Comparing soil biogeochemical processes in novel and natural boreal forest ecosystems.
Quideau, S., M. Swallow, C. Prescott, S. Grayston and S. Oh. 2013. Biogeosciences Discuss
Abstract
Emulating the variability that exists in the natural landscape prior to disturbance should
be a goal of soil reconstruction and land reclamation efforts following resource extraction.
Long-term ecosystem sustainability within reclaimed landscapes can only
be achieved with the re-establishment of biogeochemical processes between reconstructed
soils and plants. In this study, we assessed key soil biogeochemical attributes
(nutrient availability, organic matter composition, and microbial communities) in reconstructed,
novel, anthropogenic ecosystems covering different reclamation treatments
following open-cast mining for oil extraction. We compared the attributes to those
present in a range of natural soils representative of mature boreal forest ecosystems in
the same area of northern Alberta. Soil nutrient availability was determined in situ with
resin probes, organic matter composition was described with 13C nuclear magnetic
resonance spectroscopy and soil microbial community structure was characterized using
phospholipid fatty acid analysis. Significant differences among natural ecosystems
were apparent in nutrient availability and seemed more related to the dominant tree
cover than to soil type. When analyzed together, all natural forests differed significantly
from the novel ecosystems, in particular with respect to soil organic matter composition.
However, there was some overlap between the reconstructed soils and some of
the natural ecosystems in nutrient availability and microbial communities, but not in organic matter characteristics. Hence, our results illustrate the importance of considering
the range of natural landscape variability, and including several soil biogeochemical attributes
when comparing novel, anthropogenic ecosystems to the mature ecosystems
that constitute ecological targets.
