Patterns of translocation of carbon in four common moss species in a black spruce (Piceamariana) dominated forest in interior Alaska

1983 ◽  
Vol 13 (5) ◽  
pp. 869-878 ◽  
Author(s):  
O. Skre ◽  
W. C. Oechel ◽  
P. M. Miller
Keyword(s):  
Specific Activity ◽  
Black Spruce ◽  
Strong Increase ◽  
Moss Species ◽  
Carbohydrate Analysis ◽  
Interior Alaska ◽  
Storage Polysaccharide ◽  
Combustion Technique ◽  
Peak Summer ◽  
Growing Shoot

The patterns of translocation of carbon in different-age tissues of four common moss species in a black spruce (Piceamariana (Mill.) B.S.P.) dominated forest near Fairbanks, Alaska, were studied by 14C labelling and carbohydrate analysis. A simple, in-vial combustion technique was developed for combustion of small (< 10 mg) radioactively labelled samples of plant tissue. The method was used to measure specific activity of 14C in moss tissue 2 h and 5, 15, and 25 days after labelling with 14CO2 gas in sealed chambers. The procedure was repeated three times during the summer. Patterns of 14C translocation varied by species; Polytrichumcommune Hedw. retained the most label after 2 h and Sphagnumsubsecundum Nees. the least. Polytrichumcommune had the second-highest fraction of 14C in brown tissue after 35 days and S. subsecundum the highest. Hylocomiumsplendens (Hedw.) B.S.G. and Pleuroziumschreberi (Brid.) Mitt, did not show consistent patterns of translocation 2 h or 35 days after labelling. 14C was found to accumulate in the growing shoot tips and in the brown tissue of all four species. Loss of 14C because of respiration was high in all four species during the first labelling period indicating high rates of photosynthesis and growth during the peak summer season. The carbohydrate analysis indicated that the increase in 14C activity in brown tissue by the end of the season was due to translocation for storage. In all species there was a strong increase in the storage polysaccharide content by the end of the season after the growth was finished, especially in brown tissue.

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.

Evidence of temperature control of production and nutrient cycling in two interior Alaska black spruce ecosystems

1981 ◽  
Vol 11 (2) ◽  
pp. 259-274 ◽  
Author(s):  
Keith Van Cleve ◽  
Richard Barney ◽  
Robert Schlentner
Keyword(s):  
Black Spruce ◽  
Mineral Soil ◽  
Soil Nutrient ◽  
North Slope ◽  
Nutrient Pools ◽  
Soil Biological Activity ◽  
Nutrient Mineralization ◽  
Interior Alaska ◽  
Soil Temperatures ◽  
And Function

Selected indices of structure and function were used to evaluate the effect of differing soil thermal regimes on soil-permafrost-dominated (muskeg) and permafrost-free (north-slope) black spruce ecosystems in interior Alaska. The poorly drained, permafrost site displayed cooler soil temperatures and higher soil moisture content than were encountered on the well-drained north slope. Mineral soil nutrient pools generally were largest on the permafrost site. However, low soil temperature acted as a negative feedback control, suppressing soil biological activity, nutrient mineralization, and tree primary production to lower levels on the soil-permafrost-dominated site as compared with the permafrost-free site. Forty percent larger accumulation of tree biomass and 80% greater annual tree productivity occurred on the warmer site.

Posttranslational modifications of recombinant myotube-synthesized human factor IX

Blood ◽  
2001 ◽  
Vol 97 (1) ◽  
pp. 130-138 ◽  
Author(s):  
Valder R. Arruda ◽  
James N. Hagstrom ◽  
Jeffrey Deitch ◽  
Terry Heiman-Patterson ◽  
Rodney M. Camire ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Posttranslational Modifications ◽  
Half Life ◽  
Specific Activity ◽  
Factor Ix ◽  
Serine Phosphorylation ◽  
Hemophilia B ◽  
Tyrosine Sulfation ◽  
Aav Vector ◽  
Carbohydrate Analysis

Abstract Recent data demonstrate that the introduction into skeletal muscle of an adeno-associated viral (AAV) vector expressing blood coagulation factor IX (F.IX) can result in long-term expression of the transgene product and amelioration of the bleeding diathesis in animals with hemophilia B. These data suggest that biologically active F.IX can be synthesized in skeletal muscle. Factor IX undergoes extensive posttranslational modifications in the liver, the normal site of synthesis. In addition to affecting specific activity, these posttranslational modifications can also affect recovery, half-life in the circulation, and the immunogenicity of the protein. Before initiating a human trial of an AAV-mediated, muscle-directed approach for treating hemophilia B, a detailed biochemical analysis of F.IX synthesized in skeletal muscle was carried out. As a model system, human myotubes transduced with an AAV vector expressing F.IX was used. F.IX was purified from conditioned medium using a novel strategy designed to purify material representative of all species of rF.IX in the medium. Purified F.IX was analyzed by sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE), N-terminal sequence analysis, chemical γ-carboxyglutamyl analysis, carbohydrate analysis, assays for tyrosine sulfation, and serine phosphorylation, and for specific activity. Results show that myotube-synthesized F.IX has specific activity similar to that of liver-synthesized F.IX. Posttranslational modifications critical for specific activity, including removal of the signal sequence and propeptide, and γ-carboxylation of the N-terminal glutamic acid residues, are also similar, but carbohydrate analysis and assessment of tyrosine sulfation and serine phosphorylation disclose differences. In vivo experiments in mice showed that these differences affect recovery but not half-life of muscle-synthesized F.IX.

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.

Long-term monitoring of climatic and nutritional affects on tree growth in interior Alaska

2010 ◽  
Vol 40 (7) ◽  
pp. 1325-1335 ◽  
Author(s):  
J. Yarie ◽  
K. Van Cleve
Keyword(s):  
Tree Growth ◽  
Black Spruce ◽  
Growth Period ◽  
Early Spring ◽  
Large Set ◽  
Primary Control ◽  
Forest Types ◽  
Interior Alaska ◽  
State Factor

The comparative analysis of a large set of long-term fertilization and thinning studies in the major forest types of interior Alaska is summarized. Results indicate that nutrient limitations may only occur during the early spring growth period, after which moisture availability is the primary control of tree growth on warm sites. The temperature dynamics of both air and soil set seasonal bounds on the nutrient and moisture dynamics for all forest types. Air and soil temperature limitations are the primary control of intraseasonal growth in the colder topographic locations in interior Alaska. These locations are usually dominated by black spruce (Picea mariana (Mill.) Britton, Sterns, Poggenb.) vegetation types. The seasonal progression of factors controlling growth is strongly tied to the state factor structure of the landscape.

Fine root biomass in two black spruce stands in interior Alaska: effects of different permafrost conditions

Trees ◽  
2015 ◽  
Vol 30 (2) ◽  
pp. 441-449 ◽  
Author(s):  
Kyotaro Noguchi ◽  
Yojiro Matsuura ◽  
Stephen D. Sparrow ◽  
Larry D. Hinzman
Keyword(s):  
Root Biomass ◽  
Fine Root ◽  
Black Spruce ◽  
Fine Root Biomass ◽  
Interior Alaska ◽  
Spruce Stands
Sign in / Sign up

Export Citation Format

Share Document