Prediction of forest-floor moisture content on jack pine cutovers

1989 ◽  
Vol 19 (2) ◽  
pp. 239-243 ◽  
Author(s):  
Z. Chrosciewicz
Keyword(s):  
Moisture Content ◽  
Forest Floor ◽  
Mineral Soil ◽  
Jack Pine ◽  
Fuel Moisture ◽  
Fire Weather Index ◽  
Clear Cut ◽  
Moisture Contents ◽  
Best Fitting ◽  
Curvilinear Regression

Moisture contents of organic forest-floor materials were studied by strata on a clear-cut jack pine (Pinusbanksiana Lamb.) site in relation to slash distribution and changes in both duff moisture code and fine fuel moisture code, the two weather-based components of the Canadian Forest Fire Weather Index System. The best-fitting curvilinear regression (Y = a + b/X) of the duff moisture code showed distinctive patterns of variation, so that both the surface and subsurface forest-floor strata were consistently moister under slash cover than in slash openings, and for each of these two slash conditions, the subsurface forest-floor strata were consistently moister than the surface strata. Combinations of these materials down to mineral soil showed intermediate moisture contents both in slash openings and under slash cover. The straight line regression (Y = a + bX) of the fine fuel moisture code was the best-fitting moisture content relationship for the surface forest-floor materials, but only in slash openings; under slash cover, the curvilinear regression (Y = a + b/X) of the duff moisture code was more suitable. The coefficients of correlation, r, as derived from these varied regressions, were all very highly significant at P < 0.001.

Prediction of forest-floor moisture content under diverse jack pine canopy conditions

1989 ◽  
Vol 19 (11) ◽  
pp. 1483-1487 ◽  
Author(s):  
Z. Chrosciewicz
Keyword(s):  
Forest Floor ◽  
Mineral Soil ◽  
Jack Pine ◽  
Fuel Moisture ◽  
Weather Index ◽  
Fire Weather Index ◽  
Moisture Contents ◽  
Straight Line ◽  
Best Fitting ◽  
Pure Surface

Moisture contents of organic forest-floor materials were studied by strata in a semimature jack pine (Pinusbanksiana Lamb.) stand in relation to their within-stand locations and changes in both duff moisture code and fine fuel moisture code, the two weather-based components of the Canadian Forest Fire Weather Index System. The resulting best-fitting curvilinear regressions (Y = aebX) of the duff moisture code showed distinctive patterns of variation so that both the surface and subsurface forest-floor strata were consistently more moist in stand openings than under stand canopy. An initial moisture inversion between the surface and subsurface forest-floor materials manifested itself near the start of the regressions wherever live Schreber's moss (Pleuroziumschreberi (Brit.) Mitt.) and litter were the combined surface materials; otherwise, pure surface litter was consistently drier than the subsurface materials. Combinations of all these materials down to mineral soil showed intermediate moisture contents both in stand openings and under stand canopy. In contrast, the best-fitting regressions of the fine fuel moisture code just for surface forest-floor strata were of the straight line (Y = a + bX) category and had generally lower r2 values than those for the corresponding curvilinear regressions (Y = aebX) of the duff moisture code.

An index for tracking sheltered forest floor moisture within the Canadian Forest Fire Weather Index System

2005 ◽  
Vol 14 (2) ◽  
pp. 169 ◽  
Author(s):  
B. M. Wotton ◽  
B. J. Stocks ◽  
D. L. Martell
Keyword(s):  
Moisture Content ◽  
Forest Fire ◽  
Forest Floor ◽  
Jack Pine ◽  
Fire Weather ◽  
Moisture Index ◽  
Northern Ontario ◽  
Weather Index ◽  
Fire Weather Index ◽  
Overstory Trees

The Duff Moisture Code (DMC) component of the Canadian Forest Fire Weather Index (FWI) System is used by fire management agencies across Canada as an indicator of the susceptibility of the forest floor to lightning fire ignition. However, this model was developed for the moisture content of the forest floor away from the sheltering influences of overstory trees, an area where lightning strikes usually ignite the forest floor. Through destructive sampling of the forest floor in a mature jack pine stand in northern Ontario over several summers, the moisture content of the forest floor in sheltered areas close to the boles of dominant overstory trees was found to be significantly lower than in other less heavily sheltered areas of the stand. Observations from a network of in-stand rain gauges revealed that rainfall penetration through the canopy (throughfall) was correlated with both open rainfall amount and the duration of a storm. Observed throughfall amounts were used to develop a throughfall relationship for extremely sheltered locations (within ~0.5 m of the boles) in a mature jack pine stand. This throughfall model was used, along with differences in forest floor drying rate, to develop a new duff moisture index for strongly sheltered areas of the forest floor. Calculated values of this new moisture model, which has the same daily weather observation requirements as the FWI System’s DMC model, were found to match observed moisture contents quite well.

Relationships between the moisture content of fine woody fuels in lodgepole pine slash and the Fine Fuel Moisture Code of the Canadian Forest Fire Weather Index System

1988 ◽  
Vol 18 (1) ◽  
pp. 128-131 ◽  
Author(s):  
R. Trowbridge ◽  
M. C. Feller
Keyword(s):  
Moisture Content ◽  
Forest Fire ◽  
Index System ◽  
Lodgepole Pine ◽  
Fire Season ◽  
Fire Weather ◽  
Fuel Moisture ◽  
Weather Index ◽  
Fire Weather Index ◽  
Moisture Contents

Unsuccessful attempts to ignite slash resulting from the mechanical knocking down of lodgepole pine in west central British Columbia led to a short-term investigation of the relationship between the Fine Fuel Moisture Code of the Canadian Forest Fire Weather Index System and the moisture content of various fine fuel components <1 cm in diameter. Of the types of fuel sampled, the moisture contents of B.C. Forest Service fuel moisture sticks and aged slash were similar to, and well correlated (r = 0.79 and 0.81, respectively) with, the equivalent moisture content calculated from the Fine Fuel Moisture Code. The Fine Fuel Moisture Code was not designed to relate to the moisture content of uncured fuels. Thus, the moisture contents of fresh living slash (material from knocked down trees still attached to living roots) and of fresh dead slash (material unattached to living trees that had not yet experienced a complete fire season in which to fully cure) were poorly correlated with moisture content (r = 0.16 and 0.42, respectively). The moisture content of the progressively curing, needle-bearing fresh dead slash was relatively high at the beginning of the fire season, but became similar to the moisture content during the first half of July. This suggests that the Fine Fuel Moisture Code can also be used to predict the moisture content of such fine slash after these fuels have cured for approximately 3 months during the snow-free period.

The effect of prescribed burning on some physical soil properties of jack pine sites in southeastern Manitoba

1976 ◽  
Vol 6 (1) ◽  
pp. 58-68 ◽  
Author(s):  
H. P. Sims
Keyword(s):  
Soil Properties ◽  
Prescribed Burning ◽  
Mineral Soil ◽  
Jack Pine ◽  
Severe Burn ◽  
Clear Cut ◽  
Moisture Contents ◽  
Permanent Wilting Point ◽  
Organic Horizons ◽  
Wilting Point

The effect of prescribed burning on physical soil properties of clear-cut areas originally supporting jack pine (Pinusbanksiana Lamb.) was studied in southeastern Manitoba.Average temperatures recorded during three burns ranged from <52 °C at 5-cm depth to 300 °C at the mineral soil – humus interface. The most severe burn increased the weight of organic horizons by 7% because of deposition of fuel residues, while the least severe burn produced a 31% reduction in the weight of the organic mantle.Soils at 3.8 and 7.6 cm under burned seedbeds reached permanent wilting point at days 9 and 23 respectively during a 30-day rain-free period. Moisture contents at similar depths on an adjacent scarified area were significantly higher than on the burn, were much less variable, and remained above permanent wilting point for the duration of the 30-day period. Burning did not significantly affect percolation rate.

A comparison of two methods for estimating conifer live foliar moisture content

2012 ◽  
Vol 21 (2) ◽  
pp. 180 ◽  
Author(s):  
W. Matt Jolly ◽  
Ann M. Hadlow
Keyword(s):  
Moisture Content ◽  
Mean Absolute Error ◽  
Absolute Error ◽  
Fuel Moisture ◽  
Oven Drying ◽  
Moisture Contents ◽  
Content Determination ◽  
Rapid Moisture ◽  
Live Fuel Moisture ◽  
Moisture Content Determination

Foliar moisture content is an important factor regulating how wildland fires ignite in and spread through live fuels but moisture content determination methods are rarely standardised between studies. One such difference lies between the uses of rapid moisture analysers or drying ovens. Both of these methods are commonly used in live fuel research but they have never been systematically compared to ensure that they yield similar results. Here we compare the foliar moisture content of Pinus contorta (lodgepole pine) at multiple sites for an entire growing season determined using both oven-drying and rapid moisture analyser methods. We found that moisture contents derived from the rapid moisture analysers were nearly identical to oven-dried moisture contents (R2 = 0.99, n = 68) even though the rapid moisture analysers dried samples at 145°C v. oven-drying at 95°C. Mean absolute error between oven-drying and the rapid moisture analysers was low at 2.6% and bias was 0.62%. Mean absolute error was less than the within-sample variation of an individual moisture determination method and error was consistent across the range of moisture contents measured. These results suggest that live fuel moisture values derived from either of these two methods are interchangeable and it also suggests that drying temperatures used in live fuel moisture content determination may be less important than reported by other studies.

Relationships between seasonal patterns of live fuel moisture and meteorological drought indices for Mediterranean shrubland species

2007 ◽  
Vol 16 (2) ◽  
pp. 232 ◽  
Author(s):  
G. Pellizzaro ◽  
C. Cesaraccio ◽  
P. Duce ◽  
A. Ventura ◽  
P. Zara
Keyword(s):  
Moisture Content ◽  
Meteorological Drought ◽  
Meteorological Conditions ◽  
Drought Indices ◽  
Seasonal Patterns ◽  
Fuel Moisture ◽  
Fire Weather Index ◽  
Moisture Variation ◽  
Live Fuel Moisture ◽  
Fuel Moisture Content

Measurements of seasonal patterns of live fuel moisture content and ignitability (in terms of time to ignition) of four Mediterranean shrub species were performed in North Western Sardinia (Italy). Relationships between the two variables were evaluated. Relationships between live fuel moisture content and environmental conditions (i.e. rainfall, air temperature and soil moisture) were analysed. Two groups of species were identified in relation to the different response of live fuel moisture content to seasonal meteorological conditions. Seasonal patterns of live fuel moisture content were also compared with five meteorological drought indices: Duff Moisture Code and Drought Code of the Canadian Forest Fire Weather Index System, Keetch–Byram Drought Index, Canopy Drought Stress Index and Cumulative Water Balance Index. In addition, the capability of the meteorological drought indices to describe moisture variation for each species was evaluated. Although the Drought Code was formulated to describe changes in the moisture content of dead fuel, it was shown to have a good potential for modelling live fuel moisture variation of a group of shrubland species that are sensitive to meteorological conditions, with a clear and large decrease of moisture content during the drought season.

A laboratory study of weather effects on the drying rate of jack pine litter

1979 ◽  
Vol 9 (2) ◽  
pp. 267-275 ◽  
Author(s):  
C. E. Van Wagner
Keyword(s):  
Jack Pine ◽  
Absolute Temperature ◽  
Drying Rate ◽  
Fuel Moisture ◽  
Weather Index ◽  
Fire Weather Index ◽  
Free Moisture ◽  
External Conditions ◽  
Drying Rates ◽  
Two Stages

This paper describes the variation in the drying rate of jack pine (Pinusbanksiana Lamb.) litter with external conditions. Temperature, relative humidity (RH), and wind were varied separately. Drying runs were carried out in a cabinet with controlled temperature and humidity and also in the open laboratory. Most runs followed the exponential pattern, and the drying rates were measured in terms of the slope of the semilog graph of free moisture content versus time. The logarithm of this slope was found to be inversely proportional to the reciprocal of absolute temperature. The drying rate varied with 100 – RH at high RH but increased only slightly below 60% RH owing to the limiting effect of the wax and resin content on the rate of internal diffusion. Drying in wind proceeded in two stages, the first faster than the second. Wind was important at low speeds, and the drying rate increased but little above 2 km/h. These principles were used in the design of the drying equations of the Fine Fuel Moisture Code of the Canadian Forest Fire Weather Index.

The effect of forest floor manipulation on nitrogen status and tree growth in an eastern Ontario jack pine ecosystem

1985 ◽  
Vol 15 (2) ◽  
pp. 313-318 ◽  
Author(s):  
M. G. Weber ◽  
I. R. Methven ◽  
C. E. Van Wagner
Keyword(s):  
Tree Growth ◽  
Forest Floor ◽  
Mineral Soil ◽  
Complete Removal ◽  
Jack Pine ◽  
Site Quality ◽  
Stand Development ◽  
Untreated Plot ◽  
Soil Effects ◽  
Eastern Ontario

Four forest floor manipulation treatments were applied to an eastern Ontario jack pine (Pinusbanksiana Lamb.) ecosystem. These included a one-time complete removal of the forest floor to mineral soil; annual removal of the total forest floor to mineral soil; one-time removal of the forest floor, ashing of the material, and broadcast spreading of the ash onto exposed mineral soil; and an untreated control. Eight years after treatment radial tree growth on the treated plots showed a 30% reduction compared with the untreated plot. Annual removal of the forest floor caused most severe nitrogen depletion in jack pine foliage, forest floor, and mineral soil. Effects of one-time removal and burning treatments were less severe, but significant. Any interference with the normal buildup of the forest floor during stand development should be avoided if site quality is to be maintained for tree growth.

scholarly journals ESTIMATING FINE DEAD FUEL MOISTURE CONTENT UNDER EQUATORIAL CLIMATE CONDITIONS

FLORESTA ◽  
2021 ◽  
Vol 51 (3) ◽  
pp. 696
Author(s):  
Benjamin Leonardo Alves White ◽  
Maria Flaviane Almeida Silva
Keyword(s):  
Moisture Content ◽  
Fire Behavior ◽  
Great Influence ◽  
Fuel Moisture ◽  
Statistical Parameters ◽  
Fire Weather Index ◽  
Ignition Probability ◽  
Climate Conditions ◽  
Equatorial Climate ◽  
Fuel Moisture Content

The measurement of the fine dead fuel moisture content (FDFMC) is extremely important for forest fire prevention and suppression activities, as it has a great influence on the ignition probability and fire behavior. The Fine Fuel Moisture Code (FFMC) from the Fire Weather Index (FWI), is one of the most used models to estimate the FDFMC. Nevertheless, studies that assess the efficiency of this model in Brazil or in low latitude regions are rare. The present study aimed to evaluate the efficiency of the FFMC in an equatorial climate area and to develop a new model capable of estimating the FDFMC with greater precision. For this purpose, 861 random samples of fine dead fuel had their moisture content determined through oven drying. The obtained values were compared with those estimated by the FFMC and correlated with meteorological parameters to build a regression model. The results obtained show that the FDFMC was overestimated by the FFMC. The independent variables with the greatest influence on the FDFMC were, in decreasing order of significance: air relative humidity, air temperature, amount of rainfall in the last 24 hours and number of days without rainfall. The developed model presented good statistical parameters (r2 = 0.86; p <0.0001; RMSE = 0.22) and can be used, in areas with similar characteristics of the study area, to estimate the daily fire risk and to determine ideal conditions for prescribed burns.

Interactions between deadwood and soil characteristics in a natural boreal trembling aspen – jack pine stand1This article is one of a selection of papers from the International Symposium on Dynamics and Ecological Services of Deadwood in Forest Ecosystems.

2012 ◽  
Vol 42 (8) ◽  
pp. 1456-1466 ◽  
Author(s):  
Suzanne Brais ◽  
Pascal Drouin
Keyword(s):  
Populus Tremuloides ◽  
Nutrient Availability ◽  
Forest Floor ◽  
Pinus Banksiana ◽  
Mineral Soil ◽  
Chemical Properties ◽  
Wood Decay ◽  
Jack Pine ◽  
Nutrient Concentrations ◽  
Trembling Aspen

Decaying wood contribution to the heterogeneity of forest soils could depend on tree species and wood decay stage. The study was conducted in an 85-year-old trembling aspen ( Populus tremuloides Michx.) – jack pine ( Pinus banksiana Lamb.) forest in northwestern Quebec, Canada. Trees, snags, logs, and forest floor originating from wood buried within the forest floor (lignic FF) and from fine litter (alignic FF) were inventoried in fifteen 400 m2 plots (nine jack pine and six trembling aspen). Chemical properties of alignic and lignic FF and logs were measured and relative nutrient availability in the mineral soil assessed under logs and under lignic and alignic FF using PRS probes. No significant differences between forest covers were found for the proportion of C and nutrients contained in deadwood (snags, logs, and lignic FF) relative to tree biomass plus necromass (deadwood plus alignic FF) content. Lignic FF was characterized by a higher C/N ratio and exchangeable acidity than alignic FF and its nutrient concentrations were between those of alignic FF and logs. Differences in wood characteristics may explain some of the differences in forest floor properties observed between trembling aspen and jack pine. Nutrient availability in the mineral soil was affected by the overlaying materials and could reflect differences in the dynamics of individual nutrients.

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