Coarse woody debris in mixed-conifer forests, Sequoia National Park, California

1987 ◽  
Vol 17 (10) ◽  
pp. 1265-1272 ◽  
Author(s):  
Mark E. Harmon ◽  
Kermit Cromack Jr. ◽  
Bradley G. Smith
Keyword(s):  
Decay Rate ◽  
National Park ◽  
Woody Debris ◽  
Permanent Plots ◽  
Nitrogen Storage ◽  
Decay Rate Constant ◽  
Stand Volume ◽  
Sequoia National Park ◽  
Mixed Conifer Forests ◽  
Class Information

The decay rate of Abiesconcolor (Gord. & Glend.) Lindl. logs and cover, mass, and volume of logs and snags in six midelevational forest stands of Sequoia National Park, California, are reported. Based on a chronosequence, Abiesconcolor boles have a decay rate-constant of 0.05 year−1 and a half-life of 14 years. A decay classification system was developed for Abiesconcolor, Calocedrusdecurrens (Torr.) Florin, Pinusjeffreyi Grev. & Balf., and Pinuslambertiana Dougl. logs. Dimensions taken from maps of six permanent plots were combined with decay-class information to estimate volume, mass, and projected cover of logs and snags. Total mass ranged from 29 Mg ha−1 in a Pinusjeffreyi forest to 400 Mg ha−1 in a Sequoiadendrongiganteum (Lindl.) Buchh. dominated stand. Volume, projected cover, and nitrogen storage exhibited patterns similar to mass, ranging from 84 to 1160 m3 ha−1, 3.1 to 9.3%, and 41 to 449 kg ha−1, respectively.

Coarse woody debris decomposition documented over 65 years on southern Vancouver Island

1998 ◽  
Vol 28 (5) ◽  
pp. 788-793 ◽  
Author(s):  
Jeff N Stone ◽  
Andy MacKinnon ◽  
John V Parminter ◽  
Ken P Lertzman
Keyword(s):  
Decay Rate ◽  
Pacific Northwest ◽  
Rate Constant ◽  
Coarse Woody Debris ◽  
Woody Debris ◽  
Vancouver Island ◽  
Douglas Fir ◽  
Permanent Plots ◽  
Decay Rate Constant ◽  
Exponential Decay Rate

In 1929-1930, Stig Schenström and J.D. Curtis established an experiment to study thinning dynamics of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) on southern Vancouver Island, British Columbia. As a subcomponent of the experiment, the coarse woody debris (CWD) from the previous stand were mapped and the decay condition classified on five permanent plots. These scaled drawings and classifications were updated in 1945-1947 and 1995-1996. This unique 65-year period of CWD observation confirms that observations of CWD volume loss on Vancouver Island are similar to elsewhere in the Pacific Northwest. The simple exponential decay rate constant was 0.022 ·year-1 based on volume of primarily Douglas-fir on the five plots. The decay rate constant by large-end diameter was 0.067 ·year-1 for logs <= 20 cm, 0.056 ·year-1 for 21-40 cm, 0.021 ·year-1 for 41-80 cm, and 0.012 ·year-1 for logs > 80 cm.

Reversal of human-induced vegetation changes in Sequoia National Park, California

1999 ◽  
Vol 29 (4) ◽  
pp. 399-412 ◽  
Author(s):  
D Graham Roy ◽  
John L Vankat
Keyword(s):  
Ponderosa Pine ◽  
National Park ◽  
Prescribed Burning ◽  
Pine Forest ◽  
Tree Density ◽  
Permanent Plots ◽  
Vegetation Changes ◽  
Sequoia National Park ◽  
Giant Sequoia ◽  
Ponderosa Pine Forest

We resampled 76 permanent plots that had been established in the woodlands and forests of Sequoia National Park in 1969. Our objectives were to describe vegetation changes in the tree and shrub layers and determine the effects of prescribed burning that began in the 1960s. We compared changes in species importance and tree size class distributions between sample dates and between burned and unburned plots. Species composition had remained similar in all nine vegetation types sampled except in the ponderosa pine forest where Pinus ponderosa Dougl. ex P. & C. Laws. decreased in importance from 28 to 15% and Abies concolor (Gord. & Glend.) Lindl. increased from 18 to 31%. Structural changes were more common, as tree density decreased in the blue oak woodland (19%), and live oak woodlands (15%), as well as in ponderosa pine forest (41%), white fir forest (5%), giant sequoia groves (39%), and red fir forest (24%). Decreases in density were greater in burned plots but occurred in unburned plots as well, indicating that prescribed fire and self-thinning contributed to decreases in density. Tree density was unchanged in the lodgepole and subalpine forests, but increased in the Jeffrey pine forest (58%). The decreases in tree density represent a reversal of earlier trends.

Bacterial die-away rates in red sea waters

1995 ◽  
Vol 32 (2) ◽  
pp. 45-52 ◽  
Author(s):  
H. Z. Sarikaya ◽  
A. M. Saatçi
Keyword(s):  
Solar Radiation ◽  
Decay Rate ◽  
Sea Water ◽  
Membrane Filter ◽  
Linear Regression Analysis ◽  
Total Coliform ◽  
Coliform Bacteria ◽  
Decay Rate Constant ◽  
Solar Intensity ◽  
Log Normal

Total coliform bacteria have been chosen as the indicator organism. Coliform die-away experiments have been carried out in unpolluted sea water samples collected at about 100 m off the coastline and under controlled environmental conditions. The samples were transformed into one litre clean glass beakers which were kept at constant temperature and were exposed to the solar radiation. The membrane filter technique was used for the coliform analysis. The temperature ranged from 20 to 40° C and the dilution ratios ranged from 1/50 to 1/200. Coliform decay rate in the light has been expressed as the summation of the coliform decay rate in the dark and the decay rate due to solar radiation. The solar radiation required for 90 percent coliform removal has been found to range from 17 cal/cm2 to 40 cal/cm2 within the temperature range of 25 to 30° C. Applying the linear regression analysis two different equations have been given for the high (I&gt;10 cal/cm2.hour) and low solar intensity ranges in order to determine the coliform decay rate constant as a function of the solar intensity. T-90 values in the light have been found to follow log-normal distribution with a median T-90 value of 32 minutes. The corresponding T-90 values in the dark were found to be 70-80 times longer. Coliform decay rate in the dark has been correlated with the temperature.

Nitrogen storage and availability during stand development in a New Zealand Nothofagus forest

2002 ◽  
Vol 32 (2) ◽  
pp. 344-352 ◽  
Author(s):  
P W Clinton ◽  
R B Allen ◽  
M R Davis
Keyword(s):  
New Zealand ◽  
Forest Floor ◽  
Woody Debris ◽  
Mineral Soil ◽  
Stand Development ◽  
N Availability ◽  
Net N Mineralization ◽  
Nitrogen Storage ◽  
Nothofagus Forest ◽  
Mature Stands

Stemwood production, N pools, and N availability were determined in even-aged (10, 25, 120, and >150-year-old) stands of a monospecific mountain beech (Nothofagus solandri var. cliffortioides (Hook. f.) Poole) forest in New Zealand recovering from catastrophic canopy disturbance brought about by windthrow. Nitrogen was redistributed among stemwood biomass, coarse woody debris (CWD), the forest floor, and mineral soil following disturbance. The quantity of N in stemwood biomass increased from less than 1 kg/ha in seedling stands (10 years old) to ca. 500 kg/ha in pole stands (120 years old), but decreased in mature stands (>150 years old). In contrast, the quantity of N stored in CWD declined rapidly with stand development. Although the mass of N stored in the forest floor was greatest in the pole stands and least in the mature stands, N availability in the forest floor did not vary greatly with stand development. The mass of N in the mineral soil (0–100 mm depth) was also similar for all stands. Foliar N concentrations, net N mineralization, and mineralizable N in the mineral soil (0–100 mm depth) showed similar patterns with stage of stand development, and indicated that N availability was greater in sapling (25 years old) and mature stands than in seedling and pole stands. We conclude that declining productivity in older stands is associated more with reductions in cation availability, especially calcium, than N availability.

scholarly journals Time since death and decay rate constants of Norway spruce and European larch deadwood in subalpine forests determined using dendrochronology and radiocarbon dating

2015 ◽  
Vol 12 (17) ◽  
pp. 14797-14832 ◽  
Author(s):  
M. Petrillo ◽  
P. Cherubini ◽  
G. Fravolini ◽  
J. Ascher ◽  
M. Schärer ◽  
...  
Keyword(s):  
Decay Rate ◽  
Tree Rings ◽  
Rate Constants ◽  
Radiocarbon Dating ◽  
Woody Debris ◽  
Visual Assessment ◽  
Exponential Model ◽  
Alpine Valley ◽  
Species Specific ◽  
Negative Exponential

Abstract. Due to the large size and highly heterogeneous spatial distribution of deadwood, the time scales involved in the coarse woody debris (CWD) decay of Picea abies (L.) Karst. and Larix decidua Mill. in Alpine forests have been poorly investigated and are largely unknown. We investigated the CWD decay dynamics in an Alpine valley in Italy using the five-decay class system commonly employed for forest surveys, based on a macromorphological and visual assessment. For the decay classes 1 to 3, most of the dendrochronological samples were cross-dated to assess the time that had elapsed since tree death, but for decay classes 4 and 5 (poorly preserved tree rings) and some others not having enough tree rings, radiocarbon dating was used. In addition, density, cellulose and lignin data were measured for the dated CWD. The decay rate constants for spruce and larch were estimated on the basis of the density loss using a single negative exponential model. In the decay classes 1 to 3, the ages of the CWD were similar varying between 1 and 54 years for spruce and 3 and 40 years for larch with no significant differences between the classes; classes 1–3 are therefore not indicative for deadwood age. We found, however, distinct tree species-specific differences in decay classes 4 and 5, with larch CWD reaching an average age of 210 years in class 5 and spruce only 77 years. The mean CWD rate constants were 0.012 to 0.018 yr−1 for spruce and 0.005 to 0.012 yr−1 for larch. Cellulose and lignin time trends half-lives (using a multiple-exponential model) could be derived on the basis of the ages of the CWD. The half-lives for cellulose were 21 yr for spruce and 50 yr for larch. The half-life of lignin is considerably higher and may be more than 100 years in larch CWD.

scholarly journals Macromycetes of oak-hornbeam forests in the Białowieża National Park - monitoring studies

2014 ◽  
Vol 33 (2) ◽  
pp. 171-189 ◽  
Author(s):  
Alina Skirgiełło
Keyword(s):  
International Cooperation ◽  
Mycorrhizal Fungi ◽  
National Park ◽  
Permanent Plots ◽  
Oak Forests ◽  
Ecological Groups ◽  
Plant Association ◽  
Multiple Signals ◽  
Białowieża National Park ◽  
European Oak

Mycosociological observations were carried out between 1994-1996 on permanent plots within a <i>Tilio-Carpinetum</i> association in the Białowieża National Park. The project was carried out with international cooperation within the "Mycological monitoring in European oak forests" programme which was a result of multiple signals concerning the disappearance of oaks in our continent. Almost 40 years before mycosociological research in the same plant association and at the same plots were carried out. Studies were mainly concerned with analysing the terrestrial macromycetes, predominantly <i>Boletales</i> and <i>Agaricales</i>. They analysed the occurrence of saprotrophic and mycorrhizal fungi. Totaly 215 species from the above listed ecological groups, but there were only 34 species common to both studies. Dominating species within the mycorrhizal group were found.

Determination of the decay rate constant for hepatocytes immobilized in alginate microcapsules

2010 ◽  
Vol 27 (1) ◽  
pp. 86-93 ◽  
Author(s):  
Aldo Leal-Egaña ◽  
Aránzazu Díaz-Cuenca ◽  
Augustinus Bader
Keyword(s):  
Decay Rate ◽  
Rate Constant ◽  
Decay Rate Constant
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