The long-term effects of fire regime on primary production of montane grasslands in South Africa

Everson, C. S.; Everson, Terry

doi:10.2989/10220119.2015.1124922

Cited by 33 publications

(32 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, the observed higher frequency compounded by prolonged dry conditions during the JJA and SON may result in reduced livestock production due to forage shortages, the proliferation of alien invasive species, bush encroachment, soil erosion and eventually, land degradation [64][65][66]. Studies by [67] showed that for particular grasslands such as montane grasslands, regular (i.e., annual) burning is beneficial for long-term productivity, while other studies [66,68,69] indicated that the burning of semi-arid grasslands may have drastic impacts on grazing capacity, basal cover, productivity and increases the intensity of seasonal droughts. On the other hand, extensive and frequent burning of Rainfed croplands during DJF and SON can be attributed to the burning of post-harvest crop residuals in preparation for the next season [70,71].…”

Section: Seasonal Effects Of Wildfires On Land Surface Dynamicsmentioning

confidence: 99%

Assessing Spatio-Temporal Variability of Wildfires and their Impact on Sub-Saharan Ecosystems and Air Quality Using Multisource Remotely Sensed Data and Trend Analysis

Kganyago

Shikwambana

2019

Sustainability

View full text Add to dashboard Cite

Globally, wildfires are considered the most commonly occurring disasters, resulting from natural and anthropogenic ignition sources. Wildfires consist of burning standing biomass at erratic degrees of intensity, severity, and frequency. Consequently, wildfires generate large amounts of smoke and other toxic pollutants that have devastating impacts on ambient air quality and human health. There is, therefore, a need for a comprehensive study that characterizes land-atmosphere interactions with regard to wildfires, critical for understanding the interrelated and multidimensional impacts of wildfires. Current studies have a limited scope and a narrow focus, usually only focusing on one aspect of wildfire impacts, such as air quality without simultaneously considering the impacts on land surface changes and vice versa. In this study, we use several multisource data to determine the spatial distribution, frequency, disturbance characteristics of and variability and distribution of pollutants emitted by wildfires. The specific objectives were to (1) study the sources of wildfires and the period they are prevalent in sub-Saharan Africa over a 9 year period, i.e., 2007-2016, (2) estimate the seasonal disturbance of wildfires on various vegetation types, (3) determine the spatial distribution of black carbon (BC), carbon monoxide (CO) and smoke, and (4) determine the vertical height distribution of smoke. The results show largest burned areas in December-January-February (DJF), June-July-August (JJA) and September-October-November (SON) seasons, and reciprocal high emissions of BC, CO, and smoke, as observed by Modern-Era Retrospective Analysis for Research and Applications version 2 (MERRA-2) and Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO). In addition, the results reveal an increasing trend in the magnitude of BC, and CO concentration driven by meteorological conditions such as low precipitation, low relative humidity, and low latent heat flux. Overall, this study demonstrates the value of multisource remotely sensed data in characterising long-term wildfire patterns and associated emissions. The results in this study are critical for informing better regional fire management and air quality control strategies to preserve endangered species and habitats, promote sustainable land management, and reduce greenhouse gases (GHG) emissions.

show abstract

Section: Seasonal Effects Of Wildfires On Land Surface Dynamicsmentioning

confidence: 99%

Assessing Spatio-Temporal Variability of Wildfires and their Impact on Sub-Saharan Ecosystems and Air Quality Using Multisource Remotely Sensed Data and Trend Analysis

Kganyago

Shikwambana

2019

Sustainability

View full text Add to dashboard Cite

show abstract

“…The biomass calculation is done for vegetation types whose biomass changes with their growing stage. Because the vegetation of Catchment VI is short grassland, the biomass was small 29 and the change in biomass in this context was therefore insignificant and a biomass correction was not required.…”

Section: Calibrationmentioning

confidence: 99%

Cosmic ray neutrons provide an innovative technique for estimating intermediate scale soil moisture

Vather¹,

Everson²,

Mengistu³

et al. 2018

S. Afr. J. Sci.

View full text Add to dashboard Cite

Soil moisture is an important hydrological parameter, which is essential for a variety of applications, thereby extending to numerous disciplines. Currently, there are three methods of estimating soil moisture: ground-based (in-situ) measurements; remote sensing based methods and land surface models. In recent years, the cosmic ray probe (CRP), which is an in-situ technique, has been implemented in several countries across the globe. The CRP provides area-averaged soil moisture at an intermediate scale and thus bridges the gap between in-situ point measurements and global satellite-based soil moisture estimates. The aim of this study was to test the suitability of the CRP to provide spatial estimates of soil moisture. The CRP was set up and calibrated in Cathedral Peak Catchment VI. An in-situ soil moisture network consisting of time-domain reflectometry and Echo probes was created in Catchment VI, and was used to validate the CRP soil moisture estimates. Once calibrated, the CRP was found to provide spatial estimates of soil moisture, which correlated well with the in-situ soil moisture network data set and yielded an R2 value of 0.845. The use of the CRP for soil moisture monitoring provided reliable, accurate and continuous soil moisture estimates over the catchment area. The wealth of current and potential applications makes the CRP very appealing for scientists and engineers in various fields. Significance: • The cosmic ray probe provides spatial estimates of surface soil moisture at an intermediate scale of 18 hectares. • A single cosmic ray probe can replace a network of conventional in-situ instruments to provide reliable soil moisture estimates. • The cosmic ray probe is capable of estimating soil moisture in previously problematic areas (saline soil, wetlands, rocky soil). • Cosmic ray probes can provide data for hydro-meteorologists interested in land–atmosphere interactions. • The cosmic ray probe estimates can be promising for remote sensing scientists for product calibration and validation.

show abstract

“…The area experiences wet humid summers, from November to March and dry, cold winters, from May to August. The summer period is also characterised by high rainfall and high temperatures, whereas in winter, regular frosts and snowfall are typical (Everson & Everson, ). Overall, during 2016, the highest total rainfall (263.9 mm) was received in January, whereas the lowest (6.8 mm) was received in July.…”

Section: Methodsmentioning

confidence: 99%

Remotely sensed C3 and C4 grass species aboveground biomass variability in response to seasonal climate and topography

2019

View full text Add to dashboard Cite

Seasonal climate and topography influence C3 and C4 grass species aboveground biomass (AGB). Climate change further threatens these grasses AGB, thereby compromising their ability to provide ecosystem goods and services. This emphasises the need to monitor their AGB for well‐informed management. New‐generation sensors, with improved resolution capabilities present an opportunity to explore C3 and C4 AGB. This study therefore investigated the response of remotely sensed C3 and C4 grasses AGB to seasonal climate and topography. Overall, the spatial and temporal responses of AGB due to seasonal climate and topography were observed across the study area. For example, in March, a marked increase in C4 AGB was associated with an increase in rainfall, with the highest significant positive relationship (R2 = 0.82, p < 0.005). Elevation had very significant positive relationship (R2 = 0.84; p < 0.005) with C3 and highest negative (R2 = −0.77; p < 0.005) with C4 AGB. During the winter fall, AGB significantly decreased from averages of 2.592 and 1.101 kg/m2 in winter (May), to 0.718 and 0.469 kg/m2 in August, for C3 and C4 grasses, respectively. These findings provide a key step in monitoring rangelands and assessing management practices to boost productivity.

show abstract

The long-term effects of fire regime on primary production of montane grasslands in South Africa

Cited by 33 publications

References 25 publications

Assessing Spatio-Temporal Variability of Wildfires and their Impact on Sub-Saharan Ecosystems and Air Quality Using Multisource Remotely Sensed Data and Trend Analysis

Assessing Spatio-Temporal Variability of Wildfires and their Impact on Sub-Saharan Ecosystems and Air Quality Using Multisource Remotely Sensed Data and Trend Analysis

Cosmic ray neutrons provide an innovative technique for estimating intermediate scale soil moisture

Remotely sensed C3 and C4 grass species aboveground biomass variability in response to seasonal climate and topography

Contact Info

Product

Resources

About