Author: Tricia L. WurtzPublisher:
ISBN:
Category : Alder
Languages : en
Pages : 36
Book Description
Interactions Between White Spruce and Shrubby Alders at Three Boreal Forest Sites in Alaska
Author: Tricia L. WurtzPublisher:
ISBN:
Category : Alder
Languages : en
Pages : 36
Book Description
Interactions Between White Spruce and Shrubby Alders at Three Boreal Forest Sites in Alaska
Author: Tricia L. WurtzGeneral Technical Report PNW-GTR
Author: Publisher:
ISBN:
Category : Forests and forestry
Languages : en
Pages : 650
Book Description
Field Survey of Growth and Colonization of Nonnative Trees on Mainland Alaska
Author: John AldenPublisher: DIANE Publishing
ISBN: 9781422310731
Category :
Languages : en
Pages : 84
Book Description
Six of nine nonnative boreal conifers in three genera (¿Abies,¿ ¿Larix,¿ & `Pinus¿) regenerated in 11-31 years after they were introduced to mainland Alaska. Lodegole pine & the Siberian larches were the most widely introduced species. Siberian larch grew up to 6 times more stem vol. than white spruce in the first 40 years on upland sites. Lodgepole pine grew more stem wood than white spruce for 35 years after planting. Snowshoe hares & moose were the most serious pests of these conifers. Growth & age relationships were negative for all sampled conifers & positive for native white spruce. The introduction & naturalization of noninvasive tree species may improve the diversity, stability, & productivity of managed forest ecosystems. Illustrations.
The Snowshoe Hare Filter to Spruce Establishment in Boreal Alaska
Author: Justin OlnesPublisher:
ISBN:
Category : Black spruce
Languages : en
Pages : 306
Book Description
Interior Alaska is a heterogeneous landscape within the circumpolar boreal forest and is largely composed of black and white spruce (Picea mariana and P. glauca). Improving our understanding of the factors affecting patterns in spruce regeneration is particularly important because these factors ultimately contribute to shaping the boreal forest vegetation mosaic. Herbivory by snowshoe hares (Lepus americanus) is one factor that likely drives patterns in spruce establishment. The interaction between spruce and snowshoe hares provides an opportunity to study how plant-herbivore interactions can affect succession, vegetation community composition, and consequently, how herbivory influences landscape heterogeneity. I explored how herbivory by snowshoe hares alters the survival and growth of spruce seedlings across Interior Alaska’s boreal forest. I hypothesized that the survival and growth rate of regenerating spruce is significantly reduced by snowshoe hare herbivory and that snowshoe hare herbivory influences the pattern of spruce establishment across time and space. To address this hypothesis, I conducted research in three distinct vegetation communities across the region: productive lowland floodplains (Chapters 1 and 2), treeline (Chapters 3 and 4), and recently burned stands of black spruce (Chapter 5). Together these five chapters reveal that snowshoe hares affect spruce establishment across much of boreal Alaska. Where and when hares are abundant, spruce can be heavily browsed, resulting in suppressed seedling growth and increased seedling mortality. The results of these studies also reveal a consistent and predictable pattern in which this plant-herbivore interaction takes place. The snowshoe hare filter acts as a ‘spatially aggregating force’ to spruce establishment, where the potential for optimal regeneration is highest during periods of low hare abundance and where hares are absent from the landscape.
The 30-year Outcome of Assisted Regeneration Treatments in a Burned and Salvaged Interior Alaska Boreal Forest
Author: Andrew AllabyPublisher:
ISBN:
Category : Cold regions forestry
Languages : en
Pages : 252
Book Description
This study contributes to the understanding of the persistence of silvicultural treatments into the stem exclusion stage of forest development in an experiment originally designed to test the effectiveness of various white spruce (Picea glauca Moench [Voss]) regeneration practices. Many studies in the North American boreal forest address the effect of silvicultural treatments on a single tree species, specifically white spruce in the great majority of cases. The experiment measured in this study provided an excellent opportunity to compare treatment effects on white spruce density and growth. The Rosie Creek Fire Tree Regeneration Installation experiment represents an operational-scale, spatially-explicit, replicated design on a single site disturbed consecutively by high-severity wildfire and clearcut salvage harvest. Three hierarchical factors, each with multiple levels, were examined: landform type, ground scarification methods, and white spruce regeneration methods. All three of the experimental factors exercised continuing influence on the patterns of white spruce regeneration and growth. The treatment effects did not attenuate over time for white spruce, and we found statistically significant effects that the original researchers could only describe as tendencies. However, relatively few studies address treatment impacts on non-target species or determine how the silvicultural treatments affect a site's overall woody biomass production. Experimental silvicultural practices targeted in this study to improve white spruce survival had profound effects on other dominant upland tree species such as quaking aspen (Populus tremuloides Michx.) and Alaska birch (Betula neoalaskana Sarg.). Interior Alaska timber species demonstrate different regeneration strategies to post-disturbance environmental conditions, especially residual organic soil layer thickness and spatial configuration of surviving potential seed sources. Effective silvicultural practices must consider each species' unique reproductive biology, and clonal sprouting as a source of aspen persistence was a particularly important example in our study. Site differences, such as we found between the slope and ridge landforms, are a key consideration for implementing effective silvicultural practices. Significant interactions between the regeneration treatments and landform types proved to be critical to meet specific reforestation objectives, particularly the different herbaceous vegetation cover types, presence/absence of aspen clonal rootstocks, and spatial configurations regarding seed sources. Managing mixed species stands, which are common in the lightly managed portions of the boreal forest, requires not only the consideration of the future crop tree, but the interacting effects of silvicultural practices on all tree species.
Roles of Neighboring Plants and Temperature on Growth and Survival of White Spruce Seedlings Along Elevational Gradients in Alaska
Author: Kyoko OkanoPublisher:
ISBN:
Category : White spruce
Languages : en
Pages : 246
Book Description
Seedlings are the most vulnerable stage of a tree’s life and their successful survival and growth are critical to support future forests. Recent rapid warming in Alaska has promoted the movement of treeline upward in elevation, while trees at low elevations have decreased their growth. Understanding the direct effects of warming and the indirect effects induced by warming, such as species interactions, on the dominant treeline species, white spruce (Picea glauca) is key to sustaining boreal forests, from low elevations to above current treeline. The objectives of my thesis were to assess the roles that warming, neighboring interaction, habitat type, elevation and season play in the survival and growth of white spruce in Denali National Park and Preserve and Fairbanks, Alaska, USA. I planted spruce seedlings where I manipulated summer temperature and neighbor plants at seven sites (forest or tundra) along an elevational gradient that crossed treeline. I measured survival after winter and summer seasons, and harvested the seedlings for biomass after the third growing season. I found that competition — particularly light competition where seedlings were shaded — was the most important factor for seedling growth, while along elevational gradients, temperature and season had inverse effects on their survival: more seedlings at high elevations survived in summer and under warming, but more seedlings at low elevations survived in winter and under ambient temperatures. More seedlings with neighbors survived in summer and in forests, suggesting facilitation through shading. I found some evidence for a trade-off between growth and survival. Seedlings with a high relative growth in height (RGR height) in 2012 had a lower survival rate than seedlings with a low RGR height in the following hot and dry summer of 2013. More seedlings planted with neighbors that had a small diameter in 2012 also survived in 2013, but not without neighbors. These results suggest that a trade-off between survival and growth occurred only when competition for water can be expected. No difference in survival was found after the second winter and third summer. Altogether, I concluded the most important factor affecting seedling growth in my experiment was light competition, while the most important factors for seedling survival were warming and water availability for the first two years in the subarctic montane and interior Alaska.
Tanana Valley State Forest Management Plan
Author: Agroborealis
Author: A Year in Review for the Pacific Northwest Research Station
Author: Pacific Northwest Research Station (Portland, Or.)Publisher:
ISBN:
Category : Forests and forestry
Languages : en
Pages : 112
Book Description