Soil temperatures during and following low-intensity prescribed burning in a Eucalyptus pauciflora forest

Soil Research ◽  
1986 ◽  
Vol 24 (1) ◽  
pp. 33 ◽  
Author(s):  
RJ Raison ◽  
PV Woods ◽  
BF Jakobsen ◽  
GAV Bary
Keyword(s):  
Organic Matter ◽  
Prescribed Burning ◽  
Organic Matter Content ◽  
Heat Content ◽  
Soil Surface ◽  
Maximum Temperature ◽  
Fire Intensity ◽  
Daily Maximum ◽  
Low Intensity ◽  
Maximum Temperatures

Temperatures at the soil surface and at several soil depths were measured during, and at intervals, for 33 months after a low-intensity prescribed burn in a subalpine Eucalyptus pauciflora forest. The high organic matter content, low bulk density, and low moisture content of the surface soil caused steep soil temperature gradients to be generated during the fire. Mean maximum temperatures during the fire were 600 � 50, 450 � 52, 54 � 5 and 42 � 5�C in the litter and at 0, 2 and 5 cm soil depths respectively. The highest temperatures recorded at 0, 2 and 5 cm depths were 703, 94 and 44�C. Temperatures exceeding 200�C, which result in volatilization of N from soil organic matter, were estimated to have occurred in the upper 3 mm of the soil. Byram fire intensity tended to be negatively correlated with the maximum temperature measured at the soil surface, but was not correlated with the amount of heat absorbed by black cans (thermal integrators) or the increase in the heat content of the soil. After the burn, the mean daily maximum temperatures in the soil were markedly higher on burnt than on unburnt sites. For example, soon after burning increases were 6, 10, 4 and 4�C at 0, 2, 5 and 10 cm depths, respectively, during a 5-day summer period. Mean daily minimum temperatures on recently burnt plots were similar to or slightly lower than those on unburnt areas. Average day-time temperature in recently burnt forest in summer was elevated by up to 8 and 4�C at 0 and 10 cm soil depths.

scholarly journals Prescribed burning in a mediterranean-climate region mitigates the disturbance by bushfire to a critical food resource for an endangered bird, the Carnaby’s cockatoo

Fire Ecology ◽  
2019 ◽  
Vol 15 (1) ◽  
Author(s):  
Valerie S. Densmore ◽  
Emma S. Clingan
Keyword(s):  
Seed Production ◽  
Prescribed Burning ◽  
Fire Regime ◽  
Fire Hazard ◽  
Food Resource ◽  
Management Tool ◽  
Fire Intensity ◽  
Prescribed Burns ◽  
Low Intensity ◽  
Percentage Survival

Abstract Background Prescribed burning is used to reduce fire hazard in highly flammable vegetation types, including Banksia L.f. woodland that occurs on the Swan Coastal Plain (SCP), Western Australia, Australia. The 2016 census recorded well over 1.9 million people living on the SCP, which also encompasses Perth, the fourth largest city in Australia. Banksia woodland is prone to frequent ignitions that can cause extensive bushfires that consume canopy-stored banksia seeds, a critical food resource for an endangered bird, the Carnaby’s cockatoo (Calyptorynchus latirostris, Carnaby 1948). The time needed for banksias to reach maturity and maximum seed production is several years longer than the typical interval between prescribed burns. We compared prescribed burns to bushfires and unburned sites at three locations in banksia woodland to determine whether low-intensity prescribed burns affect the number of adult banksias and their seed production. Study sites were matched to the same vegetation complex, fire regime, and time-since-fire to isolate fire intensity as a variable. Results Headfire rates of spread and differenced normalized burn ratios indicated that prescribed burning was generally of a much lower intensity than bushfire. The percentage survival of adult banksias and their production of cones and follicles (seeds) did not decrease during the first three years following a prescribed burn. However, survival and seed production were significantly diminished followed high-intensity bushfire. Thus, carrying capacity for Carnaby’s cockatoo was unchanged by prescribed burning but decreased markedly following bushfire in banksia woodland. Conclusions These results suggest that prescribed burning is markedly different from bushfire when considering appropriate fire intervals to conserve canopy habitats in fire-resilient vegetation communities. Therefore, low-intensity prescribed burning represents a viable management tool to reduce the frequency and extent of bushfire impacts on banksia woodland and Carnaby’s cockatoo.

Fuel and fire characteristics in savanna - woodland of West Africa in relation to grazing and dominant grass type

2007 ◽  
Vol 16 (5) ◽  
pp. 531 ◽  
Author(s):  
Patrice Savadogo ◽  
Didier Zida ◽  
Louis Sawadogo ◽  
Daniel Tiveau ◽  
Mulualem Tigabu ◽  
...  
Keyword(s):  
Prescribed Burning ◽  
Management Tool ◽  
Fuel Load ◽  
Maximum Temperature ◽  
Fire Intensity ◽  
Fire Behaviour ◽  
Savanna Woodland ◽  
Vegetation Height ◽  
Average Maximum ◽  
Dominant Grass

Fuel characteristics, fire behaviour and temperature were studied in relation to grazing, dominant grass type and wind direction in West African savanna–woodland by lighting 32 prescribed early fires. Grazing significantly reduced the vegetation height, total fuel load, and dead and live fuel fractions whereas plots dominated by perennial grasses had higher values for vegetation height, total fuel load and the quantity of live fuel load. Although fire intensity remained insensitive (P > 0.05) to any of these factors, fuel consumption was significantly (P = 0.021) reduced by grazing, rate of spread was faster in head fire (P = 0.012), and flame length was shorter in head fire than back fire (P = 0.044). The average maximum temperature was higher (P < 0.05) on non-grazed plots, on plots dominated by annual grasses, on plots subjected to head fire, and at the soil surface. Lethal temperature residence time showed a nearly similar trend to fire temperature. Wind speed and total fuel load were best predictors of fire behaviour parameters (R2 ranging from 0.557 to 0.862). It can be concluded that grazing could be used as a management tool to modify fire behaviour, back fire should be carried out during prescribed burning to lower fire severity, and the fire behaviour models can be employed to guide prescribed early fire in the study area.

Soil organic matter and phosphorus dynamics after low intensity prescribed burning in forests and shrubland

2019 ◽  
Vol 234 ◽  
pp. 214-225 ◽  
Author(s):  
Agustín Merino ◽  
Enrique Jiménez ◽  
Cristina Fernández ◽  
Maria T. Fontúrbel ◽  
Julio Campo ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Prescribed Burning ◽  
Low Intensity ◽  
Phosphorus Dynamics

Adsorption and Efficacy of Trifluralin and Butralin as Influenced by Soil Properties

Weed Science ◽  
1985 ◽  
Vol 33 (6) ◽  
pp. 861-867 ◽  
Author(s):  
C. John Peter ◽  
Jerome B. Weber
Keyword(s):  
Organic Matter ◽  
Weed Control ◽  
Organic Matter Content ◽  
Soil Surface ◽  
Matter Content ◽  
Soil Adsorption ◽  
Glycol Monoethyl Ether ◽  
Chamber Studies ◽  
Highly Correlated ◽  
Growth Chamber Studies

Significantly higher rates of butralin [4-(1,1-dimethylethyl)-N-(1-methylpropyl)-2,6-dinitrobenzenamine] were required to produce the same level of weed control as trifluralin [2,6-dinitro -N,N-dipropyl-4-(trifluoromethyl) benzenamine] when applied to soybeans [Glycine max(L.) Merr.] on seven different soils in the field. Higher rates of butralin were also required to control barnyardgrass [Echinochloa crus-galli(L.) Beauv. ♯ ECHCG] in growth chamber studies. No differences in the extent of soil adsorption of trifluralin and butralin were apparent; therefore, differences in efficacy could not be attributed to differences in soil adsorption. Herbicide rates required for 80% weed control and Freundlich K-values (adsorption capacity indices) were mostly highly correlated with soil organic-matter content and soil surface area as measured by benzyl ethyl ether (BEE) and ethylene glycol monoethyl ether (EGME) on nine soils. Analysis of the organic-matter content of the nine soils by 10 soil testing laboratories resulted in highly significant differences among laboratories.

Heat-Transfer in the Soil During Very Low-Intensity Experimental Fires - the Role of Duff and Soil-Moisture Content

1994 ◽  
Vol 4 (4) ◽  
pp. 225 ◽  
Author(s):  
JC Valette ◽  
V Gomendy ◽  
J Marechal ◽  
C Houssard ◽  
D Gillon
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Temperature Rise ◽  
Soil Moisture Content ◽  
Soil Surface ◽  
Dry Weight ◽  
Prescribed Burns ◽  
Low Intensity ◽  
Lethal Temperatures ◽  
Maximum Temperatures

The aim of this study was to analyse the effects of duff thickness and moisture content, and of soil moisture content on the transfer of heat in the soil. The experimental design used intact soil blocks with their duff layer, subjected to controlled fires of variable very low intensities of up to 100 kW m-1. The fuel on the surface was composed of needles and twigs of Pinus pinaster. The maximum temperatures measured within the fuel were of the order of 650 degrees C and were independent of the fireline intensities. For fires with fireline intensity of the order of 30 kW m-1, the presence of the duff layer reduced from 330 degrees C the temperature rise at the soil surface. Duff thickness played only a secondary role, but increasing moisture content reinforced its insulating effect, so that the temperature rise was 2.5 times less at 1 cm depth in the duff when the moisture content exceeded 70% dry weight, than when the moisture content was less than 30%. For more intense fires (> 50 kW m-1) that produced longer-lasting surface heating, duff thickness and moisture content played an important role in significantly reducing the temperature rise at the soil surface (range 140 degrees C to 28 degrees C). Because of low soil thermal conductivity, temperature attenuation with increasing depth was noticed. In the case of low intensity fires (< 30 kW m-1) in the absence of a duff layer, the maximum temperatures were reduced from 350 degrees C at the surface to 7 degrees C at 3.5 cm. The temperature rise in the soil decreased with depth according to a negative exponential relation. The rate constant of this relation was greater when the initial surface temperature and the soil moisture content were higher. For the soil studied, and under the moisture conditions encountered (between 7 and 19% of dry weight), the rate constant could be predicted with acceptable precision (r2 = 0.67), if the surface soil temperature rise and the soil moisture content were known. In these experimental fires, which were carried out when the air temperature did not exceed 20 degrees C, lethal temperatures (> 60 degrees C) were measured in the upper few centimetres of the duff layer in very low-intensity fires, and in the upper few centimetres of the soil (where nutrients are most concentrated and biological activity most intense) in the slightly more intense fires. The fire intensities were always very moderate, and of the order of magnitude df those encountered in the prescribed burns conducted on fuel-breaks of the french Mediterranean area. Their impact on the surface of the forest soil, in terms of lethal temperatures transmitted to the horizon rich in organic matter, are not negligible. In contrast, below 3 to 5 cm depth, prescribed burns, conducted under the conditions of the experiments, would not lead to significant change to nutrients or microfaunal or microfloral activity; in particular, root tips would not be subjected to heat stress sufficient to kill them.

scholarly journals Time Series Construction of Summer Surface Temperatures for Alabama, 1883–2014, and Comparisons with Tropospheric Temperature and Climate Model Simulations

2016 ◽  
Vol 55 (3) ◽  
pp. 811-826 ◽  
Author(s):  
John R. Christy ◽  
Richard T. McNider
Keyword(s):  
Time Series ◽  
Climate Model ◽  
Spatial Scales ◽  
Heat Content ◽  
Time Frame ◽  
Maximum Temperature ◽  
Daily Minimum Temperature ◽  
Daily Maximum Temperature ◽  
Daily Maximum ◽  
Tropospheric Temperature

AbstractThree time series of average summer [June–August (JJA)] daily maximum temperature (TMax) are developed for three interior regions of Alabama from stations with varying periods of record and unknown inhomogeneities. The time frame is 1883–2014. Inhomogeneities for each station’s time series are determined from pairwise comparisons with no use of station metadata other than location. The time series for the three adjoining regions are constructed separately and are then combined as a whole assuming trends over 132 yr will have little spatial variation either intraregionally or interregionally for these spatial scales. Varying the parameters of the construction methodology creates 333 time series with a central trend value based on the largest group of stations of −0.07°C decade−1 with a best-guess estimate of measurement uncertainty from −0.12° to −0.02°C decade−1. This best-guess result is insignificantly different (0.01°C decade−1) from a similar regional calculation using NOAA’s divisional dataset based on daily data from the Global Historical Climatology Network (nClimDiv) beginning in 1895. Summer TMax is a better proxy, when compared with daily minimum temperature and thus daily average temperature, for the deeper tropospheric temperature (where the enhanced greenhouse signal is maximized) as a result of afternoon convective mixing. Thus, TMax more closely represents a critical climate parameter: atmospheric heat content. Comparison between JJA TMax and deep tropospheric temperature anomalies indicates modest agreement (r2 = 0.51) for interior Alabama while agreement for the conterminous United States as given by TMax from the nClimDiv dataset is much better (r2 = 0.86). Seventy-seven CMIP5 climate model runs are examined for Alabama and indicate no skill at replicating long-term temperature and precipitation changes since 1895.

scholarly journals Does an August Singularity Exist in the Northern Rockies of the United States?

2008 ◽  
Vol 47 (6) ◽  
pp. 1845-1850
Author(s):  
Peter T. Soulé ◽  
Paul A. Knapp
Keyword(s):  
United States ◽  
Late Summer ◽  
The United States ◽  
Maximum Temperature ◽  
Daily Maximum ◽  
Northern Rocky Mountains ◽  
Temperature Anomalies ◽  
Northern Rockies ◽  
Maximum Temperatures ◽  
Time Of Year

Abstract Climatic singularities offer a degree of orderliness to notable meteorological events that are typically characterized by significant temporal variability. Significant deviations from normal daily maximum temperatures that occur following the passage of a strong midlatitude cyclone in mid- to late August in the northern Rocky Mountains of the United States are recognized in the local culture as the “August Singularity.” Daily standardized maximum temperature anomalies for August–October were examined for eight climate stations in Montana and Idaho as indicators of major midlatitude storms. The data indicate that a single-day negative maximum temperature singularity exists for 13 August. Further, a 3-day singularity event exists for 24–26 August. It is concluded that the concept of an August Singularity in the northern Rockies is valid, because the high frequency of recorded negative maximum temperature anomalies suggests that there are specific time intervals during late summer that are more likely to experience a major midlatitude storm. The principal benefit to society for the August Singularity is that the reduced temperatures help in the efforts to control wildfires that are common this time of year in the northern Rockies.

scholarly journals El polen de Poaceae en la atmósfera de Lugo y su relación con los parámetros meteorológicos (1999-2001).

2002 ◽  
Vol 27 ◽  
pp. 49-63 ◽  
Author(s):  
F. Javier Rodríguez-Rajo ◽  
M. Victoria Jato ◽  
M. Jesús Aira
Keyword(s):  
Pollen Season ◽  
Meteorological Parameters ◽  
Maximum Temperature ◽  
Daily Maximum ◽  
Main Pollen Season ◽  
Pollen Concentrations ◽  
Poaceae Pollen ◽  
Annual Total ◽  
Maximum Temperatures ◽  
The City

RESUMEN. El polen de Poaceae en la atmósfera de Lugo y su relación con los parámetros meteorológicos (1999-2001). Se han estudiado las concentraciones de polen de Poaceae presente en la atmósfera de la ciudad de Lugo durante 3 años (1999-2001). Para ello se ha utilizado un captador volumétrico tipo Hirst, modelo Lanzoni VPPS-2000. El polen de Poaceae es el más abundante y su porcentaje frente al total de polen anual es de un 38-40%. La cantidad total de polen anual es de 8.400 granos como resultado de la media de los tres años de estudio, con un período de polinización durante los meses de Junio y Julio. A lo largo del día los máximos de concentración tienen lugar durante la tarde. Se ha realizado un análisis de correlación con los principales parámetros meteorológicos, siendo la temperatura máxima la variable que presentó el coeficiente más elevado. La suma acumulada de la temperatura máxima y la regresión múltiple integrando la temperatura máxima y las concentraciones de polen del día anterior como estimadores, resultaron métodos válidos y complementarios para realizar la predicción del inicio del periodo de polinización y de las concentraciones medias diarias que se alcanzan durante el periodo de polinización principal respectivamente.Palabras clave. Polen, Lugo, Meteorología, Predicción, lntradiario, Poaceae.ABSTRACT. The Poaceae pollen in the atmosphere of Lugo and its relationship with meteorological parameters ( 1999-2001). The pollen concentrations of Poaceae in the atmosphere of the city of Lugo has been studied during 3 years (1999-2001). A volumetric sampler type Hirst, model Lanzoni VPPS-2000 has been used. The Poaceae pollen is the most abundant and its percentage with respect to the total annual pollen ranged from 38-40 %. The annual total quantity of pollen of Poaceae were 8.400 grains as average of the three years studied, with a period of pollination during the months of June and July. The daily maximum concentrations take place during the evening. An analysis of correlation has been carried out between pollen concentrations and the main meteorological parameters, the maximum temperature being the variable that presented the highest coefficient value. The sum of maximum temperatures and the multiple regression integrating maximum temperature and pollen concentrations of the previous day as predictors, were successful and complementary methods in order to predict the beginning of the pollination period and the daily mean concentrations reached during the main pollen season respectively.Key words. Pollen, Lugo, Meteorology, Prediction, Intradiurnal, Poaceae.

Extreme temperatures analysis: A study for Campinas, Brazil

2021 ◽  
Author(s):  
Guilherme Correia ◽  
Ana Maria Ávila
Keyword(s):  
Minimum Temperature ◽  
Temperature Increase ◽  
Heat Waves ◽  
Vulnerable Groups ◽  
Maximum Temperature ◽  
Daily Maximum ◽  
P Value ◽  
Significance Level ◽  
Historical Series ◽  
Maximum Temperatures

&lt;p&gt;Extreme events such as heat waves have adverse effects on human health, especially on vulnerable groups, which can lead to deaths, thus they must be faced as a huge threat. Many studies show general mean temperature increase, notably, minimum temperatures. The scope of this work was to assess daily data of a historical series (1890-2018) available on the Instituto Agron&amp;#244;mico de Campinas (IAC), in Campinas, using a suite of indices derived from daily temperature and formulated by the Expert Team on Climate Change Detection and Indices (ETCCDI) and evaluate trends. To compute the extreme indices RClimDex 1.1 was used. The significance test is based on a t &amp;#160;test, with a significance level of 95% (p-value&lt;0,05). Temperature increase is undoubtedly through many indices, especially from 1980, as there is a continuous rise of the temperature. Annual mean maximum temperature rose from 26&amp;#176;C to 29&amp;#176;C, whereas many years consistently have more than 50 days with maximum temperatures as high as 31&amp;#176;C and more than 20% of the days within a year are beyond the 90th percentile of the daily maximum temperatures. Annual mean minimum temperature rose from 14&amp;#176;C to 18&amp;#176;C, whereas many years consistently have more than 150 days with minimum temperatures as high as 18&amp;#176;C and more than 30% of the days within a year are beyond the 90th percentile of the daily minimum temperatures. Therefore, results indicate the increase of minimum temperature is greater than the increase of maximum temperatures.&lt;/p&gt;

Effects of patchy shade on stream water temperature: how quickly do small streams heat and cool?

2004 ◽  
Vol 55 (8) ◽  
pp. 737 ◽  
Author(s):  
J. Christopher Rutherford ◽  
Nicholas A. Marsh ◽  
Peter M. Davies ◽  
Stuart E. Bunn
Keyword(s):  
Travel Time ◽  
Dynamic Equilibrium ◽  
Stream Water ◽  
Rate Of Change ◽  
Maximum Temperature ◽  
Daily Maximum Temperature ◽  
Daily Maximum ◽  
Small Streams ◽  
Maximum Temperatures ◽  
Strong Linear Relationship

Summer field observations in five 2nd order streams (width 1–2 m, depth 5–15 cm, velocity 5–10 cm s–1) in Western Australia and south-east Queensland showed that daily maximum temperatures changed by ±4°C over distances of 600–960 m (travel time 2–3 h) immediately downstream from 40–70% step changes in riparian shade. There was a strong linear relationship between the rate of change of daily maximum temperature and the change of shade such that downstream from a 100% change of shade the heating/cooling rates are ±4°C h–1 and ±10°C km–1 (upper bound ±6°C h–1 and ±15°C km–1) respectively. These high rates only apply over short distances and travel times because downstream water temperatures adjust to the new level of shade and reach a dynamic equilibrium. Shade was too patchy in the study streams to measure how long water takes to reach equilibrium, however, using an existing computer model, we estimate that this occurs after ~1200 m (travel time 4 h). Further modelling work is desirable to predict equilibrium temperatures under given meteorological, flow and shade conditions. Nevertheless, landowners and regulators can use this information to determine whether the presence/absence of certain lengths of bankside shade are likely to cause desirable/undesirable temperature decreases/increases.

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