Below-ground carbon stocks in intact and transformed subtropical thicket landscapes in semi-arid South Africa

2010 ◽  
Vol 74 (1) ◽  
pp. 93-100 ◽  
Author(s):  
A.J. Mills ◽  
R.M. Cowling
2022 ◽  
Vol 41 (1) ◽  
pp. 54-61
Author(s):  
Moyagabo K. Rapetsoa ◽  
Musa S. D. Manzi ◽  
Mpofana Sihoyiya ◽  
Michael Westgate ◽  
Phumlani Kubeka ◽  
...  

We demonstrate the application of seismic methods using in-mine infrastructure such as exploration tunnels to image platinum deposits and geologic structures using different acquisition configurations. In 2020, seismic experiments were conducted underground at the Maseve platinum mine in the Bushveld Complex of South Africa. These seismic experiments were part of the Advanced Orebody Knowledge project titled “Developing technologies that will be used to obtain information ahead of the mine face.” In these experiments, we recorded active and passive seismic data using surface nodal arrays and an in-mine seismic land streamer. We focus on analyzing only the in-mine active seismic portion of the survey. The tunnel seismic survey consisted of seven 2D profiles in exploration tunnels, located approximately 550 m below ground surface and a few meters above known platinum deposits. A careful data-processing approach was adopted to enhance high-quality reflections and suppress infrastructure-generated noise. Despite challenges presented by the in-mine noisy environment, we successfully imaged the platinum deposits with the aid of borehole data and geologic models. The results open opportunities to adapt surface-based geophysical instruments to address challenging in-mine environments for mineral exploration.


Agriculture ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 374 ◽  
Author(s):  
Patrick Nyambo ◽  
Chiduza Cornelius ◽  
Tesfay Araya

Understanding the impacts of agricultural practices on carbon stocks and CO2 emission is imperative in order to recommend low emission strategies. The objective of this study was to investigate the effects of tillage, crop rotation, and residue management on soil CO2 fluxes, carbon stock, soil temperature, and moisture in the semi-arid conditions in the Eastern Cape of South Africa. The field trial was laid out as a split-split-plot design replicated three times. The main plots were tillage viz conventional tillage (CT) and no-till (NT). The sub-plots were allocated to crop rotations viz maize–fallow–maize (MFM), maize–oat–maize (MOM), and maize–vetch–maize (MVM). Crop residue management was in the sub-sub plots, viz retention (R+), removal (R−), and biochar (B). There were no significant interactions (p > 0.05) with respect to the cumulative CO2 fluxes, soil moisture, and soil temperature. Crop residue retention significantly increased the soil moisture content relative to residue removal, but was not different to biochar application. Soil tilling increased the CO2 fluxes by approximately 26.3% relative to the NT. The carbon dioxide fluxes were significantly lower in R− (2.04 µmoL m−2 s−1) relative to the R+ (2.32 µmoL m−2 s−1) and B treatments (2.36 µmoL m−2 s−1). The carbon dioxide fluxes were higher in the summer (October–February) months compared to the winter period (May–July), irrespective of treatment factors. No tillage had a significantly higher carbon stock at the 0-5 cm depth relative to CT. Amending the soils with biochar resulted in significantly lower total carbon stock relative to both R+ and R−. The results of the study show that NT can potentially reduce CO2 fluxes. In the short term, amending soils with biochar did not reduce the CO2 fluxes compared to R+, however the soil moisture increases were comparable.


2019 ◽  
Vol 65 (4) ◽  
pp. 155-163
Author(s):  
Miriam Kizeková ◽  
Radoslava Kanianska ◽  
Ľubica Jančová ◽  
Jozef Čunderlík ◽  
Zuzana Dugátová ◽  
...  

Abstract This paper aimed to monitory the dry matter biomass production and carbon stocks of above-and below-ground biomass in five types of grasslands in Slovakia: i) lowland oversowed pasture ii) lowland hay meadows, iii) mesophilous pasture, iv) mountain hay meadows, v) abandoned grassland. Averaged over two cropping seasons the total above-and below-ground biomass differed significantly across the monitored grasslands. It ranged respectively from 2.18 to 7.86 t/ha and from 9.64 to 22.67 t/ha dry matter depending on the pedoclimatic condition and the botanical composition of each grassland type. Consequently, this resulted also in the carbon stocks in above-and below-ground biomass. Generally, the mean carbon stocks were 1.56 t/ha for above-ground biomass (24%) and 4.83 t/ha for below-ground biomass (76%). The botanical composition for all the grassland types was also described. The highest number of plant species (55) was observed in lowland hay meadow located in Slovak Karst, the lowest one (23) for the oversowed grassland located in Eastern Slovak Upland. This monitoring paper showed that semi-natural grassland habitats and improved grasslands as well are an important carbon sink, and they can play a key role in global climate change mitigation.


2021 ◽  
Author(s):  
Musa Yusuf Jimoh ◽  
Peter Bikam ◽  
Hector Chikoore ◽  
James Chakwizira ◽  
Emaculate Ingwani

New climate change realities are no longer a doubtful phenomenon, but realities to adapt and live with. Its cogent impacts and implications’ dispositions pervade all sectors and geographic scales, making no sector or geographic area immune, nor any human endeavor spared from the associated adversities. The consequences of this emerging climate order are already manifesting, with narratives written beyond the alterations in temperature and precipitation, particularly in urban areas of semi-arid region of South Africa. The need to better understand and respond to the new climate change realities is particularly acute in this region. Thus, this chapter highlights the concept of adaptation as a fundamental component of managing climate change vulnerability, through identifying and providing insight in respect of some available climate change adaptation models and how these models fit within the premises and programmes of sustainable adaptation in semi-arid region with gaps identification. The efforts of governments within the global context are examined with households’ individual adaptation strategies to climate change hazards in Mopani District. The factors hindering the success of sustainable urban climate change adaptation strategic framework and urban households’ adaptive systems are also subjects of debate and constitute the concluding remarks to the chapter.


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