Mass loss and nutrient dynamics of coarse woody debris in three Rocky Mountain coniferous forests: 21 year results

2008 ◽  
Vol 38 (1) ◽  
pp. 125-132 ◽  
Author(s):  
Steffen Herrmann ◽  
Cindy E. Prescott
Keyword(s):  
Mass Loss ◽  
Picea Glauca ◽  
Nutrient Dynamics ◽  
Woody Debris ◽  
Wood Decay ◽  
Rocky Mountain ◽  
Dry Mass ◽  
Decay Rates ◽  
Coniferous Forests ◽  
Considerable Uncertainty

Mass loss and changes in C, N, and P concentrations were measured in 20 cm long log segments of lodgepole pine ( Pinus contorta Dougl. ex Loud.), white spruce ( Picea glauca (Moench) Voss), and subalpine fir (Abies lasiocarpa (Hook.) Nutt.) that had been placed in three Rocky Mountain coniferous forests 21 years earlier. Pine, spruce, and fir lost 76%, 39%, and 64%, respectively, of their initial mass during the 21 years. The corresponding mean decay rates (k) were 0.072, 0.024 and 0.052·year–1. The decay patterns of pine and spruce were similar with the highest k between 6 and 14 years. Fir k increased during the course of decomposition with the highest rate between 14 and 21 years. The correlation between original dry mass and k was negative for pine (r = –0.28), positive for fir (r = 0.35), and not significant for spruce. C/N, C/P, and N/P ratios declined and converged to a similar value in relation to mass loss for all three species. The N/P ratios of logs of all three species stabilized at about 19. These findings indicate that patterns of wood decay are difficult to predict (even with 14 year data), and so models that incorporate wood-decay estimates will be associated with considerable uncertainty.

The contribution of coarse woody debris to carbon, nitrogen, and phosphorus cycles in three Rocky Mountain coniferous forests

1999 ◽  
Vol 29 (10) ◽  
pp. 1592-1603 ◽  
Author(s):  
Raija Laiho ◽  
Cindy E Prescott
Keyword(s):  
Coarse Woody Debris ◽  
Picea Glauca ◽  
Pinus Contorta ◽  
Woody Debris ◽  
Wood Decay ◽  
Rocky Mountain ◽  
Dry Mass ◽  
Ground Vegetation ◽  
Nitrogen And Phosphorus ◽  
Aboveground Litter

The contribution of coarse woody debris to C, N, and P cycles was assessed in forests of lodgepole pine (Pinus contorta Dougl. ex Loud.), white spruce (Picea glauca (Moench Voss), and subalpine fir (Abies lasiocarpa (Hook.) Nutt.) - Engelmann spruce (Picea engelmannii Parry ex Engelm.) in southwestern Alberta. Mass loss and changes in C, N, and P concentrations in decomposing log segments were measured for 14 years. Litter input was measured during 10 years for coarse woody debris, 1 year for ground vegetation, and 5 years for other aboveground litter types. Release of C, N and P from decomposing litter were simulated for a period of 40 years. After 14 years, log segments of pine, spruce, and fir had lost on average 71, 38, and 40%, respectively, of their dry mass. The N content of the pine logs increased, spruce changed little, and fir lost N. Phosphorus accumulated in all logs. The greatest imports of N and P occurred at the pine sites and fir sites, respectively, where these nutrients were the least available, indicating that wood decay organisms may compete with vegetation for limiting nutrients in these forests. Coarse woody debris comprised 3-24% of aboveground litter and contributed less than 5% of the N and P released. Coarse woody debris does not appear to make a significant contribution to N and P cycling in these forests.

A reanalysis of nutrient dynamics in coniferous coarse woody debris

2001 ◽  
Vol 31 (11) ◽  
pp. 1894-1902 ◽  
Author(s):  
Scott M Holub ◽  
Julie DH Spears ◽  
Kate Lajtha
Keyword(s):  
Mass Loss ◽  
Coarse Woody Debris ◽  
Nutrient Dynamics ◽  
Woody Debris ◽  
Nutrient Flux ◽  
Constant Volume ◽  
Coniferous Forests ◽  
Nutrient Concentrations ◽  
Nutrient Fluxes ◽  
Conservative Tracers

We analyzed net N, P, K, Ca, and Mg fluxes from decaying coarse woody debris (CWD) by developing a "volume-adjusted method" and applying it to existing chronosequence studies of CWD in temperate coniferous forests. Unadjusted nutrient concentrations may overestimate the amount of a given nutrient remaining or accumulating in CWD, because mass loss, primarily as microbially respired CO2, occurs during decomposition. This overall mass loss tends to increase nutrient concentrations (e.g., µg N/g CWD) by decreasing the denominator and, therefore, can be misleading as an indicator of nutrient flux. Our volume-adjusted method corrects for mass loss, by assuming a constant volume as CWD decays. Using this method we determined that (i) Ca and K were lost from CWD as decay progressed; (ii) N and P increased or had no net change in amount; and (iii) Mg results were mixed. Several studies showed net gains of Mg and several showed net losses. We discuss the applicability and limitations of the volume adjusted method and propose the use of isotopic and conservative tracers as more accurate, but more difficult, methods of investigating CWD nutrient fluxes. We also discuss possible nutrient flux pathways into and out of CWD.

Decay and nutrient dynamics of coarse woody debris in northern coniferous forests: a synthesis

2004 ◽  
Vol 34 (4) ◽  
pp. 763-777 ◽  
Author(s):  
Raija Laiho ◽  
Cindy E Prescott
Keyword(s):  
Coarse Woody Debris ◽  
Nutrient Dynamics ◽  
Woody Debris ◽  
Decay Rates ◽  
Coniferous Forests ◽  
Minor Importance ◽  
Nutrient Cycles ◽  
Northern Forests ◽  
Aboveground Litter

We synthesize current information on input, accumulation, and decay of coarse woody debris (CWD) compared with other aboveground litter to assess the role of CWD in the nutrient cycles of northern coniferous forests. CWD contributes between 3% and 73% of aboveground litter input, but <20% of N, P, K, and Ca. Although CWD accounts for up to 54% of accumulated organic matter (including forest floor and soil), it contributes <5% of the N, <10% of the P, and <25% of the K, Ca, and Mg. Decay rates of CWD in northern forests range from 0.0025 to 0.071 year-1. Nitrogen or P concentrations in CWD increase during decay, depending on the initial N/P ratio, which eventually converges at about 20. CWD is initially a sink for N and (or) P, whichever is least available, but becomes a source later in decay. CWD contributes <5% of the N released annually. There is little evidence that CWD retains significant amounts of excess N following disturbance. We conclude that CWD is of minor importance in the nutrient cycles of northern coniferous forests, and that guidelines for CWD retention should be based on other perceived benefits of CWD.

scholarly journals Changes in mass, carbon, nitrogen, and phosphorus in logs decomposing for 30 years in three Rocky Mountain coniferous forests

2017 ◽  
Vol 47 (10) ◽  
pp. 1418-1423 ◽  
Author(s):  
Cindy E. Prescott ◽  
Kirsten Corrao ◽  
Anya M. Reid ◽  
Jenna M. Zukswert ◽  
Shalom D. Addo-Danso
Keyword(s):  
Mass Loss ◽  
Woody Debris ◽  
Rocky Mountain ◽  
Nutrient Budget ◽  
Coniferous Forests ◽  
Nutrient Concentrations ◽  
Nitrogen And Phosphorus ◽  
Essential Components ◽  
Best Fit ◽  
Net Release

Estimates of decomposition rates of coarse woody debris (CWD) and fluxes of nutrients therein are essential components of carbon (C) and nutrient budget models. In a 30-year field experiment, we periodically measured mass remaining and nutrient concentrations in log segments of pine, spruce, and fir in natural, mature coniferous forests in Alberta, Canada. The predicted turnover times (t95; years) were 43–44 years for pine, 42–60 years for spruce, and 38–46 years for fir. Extrapolating from best-fit models, we predict that decomposition of these logs would be complete within 50–60 years. The ratio of carbon to nitrogen (C:N) declined for most of the decomposition period, and ratios of the three species converged at <200 at 90% mass loss. Net release of N occurred only after logs had lost 90% of their original C and C:N had declined to <200. The ratio of carbon to phosphorus (C:P) declined and converged at 500–1000 at 90% mass loss. There was no evidence of net P release from logs even at 90% mass loss. It may be possible to estimate the amounts of N and P that will be incorporated into decaying logs based on the extent to which their initial C:N differs from 200 and their initial C:P differs from 500.

Decomposition of aspen (Populustremuloides) leaf litter modified by leaching

1990 ◽  
Vol 20 (7) ◽  
pp. 943-951 ◽  
Author(s):  
William F. J. Parsons ◽  
Barry R. Taylor ◽  
Dennis Parkinson
Keyword(s):  
Mass Loss ◽  
Leaf Litter ◽  
Rocky Mountain ◽  
Exponential Model ◽  
Decay Rates ◽  
Double Exponential ◽  
Exponential Trend ◽  
Aspen Forest ◽  
Double Exponential Model ◽  
Soluble Material

In a Rocky Mountain aspen forest, the detailed pattern of mass loss from decomposing leaf litter of trembling aspen (Populustremuloides Michx.) during the first 6 months of decay was compared with that from aspen leaves modified to produce a more recalcitrant litter type by removal of leachable material (31.7% of original mass). Leaching litter removed substantial quantities of N (24%) and P (54%), but did not change the litter's C/N ratio (77:1); and leached leaves still contained 33% labile (benzene alcohol soluble) material. Decomposition of intact aspen litter was best described by a double exponential model (k1 = −7.91/year, k2 = −0.21/year), except during the first 2 weeks, when an extremely rapid mass loss (14.2%) apparently resulted from leaching. Microbial metabolism was probably responsible for most of the subsequent decay (35% total in 6 months). In contrast, decomposition of leached aspen showed no exponential trend and was best described by a simple linear regression with a slope of −19.7%/year. Additional data from a 2nd year (12–15 months decay) reduced the regression estimates of decay rates but did not alter the best fit models. Fits were improved slightly if temperature sum replaced time in the regressions, especially if 2nd-year data were included.

Coarse Particulate Detritus Dynamics in Small, Montane Streams Southwestern British Columbia

1992 ◽  
Vol 49 (2) ◽  
pp. 337-346 ◽  
Author(s):  
John S. Richardson
Keyword(s):  
British Columbia ◽  
Leaf Litter ◽  
Woody Debris ◽  
Standing Stock ◽  
Dry Mass ◽  
Decay Rates ◽  
Large Temperature ◽  
Coast Range ◽  
Second Growth ◽  
Montane Streams

The dynamics of coarse particulate organic matter (CPOM) were studied for 2 yr in three second-order streams in the Coast Range of British Columbia. Estimates of direct litterfall ranged from 201 to 481 g ash-free dry mass∙m−2∙yr−1. The magnitude of deciduous leaf litter input was similar among streams. Input of conifer needles to a stream with an old-growth canopy was higher than in two streams which drained second-growth forests. There was over a 60-fold seasonal change in deciduous leaf standing stock, but woody debris and total CPOM showed less seasonal variation. Decomposition of alder leaf packs in two of the streams showed a large temperature-dependent component and significant differences between streams, with the more retentive stream having lower rates of decomposition. From estimates of input and decay rates, models of leaf loss were made to predict benthic standing stocks of deciduous leaf litter. Comparisons of the model predictions with actual measures indicate that 70–94% of leaf material was unaccounted for and presumably lost from the study reach by export, floodplain deposition, and burial. The seasonal changes in standing stock of CPOM emphasize the variation in food supply potentially available to detritivorous stream organisms.

Decomposition of Nothofagus wood in vitro and nutrient mobilization by fungi

2009 ◽  
Vol 39 (11) ◽  
pp. 2193-2202 ◽  
Author(s):  
Peter W. Clinton ◽  
P. K. Buchanan ◽  
J. P. Wilkie ◽  
S. J. Smaill ◽  
M. O. Kimberley
Keyword(s):  
Mass Loss ◽  
Nutrient Dynamics ◽  
Wood Decay ◽  
Nutrient Release ◽  
Fungal Species ◽  
Nutrient Mobilization ◽  
Soil Matrix ◽  
Decay Fungi ◽  
Nutrient Contents

The role of fungi in determining rates of wood decomposition and nutrient release in forest ecosystems is poorly understood. The decomposition of wood from three species of Nothofagus by 12 species of widely occurring New Zealand wood-decay fungi was investigated in vitro under standardized conditions. Wood mass loss varied strongly among fungal species and to a lesser extent with the species of wood. The species of fungi in this study were divided into three groups based on the extent of mass loss after 15 weeks: (1) rapid (>65% reduction in mass, Fomes hemitephrus , Pleurotus purpureoolivaceus , Trametes versicolor , and Ganoderma cf. applanatum), (2) intermediate (15%–30%, Phellinus sp., Schizopora radula , Phellinus nothofagi , and Skeletocutis stramenticus ), and (3) slow (<10%, Armillaria novaezelandiae , Postia pelliculosa , Australoporus tasmanicus , and Laetiporus portentosus ). For several fungal species, the final contents of nitrogen, phosphorus, and calcium in the remaining wood exceeded the initial nutrient contents in the wood, indicating that nutrient sequestration from the supporting soil matrix occurred during decomposition. Nutrient dynamics during decomposition varied with wood species, but the variation among different fungal species was much greater, indicating that fungal diversity is an important factor in determining nutrient flux in decaying wood.

scholarly journals In situ decomposition of northern hardwood tree boles: decay rates and nutrient dynamics in wood and bark

2014 ◽  
Vol 44 (12) ◽  
pp. 1515-1524 ◽  
Author(s):  
Chris E. Johnson ◽  
Thomas G. Siccama ◽  
Ellen G. Denny ◽  
Mary Margaret Koppers ◽  
Daniel J. Vogt
Keyword(s):  
Mass Loss ◽  
Sugar Maple ◽  
Nutrient Dynamics ◽  
Exponential Model ◽  
Fagus Grandifolia ◽  
Decay Rates ◽  
Nutrient Concentrations ◽  
Betula Alleghaniensis ◽  
Northern Hardwood ◽  
Clear Cutting

The decomposition of coarse woody debris contributes to forest nutrient sustainability and carbon (C) balances, yet few field studies have been undertaken to investigate these relationships in northern hardwood forests. We used a paired-sample approach to study the decomposition of sugar maple (Acer saccharum Marsh.), American beech (Fagus grandifolia Erhr.), and yellow birch (Betula alleghaniensis Britt.) boles at the Hubbard Brook Experimental Forest in New Hampshire. Mass loss over 16 years followed a first-order exponential decay pattern with half-lives ranging from 4.9 to 9.4 years in bark and from 7.3 to 10.9 years in wood. Nitrogen (N) and phosphorus (P) concentrations increased significantly during decomposition, resulting in sharp decreases in C:N and C:P ratios. We did not, however, observe significant net increases in the amount of N or P stored in decomposing boles, as reported in some other studies. Calcium (Ca) concentration decreased by up to 50% in bark but more than doubled in wood of all species. The retention of Ca in decomposing wood helps maintain Ca pools in this base-poor ecosystem. Together, the exponential model for mass loss and a combined power-exponential model for changes in nutrient concentrations were able to simulate nutrient dynamics in decomposing boles after clear-cutting in an adjacent watershed.

Decay of Scots pine coarse woody debris in boreal peatland forests: Mass loss and nutrient dynamics

2017 ◽  
Vol 401 ◽  
pp. 304-318 ◽  
Author(s):  
Meeri Pearson ◽  
Raija Laiho ◽  
Timo Penttilä
Keyword(s):  
Mass Loss ◽  
Scots Pine ◽  
Coarse Woody Debris ◽  
Nutrient Dynamics ◽  
Woody Debris
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