At this time, more detailed soil profile descriptions
and soil climate data are needed for more accurate characterizations
of patterns and net change in decomposition. However, the big picture
implies that “environmental changes may have little impact on
plant productivity unless average nutrient availability also changes”
(Reynolds etc. al). This statement emphasizes the importance of decomposer
species in any given ecosystem. Since they control the nutrient availability
to an environment, they control not only plant productivity, but the
competition that consequently occurs between plants for the nutrients,
which affects evolution (according to survival of the fittest), and
in turn the nutrition of herbivores and the carnivores that feed on
the herbivores, etc. In essence, the entire food web of an ecosystem
depends upon the availability of nutrition.
That said, the impact of road dust to decomposer species is as follows:
The influence of road dust results in higher soil pH levels (moving
along the scale from acidic to basic), lower soil moisture, and greater
thaw depth; although there are yet to be experimental studies of the
impact on decomposer species specifically, the combination of the previously
mentioned conditions when applied to simulations and past studies have
shown that “soil enzyme activities in surface organic materials
were found to be affected by dust loading: Activity increased rapidly
with increased distance from the road” (Reynolds etc. al).
Even so, the biggest effects to decomposer species are likely to be
those caused by changes in soil moisture. Reynolds etc. al found that
“areas with moist tundra where water in channeled (water tracks)
have higher vascular productivity and nitrogen availability than areas
that do not.” Basically, decomposition rates are higher and nutrient
uptake is easier. Yet, without moving water—i.e. under more stagnant
conditions—wet soils relate to low nitrogen availability due to
the anaerobic, decomposition inhibiting circumstances (Reynolds etc.
al).
One of the problems that arise in evaluating the effects of disturbance
in the Arctic is that there is a major lack of information describing
the dynamic response of ecosystems to altered hydrological regimes and
accompanying change in water quality. Therefore, it is my opinion that
before conclusions concerning the impact of specific development strategies
can be drawn, more experiments need to be performed.
Furthermore, in reference to decomposer species only, most of the impacts
that I have discussed tend to operate on a more local scale. They would
likely not affect an ecosystem as a whole unless there were many such
local areas subjected to those impacts.
Reference:
1. Sarah J. Woodin & Mick Marquiss. (1997). Ecology
of Arctic Environment