fire rotation, are factors contributing overgrowing feather - PDF document

fire rotation, are factors contributing overgrowing feather factors as fire long-term climatic change. habitat, vegeta- development frequently other growth forms southeastern Labrador various species groups critical importance Gill, 1970; Walker, long-term dynamics these communities The environment conducive to growth inhibits mosses. The development over time. Thus one relate present dividual species historical conditions. This procedure pro- confirm the dynamics processes inferred from Following extensive phytosociological southeastern Labrador 1984a; Foster King, 1984; Glaser Foster, 1984) three to form the succession. These include King, 1984), Foster, 1984), large plateau Gilbert River. The selected sites are representative the three previous investigations. for stratigraphic analysis the Ellenberg, 1974). species were forested areas (spruce- open areas cover abundance were scale. Complete sets voucher specimens vascular species the University Sciences, Ottawa. Nomenclature follows Crandall-Stotler (1977) for hepatics, Culberson (1970) for lichens, two excavations were knife to expose the stratigraphic relationships monoliths for laboratory examination. The depth exposure varied the nature the habitat. Photographs were pits. Samples were for transfer to the lab. Following fire there ensues leads to 1984b). The Polytrichum juniperinum cup fruticose lichens larger fruticose (Cludonia mitis, The cover these species 1953). The periods (100-200 years) moist, acidic (Foster, 1983a, grows rapidly. similar depressions conditions are these serve as growth cause feather mosses, smothering progressively deeper maximum) towards center of growth started apparent from oblique alignment of simultaneously vertical radial. Studies average annual production are signifi- greater for for feather Rinne, 1979), allowing to overtop late-successional species. The outward from scattered depressions expanding clones creases at the expense continuous carpet. Similar bryophyte replacement series are apparent across boreal forest Heilman, 1966; Viereck, 1970), northern man, 1963, 1970), northern Michigan 1912), Que- 1933), Alberta (Lewis Fennoscandia (Siren, assumes dominance, there occurs an increase moisture content organic horizon temperature, decomposition The changing environmental trophic vascular species, progressive change occurs areas to southeastern Labrador through site (Foster Wright, 1981), process documented elsewhere 1956; Heinselman, 1963; Viereck, literature concern- Walter, 1977), southeastern Labrador fire retards recycles nutrients productive forest growth. poor fens eastern Labrador are covered acidic nature environments (Foster predominate, whereas where nutrient availability are also found. The floors are com- flocculent fine-grained material, primarily roots, King, 1984). floor, presenting hydrophilic bryo- King, 1983). changes (generally to progressively species (predominantly overtop smaller hepatics. balance. Two processes across south- eastern Labrador are described King, 1984). process similar to described for Silver Flowe Tomlinson, 1973, Labrador increases ridge degrades slightly dif- slope positions, bogs drainage streams often develop Birks, 1980) to time these streams erode floor takes abrupt transition to species covering older I38 Cladonia stelloria Cladonia stellaris a significant disturbance cyclic successional processes Osvald, 1923; Aaby, 1978). The water sensitive to climatic change from atmospheric water table, increased temperature decreased precipitation, detrimental to posite trend climatic conditions shift the other way. Thus stratigraphic sequence could represent a warmer, a reversal. operates at southeastern Labrador 1983a). Fire burns selectively tops among ericaceous shrubs, their litter, moisture content, a sequence occurs similar to post-fire succession (cf. Foster, 1984b). lichens. These species are long-term dominants pand, overtop the lichens, their pre-fire abun- dance. The presence stratigraphic sequences, along post-fire succession, establish fire factor. However, southeastern Labrador, across southeastern Labrador, suggest often a environmental change. The se- occupy a site depends life-history characteristics outcome of interspecific interactions. mire communities southeastern Labrador, species are later stages cover for extended periods environment, com- other bryophytes, and grow conditions detrimental to other species, either direction a species’ at one Slack, 1975; Egler, 1977; McIntosh, 1980). dynamics of to other species, order to explain landscape. The stratigraphic southeastern Labrador supports ferences drawn There exists a sharp delineation adjacent cryptogams described. The suggests the advancement species over Stratigraphy demonstrates often oblique, as grows up other slower-growing cryptogams. The degree of oblique the environment growth form particular species. compact, dense a relatively growth form, dense branching, strongly vertical component a sharp adjoining species. less ramifying more sprawling. feather mosses, the organic layer. Extensive pure populations form a continuous carpet older forests Labrador, similar to those forest (Horton three species, displays the of growth, accumulations. Occupying aquatic forms loose, floating carpets. The 140 D.R. FOSTER TAMM, C.O. 1953. Growth, yield and nutrition in carpets of a forest moss (Hylocomium splendens). Meddelanden Fran Statens Skogs Forskningsin- TANSLEY, A.G. 1949. The moss or bog formation. Ch. 34 in: The British Isles and their Vegetation. Vol. 11. Cambridge: Cambridge University VIERECK, L.A. 1966. Plant succession and soil development on gravel out- wash of the Muldrow Glacier, Alaska. Ecological Monographs . 1970. Forest succession and soil development adjacent to the Chena River in interior Alaska. Ecological Monographs 36: 18 1 - 199. VITT, D.H. and SLACK, N.G. 1975. An analysis of the vegetation of Sphagnumdominated kettle-hole bogs in relation to environmental gra- dients. Canadian Journal of Botany 53:2776-2795. VITT, D.H., ACHUFF. P. and ANDRUS, R.E. 1975. The vegetation and chemical properties of patterned fens in the Swan Hills, North Central Al- berta. Canadian Journal of Botany 53:2776-2795. WAKSMAN, S.A. 1930. Chemical composition of peat and the role of micro- organisms in its formation. American Journal of Science 19:32-53. WALKER, D. 1970. Direction and rate in some British post-glacial hydro- sers. In: Walker, D. and West, R.G. (eds.). Studies in the Vegetation History of the British Isles. Cambridge: Cambridge University Press. 43-57. WALTER, H. 1977. The oligotrophic peatlands of Western Siberia - the largest Peino-Helobrome in the world. Vegetatio Acta Geobotanica WENNER, C.G. 1947. Pollen diagrams from Labrador. Geografiska Anna- ler H. 3-4: 137-374. WRIGHT, H.E. 1981. The role of tire in land/water interactions. In: Mooney, H.A., Bonnicksen, T.M.. Christensen. N.L., Lotan, J.E., and Reiners, W.A. (eds.). Fire Regimes and Ecosystem Properties. Washington; D.C.: U.S. Dept. of Agriculture. General Technical Report WO-26:421-454. j stitut.,Band 43. NR1:1-139. PRSS. 1108-1 137. 36:181-199. ' 34: 167-178.