Age Structure and Growth of the Tree-seedling Bank in Subalpine Spruce-fir Forests of South-central British Columbia

• Published in: The American midland naturalist Vol. 143; no. 2; pp. 342 - 354
• Main Authors: ANTOS, JOSEPH A, PARISH, ROBERTA, CONLEY, KEVIN
• Format: Journal Article
• Language: English
• Published: Notre Dame University of Notre Dame 01.04.2000; University of Notre Dame, Department of Biological Sciences; American Midland Naturalist
• Subjects: Age structure; Botany; Contents; Forest canopy; Forest dynamics; Forest ecology; Forest growth; Forest regeneration; Old growth forests; Seedlings; Seeds; Spruce; Subalpine forests; Trees; Understory; British Columbia; British Columbia Canada
• ISSN: 0003-0031; 1938-4238
• DOI: 10.1674/0003-0031(2000)143[0342:ASAGOT]2.0.CO;2

We examined the dynamics of the tree-seedling bank in old-growth, subalpine Picea engelmannii—Abies lasiocarpa forests in south-central British Columbia by collecting all individuals <1.3 m tall within belt transects at two sites (n = ca. 500 per site) and determining their height, basal diameter and age. Seedlings were up to 149 y old. Regressions showed that spruce 1-m tall averaged 65-y old and fir 92-y old. Age structures indicated that recruitment into the seedling bank was variable with time, but that individuals of both species occurred in almost all 5-y age classes. Regressions of height and diameter vs. age had high predictability and showed that spruce grew more rapidly than fir. Allometric (height/diameter) relationships differed significantly between species; spruce had a much greater height/diameter ratio than fir. Seedlings accumulate gradually and persist for long periods in the seedling bank, thus forming a large pool of individuals that can potentially respond to opening of the canopy.