Ecological Studies of Fungi Growing on Insolated wood

Abstract

The widespread occurrence of thermophilous microfungi on wood is reported. Imported timber, in-service timber joinery and wood employed in colonization experiments were sampled and a list of cellulolytic fungi including thermophilous and soft rot fungi is submitted. The influence of insolation on the temperature and moisture ranges in wood was investigated. deere up to 16°C above ambient were recorded as a result of insolation and data is submitted on the diurnal temperature cycle in a block of wood undergoing insolation. It is recorded that colour had no significant effect upon the moisture content of insolated wood in soil contact. Using a simple moisture gradient apparatus the surface ara and penetration of thermophilous fungi were investigated at above ambient temperatures, showing that thermophilous fungi could grow at the surface and within beech veneers at moisture levels below the 20% minimum recorded in the literature, it is considered that the biological activity of water is increased at above ambient temperatures. The effect of constant, alternating and fluctuating temperatures on the growth ofmicrofungi was investigated. A temperature cycle simulator was devised producing a diurnal cycle similar to that occurring in insolated wood. Addition, stimulation and retardation of growth were recorded as a result of temperature alternation, whilst evidence is submitted that some thermophilous wood inhabiting microfungi were better adapted to temperature fluctuations than mesophilic forms. Interaction studies between pairs of wood inhabiting microfungi were undertaken at above ambient temperature and under conditions of fluctuating temperature. Evidence that metabolic products influence interactions is offered, and that under conditions of fluctuating temperature thermophilous fungi can play a significant role in ecological sequences. Preliminary experiments into the tolerance of cellulolytic thermophilous microfungi to wood preservatives indicate that they were more tolerant to preservatives at at above ambient temperature than at 25°C.