Concurrent and antecedent soil moisture relate positively or negatively to probability of large wildfires depending on season

2016 ◽  
Vol 25 (6) ◽  
pp. 657 ◽  
Author(s):  
Erik S. Krueger ◽  
Tyson E. Ochsner ◽  
J. D. Carlson ◽  
David M. Engle ◽  
Dirac Twidwell ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Growing Season ◽  
Fuel Moisture ◽  
Fuel Production ◽  
Antecedent Soil Moisture ◽  
Plant Water Stress ◽  
Wildfire Occurrence ◽  
Water Capacity ◽  
Available Water Capacity ◽  
Dormant Season

Measured soil moisture data may improve wildfire probability assessments because soil moisture is physically linked to fuel production and live fuel moisture, yet models characterising soil moisture–wildfire relationships have not been developed. We therefore described the relationships between measured soil moisture (concurrent and antecedent), as fraction of available water capacity (FAW), and large (≥405 ha) wildfire occurrence during the growing (May–October) and dormant (November–April) seasons from 2000 to 2012 in Oklahoma, USA. Wildfires were predominantly grass and brush fires but occurred across multiple fuel types including forests. Below-average FAW coincided with high wildfire occurrence each season. Wildfire probability during the growing season was 0.18 when concurrent FAW was 0.5 (a threshold for plant water stress) but was 0.60 when concurrent FAW was 0.2 (extreme drought). Dormant season wildfire probability was influenced not only by concurrent but also by antecedent FAW. Dormant season wildfire probability was 0.29 and 0.09 when FAW during the previous growing season was 0.9 (near ideal for plant growth) and 0.2, respectively. Therefore, although a wet growing season coincided with reduced wildfire probability that season, it also coincided with increased wildfire probability the following dormant season, suggesting that the mechanisms by which soil moisture influences wildfire probability are seasonally dependent.

scholarly journals The dependence of maize (Zea mays) hybrids yielding potential on the water amounts reaching the soil surface

Genetika ◽  
2013 ◽  
Vol 45 (1) ◽  
pp. 261-272 ◽  
Author(s):  
Branka Kresovic ◽  
Vesna Dragicevic ◽  
Bosko Gajic ◽  
Angelina Tapanarova ◽  
Borivoj Pejic
Keyword(s):  
Zea Mays ◽  
Soil Moisture ◽  
Block Design ◽  
Soil Surface ◽  
Growing Season ◽  
Maize Hybrids ◽  
Water Capacity ◽  
Set Up ◽  
Water Amount

The aim of the present study was to observe the response of maize hybrids under rainfed and irrigation conditions of the soil in order to establish the dependence of yielding potential on the water amounts reaching the soil surface during the growing season. The four-replicate trail was set up according to the randomised complete-block design on chernozem. Pre-watering soil moisture was approximately 70% of field water capacity, and soil moisture was established thermogravimetrically. During the five-year studies, the following differences in yields could be as follows: 12.68 t ha-1 (ZP 341); 12.76 t ha-1 (ZP 434); 13.17 t ha-1 (ZP 578); 14.03 t ha-1 (ZP 684) and 13.75 t ha-1 (ZP 704) under conditions of 440 mm, 440 mm, 424 mm, 457 mm and 466 mm of water, respectively. The hybrid ZP 341, i.e. ZP 578 expressed the highest, i.e. the lowest tolerance in dry relative seasons, respectively. The reduction of the water amount for every 10 mm decreased the yield by 119.4 kg ha-1 (ZP 341), 156.7 kg ha-1 (ZP 434), 172.3 kg ha-1 (ZP 578), 148.9 kg ha-1 (ZP 684) and 151.1 kg ha-1 (ZP 704).

Statistical equations for estimating field capacity, wilting point and available water capacity of soils from their saturation percentage

1988 ◽  
Vol 110 (3) ◽  
pp. 515-520 ◽  
Author(s):  
I. S. Dahiya ◽  
D. J. Dahiya ◽  
M. S. Kuhad ◽  
S. P. S. Karwasra
Keyword(s):  
Soil Moisture ◽  
Estimation Error ◽  
Chemical Properties ◽  
Field Capacity ◽  
Regression Equations ◽  
Data Set ◽  
Water Capacity ◽  
Available Water ◽  
Available Water Capacity ◽  
Wilting Point

SummaryStatistical equations were derived for estimating three soil moisture constants, i.e. field capacity (FC), wilting point (WP) and available water capacity (AWC), from soil saturation percentage (SP), which is an easily determinable parameter. The regression equations were evaluated from a data set obtained on 438 soil samples collected from different horizons of 111 profiles of the Indogangetic Plains in northern India, having a wide variation of texture and other physico-chemical properties. The three soil moisture constants were positively correlated with logarithms of SP (r = 0·985 for FC v. In SP, 0·979 for WP v. In SP, and 0·914 for AWC v. In SP). The regression equations were thetested on an independent set of experimental data on 57 samples collected from 14 representative soil profiles of the study area. Values of the three moisture constants of this data set, predicted from the regression equations, were in exceptionally good agreement with the observed values. The mean estimation error (the error of the estimated value relative to the measured value) was only 0·55% for FC, 0·12% for WP and 0·67% for AWC.

In a native pasture, landscape properties influence soil moisture more than grazing management

2017 ◽  
Vol 57 (9) ◽  
pp. 1799 ◽  
Author(s):  
D. C. Mitchell ◽  
W. B. Badgery ◽  
P. Cranney ◽  
K. Broadfoot ◽  
S. Priest ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Soil Water ◽  
Grazing Management ◽  
Near Surface ◽  
Water Capacity ◽  
Available Water ◽  
Available Water Capacity ◽  
High Production ◽  
Plant Available Water ◽  
Production Zone

It has been proposed that changes to grazing systems, from continuous to rotational grazing, alter the pasture mass and composition, which are reflected in changes to stored soil water. Additionally, in highly variable landscapes, determining whether the variation in soil water is due to the inherent landscape properties rather than the imposed grazing management has long been a contentious argument. To address this question, soil moisture was measured across a highly variable landscape under three differing grazing treatments (1-, 4- and 20-paddock systems). From the soil-water measurements, plant-available water and plant-available water capacity were determined. Different production zones (high, medium and low) were identified in the landscape by visually estimating green herbage mass in late spring. There were no observed differences in the measured plant-available water capacity across the grazing treatments; however, significant differences occurred in plant-available water capacity across the three production zones (high-production zone, 114 mm; medium-production zone, 102 mm; low-production zone, 88 mm) within the study period. There appears to be a trend between the plant-available water capacity and near-surface gravel content as measured in production zones. The high production zones held more plant-available water than did the low production zones, enabling more biomass and longer pasture growth during spring and autumn. The plant-available water in the low production zones significantly decreased with time. In all, 22 of the 50 soil-moisture monitoring locations displayed high temporal stability and were identified as being catchment-average soil water-content monitoring locations. A majority of these locations occurred in the medium production zone, demonstrating that representative soil moisture can be measured in these landscapes.

Erosion effects on soil moisture and corn yield on two soils at Mlingano, Tanzania

1998 ◽  
Vol 13 (2) ◽  
pp. 83-89 ◽  
Author(s):  
A.J. Tenge ◽  
F.B.S. Kaihura ◽  
R. Lal ◽  
B.R. Singh
Keyword(s):  
Soil Moisture ◽  
Soil Erosion ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Moisture Content ◽  
Soil Moisture Content ◽  
Corn Yield ◽  
Water Capacity ◽  
Available Water Capacity ◽  
Use Efficiency

AbstractSoil erosion is a major threat to sustaining agricultural production in Tanzania. However, quantitative information is scanty on its effects on yields of major crops for principal soils and management practices. We conducted this study to determine erosion effects on soil moisture, related properties and corn yield on Tropeptic Haplustox and Ultic Haplustalf soils at Mlingano in Tanzania. Four erosion classes (least, slight, moderate, and severe) on Tropeptic Haplustox and three erosion classes (slight, moderate, and severe) on Ultic Haplustalf were established according to the thickness of the Ap horizon under natural field conditions. Accelerated soil erosion reduced soil moisture content, soil organic carbon, available water capacity and water use efficiency. Mean volumetric soil moisture content (average of both soils) during the growing season was 23.3% for severe, 24.8% for moderate, and 25.7% for slight erosion. Mean soil organic carbon content was 1.15% for severe, 1.64% for moderate and 1.97% for slight erosion. Mean available water capacity was 2.6 cm for severe, 3.5 cm for moderate, and 4.0 cm for slight erosion. Soil bulk density and excessive degree days of soil temperature above 25°C increased with severity of erosion. These adverse changes accentuated constraints on crop growth and reduced corn (Zea mays) yield on severely eroded soil by 45% and 59% for Tropeptic Haplustox and Ultic Haplustalf soils, respectively. The water use efficiency of corn was 21.6 kg ha-1cm-1in the least eroded class versus 17 kg ha-1cm-1in the severely eroded class for the Tropeptic Haplustox, and 23 kg ha-1cm-1in the slightly eroded and 18.1 kg ha-1cm-1in the severely eroded class for Ultic Haplustalf.

Soil fertility changes in the long-term experimental plots at Kybybolite, South Australia. IV. Changes in certain moisture characteristics

1964 ◽  
Vol 15 (1) ◽  
pp. 91 ◽  
Author(s):  
JS Russell ◽  
RC Shearer
Keyword(s):  
Organic Matter ◽  
Soil Moisture ◽  
Plant Growth ◽  
Soil Fertility ◽  
Surface Soil ◽  
South Australia ◽  
Water Capacity ◽  
Available Water Capacity ◽  
Experimental Plots

A study of soils from various pasture treatments at Kybybolite has shown that changes in soil moisture characteristics have occurred in association with increases in organic matter. The 15 atmospheres (atm), 0.33 atm, and available water capacity (A.W.C.) values have all shown increases which can be related to organic matter changes. The largest increase has occurred in soil moisture-holding capacity (0.33 atm). Less than half of this increase, however, is available for plant growth, owing to corresponding increases in 15 atm values. Calculations of A.W.C. in terms of depth of soil water has shown that the magnitude of the change has been relatively small in relation to the large increases in organic matter. The results indicate that the scope for substantially increasing A.W.C. in coarse-textured soils by pasture improvement is limited. Possible beneficial and deleterious effects on plant growth due to observed changes in moisture characteristics of the surface soil are discussed.

scholarly journals Soil moisture as an indicator of growing-season herbaceous fuel moisture and curing rate in grasslands

2020 ◽  
Author(s):  
Sonisa Sharma ◽  
J. D. Carlson ◽  
Erik S. Krueger ◽  
David M. Engle ◽  
Dirac Twidwell ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Growing Season ◽  
Fuel Moisture

scholarly journals Fire, land cover, and temperature drivers of bat activity in winter

Fire Ecology ◽  
2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Marcelo H. Jorge ◽  
Sara E. Sweeten ◽  
Michael C. True ◽  
Samuel R. Freeze ◽  
Michael J. Cherry ◽  
...  
Keyword(s):  
Land Cover ◽  
Habitat Management ◽  
Deciduous Forest ◽  
Pinus Palustris ◽  
Growing Season ◽  
Early Spring ◽  
Bat Activity ◽  
White Nose Syndrome ◽  
Dormant Season ◽  
Wind Energy Development

Abstract Background Understanding the effects of disturbance events, land cover, and weather on wildlife activity is fundamental to wildlife management. Currently, in North America, bats are of high conservation concern due to white-nose syndrome and wind-energy development impact, but the role of fire as a potential additional stressor has received less focus. Although limited, the vast majority of research on bats and fire in the southeastern United States has been conducted during the growing season, thereby creating data gaps for bats in the region relative to overwintering conditions, particularly for non-hibernating species. The longleaf pine (Pinus palustris Mill.) ecosystem is an archetypal fire-mediated ecosystem that has been the focus of landscape-level restoration in the Southeast. Although historically fires predominately occurred during the growing season in these systems, dormant-season fire is more widely utilized for easier application and control as a means of habitat management in the region. To assess the impacts of fire and environmental factors on bat activity on Camp Blanding Joint Training Center (CB) in northern Florida, USA, we deployed 34 acoustic detectors across CB and recorded data from 26 February to 3 April 2019, and from 10 December 2019 to 14 January 2020. Results We identified eight bat species native to the region as present at CB. Bat activity was related to the proximity of mesic habitats as well as the presence of pine or deciduous forest types, depending on species morphology (i.e., body size, wing-loading, and echolocation call frequency). Activity for all bat species was influenced positively by either time since fire or mean fire return interval. Conclusion Overall, our results suggested that fire use provides a diverse landscape pattern at CB that maintains mesic, deciduous habitat within the larger pine forest matrix, thereby supporting the diverse bat community at CB during the dormant season and early spring.

Ecological responses of Stipa steppe in Inner Mongolia to experimentally increased temperature and precipitation. 3. Soil respiration

2018 ◽  
Vol 40 (2) ◽  
pp. 153 ◽  
Author(s):  
Xuexia Wang ◽  
Yali Chen ◽  
Yulong Yan ◽  
Zhiqiang Wan ◽  
Ran Chao ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Soil Respiration ◽  
Soil Temperature ◽  
Respiration Rate ◽  
Inner Mongolia ◽  
Growing Season ◽  
Climatic Warming ◽  
Soil Respiration Rate ◽  
Natural Rainfall ◽  
Temperature And Precipitation

The response of soil respiration to simulated climatic warming and increased precipitation was evaluated on the arid–semi-arid Stipa steppe of Inner Mongolia. Soil respiration rate had a single peak during the growing season, reaching a maximum in July under all treatments. Soil temperature, soil moisture and their interaction influenced the soil respiration rate. Relative to the control, warming alone reduced the soil respiration rate by 15.6 ± 7.0%, whereas increased precipitation alone increased the soil respiration rate by 52.6 ± 42.1%. The combination of warming and increased precipitation increased the soil respiration rate by 22.4 ± 11.2%. When temperature was increased, soil respiration rate was more sensitive to soil moisture than to soil temperature, although the reverse applied when precipitation was increased. Under the experimental precipitation (20% above natural rainfall) applied in the experiment, soil moisture was the primary factor limiting soil respiration, but soil temperature may become limiting under higher soil moisture levels.

Populations of endogonaceous fungi at two locations in central Iowa

1982 ◽  
Vol 60 (12) ◽  
pp. 2518-2529 ◽  
Author(s):  
Christopher Walker ◽  
Carl W. Mize ◽  
Harold S. McNabb Jr.
Keyword(s):  
Soil Moisture ◽  
Growing Season ◽  
Experimental Period ◽  
Spore Production ◽  
Moisture Level ◽  
Small Samples ◽  
Soil Moisture Level ◽  
Hybrid Poplars ◽  
Herbicide Treatment

Two different sites in central Iowa were planted with hybrid poplars and subsequently sampled over a growing season for spores of endogonaceous fungi. At one of the sites, the effects of plowing and herbicide treatment on spore numbers also were examined. Ten species of fungi in the genera Acaulospora, Gigaspora, and Glomus were recorded at the first site. The second location yielded 12 species from the same genera. In both sites, the distribution of spores was highly variable. The poplars rarely became endomycorrhizal and had no effect on spore populations during the experimental period. Changes in spore populations were correlated with soil-moisture level. Evidence was found for some depression of spore production caused by plowing and herbicide treatment. The conclusion was drawn that small samples with but few replicates may not adequately represent populations of endogonaceous spores.

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