Ancient Tree Forum

Ganoderma pfeifferi – on an ancient beech tree.		In recent years there has been a dramatic change in the way we look at the roles of fungi. No longer is fungal decay and hollowing of ancient trees seen as detrimental, instead they seem to be the key to prolonging the lives of trees. Although we only perceive the tree, the relationship appears to be so close that every tree has been described as creating a unique and dynamic support system for fungi. Strip away the cellulose and lignin and you are likely to still see the whole tree in ghostly fungal relief. They can also be extremely large organisms - a honey fungus in the USA has been measured at over 50km in diameter. Some fungi can also very long lived; perhaps living forever as some are known to grow continuously. Fungi fulfil a host of important roles in all parts of the tree - within cells, between cells and on the surface of all parts of the tree, from the leaves in the canopy down to the root hairs. They also occur throughout all stages of a tree's life.

		In the woodland ecosystem many are essential as vital decomposers and recyclers of plant remains others are key transporters of nutrients for the health and optimum growth of plants. Most fungi can be separated into these two main groups: - Decomposition [recycling] fungi - associated with wood, leaf litter and other plant and animal matter. The saproxylic fungi are associated particularly with wood decomposition of living standing trees and fallen decaying wood. Mycorrhizal [food gathering] fungi - forming symbiotic associations with the roots of trees. In both groups some fungi are associated with a wide range of tree and plant species, others are very specific in their choice of partners. The fungal fruiting body is a very tiny part of the organism; much is out of sight as a mycelium growing within and around plants tissues. The presence of fungal fruiting bodies has often led to much concern, however few fungi are major pathogens and in natural systems active pathogens may have a function in glade creation. They pose us a threat only in our dense single stand crops of trees or ornamental areas. Like other species in the ecology of ancient trees some of the fungi are rare and threatened. Of the 447 macrofungi on the British Red Data Book list nearly 400 are from Ancient Woodland and lowland pasture woodland. Many of those naturally hollowing the heart wood of trees have very restricted distributions. Loss of habitat is still a major concern in the conservation of fungi. Major losses appear to be happening due to acidification and increased nitrogen levels in soils.

Fungi and other wildife Fungi of some description		It is not only the trees which are dependent on fungi. Many woodland invertebrates could not take advantage of the wood without the fungi ‘softening’ it up first. The invertebrate community changes as the decay process proceeds and some invertebrates are more dependent on the type of decay than of the species of tree. Other invertebrates are dependent on fungi fruiting bodies.

Fungi