Relationships between cellulose decomposition, Jenny's k, forest-floor nitrogen, and soil temperature in Alaskan taiga forests

1983 ◽  
Vol 13 (5) ◽  
pp. 789-794 ◽  
Author(s):  
John F. Fox ◽  
Keith Van Cleve
Keyword(s):  
Decomposition Rate ◽  
Forest Floor ◽  
Black Spruce ◽  
Nitrogen Concentration ◽  
Major Influence ◽  
Decomposition Rates ◽  
Cellulose Decomposition ◽  
Taiga Forest ◽  
Wide Range ◽  
Cellulose Filter

Forest-floor decomposition is compared among 16 Alaskan taiga forest stands. These include black spruce (Piceamariana (Mill.) B.S.P.), white spruce (Piceaglauca (Moench) Voss), and birch (Betulapapyrifera Marsh.), aspen {Populustremuloides Michx.), and balsam poplar (Populusbalsamifera L.) types, spanning a wide range in decomposition rates, forest-floor microclimates, and litter quality. Jenny's index of decomposition rate, k, is reasonably well correlated with annual cellulose (filter-paper) decomposition differences among stands. Both estimates of decomposition rate are correlated with forest-floor heat sum and forest-floor nitrogen concentration. These between-site correlations support inferences based upon experimental work claiming that temperature and forest-floor chemical quality have a major influence upon the level of decomposition in a particular stand. Inferences about the factors regulating decomposition rate around an average level within one stand cannot legitimately be made from the same correlations. Moisture has not been considered in this analysis, but could also be important to between-stand differences in decomposition rate.

Bioassay of forest floor nitrogen supply for plant growth

1986 ◽  
Vol 16 (6) ◽  
pp. 1320-1326 ◽  
Author(s):  
K. Van Cleve ◽  
O. W. Heal ◽  
D. Roberts
Keyword(s):  
Forest Floor ◽  
Black Spruce ◽  
Nitrogen Concentration ◽  
N Uptake ◽  
Mineral Soil ◽  
Forest Types ◽  
N Supply ◽  
Paper Birch ◽  
Forest Floors ◽  
P Supply

Using a bioassay approach, this paper considers the nitrogen-supplying power of forest floors from examples of the major forest types in interior Alaska. Yield and net N uptake by paper birch seedlings grown in standardized mixtures of quartz sand and forest floor organic matter, and separate incubation estimates of N mineralization and nitrification for the forest floors, were employed to evaluate potential N supply. Black spruce and floodplain white spruce forest floors supplied only one-fifth the amount of N taken up by seedlings growing in other forest floors. Incubation estimates showed these forest floors yielded 4 and 15 times less extractable N, respectively, than the more fertile birch forest floors. In comparison with earlier estimates of P supply from these same forest floors, the upland types showed greater deficiency of N whereas floodplain types showed greater deficiency of P in control of seedling yield. The latter condition is attributed to the highly calcareous nature of the floodplain mineral soil, the consequent potential for P fixation, and hence greater potential deficiency of the element compared with N in mineralizing forest floors. Nitrogen concentration of the forest floors was the best predictor of bioassay response.

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.

Fire severity as a determinant factor of the decomposition rate of fire-killed black spruce in the northern boreal forest

2011 ◽  
Vol 41 (2) ◽  
pp. 370-379 ◽  
Author(s):  
Yan Boulanger ◽  
Luc Sirois ◽  
Christian Hébert
Keyword(s):  
Moisture Content ◽  
Boreal Forest ◽  
Decomposition Rate ◽  
Black Spruce ◽  
Woody Debris ◽  
Fire Severity ◽  
Decomposition Process ◽  
Vertical Position ◽  
Decomposition Rates ◽  
Considerable Impact

Several attributes might influence the decomposition process of fire-killed trees. Here, we tested various tree- and plot-level variables on the decomposition rate of fire-killed black spruce ( Picea mariana (Mill.) BSP) in the northern boreal forest. Data were collected from 474 individuals burned 17 years prior to sampling. Mean decomposition rate was relatively slow (k = 0.013) and was lowest for severely burned snags (k = 0.001) and highest for lightly burned logs (k = 0.027–0.036). Vertical position and fire severity were the most important variables influencing the decomposition rates, while plot-level variables were marginally significant. Both predictors strongly influenced the moisture content of fire-killed trees. Logs with greater contact with the ground and lightly burned trees had higher moisture content and faster decomposition rates. Very severely burned trees had lower moisture content because of faster bark shedding. This hampered the decomposition process by slowing the snag falling rate. Higher decomposition rates in lightly burned trees may result from greater colonization by early xylophagous species. By having a considerable impact on the decomposition of woody debris, fire severity may strongly influence many post-fire biological processes related to the woody necromass as well as carbon emission from burned stands.

Postfire dynamics of black spruce coarse woody debris in northern boreal forest of Quebec

2006 ◽  
Vol 36 (7) ◽  
pp. 1770-1780 ◽  
Author(s):  
Yan Boulanger ◽  
Luc Sirois
Keyword(s):  
Moisture Content ◽  
Boreal Forest ◽  
Nitrogen Content ◽  
Decomposition Rate ◽  
Coarse Woody Debris ◽  
Black Spruce ◽  
Woody Debris ◽  
Decomposition Rates ◽  
Asymbiotic Nitrogen Fixation ◽  
Study Sites

In this study, postfire coarse woody debris (CWD) dynamics in northern Quebec, Canada, were assessed using a 29-year chronosequence. Postfire woody-debris storage, decomposition rates, and variation of nitrogen and carbon contents of black spruce CWD (Picea mariana (Mill.) BSP) are estimated. The decomposition rate for postfire snags is exceptionally slow (k = 0.00), while the decomposition rate for logs (k = 0.019–0.021) is within previously recorded values for the boreal forest. The low decomposition rate for snags could be related to low moisture content associated with the position of debris and fast bark shedding. Given the low CWD decomposition rates and CWD storage (21.3–66.8 m3·ha–1), carbon losses from postfire CWD are relatively low, varying between 35.5 and 128.8 kg·ha–1·year–1 at the study sites. The nitrogen content in CWD drops quickly between living trees and snags and increases slightly with time since fire in logs. Nitrogen content is not related to wood density or to moisture content of deadwood. Rapid loss of nitrogen is associated with fast decomposition of subcortical tissues, leaching, and insect comminution. The increase in nitrogen content at the oldest site could result from asymbiotic nitrogen fixation, although a longer time span in the chronosequence would probably have revealed a greater nitrogen gain in increasingly decayed CWD.

scholarly journals Cellulose decomposition rate and features of organic matter in forest soils in the Tatra mountains

2014 ◽  
Vol 15 (1-2) ◽  
pp. 70-80
Author(s):  
K. Wasak
Keyword(s):  
Organic Matter ◽  
Decomposition Rate ◽  
Tree Species ◽  
Beech Forest ◽  
Spruce Forest ◽  
Tatra Mountains ◽  
Decomposition Rates ◽  
Thin Sections ◽  
Cellulose Decomposition ◽  
The Tatra Mountains

The cellulose decomposition rate measurement and soil micromorphology have been used to determine the influence of parent material and tree species on mechanisms responsible for organic matter form differentiation in woodland soils in the Tatra Mountains in Poland. The study area is located in the lower montane belt of the Tatra Mountains. Investigated soils are developed on dolomites and shale. In the past, beech and beech-fir forests had been the dominant form of vegetation in the study area. Since the 16th century, these areas were deforested until the 19th century, when reforestation efforts were undertaken. Reforestation efforts provided mainly spruce; hence, it is the dominant species in the lower montane belt at the moment, although in some areas, natural or semi-natural beech and beech-fir forests have survived. Four plots were compared – two with soils developed on calcareous material (Rendzic Leptosols), one under beech forest and one under spruce forest, and two developed on shale (Haplic Cambisols), one under beech forest and one under spruce forest. Cellulose filters were placed in organic O-horizons and humus A-horizons in every plot to measure the cellulose decomposition rate. Before being placed in the soil, cellulose filters were boiled in KOH, rinsed in distilled water, dried, weighed, and set on glass plates in a nylon bag (1.5 mm mesh). The bags were placed in the soil vertically at approx. 15 cm intervals. After taken up, the filters were boiled in KOH, rinsed, dried, and weighed. The amount of ash was determined via combustion. The research was carried out during a period of 10 weeks between June and August as well as during a period of 1 year. Measurements were repeated ten times. A weighted average and standard deviation were calculated for every plot. The cellulose filter method is useful because of the homogeneity of the substrate, which helps to exclude differences connected with the chemical composition of the plant material, a factor that affects the decomposition rate. Undisturbed soil samples were taken from humus A-horizons in every soil profile. The thin sections were prepared and features of organic matter were described. It was concluded that the presence of calcarous material negatively affects organic matter decomposition rates which is pronounced in both: higher amount of organic matter residues in humus-A horizons and slower cellulose decomposition rates in Rendzic Leptosols than in Haplic Cabisols. The influence of tree species on organic matter features is observed only in Haplic Cambisols, where the cellulose decomposition rate under spruce is lower than under beech. This suggests that tree species indirectly affect the cellulitic microflora only in acidic soils.

Forest floor respiration in a black spruce taiga forest ecosystem in Alaska

Ecography ◽  
1981 ◽  
Vol 4 (4) ◽  
pp. 229-237 ◽  
Author(s):  
Joanne E. Cowling ◽  
Stephen F. MacLean
Keyword(s):  
Forest Ecosystem ◽  
Forest Floor ◽  
Black Spruce ◽  
Taiga Forest

scholarly journals Soil Nitrogen Dynamics in a Managed Temperate Grassland Under Changed Climatic Conditions

Water ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 931
Author(s):  
Mona Giraud ◽  
Jannis Groh ◽  
Horst H. Gerke ◽  
Nicolas Brüggemann ◽  
Harry Vereecken ◽  
...  
Keyword(s):  
Nitrogen Uptake ◽  
Inorganic Nitrogen ◽  
Nitrogen Concentration ◽  
Nitrogen Dynamics ◽  
Climatic Conditions ◽  
Undisturbed Soil ◽  
Nitrogen Emissions ◽  
Growing Period ◽  
Grassland Type ◽  
Wide Range

Grasslands are one of the most common biomes in the world with a wide range of ecosystem services. Nevertheless, quantitative data on the change in nitrogen dynamics in extensively managed temperate grasslands caused by a shift from energy- to water-limited climatic conditions have not yet been reported. In this study, we experimentally studied this shift by translocating undisturbed soil monoliths from an energy-limited site (Rollesbroich) to a water-limited site (Selhausen). The soil monoliths were contained in weighable lysimeters and monitored for their water and nitrogen balance in the period between 2012 and 2018. At the water-limited site (Selhausen), annual plant nitrogen uptake decreased due to water stress compared to the energy-limited site (Rollesbroich), while nitrogen uptake was higher at the beginning of the growing period. Possibly because of this lower plant uptake, the lysimeters at the water-limited site showed an increased inorganic nitrogen concentration in the soil solution, indicating a higher net mineralization rate. The N2O gas emissions and nitrogen leaching remained low at both sites. Our findings suggest that in the short term, fertilizer should consequently be applied early in the growing period to increase nitrogen uptake and decrease nitrogen losses. Moreover, a shift from energy-limited to water-limited conditions will have a limited effect on gaseous nitrogen emissions and nitrate concentrations in the groundwater in the grassland type of this study because higher nitrogen concentrations are (over-) compensated by lower leaching rates.

Prescribed burning for lowland black spruce regeneration in northern Minnesota

1984 ◽  
Vol 14 (1) ◽  
pp. 107-113 ◽  
Author(s):  
Scott E. Aksamit ◽  
Frank D. Irving
Keyword(s):  
Prescribed Burning ◽  
Black Spruce ◽  
Controlled Study ◽  
University Of Minnesota ◽  
Feather Moss ◽  
Wide Range ◽  
Labrador Tea ◽  
Tall Shrub ◽  
The University ◽  
Larger Sample

Concern over the variability of black spruce (Piceamariana (Mill.) B.S.P.) regeneration on peatlands in northern Minnesota following prescribed burning led to a cooperative study between the University of Minnesota and the Minnesota Department of Natural Resources. Twenty-seven black spruce cutovers on State lands that had been prescribed burned and either seeded or left to regenerate naturally were sampled. These were stratified into sphagnum – Labrador-tea – leather-leaf (SPHG) sites (10), feather moss (FM) sites (9), and alder – graminoid – other tall shrub (ALDR) sites (8). Results indicate that fire was not necessary to regenerate SPHG sites. FM sites required fire to modify unfavorable seedbeds and to reduce competition. Best results were obtained by burning when the upper layers of the peat were highly desiccated. ALDR sites occupied a wide range of ecological conditions which led to highly variable regeneration results. A larger sample size and possibly more carefully controlled study conditions are needed to fully understand ALDR site regeneration. Seeding results were uncertain for all sites.

Early growth of lodgepole pine after establishment of alsike clover–Rhizobium nitrogen-fixing symbiosis

1992 ◽  
Vol 22 (8) ◽  
pp. 1089-1093 ◽  
Author(s):  
R. Trowbridge ◽  
F.B. Holl
Keyword(s):  
Forest Floor ◽  
Lodgepole Pine ◽  
Nitrogen Concentration ◽  
Growing Season ◽  
Early Growth ◽  
Percent Cover ◽  
Foliar Nitrogen ◽  
Growing Seasons ◽  
Pine Seedlings ◽  
Needle Mass

An overdense lodgepole pine (Pinuscontorta Dougl. ex Loud.) stand was knocked down and the site was prepared by broadcast burn, windrow burn, or mechanical forest floor removal. Inoculated alsike clover (Trifoliumhybridum L.) was seeded at 0, 10, 20, and 30 kg/ha for the three different site preparation treatments to determine the effects of (i) site preparation on infection and effectiveness of the clover–Rhizobium symbiosis and clover percent cover and (ii) the clover–Rhizobium N2-fixing symbiosis on survival, early growth, and foliar nitrogen concentration of lodgepole pine seedlings. The N2-fixing symbiosis established well in all treatments. Clover percent cover increased with increasing rate of seeding, although by relatively few percent in the clover seeded plots. Broadcast burning, windrow burning, and mechanical forest floor removal did not affect the establishment of the N2-fixing symbiosis or clover percent cover. Lodgepole pine survival was not affected by the seeding treatments in any year, nor were height measurements during the first three growing seasons. Seedling height was slightly less in clover-seeded plots compared with controls in the fourth growing season. Lodgepole pine seedlings on clover-seeded plots had decreased diameter growth compared with controls during the first three growing seasons, but incremental diameter growth no longer showed this effect by the fourth growing season. Needle mass (g/100 needles) was less in clover-seeded plots at the end of the second growing season, but this effect was reversed by the fourth growing season, when both needle mass and foliar nitrogen concentration in lodgepole pine foliage were greater in clover-seeded plots.

scholarly journals Changes to the chemical state of the northern hemisphere atmosphere during the second half of the twentieth century

2016 ◽  
Author(s):  
Mike J. Newland ◽  
Patricia Martinerie ◽  
Emmanuel Witrant ◽  
Detlev Helmig ◽  
David R. Worton ◽  
...  
Keyword(s):  
Northern Hemisphere ◽  
Large Scale ◽  
Atmospheric Composition ◽  
The Arctic ◽  
Major Influence ◽  
Secondary Products ◽  
Alkyl Nitrates ◽  
Mixing Ratios ◽  
Wide Range

Abstract. The NOX (NO and NO2) and HOX (OH and HO2) budgets of the atmosphere exert a major influence on atmospheric composition, controlling removal of primary pollutants and formation of a wide range of secondary products, including ozone, that can influence human health and climate. However, there remain large uncertainties in the changes to these budgets over recent decades. Due to their short atmospheric lifetimes, NOX and HOX are highly variable in space and time, and so the measurements of these species are of very limited value for examining long term, large scale changes to their budgets. Here, we take an alternative approach by examining long-term atmospheric trends of alkyl nitrates, the formation of which is dependent on the atmospheric NO / HO2 ratio. We derive long term trends in the alkyl nitrates from measurements in firn air from the NEEM site, Greenland. Their mixing ratios increased by a factor of 4–5 between the 1970s and 1990s. This was followed by a steep decline to the sampling date of 2008. Moreover, we examine how the trends in the alkyl nitrates compare to similarly derived trends in their parent alkanes (i.e. the alkanes which, when oxidised in the presence of NOX, lead to the formation of the alkyl nitrates). The ratios of the alkyl nitrates to their parent alkanes increase from around 1970 to the late 1990's consistent with large changes to the [NO] / [HO2] ratio in the northern hemisphere atmosphere during this period. These could represent historic changes to NOX sources and sinks. Alternatively, they could represent changes to concentrations of the hydroxyl radical, OH, or to the transport time of the air masses from source regions to the Arctic.

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