds and amounts of lichens, mosses, fungi, and microbesand the surrounding plants. The original goal was to monitor the spread of a nonnative plant called cheatgrass and its effects on the biocrust and other life. The researchers were able to compare their findings with results of a study in the park done in the late 1960s. It is truly impressive that the authors have these records over such a long timespan, Weber says.
The U.S. Southwest is rapidly warming, and Canyonlands is no exception, says USGS ecologist Rebecca Finger-Higgens, who led the analysis. Weather measurements over the past 50 years reveal temperatures in that park have increased 0.27°C each decade, and recent summers have been particularly warm.
At the same time, almost all the lichens have been waning, particularly the kinds that help convert nitrogen in the air to a form organisms can use, Finger-Higgens and her team report today in the Proceedings of the National Academy of Sciences...
Don't worry, be happy.
Expanding deserts are good for solar thermal facilities after all and they're great, since they bring down birds precooked and ready to eat.
I've been hearing how solar and wind would save us all my whole life, so are we there yet? Surely we are. No?
Chant after me: Solar, Wind, Battery, Electric Car...Solar, Wind, Battery, Electric Car... Solar, Wind, Battery, Electric Car...Solar, Wind, Battery, Electric Car...
Maybe you'll feel better.
I don't, but who cares what I think?
History will not forgive us, nor should it.
hunter
(38,335 posts)... and I'm seeing the change.
Weren't these changes supposed to be gradual, beyond the lifetime experience of any individual???
My in-laws have a home along a Sierra foothill river. Last year the river dried up to just a trickle of water going completely underground less than a mile downstream, and that was amidst the mandatory fire evacuations. Never seen that before.
This ain't right.
It will be worse this summer.
jfz9580m
(14,529 posts)eppur_se_muova
(36,302 posts)but it's sure not something that stuck in my memory.
So much research has been focused on the enzymes in rhizobia from legume root nodules, how much on similar enzymes in lichens ?
NNadir
(33,567 posts)...about Molybdenum?"
She just laughed, "lots of orbitals, I guess." (Her catalyst was molybdenum based, and there are molybdenum centers in almost nitrogen fixing enzymes.)
To my knowledge there are only two fifth period elements that are essential to life, molybdenum and iodine, although most organisms contain rubidium albeit with no known role other than to be carried along with potassium, for which it can serve as mimetic.
I always assumed there had to be lots of other nitrogen fixers, particularly at sea, and of course, there is abiotic nitrogen fixation. But no, I never thought about lichen, but it makes sense if you think about it.
I searched on Google scholar, with the search terms "lichen" and "molybdenum."
There are close to 7,000 hits, most relating to nitrogen fixation. Here's a really interesting one though that sort of blew my mind:
Brendan P. Hodkinson, Jessica L. Allen, Laura L. Forrest, Bernard Goffinet, Emmanuël Sérusiaux, Ólafur S. Andrésson, Vivian Miao, Jean-Philippe Bellenger & François Lutzoni European Journal of Phycology, 49:1, 11-19, (2014) Lichen-symbiotic cyanobacteria associated with Peltigera have an alternative vanadium-dependent nitrogen fixation system
Vanadium? Who knew?
eppur_se_muova
(36,302 posts)I knew from way back that V was a micronutrient, but had no idea what (else) for.
NNadir
(33,567 posts)This one: Iron-Only and Vanadium Nitrogenases: Fail-Safe Enzymes or Something More? Caroline S. Harwood Annual Review of Microbiology 2020 74:1, 247-266
It's a fascinating digression.
Drop me a line if you're interested.