|Simon Davey studying lichens in Jersey|
|Lichenologists in a Dutch churchyard|
This is the lichen Xanthoria parietina. With something like 1800 species in Britain, lichens present a challenge that could keep any naturalist inspired and occupied for a lifetime. As with birds, some are easily identified, while the identification procedures to name others require a series of complex processes involving chemicals, high power microscopes and the accurate measurement of structures such as spores. Lichens are probably the fussiest group about the environment in which they can survive. The presence or absence of many allows an ecologist to make a rapid initial evaluation of the health and ecological importance of a site. It is well known that lichens cannot tolerate acid rain. It was probably lichens that caused environmentalists to take seriously the problems, to us all, of industrial air pollution more than anything else. A few groups of species, and especially lichens, beetles and hoverflies indicate by their presence or absence the ecological continuity and lack of negative disturbance in the places in which they live.
|Mothing in Beckley Wood, East Sussex|
Some years ago I was given a contract to look at the lichens of an important nature reserve. Lichens require light as they prosper through the photosynthetic ability of the algal partner. The dense woodland in much of Britain is unsuitable for lichens, and it was only a restricted open part of the reserve that was important for lichens. Much of the reserve had a dense understorey dominated by holly and regeneration, preventing totally the development of a lichen flora. The lichen lobby successfully suggested the removal of much of this dense understorey, stating that it would be beneficial to the important lichen flora of the reserve. The fact that of at least equal importance with the lichens were bats was not taken into account. A most important and rare bat species in the reserve requires a dense understorey to maintain a supply of milk for its babies. Without this, the air in the understorey become dry, and the bat mothers cease to lactate effectively. One of the most important aspects of lichens is that many of the scarcer species do not colonise into new areas rapidly. One theory about the dispersal and colonisation of lichens is that, in some of the scarcer species, this is done in the digestive tracks of molluscs. Mollusc slime is an ideal adhesive for the spores as they develop on new tree bark. However, the rate of dispersal by this method is very slow. No self respecting slug will ever cross a motorway to deliver lichen spores to another piece of woodland. It just won’t happen. Without a very considerable passage of time, the clearance of an area of understorey would have had no effect on the lichen flora whatsoever. In fact, the bats require open woodland suitable for lichens in which to forage. Once the bat and lichen conservationists started talking to one another, a perfect solution for one aspect of the conservation of the reserve was arrived at.
|Birding in Scilly|
I launched myself as a freelance ecologist in 1988. One of the aspects of my new, freelance life was tour leading, and this took me to many parts of the world. My pan listing activities unlike that of most of my pan listing colleagues have been global. In this blog, I hope to be able to share not only those British species I have seen across the board, but also those from the whole world. This will be a challenge, and I hope that looking at both my British, and world lists will give amusement to some, and inspiration to others, and especially the fellow pan listers on Mark Telfer’s website. Mark Telfer estimates that there are some 80,000 species that make up the life total for Britain. The highest score of any pan listers is just over 10,000 and my British score has just topped the 6300 mark. What a lifetime challenge this fact presents. The total for the world will run into millions. One problem that the pan lister can never suffer is boredom! By keeping alert to the world around, the opportunities for being inspired by the natural world are ever-present.
Anyone who would like to make any comment, it would be really good to have your thoughts...