During a recent visit to the Miranda area we stumbled upon the Waharau Regional Park. We found a map of walks beside the unstaffed visitor centre and chose one of the loop tracks, careful to use the disinfectant and brush on the soles of our shoes as we entered and left the walk (in an effort to prevent the spread of kauri dieback disease).
Not far along the track were ‘fluffy clouds’ of lichen growing on the ground, so I took a photo and in an effort to identify the lichen found a superb NZ Geographic article (undated) by Derek Grzelewski, The microscopic world of lichens.
Writing for Te Ara, Maggy Wassilieff describes a lichen’s unusual parentage: A lichen is an amalgamation of a fungus and one or more photosynthetic organisms (those that make food from sunlight, water and carbon dioxide). No fungi can make their own food, but they have evolved ways to barter or steal it from other living things. A fifth of the world’s fungi do that by partnering with photosynthetic algae and/or cyanobacteria – their partnership is called a lichen. Read more here.
From the Grzelewski article: They not only become soil and humus, they actively create it. In some species the hair-like ‘roots’ can penetrate rock and oxalic acid within them reacts with most minerals and metals until it’s impossible to tell where the lichen ends and rock begins!
Waharau park is in the Hunua district which, as one local resident told me late last year (while it was raining), had a madly wet winter and spring – so wet her seed potatoes had rotted in the ground. The high rainfall may well account for the beautiful crop of lichen growing across, through and around her scoria walls.
A stroll through the historic Bolton Street Cemetery in Wellington is always worthwhile and on this occasion produced …
Last year in southeast Alaska we were told that the ‘beard’ lichens hanging from trees were an indicator the air was 98% pure as these lichens, Usnea species, otherwise won’t grow.