Bogs and coal acid mine drainage are closely linked at the
Victoria Junction Coal processing plant of DEVCO in Sydney, Cape
Breton, Nova Scotia. This geographical setting facilitates the
investigation of these bogs with respect to the effects of AMD on
the ecosystem and determine their use in ameliorating the acidic
conditions. The species assemblage is typical of that encountered
in dwarf-shrub bogs of the Northeastern regions of the United
States and Canada. These bogs are dominated by Chamaedaphne
calyculata.
This report describes the status of the vegetation in both bogs
which have received AMD for varying times. It summarizes both onsite
and laboratory investigations. Through the use of
morphological-anatomical techniques, the death or growth of plant
parts is determined. The old bog, exhibits significant acid stress, although it had only
received aerial deposition of coal and a diffuse flow of AMD. A
second bog, the new bog, located immediately above the stressed bog
was healthy and unaffected by acid mine drainage until AMD seepage
was diverted into the bog at the end of summer 1988. In the new bog
the vegetation damage is much more severe than in the old bog and
prognosis for continued survival is not good for many of the
species that form the natural species assemblage of the bogs. The majority of shoot tips and lateral buds were found to be dead,
suggesting little hope for recovery of the plants in subsequent
years. Although damage was also observed in the same species of the
old bog, the symptoms were not as severe as those seen in the new
bog. Roots and rhizomes tended to show some damage but this was
much reduced in comparison to that observed in the new bog. The most important species being able to survive is Typha
latifolia. Other grasses, sedges, and rushes may however compete
in the colonizing of the dying bogs. Thus, a change in species
composition of the bogs can be expected. To promote the growth of
cattails in AMD conditions foliar fertilizers were tested.
Treatment with noticeable beneficial effects was the application
of 4-18-16 at a dilution of 1O:l.
Morphological investigations of cattail roots indicated large
accumulation of metals on the epidermis and the hypodermal layers.
In dead lateral roots, metal concentrations are highest and have
penetrated the entire root cross section. Analysis of X-ray spectra
of the metals by SEM of root cross sections, indicated that high
concentrations of Fe are associated with high levels of S and
greatly reduced concentrations of Ca. Crystal formation was noted
in the iron-sulphate plaque accumulation in the roots. X-ray scans
of cattail leaves growing in AMD conditions indicate the presence of glandular cell regions, called hyropoten with Fe levels three
times that of the adjacent epidermal regions. These findings
suggest, that the cattail rhizosphere may be active in ameliorating
AMD and that adaptations to high iron concentrations through
activation of particular cell regions of the leaves may occur