Morphological/anatomical investigation of cattail transplants and bog vegetation : final report

Abstract

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.