Getting to grips with lichens, bryophytes & fungi

Every year, we try to keep our 'continued professional development' (CPD) profiles updated by attending conferences and training courses. Not only are these important professionally; they are rewarding, enjoyable and educational. This week I attended an excellent CIEEM training course in Somerset on lichens, bryophytes (mosses and liverworts) and fungi. 

The course was not meant to be a quick-fix identification class whereby participants would acquire diagnostic expertise overnight; rather it was a lesson in the importance of lower plants and fungi (traditionally known as 'cryptogams') to ecological understanding, nature conservation and wildlife mitigation. The awareness-raising exercise began with a highly-educational class in the biology and ecology of these groups. Although it was a whistlestop tour of the subject, it felt as if the information was truly being absorbed. All credit to the trainer.

We were treated to clear explanations of what lichens are. Most of us know it's a symbiotic relationship between an alga and a fungus, but perhaps not that the fungus symbiont defines the species name. We also learnt that fungi may be saprophytic (feeding on dead material), parasitic  (feeding on live hosts), or mycorrizhal (living as a symbiont with a plant or animal). Bryophytes, on the other hand, are not quite as simple to separate into mosses and liverworts as one might expect. Close inspection with a hand lens may be needed, to identify whether the leaves have a midrib (moss) or not (liverwort).

The field session took the group of a dozen or so participants through a limestone gorge, thickly wooded with deciduous trees, including some veteran oaks and beech, and lots of deadwood. Instantly the benefits of the classroom session became clear, and previous narrow perceptions of what lichens should look like were  overturned. Pale speckles on a hazel trunk, and a pale patina on field maple, were now recognised as lichens. Hand-lens inspection of 'mosses' showed them in fact to be liverworts. A range of fungal fruit were examined and discussed, including impressive mazegill brackets on old oak deadwood.

We were presented with several useful indicator species from each of the three taxonomic groups, with an emphasis on those that rely upon diverse and ancient environments. In fact, the phrase of the day was 'ecological continuity', and the most important ecological driver of lichen, bryophyte and fungal diversity is this long-term environmental stability. Interestingly, heavily-coppiced woodland is far inferior to that which has only ever been lightly harvested and selectively pruned.

The final classroom session of the day covered conservation issues, and the dramatic effect that environmental pollution has on lichen, bryophyte and fungi communities. Acid rain has been replaced by nitrogen pollution in the modern landscape, and this is reflected by declines in sensitive species, and rapid expansion of a few nitrogen-loving species.

Landscape management through controlled burning has a dramatic effect on lichen and bryophyte diversity. A few species benefit from burning, but most do not, and the bryophyte and lichen understory is lost through burning large areas. Again, it is ecological continuity that benefits community diversity, and the management history of a site can be used as a prism for interpreting and learning from current community composition.

This was a really enjoyable day - not to mention an educational and rewarding one - and excellent value at £90 for CIEEM members. The trainer was Justin Smith, Woodland & Wildlife Officer for Bristol City Council. The venue was Cleeve Village Hall in North Somerset, followed by a field visit on foot to Goblin Combe, a limestone gorge with ancient deciduous woodland.

By Chris Gleed-Owen, Director & Principal Ecologist, CGO Ecology Ltd.