![]() This study demonstrated that roots and the rooting zone in boreal fens support organisms likely capable of methanogenesis, iron cycling, and fungal endophytic association, and are directly or indirectly affecting carbon cycling in these ecosystems. Our results were indicative of two main methanogen communities: a rooting zone community dominated by the archaeal family Methanobacteriaceae and a deep peat community dominated by family Methanomicrobiaceae. Fungal lignocellulose degraders were enriched in the lowered water table treatment. Fungal endophytes (particularly Acephala spp.) were enriched in sedge and grass roots, which may have underappreciated implications for organic matter breakdown and cycling. The fungal community was affected largely by plant functional group, especially cinquefoils. Iron cyclers, particularly members of the family Geobacteraceae, were enriched around the roots of sedges, horsetails, and grasses. Bacterial and archaeal communities were most sensitive to the water table treatments, particularly at the 10-20 cm depth-this area coincides with the rhizosphere or rooting zone. Depth had a strong effect on microbial and fungal communities across all water table treatments. All samples were sequenced and processed for bacterial, archaeal (16S rDNA-V4), and fungal (ITS2) DNA. This study investigated the effects of experimentally manipulated water tables (lowered, raised) and plant functional groups on the peat and root microbiomes in a boreal rich fen. Carbon cycling in these systems is carried out by microorganisms and plants in close association. Hydrologic shifts due to climate change will affect the cycling of carbon (C) stored in boreal peatlands. ![]() Further research is needed to examine the interactions of nutrient limitation, soil physical barriers, and other possible drivers of ecosystem retrogression. Ecosystem retrogression is apparent in the latter stages of the chronosequence – a phenomenon not previously documented in coastal BC. Despite a mild, moist climate conducive to chemical weathering, all soils had similarly low values for the Chemical Index of Alteration, suggesting that congruent dissolution of primary minerals may be occurring. Organo-metallic complexation appeared to be the dominant mechanism involved in podzolization. Within ~3,500 years a mature Podzol had formed, with cemented horizons (ortstein and placic) present. Soil samples from each genetic horizon were analyzed for bulk density, pH and concentrations of total carbon (C), pyrophosphate- and oxalate-extractable aluminum (Al) and iron (Fe), and total elements. The sequence spans 10,760 ± 864 years over eight sites and is the first documented chronosequence in coastal BC to span most of the Holocene Epoch. This study examined the rate and mechanisms of Podzol development and related forest productivity in a sand dune chronosequence in a hypermaritime climate in coastal British Columbia (BC). In cool or temperate humid environments, Podzols are the predominant soil type formed under coniferous forests in coarse-textured parent material and have been a major focus of chronosequence studies. A similar powered system can also be used for increment boring of trees.Ĭhronosequence studies of soil formation and ecosystem development provide important insights into the pathways and rates of change occurring on centennial and millennial time scales. In addition to sampling forest floors, the corer has proven suitable for sam- pling moss and lichen layers and mineral soil down to about 20 cm. Ten samples per stand gave adequate precision for a study of forest floor dynamics and autocorrelation did not appear to be a problem with five-metre sampling intervals. ![]() We found that coefficients of variation were typically 30 % for forest floor organic matter and bulk density, and tended to be higher in Pinus banksiana stands than in Picea glauca and Populus tremuloides. It has been used extensively to obtain samples in 114 boreal forest stands of western Canada. The corer is simple to fabricate, is lightweight (3.5 kg) and can be used easily by one person to obtain intact, natural volume cores of the forest floor. It is based on a rechargeable, battery-powered drill that drives a sharpened steel coring tube. ![]() We describe an effective and inexpensive device for sampling forest floors. A new forest floor corer for rapid sampling, minimal disturbance and adequate precision. ![]()
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