Nitrogen dynamics in the forest floor of interior Alaska black spruce ecosystems

1981 ◽  
Vol 11 (4) ◽  
pp. 743-751 ◽  
Author(s):  
M. G. Weber ◽  
K. Van Cleve
Keyword(s):  
Soil Temperature ◽  
Total Nitrogen ◽  
Forest Floor ◽  
Black Spruce ◽  
Nitrogen Dynamics ◽  
Nitrogen Pool ◽  
Feather Moss ◽  
Interior Alaska ◽  
Moss Layer ◽  
High Enrichment

Low addition levels of high enrichment isotope (>1% of the total nitrogen pool with 99 at.% excess 15N) were used to follow nitrogen movement through selected forest floor components of permafrost-free and permafrost-dominated black spruce ecosystems in subarctic Alaska. The nitrogen pool examined in this study was the total nitrogen pool. 15N was retained most effectively by the feather moss layer (Pleuroziumschreberi (BSG.) Mitt. and Hylocomiumsplendens (Hedw.) BSG.) on both black spruce sites. Twenty-eight months after isotope application the feather moss layer still contained over 90% of the 15N that could be recovered. The limited movement of 15N between feather moss layers and underlying forest floor horizons appeared to be slightly affected by climatological events. Differences in 15N movement patterns between permafrost-free and permafrost-dominated black spruce sites are discussed in terms of precipitation, soil temperature, and biological controls.

Nitrogen transformations in feather moss and forest floor layers of interior Alaska black spruce ecosystems

1984 ◽  
Vol 14 (2) ◽  
pp. 278-290 ◽  
Author(s):  
M. G. Weber ◽  
K. Van Cleve
Keyword(s):  
Forest Floor ◽  
Black Spruce ◽  
Vascular Plant ◽  
N Uptake ◽  
Nitrogen Transformations ◽  
Organic Matter Quality ◽  
Available N ◽  
Moss Species ◽  
Feather Moss ◽  
Interior Alaska

Permafrost-free and permafrost-dominated black spruce (Piceamariana (Mill.) B.S.P.) ecosystems in interior Alaska were treated with low addition levels of high enrichment isotope (<1% of the total nitrogen pool with 99 at.% excess 15N) to describe nitrogen dynamics through pools of selected forest floor components. A thick carpet of mosses, made up primarily of the feather moss species Hylocomiumsplendens (Hedw.) B.S.G. and Pleuroziumschreberi (B.S.G.) Mitt, seemed to play a vital role in the nitrogen economy of the forest floor. Nitrogen, quickly immobilized in the moss layers (green, brown) and retained there, was released very slowly to the lower organic layers (021 + 022) where most of the vascular plant roots were located. 15N uptake by the vascular understory was minimal, as was15Nexport via the soil solution. Periodic mineralization episodes, more frequent and dynamic at the permafrost-free site (where C/N ratios were lower), were largely restricted to the moss layers since available N fractions in deeper forest floor layers incorporated little label over the 3-year period. In the lower layers of the forest floor (021 + 022) temperature rather than organic matter quality appeared to be the overriding factor controlling N flow.

Productivity and nutrient cycling in taiga forest ecosystems

1983 ◽  
Vol 13 (5) ◽  
pp. 747-766 ◽  
Author(s):  
Keith Van Cleve ◽  
Lola Oliver ◽  
Robert Schlentner ◽  
Leslie A. Viereck ◽  
C. T. Dyrness
Keyword(s):  
Nutrient Cycling ◽  
Soil Temperature ◽  
Forest Floor ◽  
Black Spruce ◽  
Lignin Content ◽  
Mineral Soil ◽  
Forest Types ◽  
Interior Alaska ◽  
Taiga Forest ◽  
Tree Production

This paper considers the productivity and nutrient cycling in examples of the major forest types in interior Alaska. These ecosystem properties are examined from the standpoint of the control exerted over them by soil temperature and forest-floor chemistry. We conclude that black spruce Piceamariana (Mill.) B.S.P. occupies the coldest, wettest sites which support tree growth in interior Alaska. Average seasonal heat sums (1132 ± 32 degree days (DD)) for all other forest types were significantly higher than those encountered for black spruce (640 ± 40 DD). In addition, black spruce ecosystems display the highest average seasonal forest-floor and mineral-soil moisture contents. Forest-floor chemistry interacts with soil temperature in black spruce to produce the most decay-resistant organic matter. In black spruce the material is characterized by the highest lignin content and widest C/N (44) and C/P (404) ratios. Across the range of forest types examined in this study, soil temperature is strongly related to net annual aboveground tree production and the annual tree requirement for N, P, K, Ca, and Mg. Forest floor C/N and C/P ratios are strongly related to annual tree N and P requirement and the C/N ratio to annual tree production. In all cases these controls act to produce, in black spruce, the smallest accumulation of tree biomass, standing crop of elements, annual production, and element requirement in aboveground tree components.

Response of black spruce (Piceamariana) ecosystems to soil temperature modification in interior Alaska

1990 ◽  
Vol 20 (9) ◽  
pp. 1530-1535 ◽  
Author(s):  
Keith Van Cleve ◽  
Walter C. Oechel ◽  
John L. Hom
Keyword(s):  
Soil Temperature ◽  
Soil Solution ◽  
Forest Floor ◽  
Black Spruce ◽  
Mineral Soil ◽  
Nutrient Content ◽  
Experimental Period ◽  
Degree Days ◽  
Soil Heating ◽  
Interior Alaska

This paper reports results of a study designed to examine the control that soil temperature exerts on soil processes associated with nutrient flux, and in turn, on tree nutrition in interior Alaska black spruce ecosystems. Approximately 50 m2 of forest floor in a 140-year-old black spruce ecosystem, which had developed on permafrost, was heated to 8–10 °C above ambient temperature. This perturbation amounted to approximately a 1589 degree-day seasonal heat sum (above 0 °C), 1026 degree-days above the control total of 563 degree-days. The forest floor, surface 5 cm of mineral soil, and soil solution were compared with those of an adjacent control plot to evaluate the change in nutrient content and decomposition rate of the forest floor. The nutritional response to soil heating of current black spruce foliage also was evaluated. Soil heating significantly increased decomposition of the forest floor, principally because of an increase in biomass loss of the O21 layer. The increased decomposition resulted in greater extractable N and P concentrations in the forest floor, higher N concentrations in the soil solution, and elevated spruce needle N, P, and K concentrations for the experimental period. These results are discussed in light of the importance of soil temperature and other state factors that mediate ecosystem function.

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.

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.

scholarly journals Environmental factors regulating winter CO<sub>2</sub> flux in snow-covered boreal forest soil, interior Alaska

2012 ◽  
Vol 9 (1) ◽  
pp. 1129-1159 ◽  
Author(s):  
Y. Kim ◽  
Y. Kodama
Keyword(s):  
Environmental Factors ◽  
Soil Temperature ◽  
Forest Soil ◽  
Atmospheric Pressure ◽  
Co2 Emission ◽  
Black Spruce ◽  
Co2 Flux ◽  
Atmospheric Temperature ◽  
Spruce Forest ◽  
Interior Alaska

Abstract. Winter CO2 flux is an important element to assess when estimating the annual carbon budget on regional and global scales. However, winter observation frequency is limited due to the extreme cold weather in sub-Arctic and Arctic ecosystems. In this study, the continuous monitoring of winter CO2 flux in black spruce forest soil of interior Alaska was performed using NDIR CO2 sensors at 10, 20, and 30 cm above the soil surface during the snow-covered period (DOY 357 to 466) of 2006/2007. The atmospheric pressure was divided into four phases: >1000 hPa (HP: high pressure); 985<P<1000 (IP: intermediate pressure); <986 hPa (LP: low pressure); and a snow-melting period (MP); for the quantification of the effect of the environmental factors determining winter CO2 flux. The winter CO2 fluxes were 0.22 ± 0.02, 0.23 ± 0.02, 0.25 ± 0.03, and 0.17 ± 0.02 gCO2-C/m2 d−1 for the HP, IP, LP, and MP phases, respectively. Wintertime CO2 emission represents 20 % of the annual CO2 emissions in this boreal black spruce forest soil. Atmospheric temperature, pressure, and soil temperature correlate at levels of 56, 25, and 31 % to winter CO2 flux, respectively, during the snow-covered period of 2006/2007, when snow depth experienced one of its lowest totals of the past 80 years. Atmospheric temperature and soil temperature at 5 cm depth, modulated by atmospheric pressure, were found to be significant factors in determining winter CO2 emission and fluctuation in snowpack. Regional/global process-based carbon cycle models should be reassessed to account for the effect of winter CO2 emissions, regulated by temperature and soil latent-heat flux, in the snow-covered soils of Arctic and sub-Arctic terrestrial ecosystems of the Northern Hemisphere.

Black Spruce Fuel Weights and Biomass in Two Interior Alaska Stands

1973 ◽  
Vol 3 (2) ◽  
pp. 304-311 ◽  
Author(s):  
Richard J. Barney ◽  
Keith Van Cleve
Keyword(s):  
Black Spruce ◽  
Basal Area ◽  
Total Biomass ◽  
Biomass Distribution ◽  
Dead Tree ◽  
Interior Alaska ◽  
Moss Layer

This study reports the fuel weight and biomass distribution in a 51-year-old lowland and a 55-year-old upland black spruce (Piceamariana [Mill.] B.S.P.) stand in interior Alaska. Biomass distribution is shown for overstory, standing and down dead tree components, herbaceous understory, and the moss layer. The lowland stand contained over 11000 stems/acre (27170 stems/ha) and 82 ft2 of basal area per acre (18.8 m2 of basal area per hectare), and the upland stand contained 6000 stems/acre (14820 stems/ha) and 96 ft2 of basal area per acre (22.0 m2 of basal area per hectare). Moss layers contributed 54.6 and 45.5 t/acre (120.1 and 100.1 metric t/ha) to biomass totals in the lowland and upland sites, respectively. Total biomass was 64.7 t/acre (142.3 metric t/ha) in the lowland site and 58.0 t/acre (127.6 metric t/ha) in the upland site.

Bioassay of forest floor phosphorus supply for plant growth

1985 ◽  
Vol 15 (1) ◽  
pp. 156-162 ◽  
Author(s):  
K. Van Cleve ◽  
F. Harrison
Keyword(s):  
Forest Floor ◽  
Black Spruce ◽  
Forest Types ◽  
P Deficiency ◽  
Interior Alaska ◽  
Rooting Medium ◽  
Forest Floors ◽  
Work Supports ◽  
Plant Bioassays

This paper considers the extent to which phosphorus (P) supply for plant use is controlled by the chemical quality of forest floor organic matter, independent of climate. Using plant bioassays, forest floor materials from representative examples of each of the major forest types in interior Alaska were examined for nutrient supplying power. The work supports conclusions reached in earlier studies which indicated that black spruce forest floors were highly nutrient limited compared with those of other interior Alaska forest types. In addition, floodplain white spruce forests may experience marked P deficiency because of dilution of the element by periodic siltation. Potential phosphorus supply for seedling growth was best described by P concentration of the rooting medium. The supply also was related to the concentrations of lignin and tannin which control forest floor decomposition and recycling of P within the microbial population.

Soil carbon stabilization along climate and stand productivity gradients in black spruce forests of interior Alaska

2005 ◽  
Vol 35 (9) ◽  
pp. 2118-2129 ◽  
Author(s):  
E S Kane ◽  
D W Valentine ◽  
E AG Schuur ◽  
K Dutta
Keyword(s):  
Organic Matter ◽  
Primary Production ◽  
Soil Temperature ◽  
Black Spruce ◽  
Mineral Soil ◽  
Soil C ◽  
Stand Productivity ◽  
Interior Alaska ◽  
C Balance ◽  
Soil C Balance

The amount of soil organic carbon (SOC) in stable, slow-turnover pools is likely to change in response to climate warming because processes mediating soil C balance (net primary production and decomposition) vary with environmental conditions. This is important to consider in boreal forests, which constitute one of the world's largest stocks of SOC. We investigated changes in soil C stabilization along four replicate gradients of black spruce productivity and soil temperature in interior Alaska to develop empirical relationships between SOC and stand and physiographic features. Total SOC harbored in mineral soil horizons decreased by 4.4 g C·m–2 for every degree-day increase in heat sum within the organic soil across all sites. Furthermore, the proportion of relatively labile light-fraction (density <1.6 g·cm–3) soil organic matter decreased significantly with increased stand productivity and soil temperature. Mean residence times of SOC (as determined by Δ14C) in dense-fraction (>1.6 g·cm–3) mineral soil ranged from 282 to 672 years. The oldest SOC occurred in the coolest sites, which also harbored the most C and had the lowest rates of stand production. These results suggest that temperature sensitivities of organic matter within discrete soil pools, and not just total soil C stocks, need to be examined to project the effects of changing climate and primary production on soil C balance.

Variation in postfire organic layer thickness in a black spruce forest complex in interior Alaska and its effects on soil temperature and moisture

2005 ◽  
Vol 35 (9) ◽  
pp. 2164-2177 ◽  
Author(s):  
Eric S Kasischke ◽  
Jill F Johnstone
Keyword(s):  
Soil Temperature ◽  
Fuel Consumption ◽  
Fire History ◽  
Black Spruce ◽  
Mineral Soil ◽  
Stand Age ◽  
Organic Layer ◽  
Layer Depth ◽  
Interior Alaska ◽  
Soil Temperature And Moisture

This study investigated the relationship between climate and landscape characteristics and surface fuel consumption as well as the effects of variations in postfire organic layer depth on soil temperature and moisture in a black spruce (Picea mariana (Mill.) BSP) forest complex in interior Alaska. Mineral soil moisture and temperature at the end of the growing season and organic layer depth were measured in three burns occurring in different years (1987, 1994, 1999) and in adjacent unburned stands. In unburned stands, average organic layer and humic layer depth increased with stand age. Mineral soil temperature and moisture varied as a function of the surface organic layer depth in unburned stands, indicating that as a stand matures, the moisture content of the deep duff layer is likely to increase as well. Fires reduced the depth of the surface organic layers by 5 to 24 cm. Within each burn we found that significant variations in levels of surface fuel consumption were related to several factors, including mineral soil texture, presence or absence of permafrost, and timing of the fires with respect to seasonal permafrost thaw. While seasonal weather patterns contribute to variations in fuel moisture and consumption during fires, interactions among the soil thermal regime, surface organic layer depth, and previous fire history are also important in controlling patterns of surface fuel consumption.

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