Seed dispersal, seedling emergence, and early survival of Larix laricina (DuRoi) K. Koch in the Tanana Valley, Alaska

• Published in: Canadian Journal of Forest Research
• Main Authors: Brown, K.R., Zobel, D.B., Zasada, J.C.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1988
• Subjects: Ecology; Forestry; Global and Planetary Change; Fairbanks; permafrost; Alaska
• Online Access: http://dx.doi.org/10.1139/x88-047; http://www.nrcresearchpress.com/doi/pdf/10.1139/x88-047

The seasonal and spatial patterns of seed release, germling emergence, and early survival of Larixlaricina (DuRoi) K. Koch were studied in 1980–1981 near Fairbanks, Alaska. Dispersal was studied on one wetland site. Seedling emergence and 1-year survival were studied on three wetland microsite types (troughs, feathermoss, and tussock tops, located at increasing elevations above permafrost) and in mineral soil and undisturbed feathermoss seedbeds in a mature Piceaglauca stand of alluvial origin. Approximately 95% of the viable Larix seed from the 1980 cone crop fell by November 1980. Spatial distribution of seed away from the stand was erratic because of variable winds and the presence of a single Larix away from the stand edge. Average dispersal distances were less than those reported for other coniferous species. Emergence and early survival in both site types were affected by seedbed type. In the alluvial stand, germination and 1-year survival were greater on mineral seedbeds than on feathermoss. Emergence began in mid-July, well after minimum temperatures required for germination had been reached; timing appeared to be related to differences in volumetric moisture contents of the two seedbed types. Although cumulative totals of emergence and mortality did not differ between microsite types in the wetland, seasonal patterns of each differed with microsite. Emergence in troughs was delayed until early July by cold seedbed temperatures; increased precipitation in mid to late July raised the water table and flooded newly emerged seedlings in trough microsites but moistened feathermoss sufficiently to promote germination. Variation in emergence and mortality was high within a given microsite type.