The yellow lichen Xanthoria parietina...a community of fungus, yellow and green algae that inhabit this tree.
It snowed a bit yesterday in our area and the roofs were all white, but later on... the sun was up and the temperatures climbed-up leaving melted snow dripping-off the roof down to the drainage. Looking down from the window on the top most part of our house , I noticed the dark spots on the roof tiles which I thought to be some collected dusts over the years. Have you noticed the same on some roof of houses covered with those yellow green moss or those dark green algae that look like accumulated dirt? I became so fascinated with what I see and so I made a research on this topic. Please read on.
the moss build-up on our rooftop
We were walking Lily, our chihuahua yesterday along the pathway parallel to the Marchfeldkanal near our home. I noticed that some trees were covered with those algae/fungus-like layers or moss that are either yellow or green in color... Before, I used to think they are bad for the plants and now when I saw them with vivid colors, it got me interested to see what they really are.
CRYPTOGAMS
These algae, lichens and moss or fungus -like organisms are called cryptogams and they are the oldest form of life on earth. They are very important to the ecosystem of our planet. We see them on roofs, walls, rocks, on trees and almost everywhere. They are organisms that gain their energy through the process of photosynthesis and they grow and multiply themselves through spores as they do not have seeds nor flowers.
Indeed, they are natural organism that are very important to the earths´s ecosystem because they absorb the carbon dioxide and nitrate oxide which are being fixed in its layers and then supplied to the soil where plants grow. Said to be very important because they stabilize the soil and its fertility.
The research done by the Max Planck Institute of Chemistry in Germany found out that these cryptogamic layers
bind around 14 billion tons of of carbon dioxide and 50 billion tons of Nitrogen yearly which totalleds 50% of the world´s natural land grown-nitrogen. There were too many researches and studies done on these organism.. but (!) the importance of their functions were not really given full attention or shall we say neglected...these two newfound facts on CO2 and and nitrogen showed what the cryptogamic layers could do to help us with our environmental problems and could balance the earth´s carbon cycle.
Since plants cannot absorb nitrogen directly from the air, they must be processed first by the cryptograms by means of absorbing it in their layers to produce nitrate and other compounds to help the plant grow.
In Austria and Germany and other Scandinavian countries in Europe, some companies are offering the Green Roof system. It is the process of converting the roofs into a green zone, which means that roofs are planted with a specialized kind of moss or vegetation that help minimize energy costs. This green roofs provide healthy urban environment, insulate and help with the nose reduction. Aside from the above benefits, the green roof also filters particles and dust and thus, makes the air that we breath become cleaner.
Source references:
http://www.scinexx.de/wissen-aktuell-14810-2012-06-05.html
https://www.solarify.eu/2012/06/03/kohlendioxidfresser-kryptogame-schichten/
http://advantage-environment.com/buildings/green-roofs-for-a-healthier-urban-environment/
