Northernmost North AmericanPinus contortavar.latifolia(lodgepole pine) sociations and vegetation diversity relative to its central range east of the Rocky Mountains
| Autor: | W. L Strong |
|---|---|
| Rok vydání: | 2013 |
| Předmět: |
Pinus contorta
Calamagrostis biology Cladonia Ecology ved/biology ved/biology.organism_classification_rank.species Plant Science biology.organism_classification Shrub Botany Alnus viridis Calamagrostis purpurascens Ecology Evolution Behavior and Systematics Hylocomium splendens Rhododendron groenlandicum |
| Zdroj: | Nordic Journal of Botany. 32:222-232 |
| ISSN: | 0107-055X |
| DOI: | 10.1111/j.1756-1051.2013.00126.x |
| Popis: | Lodgepole pine (Pinus contorta var. latifolia) stands were sampled in central Yukon, Canada (61.5–64°N latitude), which represented the northernmost 9% of the tree's North American range. Within this area, lodgepole pine occupied only ˜ 2% of the landscape. This study determined: 1) what forest sociations occurred (i.e. structural dominance-types); 2) how plant growth form composition and richness differed from the central portion of the species’ geographical range; and 3) if stands were biased towards occurring on more thermally favorable south-facing slopes. Five lodgepole pine sociations were recognized among 100 releves: Rhododendron groenlandicum (Labrador tea); Cladonia arbuscula (green reindeer lichen); Calamagrostis purpurascens (purple reedgrass); Hylocomium splendens (stairstep moss) and Alnus viridis (green alder, n = 4 releves). Rhododendron stands were proportionally more common on low gradient sites and had more total plant cover than the other sociations. Cladonia and Calamagrostis stands were typically associated with dry coarse-textured soils and warm dry sites, respectively; whereas the composition of the Hylocomium sociation reflected the detrimental influences of atypically dense forest canopies on understory vascular plants. Only the Calamagrostis sociation was unique to the study region. Species richness among common northern lodgepole pine sociations averaged 16–19 taxa per releve (p > 0.05). Northern compared to central range (n = 1394) releves were compositionally different based on little overlap of their datasets in the ordination space. Northern vegetation had less (p < 0.001) total plant (129% vs 184%), deciduous shrub (9% vs 26%), broad-leaved herb (5% vs 25%), and bryophyte (27% vs 54%) cover; had greater macro-lichen cover (13% vs 5%) and lower floristic richness (11 vs 24 taxa) and was less than half as phytosociological diverse. Lodgepole pine stands in the northernmost portion of their range were not biased towards occurring on south-facing slopes, which suggested an ecological potential for range expansion. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Plný text