Vegetation, soils, and forest productivity in selected forest types in interior Alaska

1983 ◽  
Vol 13 (5) ◽  
pp. 703-720 ◽  
Author(s):  
Leslie A. Viereck ◽  
C. T. Dyrness ◽  
Keith Van Cleve ◽  
M. Joan Foote
Keyword(s):  
Soil Moisture ◽  
Standing Crop ◽  
Environmental Gradient ◽  
Forest Type ◽  
Black Spruce ◽  
White Spruce ◽  
Forest Productivity ◽  
Balsam Poplar ◽  
Interior Alaska ◽  
Annual Productivity

Vegetation, forest productivity, and soils of 23 forest stands in the taiga of interior Alaska are described. The stands are arranged on an environmental gradient from an aspen (Populustremuloides Michx.) stand on a dry, steep south-facing bluff, to open black spruce (Piceamariana (Mill.) B.S.P.) stands underlain by permafrost on north-facing slopes. The coldest site is a mixed white spruce (Piceaglauca (Moench) Voss) and black spruce woodland at the treeline. Mesic upland sites are represented by successional stands of paper birch (Betulapapyrifera Marsh.) and aspen, and highly productive stands of white spruce. Several floodplain stands represent the successional sequence from productive balsam poplar (Populusbalsamifera L.) and white spruce to black spruce stands underlain by permafrost on the older terraces. The environmental gradient is described by using two soil factors: soil moisture and annual accumulated soil degree days (SDD), which range from 2217 SDD for the warmest aspen stand to 480 SDD for the coldest permafrost-dominated black spruce site. Soils vary from Alfie Cryochrepts on most of the mesic sites to Histic Pergelic Cryochrepts on the colder sites underlain by permafrost. A typical soil profile is described for each major forest type. A black spruce stand on permafrost has the lowest tree standing crop (15806 g•m−2) and annual productivity (56 g•m−2•year−1) whereas a mature white spruce stand has the largest tree standing crop (24 577 g•m−2) and an annual productivity of 540 g•m−2•year−1, but the successional balsam poplar stand on flood plain alluvium has the highest annual tree increment (952 g•m−2•year−1). The study supports the hypothesis that black spruce is a nutrient poor, unproductive forest type and that its low productivity is primarily the result of low soil temperature and high soil moisture.

Carbon balance of the taiga forest within Alaska: present and future

2002 ◽  
Vol 32 (5) ◽  
pp. 757-767 ◽  
Author(s):  
John Yarie ◽  
Sharon Billings
Keyword(s):  
Boreal Forest ◽  
Black Spruce ◽  
White Spruce ◽  
Carbon Dynamics ◽  
Mean Annual Temperature ◽  
Century Model ◽  
Inventory Data ◽  
Balsam Poplar ◽  
Taiga Forest ◽  
Paper Birch

Forest biomass, rates of production, and carbon dynamics are a function of climate, plant species present, and the structure of the soil organic and mineral layers. Inventory data from the U.S. Forest Service (USFS) Inventory Analysis Unit was used to develop estimates of the land area represented by the major overstory species at various age-classes. The CENTURY model was then used to develop an estimate of carbon dynamics throughout the age sequence of forest development for the major ecosystem types. The estimated boreal forest area in Alaska, based on USFS inventory data is 17 244 098 ha. The total aboveground biomass within the Alaska boreal forest was estimated to be 815 330 000 Mg. The CENTURY model estimated maximum net ecosystem production (NEP) at 137, 88, 152, 99, and 65 g·m–2·year–1 for quaking aspen (Populus tremuloides Michx.), paper birch (Betula papyrifera Marsh.), balsam poplar (Populus balsamifera L.), white spruce (Picea glauca (Moench) Voss), and black spruce (Picea mariana (Mill.) BSP) forest stands, respectively. These values were predicted at stand ages of 80, 60, 41, 68, and 100 years, respectively. The minimum values of NEP for aspen, paper birch, balsam poplar, white spruce, and black spruce were –171, –166, –240, –300, and –61 g·m–2·year–1 at the ages of 1, 1, 1, 1, and 12, respectively. NEP became positive at the ages of 14, 19, 16, 13, and 34 for aspen, birch, balsam poplar, white spruce, and black spruce ecosystems, respectively. A 5°C increase in mean annual temperature resulted in a higher amount of predicted production and decomposition in all ecosystems, resulting in an increase of NEP. We estimate that the current vegetation absorbs approximately 9.65 Tg of carbon per year within the boreal forest of the state. If there is a 5°C increase in the mean annual temperature with no change in precipitation we estimated that NEP for the boreal forest in Alaska would increase to 16.95 Tg of carbon per year.

Survival and Growth of Planted Black Spruce, Alder, Aspen and Willow After Fire on Black Spruce/Feather Moss Sites in Interior Alaska

1987 ◽  
Vol 63 (2) ◽  
pp. 84-88 ◽  
Author(s):  
John C. Zasada ◽  
Rodney A. Norum ◽  
Christian E. Teutsch ◽  
Roseann Densmore
Keyword(s):  
Key Words ◽  
Prescribed Burning ◽  
Black Spruce ◽  
Seedling Survival ◽  
Height Growth ◽  
Balsam Poplar ◽  
Feather Moss ◽  
Interior Alaska ◽  
Survival And Growth ◽  
Broad Leaved Species

Seedlings of black spruce, aspen, green alder, and grayleaf willow planted on black spruce/feather moss sites in the boreal forest in interior Alaska survived and grew relatively well over a 6-year period after prescribed burning. Survival of black spruce was significantly greater than that of the broad-leaved species, but height growth was significantly less. Development of feltleaf willow and balsam poplar from unrooted cuttings was poor. Severity of burn appeared to have an important effect on height growth of all species but not on seedling survival. Key words: Planting, Picea, Alnus, Populus, Salix, microsite.

An overview of the vegetation and soils of the floodplain ecosystems of the Tanana River, interior Alaska

1993 ◽  
Vol 23 (5) ◽  
pp. 889-898 ◽  
Author(s):  
L.A. Viereck ◽  
C.T. Dyrness ◽  
M.J. Foote
Keyword(s):  
Forest Succession ◽  
Black Spruce ◽  
White Spruce ◽  
Organic Layer ◽  
Organic Layers ◽  
Balsam Poplar ◽  
Feather Mosses ◽  
Successional Stages ◽  
Salt Affected Soils ◽  
Stochastic Events

The soils and vegetation of 12 stages of forest succession on the floodplain of the Tanana River are described. Succession begins with the invasion of newly deposited alluvium by willows (Salix spp.) and develops through a willow–alder (Alnustenuifolia Nutt.) stage to forest stands of balsam poplar (Populusbalsamifera L.), followed by white spruce (Piceaglauca (Moench) Voss), and finally black spruce (Piceamariana (Mill.) B.S.P.). The principal changes in substrate characteristics during the successional sequence are (i) change from sand to silt loam, (ii) increase in terrace height and distance from the water table, (iii) development of a forest floor, first of leaf litter and then live and dead feather mosses, (iv) burial of organic layers by flooding, and (v) the development of permafrost as soils are insulated by a thick organic layer. Soils and vegetation of six stands occurring in three successional stages used in the salt-affected soils study are described in detail: open willow stands (stage III), balsam poplar–alder stands (stage VI), and a mature white spruce stand (stage VIII). There is a general progression of plant species resulting from the modification of the environment by the developing vegetation and changes in soil characteristics. Life history and stochastic events are important in the early stages of succession, and biological controls such as facilitation and competition become more important in middle and late stages of succession.

Artificial regeneration of trees and tall shrubs in experimentally burned upland black spruce/feather moss stands in Alaska

1983 ◽  
Vol 13 (5) ◽  
pp. 903-913 ◽  
Author(s):  
John C. Zasada ◽  
Rodney A. Norum ◽  
Robert M. Van Veldhuizen ◽  
Christian E. Teutsch
Keyword(s):  
Black Spruce ◽  
Seedling Survival ◽  
Forest Types ◽  
Artificial Regeneration ◽  
Balsam Poplar ◽  
Feather Moss ◽  
Interior Alaska

Fall seed-dispersing species, birch (Betulapapyrifera Marsh.), alder (Alnuscrispa (Ait.) Pursh), and black spruce Piceamariana (Mill.) B.S.P.), and summer-seeding species, aspen (Populustremuloides Michx.), balsam poplar (P. balsamifera L.), feltleaf willow (Salixalaxensis (Anderss.) Cov.), Scouler willow (Salixscouleriana Barratt), and Bebb willow (Salixbebbiana Sarg.), were artificially sown on seedbeds created by experimental burning in the upland black spruce/feather moss forest types in interior Alaska. At least 40% of the seeds dispersed in the fall had germinated before dispersal of summer seeds began. Germination occurred on moderately and severely burned seedbeds but not on scorched and lightly burned surfaces. Seedling survival occurred almost exclusively on severely burned surfaces. After 3 years, 82% of the plots containing some severely burned surfaces and sown with seeds from species seeded in the fall were stocked whereas 32% of the plots sown with species seeded in the spring and with the same seedbed condition were stocked.

Boreal forest ecosystem dynamics. II. Application of the model to four vegetation types in interior Alaska

2000 ◽  
Vol 30 (6) ◽  
pp. 1010-1023 ◽  
Author(s):  
John Yarie
Keyword(s):  
Forest Ecosystem ◽  
Forest Floor ◽  
White Spruce ◽  
Ecosystem Dynamics ◽  
Vegetation Types ◽  
Litter Fall ◽  
Individual Tree ◽  
Balsam Poplar ◽  
Interior Alaska ◽  
Site Types

The Spatial Alaskan Forest Ecosystem Dynamics (SAFED) model was validated across four of the most common vegetation types found in interior Alaska. The vegetation types were an alder (Alnus spp.) - balsam poplar (Populus balsamifera L.) site (FP2), an old-growth balsam poplar and white spruce (Picea glauca (Moench) Voss) site (FP3), a mixed deciduous (primarily birch (Betula papyrifera Marsh.) and aspen (Populus tremuloides Michx.)) and white spruce site (UP2), and a mature white spruce site (UP3). The FP site types are common on the floodplain along the Tanana River and the UP site types are common in the uplands in interior Alaska. SAFED is based on nitrogen productivity for vegetation growth, litter fall quantity and quality, and microbial efficiency for forest floor decomposition. The state factors (climate, topography, and disturbance) are used to describe a broad-scale classification of the landscape to define basic limitations for the driving variables. Climate and ecosystem-level disturbances are handled as restricted stochastic processes. The model has been programed in a spatial framework as an ARC/INFO AML within the GRID package. The current version of the model has been validated as functional from an individual tree basis (1-m2 cell size) in a number of forest types found in interior Alaska. The growth, litter fall, and forest floor decomposition were compared with data from the sites. An estimate of yearly carbon balance for the four sites was calculated.

Embryo growth in Alaskan white spruce seeds

1988 ◽  
Vol 18 (1) ◽  
pp. 64-67 ◽  
Author(s):  
John C. Zasada
Keyword(s):  
Soil Moisture ◽  
Seed Dispersal ◽  
Embryo Development ◽  
Growing Season ◽  
White Spruce ◽  
High Elevation ◽  
Seed Collection ◽  
Interior Alaska ◽  
Lower Elevation ◽  
Soil Temperatures

Embryo development in white spruce seeds was studied in five stands in interior Alaska. Cones and seeds were collected at 10- to 14-day intervals starting in mid-July and continuing until just before seed dispersal began. Significant differences were found in embryo development between stands, between trees within stands, and between cones within trees. The four stands at lower elevations produced seeds that had embryos filling 95% or more of the embryo cavity; this percentage was significantly higher than the highest elevation stand where embryos filled about 75% of the embryo cavity at the end of the growing season. Relative cotyledon length was generally greater than 25% in the lower elevation stands and slightly less than 20% in the high elevation stand. Although seed collection can be started when embryos fill 75% of the embryo cavity, the results of this and other studies suggest that collecting seeds when embryos are more mature will result in better quality seeds. Air and soil temperatures and soil moisture levels associated with embryo development are presented.

Potential changes in carbon dynamics due to climate change measured in the past two decades

2005 ◽  
Vol 35 (9) ◽  
pp. 2258-2267 ◽  
Author(s):  
John Yarie ◽  
Bill Parton
Keyword(s):  
Climate Change ◽  
Carbon Balance ◽  
Carbon Capture ◽  
Black Spruce ◽  
White Spruce ◽  
Carbon Dynamics ◽  
Age Classes ◽  
The Past ◽  
Interior Alaska ◽  
Taiga Forest

Evidence suggests that climate change dynamics have been occurring in the northern latitudes for the past two and a half decades. The CENTURY ecosystem model was used for a set of simulations related to the carbon dynamics of interior Alaska taiga forest types. The functional dynamics of three age-classes (young, middle, and mature) of three ecosystem types (white spruce (Picea glauca (Moench) Voss), black spruce (Picea mariana (Mill.) BSP), and hardwoods) were compared using an average climate that was present prior to 1980 and the climate record from 1980 to 2000. Estimates for total ecosystem production indicate a decrease in tree carbon capture for hardwood stands for all three age-classes summed across a 20-year climate change period. White spruce displayed increases in carbon capture for the three age-classes. Young and mid-aged black spruce stands showed a decrease in ecosystem productivity. The old-growth black spruce stand showed a small increase in carbon capture. Dynamics displayed for the entire ecosystem (soil organic matter, tree dynamics, dead wood, and forest litter) followed the same trends as vegetation productivity. For the same 20-year climate period and across all three age-classes, carbon capture decreased for hardwood ecosystems and increased for white spruce ecosystems. The young black spruce system showed a change from a positive carbon balance to a negative carbon balance. Based on the landscape area covered by each vegetation type, we suggest that the net effect of climate warming over the past 20 years has been a substantial decrease in carbon capture in the forests of interior Alaska.

FOREST COMMUNITIES IN NORTHWESTERN ALBERTA

1953 ◽  
Vol 31 (2) ◽  
pp. 212-252 ◽  
Author(s):  
E. H. Moss
Keyword(s):  
Populus Tremuloides ◽  
Black Spruce ◽  
Abies Balsamea ◽  
White Spruce ◽  
Balsam Fir ◽  
Peat Moss ◽  
Mixed Stands ◽  
Natural Succession ◽  
Balsam Poplar ◽  
Feather Moss

Spruce, tamarack (larch), balsam fir, pine, and poplar communities of the region are described in terms of floristic composition and ecological relationships. The white spruce (Picea glauca) association is regarded as the climax type of the region. Of four phases or faciations presented by the white spruce association, the feather moss faciation appears to be the climax to which the other faciations tend to develop. Two black spruce (Picea mariana) communities are recognized, the black spruce – feather moss association and the black spruce–peat moss association. Of these, the former is characterized by "feather mosses" such as Hylocomium splendens and has developed on relatively level terrain without much peat formation, whereas the latter has a Sphagnum floor and has arisen in definite depressions through acid bog stages with the production of considerable peat. The black spruce – bog moss community is interpreted as subclimax, with natural succession to the black spruce – feather moss association. The tamarack (Larix laricina) community has many features in common with the black spruce – peat moss association but differs markedly, not only in its dominant species, but because of its development from a Drepano-cladus–Carex–Betula bog under persisting wet conditions. Succession to black spruce commonly occurs. Balsam fir (Abies balsamea) is relatively rare in the region and usually grows in mixed stands with white spruce, paper birch, aspen, and balsam poplar. Two divisions of the pine association are recognized, the jack pine (Pinus banksiana) and the lodgepole pine (P. contorta var. latifolia) consociations. For each of these, two phases are described, the pine – feather moss faciation on the more shaded sites and the pine–heath faciation on the more open and drier areas. Knowledge of the ranges of these two pines in northern Alberta and concerning hybrids between the species is extended. The poplar association, classified as aspen (Populus tremuloides) and balsam poplar (P. balsamifera) consociations, is considered in relation to other vegetation, especially prairie grassland and white spruce. Encroachment of aspen poplar upon native grassland is counteracted by various factors, notably burning. Natural succession of poplar and pine to white spruce is impeded chiefly by forest fires. Some attention is given to phytogeographical problems of this transition region.

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