Microhabitat relationships of five co-occurring saxicolous mosses on cliffs and scree slopes in eastern Newfoundland
| Autor: | Terry A. Hedderson, Guy R. Brassard |
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| Rok vydání: | 1990 |
| Předmět: | |
| Zdroj: | Ecography. 13:134-142 |
| ISSN: | 1600-0587 0906-7590 |
| DOI: | 10.1111/j.1600-0587.1990.tb00599.x |
| Popis: | The microhabitat relationships of five mosses, which co-occur on cliffs and scree-slopes in eastern Newfoundland, were evaluated by discriminant functions (DFA) and multiple regression analysis (MRA). The first three discriminant functions account for 91.3% of the among-species variation in microhabitat characteristics, and are interpreted as representing species separation along 1) water deficit, 2) pH, and 3) temperature gradients. Multiple regression of individual species’abundances on measured microhabitat variables was successful, and highly significant regression equations accounting for 78% to 91% of variation in abundance were developed for all but one of the species studied. The combined DFA and MRA results show that the five moss species have distinct and different microhabitats within the cliff/scree-slope habitat. Microdistribution of Grimmia torquata, an arctic-montane moss at its southern limit, appears to be determined by sensitivity to high summer temperatures. Two southern mosses at their northern limit (Aulacomnium androgynum, Isothecium myosuroides) appear to be limited by water availability and, possibly, by low winter temperatures. The abundance of two species whose distributions extend both north and south of the study area (Encalypta procera, Eurhynchium pulchellum) shows no clear relationship with microclimate, though the microdistribution of the former species appears to be highly dependant on pH. |
| Databáze: | OpenAIRE |
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