scholarly journals Herbivory and misidentification of target habitat constrain region-wide restoration success of spekboom (Portulacaria afra) in South African subtropical succulent thicket

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11944
Author(s):  
Marius L. van der Vyver ◽  
Anthony J. Mills ◽  
Mark Difford ◽  
Richard M. Cowling
Keyword(s):  
Carbon Sequestration ◽  
South African ◽  
Negative Impact ◽  
Climatic Factors ◽  
Warm Season ◽  
Prediction Rule ◽  
Moisture Stress ◽  
Public Works ◽  
Sloping Ground ◽  
Restoration Success

Restoration of degraded subtropical succulent thicket, via the planting of Portulacaria afra (spekboom) truncheons, is the focus of a public works programme funded by the South African government. The goals of the programme, which started in 2004, are to create jobs, sequester carbon, restore biodiversity, reduce erosion, improve soil water holding capacity and catalyse private sector investment for upscaling of restoration. Here we report on a region-wide experiment to identify factors that can improve project success. Measures of success were survivorship and annual aboveground biomass carbon sequestration (ABCsr) of spekboom truncheons some 33–57 months after planting—starting in March 2008—into 173 fenced plots (0.25 ha) located throughout the global extent of spekboom thicket vegetation. We also collected data for 18 explanatory variables under the control of managers, and an additional 39 variables reflecting soil physical and chemical characteristics and rainfall patterns post restoration, all beyond the influence of managers. Since the latter covariates were available for only 83 plots, we analysed the two data sets separately. We used a prediction rule ensemble to determine the most important predictors of restoration success. There was great variation in percentage survivorship (median = 24, range = 0–100%) and ABCsr (median = 0.009, range = 0–0.38 t C ha−1 yr−1). The model using management variables explained less variance (53%) in survivorship than the model incorporating additional soil and rainfall covariates (62%). ABCsr models were better fits (78 and 88% variance explained, respectively). All model configurations identified browse intensity as a highly influential predictor of restoration success. Predicted success was highest for plots located in target habitat; however, only 45% were thus located, suggesting the need for expert input and habitat modelling for improving target habitat identification. Frost exposure was another important predictor influencing all models but was likely a consequence of locating sites off target habitat. Sites planted on equatorward slopes during the warm season showed reduced carbon sequestration, possibly due to elevated soil moisture stress associated with high radiation loads. Physiographic factors associated with improved restoration success were location on sloping ground (reduced frost exposure), increasing longitude (more warm-season rainfall) and increasing latitude (less frost coastwards). Few trends were evident among post-restoration climatic factors beyond the control of managers. Higher rainfall during the year post restoration had a negative impact on carbon sequestration while higher rain during the early months post restoration had a positive effect on both carbon sequestration and survivorship. Soil factors showed little importance for the survivorship model, whereas silt content, % K and Mg CEC emerged as predictors of carbon sequestration. Our results have direct relevance for improving the success of landscape-scale restoration projects envisioned for the ca. 8,930 km2 of degraded spekboom thicket.

Reading for pleasure : the influence of reading clubs in selected Bahananwa Limpopo primary schools

2020 ◽  
Vol 1 (3) ◽  
pp. 133-155
Author(s):  
Kgomotlokoa Linda Thaba-Nkadimene ◽  
Maletšema Ruth Emsley
Keyword(s):  
South African ◽  
Primary Schools ◽  
Cultural Theory ◽  
Negative Impact ◽  
Positive Influence ◽  
Reading For Pleasure ◽  
Theory Of Reading ◽  
Research Findings ◽  
African Youth ◽  
Reading Clubs

The challenges of reading experienced by learners exerts a negative impact on reading for pleasure, and learners' outcomes. In an attempt to address such reading challenges, Reading Clubs were launched to promote reading for pleasure among South African youth. This study examines the influence of Reading Clubs on learners' attitudes to Reading for Pleasure and the outcomes thereof. The study was informed by the Top-Down Model of Reading and the Cultural Theory of reading for pleasure. Interviews were conducted in five purposively selected schools with five Sparker coaches and five teachers. The research findings reveal a positive influence of Reading Clubs on reading for pleasure and learners' outcomes. This is reflected through improved levels of reading for pleasure. This study ultimately recommends that schools learn from best practices of Reading Clubs, and that government strive to make Reading Clubs a sustainable project.

scholarly journals Effect of Climatic Factors on Stem Biomass and Carbon Stock of Larix gmelinii and Betula platyphylla in Daxing’anling Mountain of Inner Mongolia, China

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Dilawar Khan ◽  
Muhammad Atif Muneer ◽  
Zaib-Un- Nisa ◽  
Sher Shah ◽  
Muhammad Amir ◽  
...  
Keyword(s):  
Inner Mongolia ◽  
Negative Impact ◽  
Climatic Factors ◽  
High Temperature Stress ◽  
Climatic Conditions ◽  
Larix Gmelinii ◽  
Maximum Temperature ◽  
Betula Platyphylla ◽  
Stem Biomass ◽  
Annual Minimum Temperature

Climate change has become a global concern for scientists as it is affecting almost every ecosystem. Larix gmelinii and Betula platyphylla are native and dominant forest species in the Daxing’anling Mountains of Inner Mongolia, playing a major role in carbon sequestration of this region. This study was carried out to assess the effect of climate variables including precipitation and temperature on the biomass of Larix gmelinii and Betula platyphylla forests. For this purpose, we used the climate-sensitive stem biomass allometric model for both species separately to find out accurate stem biomass along with climatic factors from 1950 to 2016. A total of 66 random plots were taken to attain the data from this study area. Larix gmelinii and Betula platyphylla stem biomass have a strong correlation with annual precipitation (R2 = 0.86, R2 = 0.71, R2 = 0.79, and R2 = 0.59) and maximum temperature (R2 = 0.76, R2 = 0.64, R2 = 0.67, and R2 = 0.52). However, annual minimum temperature (R2 = 0.58, R2 = 0.43, R2 = 0.55, and R2 = 0.46) and annual mean temperature (R2 = 0.40, R2 = 0.22, R2 = 0.36, and R2 = 0.19) have a relatively negative impact on tree biomass. Therefore, we suggest that both species have a very strong adaptive nature with climatic variation and hence can survive under drought and high-temperature stress climatic conditions.

Reconsidering criminal law-based liability for corporations and directors in South Africa

2019 ◽  
Vol 26 (4) ◽  
pp. 1085-1094
Author(s):  
Herbert Kawadza
Keyword(s):  
South Africa ◽  
South African ◽  
Criminal Law ◽  
Negative Impact ◽  
Criminal Liability ◽  
Annual Reports ◽  
Content Type ◽  
Criminal Sanctions ◽  
Fresh Perspective ◽  
African Context

Purpose It is recognised that the mere proscription of corporate offences is not adequate to deter misconduct or engender compliance. There is a need for the enforcement of the rules through robust culture-changing sanctions. The purpose of this paper is to demonstrate the inadequacies of criminal law liability in ensuring compliance with ethical corporate conduct in South Africa. Design/methodology/approach This paper is purely qualitative. For expository purposes, it draws from the Criminal Procedure Act, 51 of 1977 as well the corporate criminality enforcement trends and data from the National Prosecutions Agency’s annual reports to demonstrate that much as criminal liability is enshrined in a statute it has, however, not yielded the expected results. It situates the debate within the broader economic criminological scholarship. Findings This paper argues that even though the option of prosecuting corporations and directors is part of South African law, many corporate offences are not brought into the criminal justice system. Judging by its erratic imposition, criminal liability has failed to express the indignation and condemnation that are normally attached to criminal sanctions. Several reasons account for this. These include evidentiary, legal, technical and definitional complexities of some corporate offences, which lead to them being regarded as “unprosecutable crimes”. This has a negative impact on enforcement. Originality/value This paper is novel because it approaches the debate from a fresh perspective, economics and criminology. Not much scholarly attention has been devoted to analysing the efficacy of criminal sanctions in the South African context. This paper attempts to fill that gap.

scholarly journals Seasonal/Interannual Variations of Carbon Sequestration and Carbon Emission in a Warm-Season Perennial Grassland

2014 ◽  
Vol 2014 ◽  
pp. 1-13
Author(s):  
Deepa Dhital ◽  
Tomoharu Inoue ◽  
Hiroshi Koizumi
Keyword(s):  
Carbon Sequestration ◽  
Soil Carbon ◽  
Carbon Emission ◽  
Warm Season ◽  
Growing Season ◽  
Interannual Variations ◽  
Root Carbon ◽  
Ground Biomass ◽  
Below Ground ◽  
Perennial Grassland

Carbon sequestration and carbon emission are processes of ecosystem carbon cycling that can be affected while land area converted to grassland resulting in increased soil carbon storage and below-ground respiration. Discerning the importance of carbon cycle in grassland, we aimed to estimate carbon sequestration in photosynthesis and carbon emission in respiration from soil, root, and microbes, for four consecutive years (2007–2010) in a warm-season perennial grassland, Japan. Soil carbon emission increased with increasing growing season temperature which ranged from 438 to 1642 mg CO2 m−2 h−1. Four years’ average soil carbon emission for growing season, nongrowing season, and annual emission was 1123, 364, and 1488 g C m−2, respectively. Nongrowing and snow covered season soil carbon emission contributed 23–25% and 14–17% to the annual emission. Above-ground biomass varied seasonally and variation in green biomass affected soil carbon emission with increasing temperature and precipitation. Temperature effect on root carbon emission contributed about 1/4th of the total soil carbon emission. Variation in soil and root carbon emission is affected by below-ground biomass. Long-term estimation concluded that seasonal and interannual variations in carbon sequestration and emission are very common in grassland ecosystem.

scholarly journals Positive biodiversity–productivity relationships in forests: climate matters

2018 ◽  
Vol 14 (4) ◽  
pp. 20170747 ◽  
Author(s):  
H. Jactel ◽  
E. S. Gritti ◽  
L. Drössler ◽  
D. I. Forrester ◽  
W. L. Mason ◽  
...  
Keyword(s):  
Climate Change ◽  
Carbon Sequestration ◽  
Tree Species ◽  
Climatic Factors ◽  
Meta Analysis ◽  
Global Scale ◽  
Tree Age ◽  
Drought Severity ◽  
Natural Forests ◽  
Mixed Species

While it is widely acknowledged that forest biodiversity contributes to climate change mitigation through improved carbon sequestration, conversely how climate affects tree species diversity–forest productivity relationships is still poorly understood. We combined the results of long-term experiments where forest mixtures and corresponding monocultures were compared on the same site to estimate the yield of mixed-species stands at a global scale, and its response to climatic factors. We found positive mixture effects on productivity using a meta-analysis of 126 case studies established at 60 sites spread across five continents. Overall, the productivity of mixed-species forests was 15% greater than the average of their component monocultures, and not statistically lower than the productivity of the best component monoculture. Productivity gains in mixed-species stands were not affected by tree age or stand species composition but significantly increased with local precipitation. The results should guide better use of tree species combinations in managed forests and suggest that increased drought severity under climate change might reduce the atmospheric carbon sequestration capacity of natural forests.

Effects of rainfall, moisture stress, and stocking rate on the persistence of white clover over 30 years

1995 ◽  
Vol 35 (7) ◽  
pp. 1039 ◽  
Author(s):  
KJ Hutchinson ◽  
KL King ◽  
DR Wilkinson
Keyword(s):  
Soil Water ◽  
White Clover ◽  
Warm Season ◽  
Late Summer ◽  
Ground Level ◽  
Moisture Stress ◽  
Smoothing Splines ◽  
Water Model ◽  
Stocking Rate

The effects of spring rainfall, critical levels of summer moisture stress, and sheep stocking rates on the persistence of white clover (Trifolium repens cv. Huia) have been evaluated in a 30-year experiment (1964-93) based on sown, well-fertilised pasture. Plant species presence was measured each year as basal cover using a vertical 10-pin frame. Hits at ground level from 800 points/plot were recorded in late September on duplicate plots, which were set-stocked at 3 rates (10, 20 reduced to 15, 30 reduced to 20 d.s.e./ha). A soil-water model based on rainfall and tank evaporation was calibrated against on-site soil water measurements (0-260 mm) and used to predict soil water (mm) for weekly time steps over 30 years. Smoothing of long-term rainfall data (SYSTAT, Lowess) showed an overall decline in warm-season rainfall (October-March), which was punctuated by above-average (1969-74) and average runs of years (1983-90). Flexible smoothing splines (SAS) were used to indicate patterns of yearly white clover presence. For all stocking treatments, there were significant declines in the presence of white clover over 3 decades. At the highest stocking rate, the recovery of white clover following the 1965 drought was poor. Late summer (January-March) moisture stress, defined as the number of weeks when soil water (0-260 mm) was <15 mm, was critical in determining white clover presence in the following spring (September). Rainfall received from October to December generally had a positive effect. These climate-based relationships reinforce the importance of stolon growth and survival as a regenerative strategy for white clover. However, over the 30 years, the species showed decreasing resilience post drought, which suggests a long-term failure of seed-based regeneration. Annual rates of soil nitrogen build-up ranged from 29 to 54 kg N/ha.year and were poorly related to white clover presence in the stocking treatments. Governing mechanisms, based on interactions between seasonal moisture stress, sheep stocking rate, interspecific plant competition, and seed pool dynamics, are proposed to explain the nature of long-term decline in white clover presence in well-fertilised, sown pastures in the Northern Tablelands of New South Wales.

scholarly journals Pornography: Human right or human rights violation?

2010 ◽  
Vol 66 (2) ◽  
Author(s):  
Elisabet Le Roux
Keyword(s):  
South African ◽  
Clinical Evidence ◽  
Negative Impact ◽  
South African Population ◽  
Human Right ◽  
Faith Based ◽  
The Social ◽  
Systemic Discrimination ◽  
Human Rights Violation

The article investigates the availability of pornographic media to under-aged users, specifically the already marginalised under-aged sector of the South African population. It argues that the availability of pornography is just another illustration of the systemic discrimination against this section of the population. Theoretical, non-experimental and clinical evidence illustrating the negative impact that the exposure to pornography has on children is presented against the background of the social reality of South Africa. The article finds that exposure to pornography leaves children even more vulnerable than they already are. The investigation of relevant legislation indicates that those who broadcast and/or sell pornography contravene South African law. The article concludes that the effects of pornography on children are far-reaching and potentially harmful. Children should be more effectively protected against exposure to pornography. Lastly, the role of faith-based organisations (FBOs) and the possibilities of their effective involvement, is explored.

Globalisation on the Margins: Mapping Post-Apartheid South Africa's Trade and Industrial Policy

1998 ◽  
Vol 3 (1-2) ◽  
pp. 167-205
Author(s):  
Firoz Khan ◽  
David Hemson
Keyword(s):  
South African ◽  
Industrial Policy ◽  
Industrial Development ◽  
World Economy ◽  
Negative Impact ◽  
African State ◽  
State Intervention ◽  
Sustainable Growth ◽  
Social Unrest ◽  
Growth State

Industrial policy is a key avenue for the post-apartheid South African state to overcome the threats of social unrest and promote economic development. Although globalisation presents Third World countries with significant opportunities for sustained industrial development, it is critically important to underscore the impulses that undermine it through an examination of the manner in which technology is transferred from the industrialised to the developing countries. The indiscriminate adoption of a neo-liberal economic programme in South Africa has had a negative impact on sustainable growth and has given way to deindustrialisation and a rentier economy. This paper suggests that an endogenous approach — one that emphasises the unique factors of the spatial milieu in which economic activity occurs — paired to a recognition of the embeddedness of this milieu within larger structures is a more suitable paradigm for stirring sustainable growth. State intervention is not an impediment but a precondition for a flexible and responsive industrial policy in an increasingly globalised world economy.

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