Early changes in soil under birch and heather
Heather plants were established, by Dr. John Miles, in gaps created in existing birch stands in 1979 at Craggan (NJ190322) and birch trees planted in heather moorland during 1977-1980 at Delnalyne (NJ189175). This study attempts to identify the processes leading to differential soil development beneath the two contrasting vegetation types over the period 1985-88 i.e. c 6 years after establishment. Field work involved the chemical analysis of soil solution and estimates of microbial biomass and basal respiration rates under birch and heather at both sites. Laboratory-based experiments were conducted to investigate the trends observed in the field. Major changes in soil processes were attributed to rapid growth and therefore nutrient uptake by the transplanted species. However, some of the changes due to birch trees, which were observed during studies of birch chronosequences by Miles &'38 Young (1980) and Miles (1981) can be attributed to high nutrient inputs in throughfall and litter under birch, which affect abiotic processes and stimulate microbial activity and nutrient transformation rates. Root inputs also influenced biological processes.