scholarly journals Biomass of Coarse Woody Debris Following Disturbance in Rocky Mountain Coniferous Forests

1996 ◽  
Vol 20 ◽  
pp. 115-117
Author(s):  
Daniel Tinker ◽  
Dennis Knight
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Coarse Woody Debris ◽  
Woody Debris ◽  
Mineral Soil ◽  
Rocky Mountain ◽  
Timber Harvest ◽  
Ecosystem Processes ◽  
Timber Harvesting ◽  
Natural Variability

Primary productivity, the accumulation of nutrients, and other important ecosystem processes are largely dependent on the mineral soil organic matter that has developed during hundreds or thousands of years. In forest ecosystems, the decomposition of coarse woody debris, woody roots, twigs, leaves and micro-organisms is a primary source of this organic matter. Large quantities of coarse woody debris are typically produced following natural disturbances such as fires, pest/pathogen outbreaks, and windstorms, and make a significant contribution to the formation of soil organic matter (SOM). In contrast, timber harvesting often removes most of the coarse woody debris (CWD), which could result in a decrease in the quantity and a change in the quality of mineral soil organic matter. The 1988 fires in Yellowstone National Park continue to provide an excellent opportunity to study the effects of fires of various intensities on ecosystem processes. Ecosystems develop under conditions that are constantly changing, but which remain within some range of natural variability. At present, national forest managers are uncertain as to the quantity of CWD which should be left in a stand following timber harvest in order to maintain levels of SOM which are within the range of natural variability. Little empirical data exist which help characterize the range of natural variability with regard to CWD in lodgepole pine forests, and it is therefore difficult to assess current timber harvesting practices in terms of how much CWD should be left at each site. We began a pilot study in late summer 1995 to begin to address this deficiency. A larger study of broader scope is planned for an additional two to three years, beginning this year, in 1996. This research will attempt to measure specific processes which include the distribution, decomposition, combustion by natural fires, and removal of CWD. The specific objectives of our study are: i) compare the mass and distribution of coarse woody debris that remains following fires of varying intensities to that which remains following clearcutting in the Rocky Mountain Region; ii) estimate the amount of CWD that is combusted or converted to charcoal following fires of varying intensities in stands of varying stages of development; and iii) estimate the length of time necessary for every square meter of the forest soil to be affected by CWD under natural conditions.

scholarly journals The Effects of Fire on Coarse Woody Debris in Rocky Mountain Coniferous Forests

1995 ◽  
Vol 19 ◽  
pp. 37-38
Author(s):  
Dennis Knight ◽  
Daniel Tinker
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Coarse Woody Debris ◽  
Woody Debris ◽  
Mineral Soil ◽  
Primary Source ◽  
Rocky Mountain ◽  
Timber Harvesting ◽  
Micro Organisms

Primary productivity, the accumulation of nutrients, and other important ecosystem processes are largely dependent on the mineral soil organic matter that has developed during hundreds or thousands of years. In forest ecosystems, the decomposition of coarse woody debris, woody roots, twigs, leaves and micro-organisms is a primary source of this organic matter. Large quantities of coarse woody debris are typically produced following natural disturbances such as fires, pest/pathogen outbreaks, and windstorms, which make a significant contribution to the formation of soil organic matter (SOM). In contrast, timber harvesting often removes most of the coarse woody debris (CWD), which could result in a decrease in the quantity and a change in the quality of mineral soil organic matter.

scholarly journals Biomass of Coarse Woody Debris Following Fire and Clearcutting in Lodgepole Pine Forests

1997 ◽  
Vol 21 ◽  
pp. 33-35
Author(s):  
Dennis Knight ◽  
Daniel Tinker
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Coarse Woody Debris ◽  
Significant Contribution ◽  
Woody Debris ◽  
Mineral Soil ◽  
Primary Source ◽  
Timber Harvesting ◽  
Micro Organisms

In forest ecosystems, the decomposition of coarse woody debris, woody roots, twigs, leaves and micro-organisms is a primary source of mineral soil organic matter. Primary productivity, the accumulation of nutrients, and other important ecosystem processes are largely dependent on the mineral soil organic matter that has developed during hundreds or thousands of years. Large quantities of coarse woody debris are typically produced following natural disturbances such as fires, pest/pathogen outbreaks, and windstorms, and make a significant contribution to the formation of soil organic matter (SOM). In contrast, timber harvesting often removes much of the coarse woody debris (CWD), which could result in a decrease in the quantity and a change in the quality of mineral soil organic matter.

scholarly journals The Use of Radiocarbon to Measure the Effects of Earthworms On Soil Development

Radiocarbon ◽  
1980 ◽  
Vol 22 (3) ◽  
pp. 892-896 ◽  
Author(s):  
J D Stout ◽  
K M Goh
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Soil Profile ◽  
Mineral Soil ◽  
Soil Development ◽  
Plant Debris ◽  
Grassland Soils ◽  
Fresh Plant

Δ14C and δ13C values for organic matter in forest and grassland soils, in the presence or absence of earthworms, indicate that it should be possible to quantify the effects of earthworms on soil organic matter by this means. Without earthworms, both in forest and grassland soils, plant debris tends to accumulate on the surface of the mineral soil and little organic matter is incorporated into or is translocated down the soil profile. Where earthworms are present, there is much more marked incorporation of fresh plant debris in the mineral soil. This is shown especially by the pulse of ‘bomb’ carbon and also by the δ13C values.

scholarly journals Radiocarbon Dating of Soil Organic Matter Fractions in Andosols in Northern Ecuador

Radiocarbon ◽  
2006 ◽  
Vol 48 (3) ◽  
pp. 337-353 ◽  
Author(s):  
Femke H Tonneijck ◽  
Johannes van der Plicht ◽  
Boris Jansen ◽  
Jacobus M Verstraten ◽  
Henry Hooghiemstra
Keyword(s):  
Organic Matter ◽  
Humic Acid ◽  
Soil Organic Matter ◽  
Forest Floor ◽  
Radiocarbon Dating ◽  
Mineral Soil ◽  
Soil Samples ◽  
Acid Extraction ◽  
Independent Evidence ◽  
Organic Horizons

Volcanic ash soils (Andosols) may offer great opportunities for paleoecological studies, as suggested by their characteristic accumulation of organic matter (OM). However, understanding of the chronostratigraphy of soil organic matter (SOM) is required. Therefore, radiocarbon dating of SOM is necessary, but unfortunately not straightforward. Dating of fractions of SOM obtained by alkali-acid extraction is promising, but which fraction (humic acid or humin) renders the most accurate 14C dates is still subject to debate. To determine which fraction should be used for 14C dating of Andosols and to evaluate if the chronostratigraphy of SOM is suitable for paleoecological research, we measured 14C ages of both fractions and related calibrated ages to soil depth for Andosols in northern Ecuador. We compared the time frames covered by the Andosols with those of peat sequences nearby to provide independent evidence. Humic acid (HA) was significantly older than humin, except for the mineral soil samples just beneath a forest floor (organic horizons), where the opposite was true. In peat sections, 14C ages of HA and humin were equally accurate. In the soils, calibrated ages increased significantly with increasing depth. Age inversions and homogenization were not observed at the applied sampling distances. We conclude that in Andosols lacking a thick organic horizon, dating of HA renders the most accurate results, since humin was contaminated by roots. On the other hand, in mineral soil samples just beneath a forest floor, humin ages were more accurate because HA was then contaminated by younger HA illuviated from the organic horizons. Overall, the chronostratigraphy of SOM in the studied Andosols appears to be suitable for paleoecological research.

Movement and characteristics of stream-borne coarse woody debris in adjacent burned and undisturbed watersheds in Wyoming

1994 ◽  
Vol 24 (9) ◽  
pp. 1933-1938 ◽  
Author(s):  
Michael K. Young
Keyword(s):  
Coarse Woody Debris ◽  
Woody Debris ◽  
Rocky Mountain ◽  
Mountain Streams ◽  
Bank Stability ◽  
Stream Surface ◽  
Riparian Trees ◽  
Mean Diameter ◽  
Debris Transport ◽  
The Mean

Following fire, changes in streamflow and bank stability in burned watersheds can mobilize coarse woody debris. In 1990 and 1991, I measured characteristics of coarse woody debris and standing riparian trees and snags in Jones Creek, a watershed burned in 1988, and in Crow Creek, an unburned watershed. The mean diameter of riparian trees along Jones Creek was less than that of trees along Crow Creek, but the coarse woody debris in Jones Creek was greater in mean diameter. Tagged debris in Jones Creek was three times as likely to move, and moved over four times as far as such debris in Crow Creek. In Jones Creek, the probability of movement was higher for tagged pieces that were in contact with the stream surface. Larger pieces tended to be more stable in both streams. It appears that increased flows and decreased bank stability following fire increased the transport of coarse woody debris in the burned watershed. Overall, debris transport in Rocky Mountain streams may be of greater significance than previously recognized.

Coarse woody debris in mid-aged stands: abandoned agricultural versus long-term forest land

2005 ◽  
Vol 35 (6) ◽  
pp. 1502-1506 ◽  
Author(s):  
Asko Lõhmus ◽  
Piret Lõhmus
Keyword(s):  
Coarse Woody Debris ◽  
Dead Wood ◽  
No Reduction ◽  
Woody Debris ◽  
Large Diameter ◽  
Timber Harvesting ◽  
Forest Land ◽  
Successional Forests ◽  
Agricultural Areas

During the 20th century, large agricultural areas in Eastern Europe became forested after their abandonment. To explore the value of these new forests for biota, we assessed volumes of coarse woody debris (CWD) on random transects in mid-aged (40–75 years old) stands. In mixed and deciduous forests that were not forested in the 1930s, downed tree (log) volumes were about two times lower than in cutover sites. The effect on snag volume depended on site type and was generally nonsignificant. Large-diameter CWD showed similar proportions in the long-term and new forest areas, but large, well-decayed trunks tended to be less frequent in the latter. No reduction of dead wood volume was found in new pine stands, 98% of which had previously been classified as mires (bogs). Hence the origin of mid-aged successional forests had affected their CWD supply (particularly logs) to some extent, but the general scarcity of CWD all over the forest land indicated much larger (at least five-fold) losses due to timber harvesting. We conclude that naturally reforested areas should not be automatically excluded from reserve establishment or other CWD-related conservation programmes.

Effects of timber harvesting on coarse woody debris in red pine forests across the Great Lakes states, U.S.A.

1999 ◽  
Vol 29 (12) ◽  
pp. 1926-1934 ◽  
Author(s):  
Matthew D Duvall ◽  
David F Grigal
Keyword(s):  
Great Lakes ◽  
Coarse Woody Debris ◽  
Woody Debris ◽  
Pinus Resinosa ◽  
Timber Harvesting ◽  
Red Pine ◽  
Managed Forests ◽  
Timber Management ◽  
Great Lakes States ◽  
Young Forests

Coarse woody debris (CWD) chronosequences were developed for managed and unmanaged red pine (Pinus resinosa Ait.) stands across the Great Lakes states. Throughout stand development, there is less CWD in managed than in unmanaged forests, and effects of management are strongest in young forests (0-30 years old). At stand initiation, CWD is 80% lower in managed than unmanaged forests, 20 200 versus 113 200 kg·ha-1, while at 90 years, CWD is 35% lower, 6600 versus 10 400 kg·ha-1. Timber management especially affects snags. In young managed forests, snag biomass is less than 1% of that in unmanaged forests, 150 versus 58 200 kg·ha-1, while log biomass is 80% lower, 5000 versus 22 800 kg·ha-1. This trend continues in mature forests (91-150 years old), where snag biomass is 75% lower in managed than in unmanaged forests, 1700 versus 6400 kg·ha-1. Management has relatively little impact on total log biomass of mature forests but increases the biomass of fresh logs nearly 10-fold, to 1400 versus 150 kg·ha-1. CWD in managed forests is highly variable, primarily related to thinning schedules in individual stands.

Lignin, carbohydrate, and amino sugar distribution and transformation in the tropical highland soils of northern Thailand under cabbage cultivation, Pinus reforestation, secondary forest, and primary forest

Soil Research ◽  
2002 ◽  
Vol 40 (6) ◽  
pp. 977 ◽  
Author(s):  
A. Möller ◽  
K. Kaiser ◽  
W. Zech
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Secondary Forest ◽  
Mineral Soil ◽  
Amino Sugar ◽  
Primary Forest ◽  
Organic Layer ◽  
Amino Sugars ◽  
Northern Thailand ◽  
Wet Chemical

Structure and transformation processes of soil organic matter (SOM) are extremely complex, but advancing our knowledge on SOM cycling is a prerequisite for a sustainable soil management. To get a better insight to this issue, we determined the vertical distribution of lignin, carbohydrates, and amino sugars in bulk soils and NaOH-extracts using wet chemical techniques. These results were compared with those obtained by solution 13C nuclear magnetic resonance (NMR) spectroscopy after alkaline extraction. Soil samples were taken under a primary forest, a secondary forest, a 20-year-old Pinus kesiya (Royle ex Gordon) reforestation established following 15 years of cultivation, and a cabbage cultivation site in northern Thailand. Significantly lower contents of organic C and N at the cabbage cultivation and reforestation sites indicated that the replacement of forests by arable land at the reforestation and cabbage cultivation sites about 30 years ago resulted in enhanced breakdown of SOM. This means that after 20 years of Pinus growth, reforestation did not lead to a significant build-up of organic matter in the mineral soil. With increasing soil depth the sites showed comparable decreases in soil organic matter, exhibiting a typical pattern of decomposition expressed by a higher degree of side chain oxidation, increasing carboxyl functionality, and a decrease of lignin-derived phenols and aromatic compounds. Microbial contribution to SOM was determined using the carbohydrate and amino sugar biomarker approach. The amino sugars were predominantly of fungal origin in the organic layer. In the mineral soil, bacterial amino sugars dominated and the relative contribution of amino sugars to SOM increased with depth. Comparison of results from wet chemical analyses and of liquid-state 13C NMR signatures requires that alkaline-extractable organic matter is representative for bulk soil organic matter. This seemed to apply to lignin-derived phenols and amino sugars but not to neutral sugars and uronic acids. Significant correlations were found for lignin-derived phenols with phenolic C (R = 0.74, P < 0.01) for the bulk forest site samples and amino sugars with O-alkyl C (R = 0.93, P < 0.001) for the mineral soil horizons, whereas the carbohydrate contents did not show any clear correlation. Therefore, we concluded that most of the phenolic C signal intensity might be attributed to lignin, and the enrichment of O-alkyl C with depth may be a result of bacterial resynthesis with a significant contribution of amino sugars.

Fire severity effects on soil organic matter from a ponderosa pine forest: a laboratory study

2010 ◽  
Vol 19 (5) ◽  
pp. 613 ◽  
Author(s):  
Jeff A. Hatten ◽  
Darlene Zabowski
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Ponderosa Pine ◽  
Fire Severity ◽  
Mineral Soil ◽  
High Severity ◽  
Hydrophobic Compounds ◽  
C And N ◽  
Labile Soil Organic Matter ◽  
Ponderosa Pine Forest

This study investigated the changes in soil organic matter composition by controlling fire severity of laboratory burns on reconstructed surface soil profiles (O, A1 (0–1 cm), and A2 (1–2 cm)). Laboratory burning simulated prescribed burns that would be typical in the understorey of a ponderosa pine forest at low, moderate, and high–moderate severity levels. Soils were analysed for C, N and soil organic matter composition. Soil organic matter was fractionated into humin, humic acid, fulvic acid, soluble non‐humic materials and other hydrophobic compounds. In the O horizon, low‐, moderate‐, and high‐severity treatments consumed an increasing proportion of C and N. Carbon content of the mineral soil was unaffected by burning; however, N content of the A2 horizon decreased after the moderate‐ and high‐severity treatments, likely as a result of N volatilisation. The proportion of non‐soluble material in the O horizon increased with fire severity, whereas the proportion of humin C as total C of the A horizon decreased with fire severity. The decrease in humin was followed by an increase in the other hydrophobic compounds. The higher fire intensity experienced by the burning O horizon created recalcitrant materials while an increase in labile soil organic matter was observed in mineral soil. An increase in labile soil organic matter may cause elevated C and N mineralisation rates often seen after fire.

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