This is the time for wildflower hikes, more to be found every single week. It is also the time where there is enough moisture and warmth in the air that mosses and lichens awake from potential dormancy and fill the world with green, or, for that matter, orange, yellow, white and black, depending on the species.
The distinction between mosses and lichens, at my pay grade, is simple. One is a plant and the other a sandwich. Or so claim the teaching materials trying to instruct grade schoolers about their environment. Mosses are multicellular organisms that are able to use photosynthesis, like any other plant. They can’t transport moisture though, and thus need to stay close to the surface to absorb it.
Lichen, in contrast. are a mix of different organisms, one enveloping the other, thus the metaphor. The assembly consists of fungi fused with algae or cyanobacteria, and, only recently discovered, yeast. The individual ingredients benefit each other – the algae provide food for the fungus via photosynthesis and the fungal layer protects the algae from drying out, or being damaged by the sun. The yeast, as it turns out, produces noxious stuff that keeps animals from eating certain lichen. The resulting intact surfaces of lichen carpets help to keep things where they’re supposed to be, sort of gluing them down.
Most interestingly, lichens are a superb bioindicator – another sentinel warning us of environmental danger and destruction. “Because lichens have no specialized protective barriers, they also readily absorb contaminants and are among the first organisms to die when pollution increases, making them good sentinels for air quality.” They are sensitive to acid rain (the culprit being sulfur dioxide, from coal plants or long range industrial emissions.) They also get hurt by ammonia and nitrates used in agriculture, and they accumulate metals from power plant emissions. When they die off, we know WE are in trouble.
The US Forest Service has had a bio-monitoring program for lichen since the 1990s,
http://gis.nacse.org/lichenair/
“in which scientists record census data on the diversity and abundance of lichens in thousands of designated survey plots across the country. They collect some samples and send them off to a lab for elemental analysis to identify the type and amount of pollutants. The data help federal agencies set pollution targets and map out areas where the targets are not being met, and they also help state and federal agencies that review emissions permit applications and existing regulations.”
https://cen.acs.org/articles/95/i46/meet-the-sentinels.html
Who wants to bet that under the current administration pollution targets are changing, regulations are shifted – or for that matter, whole programs like these are terminated? Luckily, lichen are ubiquitous, and one or another of the up to 17.000 species will survive in regions where none of us would. We are the ones that will pay the health and environmental cost in our areas, when pollution is again unchecked.
In any case, I find all this fascinating; if you don’t, perhaps you can at least enjoy the beauty of these lifeforms as they cling to the surfaces around us.
Music today shall be Mahler’s 3rd – probably of his symphonies the closest to nature, in its description of glory and wrath, both. That should make your morning lively!!
Bonus: some daily wildlife!
On Monday we mentioned evidence that face recognition follows different rules than other forms of recognition and is served by specialized brain tissue. But what are those rules?
There seems to be no evidence whatsoever at this point that GMO engineered food is bad for you or for the animals fed with it. People have crossbred for centuries, and now they are doing it more efficiently and with required hoops of testing. What is the net environmental impact, you might ask? Do herbicide resistant crops increase the use of herbicides? Yes they do, but they also reduce the need for tilling the soil, which is bad for it and releases CO2 into the environment. It becomes a question of agricultural diversification – if you plant a mix of GMO and non-GMO crops you are ahead in terms of producing more food and doing so economically, without hurting the environment. The same is true for insecticide engineered crops: they reduce the need to spray those poisons, but they might increase the number of resistant bugs. Note that BT, the insecticide from a bacterium that has been added, is widely used by organic farmers in its original form since it is deemed environmentally safe. Again, sustainable strategies would call for a mix of both kinds of crops.
