The ferns that saved the world
A CBS news report is that the north pole once had a tropical climate cause by a runaway greenhouse effect- follow the link to read the article for yourself. The unlikely herothat pumped the CO2 out of the sky was a small floating fern calledAzolla. Apparently, it liked the living in the vast numbers offreshwater lakes and as its remains sank to the bottoms of those lakes,it took a lot of carbon out of circulation. Azolla can be seen doingexactly this process in the freshwater lake of (Flecker) Cairns Botanic.Azolla with a paperbark leafAnother fern that featured boldly in the history of the planet is alligator fern (Stenochlaena palustris).This ancient swamp dwelling, tree climbing fern once accounted as muchas 90% of the vegetation biomass in continental North America!Some millions of years ago, North America was blasted bare by thecollision of the largest ever meteor to hit the earth. Only the verybottoms of some valleys and some pockets sheltered behind the RockyMountains survived. The first plant to recolonise this vast blastedwasteland was alligator fern. For a very long period the entirecontinent was covered in little more that a vast blanket of the stuffwith a few herbaceous willows in the creeks and in the mountains,perhaps a few California redwoods. The closest experience what theplace would have been like today would be one an alligator fern swampnear Tully. In Cairns, we also have an alligator fern swamp developingat the edge of the freshwater lake in the botanic gardens. Alligator fern on a pandanusTim Flannery’s book, the Eternal Frontierwas the source of information on the alligator fern. Tim is a scientistwho works at the South Australian Museum and who writes books on thegeology, geography and ecology created the animals and plants thatexist in the world today. Maybe history will regard his contribution asone of the greatest ecological reviews of the twentieth century yet itis a gripping read for the average person. If you want to understandthe environment this is a good place to start.