Aspen regeneration on log decking areas as influenced by season and duration of log storage

Abstract

This study assessed aspen regeneration on decking areas as affected by season of log deck building and duration of log storage; as well as root wounding, soil compaction, and slash depth. On former decking areas that were built after a summer harvest, aspen regeneration was 50% lower and root death 35% greater compared to former decking areas of a fall harvest. Duration of log storage after a fall harvest had little effect on aspen regeneration; short (1.5-3 months) or long (11 months) storage resulted in similar regeneration. Slash load was greatly increased on decking areas while root wounding and soil bulk density were only slightly increased compared to controls. For best management practices, log storage after summer harvest should be avoided especially when logs are kept over the growing period when suckering occurs. Additionally, removing the interwoven mat of slash covering decking areas and limiting machine traffic to frozen soil will ensure vigorous suckering.

Suckering response of aspen to traffic-induced-root wounding and the barrier-effect of log storage

“…Initially we had hypothesized that a physical barrier applied in the summer would have a more negative impact than one applied in the winter based on the field observations of Renkema et al (2009), where summer storage was more detrimental to suckering than winter storage. However, this growth-chamber study showed that winter-cutting with coverage and maintenance of soil temperatures of 5 8C was equal or possibly slightly more negative to aspen regeneration (Fig.…”

“…In a field study Renkema et al (2009) found that log decks built in the fall had less impact on suckering than log decks built in the summer. They hypothesized that the seasonal effect was due to the effect of the log decks on soil temperature.…”

“…These conditions include hormonal balance, carbohydrate content, root damage, soil temperature, and soil strength and aeration. During harvest, machine traffic can damage the root system and change soil conditions (Bates et al, 1993;Shepperd, 1993;Berger et al, 2004;Zenner et al, 2007), and log storage has been speculated to reduce soil temperature and root carbohydrate reserves (Renkema et al, 2009). As a result, on heavily impacted areas such as roads, landings, and skid trails, aspen regeneration is often poor, or in some instances does not occur at all (e.g.…”

“…log decks can cause large reductions in suckering (Renkema et al, 2009) and affect a significant portion (6-8%) of a harvested area (MacIsaac et al, 2006). In a field study Renkema et al (2009) found that log decks built in the fall had less impact on suckering than log decks built in the summer.…”

Quantifying Cumulative Effects of Harvesting on Aspen Regeneration through Fuzzy Logic Suitability Mapping

“…However, mechanical harvesting events can also influence aspen regeneration through the alteration of soil physical properties (bulk density, aeration, water movement, etc. ), soil temperature regime, and disturbance of the shallow rooting system of aspen found in the forest floor that is responsible for the majority of regeneration (Lieffers‐Pritchard, 2004; Zenner et al, 2007; Puettmann et al, 2008; Renkema et al, 2009). While these studies are important for establishing our understanding of how these individual factors influence aspen regeneration, they often fail to emulate the natural environment in which several of these factors are acting together to govern the level and success of aspen regeneration.…”