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After severe storms timber is often wasted because it cannot be processed before being damaged by fungi and insects and excess oftimber can flood the market causing economic problems. Effective storage of sawlogs is therefore essential. However, this often involves water storage causing problems in environmentally sensitive sites. 'Vater storage also leads to bacterial attack ofthe wood which increases its porosity. A method receiving current interest relies on the exclusion of oxygen by wrapping stacks in plastic film. This method has been shown to be effective on certain species, particularly Norway spruce, in Germany. In this study the method was restricted to Pinus sylvestris in the UK. which is far more susceptible to sapstain. In previous work the oxygen exclusion relied on a perfect seal being maintained during storage. Combining wrapping with biological control micro-organisms and with a strain ofSaccharomyces cerevisiae was also tested. Sapstain development, oxygen and carbon dioxide levels were monitored in laboratory and field tests. In the laboratory, airtight containers were developed using gas piping to test variables prior to field trials. In field trials. wrapping resulted in almost complete control ofbluestain fungi in Pinus sylvestris. 'After over four months storage, in both field trials, the stain on wrapped timber was less than 1 % compared to over 33% in control stacks. In all wrapped stacks the COl levels increased and the 0, concentration decreased, reaching zero within about 14 days. The addition ofyeast aided the depletion ofoxygen and the increase in carbon dioxide in wrapped stacks, although it had no significant effect on stain development. Further trials with even simpler wrapping systems are needed to fully assess the additive effect ofusing Yeasts to help maintain low oxygen levels under such conditions.

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There is a growing but inconclusive body of work on effects of litter-mixing on ecological processes, but few have considered interactions among foliar and woody litters. Further, most work on litter decomposition assumes that litterfall reaches the ground, and the effects of interception of litter (e.g. by ferns or logs) remains largely unexplored. Three studies were perfonned to investigate these issues. The first study was in a long-tenn chronosequence in the Swedish boreal forest where decomposition' rate declined with ecosystem retrogression. Field measurements showed that the ratio of twig to foliage in litterfall increased with prolonged absence ofdisturbance. In a mesocosm experiment, combining foliar and twig litters in their natural proportions reduced overall decomposition rates, suggesting that the increased twig proportion may contribute to the large increase in humus build-up found with prolonged absence of disturbance. The second study was in a New Zealand temperate rainforest, and showed that logs fonned an important microsite for decomposition, with strongly contrasting microbial activity and organic matter content compared with ~e ground. Microbial activity on logs was variable, probably linked to differences in phenolics and decay stage. The third study, also in a New Zealand temperate rainforest, showed that the fern Blechnum discolor has the potential to intercept and retain 10% of falling litter. A higher twig to foliage ratio was found in the litter accumulated in fern crowns than in the incoming litterfall or on the forest floor. Organic matter content, basal respiration and microbial activity were significantly higher in fein crowns than on the forest floor. Further, foliar litter decomposed significantly faster in fern crowns than away from the crown, but not faster than at the trunk base. Consequently, litter interception by ferns may affect nutrient cycling through concentrating nutrients and organic matter in and under ferns.

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