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Biodiversity patterns are shaped by the interplay between geodiversity and organismal characteristics. Superimposing genetic structure onto landscape heterogeneity (i.e., landscape genetics) can help to disentangle their interactions and better understand population dynamics. Previous studies on the sub‐Antarctic Prince Edward Islands (located midway between Antarctica and Africa) have highlighted the importance of landscape and climatic barriers in shaping spatial genetic patterns and have drawn attention to the value of these islands as natural laboratories for studying fundamental concepts in biology. Here, we assessed the fine‐scale spatial genetic structure of the springtail, Cryptopygus antarcticus travei, which is endemic to Marion Island, in tandem with high‐resolution geological data. Using a species‐specific suite of microsatellite markers, a fine‐scale sampling design incorporating landscape complexity and generalised linear models (GLMs), we examined genetic patterns overlaid onto high‐resolution digital surface models and surface geology data across two 1‐km sampling transects. The GLMs revealed that genetic patterns across the landscape closely track landscape resistance data in concert with landscape discontinuities and barriers to gene flow identified at a scale of a few metres. These results show that the island's geodiversity plays an important role in shaping biodiversity patterns and intraspecific genetic diversity. This study illustrates that fine‐scale genetic patterns in soil arthropods are markedly more structured than anticipated, given that previous studies have reported high levels of genetic diversity and evidence of genetic structing linked to landscape changes for springtail species and considering the homogeneity of the vegetation complexes characteristic of the island at the scale of tens to hundreds of metres. By incorporating fine‐scale and high‐resolution landscape features into our study, we were able to explain much of the observed spatial genetic patterns. Our study highlights geodiversity as a driver of spatial complexity. More widely, it holds important implications for the conservation and management of the sub‐Antarctic islands. [ABSTRACT FROM AUTHOR]

This research explores intra-gully sediment volume changes of a massive gully network (42 ha) located in the Eastern Cape, RSA, in response to high rainfall events during a three-year study period (2017–2020). Unmanned aerial vehicles (UAVs) and photogrammetric processing were used to generate high resolution digital surface models (DSMs). Volumetric calculations were run to estimate the extent of gully expansion within the system to determine intra-gully changes and sediment erosion over the study period. The gully was categorised into four zones based on predominant structure and processes. These are the Extension Zone, Expansion Zone, Transport/Deposition Zone and the Side Branches. Rainfall data from a rainfall station (10 km away) was used to investigate the correlation between rainfall depth, rainfall intensity, and flow accumulation over two wetter years and one drier year with gully expansion experienced during these periods. The gully network encountered a total gully sediment volume erosion of 104,489 m3 (6.01%) over the study period. Nineteen high to extreme intensity (>20 mm per day) rainfall events produced the runoff necessary for gully expansion during the 2017 and 2018 hydrological years. Notably, lower gully growth was recorded in the Expansion and Transport/Deposition Zones during the subsequent below average hydrological year in 2019–2020. [ABSTRACT FROM AUTHOR]

South Africa has undergone transformation since the end of apartheid governance in 1994. Legislatively enforced, this transformation has permeated most sectors of society, including higher education. Questions remain, however, about the extent to which transformation has occurred in Higher Education Institutions (HEIs) in general, and across the academic staff body in HEIs in particular. In this study, we examine the transformation of academic staff profiles at HEIs throughout the country. Initially, we graph the racial profile of academics across multiple positions (junior lecturer to professor) from 2005 to 2013. We then use correlational analysis to identify which characteristics of universities in South Africa can be used to explain the racial inequities evident in South African HEIs. Our results indicate that world university ranking; percentage black African staff; percentage black African student body; and whether the university is "historically disadvantaged", all influence the racial profile of the academic staff body to varying degrees. The size of the overall staff and study body does not appear to influence the racial profile of universities' staff component. We conclude that transformation of the academic staff body of HEIs in South Africa is indeed occurring, albeit slowly. Rather than seeing this as a negative, we argue that the pace of "academic" transformation in the country needs to be interpreted within the framework of academic governance.

Mauritius is a Small Island Developing State (SIDS) with a high population density and increasing agricultural, urban and infrastructural demands, superimposed over limited physical resources. Soil and coastal erosion are recognized as an important environmental challenge facing the island. Here we review the studies on soil erosion over the past two decades and more recent advances in understanding the coastal erosion dynamics. Soil erosion studies have focussed on catchment erosion rates using recognized modelling techniques that have also permitted the mapping of erosion risk for the island. Rainfall assessments using six-minute rainfall data have detailed erosivity conditions for a section of the island but these findings still need to be incorporated into island-scale models. On Round Island, an off-shore Nature Reserve, erosion forms and rates have been measured in support of conservation and restoration programmes. Along the coastline, erosion had been long-recognized as a concern, particularly where development encroaches on the shoreline, and ongoing monitoring is assisting in understanding coastal sediment changes. Further research opportunities are noted and these include a coastal vulnerability assessment and modelling catchment sediment source-sink attributes where there is an impact on lagoon and coral structures. Climate-change scenarios, notably the effects on rainfall erosivity and sea level, are still to be incorporated in studies. [ABSTRACT FROM AUTHOR]

Round Island, a small (219‐ha) volcanic island 22.5 km north of Mauritius, has steep slopes and thin soils. This small tropical island was previously subjected to overgrazing by goats and rabbits, which detrimentally affected ecosystem functioning. Classified as a nature reserve since 1957, Round Island houses the last remnant of palm savannah that has been lost on mainland Mauritius and is a refuge to several endemic and endangered species. Landscape restoration and ecosystem functioning on Round Island are key conservation objectives, but soil erosion remains a significant hindrance to habitat restoration and ecosystem functioning. Here, we investigate soil erosion on Round Island and assess the implications for conservation and management. Sediment movement was monitored monthly (2015–2018) at seven soil erosion plots coupled with rainfall and erosivity measurements. A mean annual sediment movement rate of 0.2136 t ha−1 yr −1 is calculated. Although this rate of sediment movement is low for humid tropical regions, the barren landscape and low contemporary rates of soil erosion suggest that most of the erodible soil has already been eroded. Interrill erosion of the shallow soils and friable parent material is closely correlated with rainfall erosivity and exacerbated by limited vegetation cover. Continued revegetation is recommended to retard soil erosion and restore ecosystem functioning. The paper also emphasises that rainstorms are the greatest single phenomena affecting earth surface processes on and around the island of Mauritius. As such, long‐term monitoring of the interaction between the surface and climate is required to provide insights for conservation management. [ABSTRACT FROM AUTHOR]

Concentrations of major ions in stream water from the Soft Plume River on Subantarctic Marion Island were measured. During the annual relief voyage, samples were collected daily over a 16-day period (21 April–6 May 2015) from three sites along the stream to better understand temporal and spatial variability of stream water chemistry on the island. The chemical composition of the stream is dominated by the sea salts Na+ and Cl−. Mean solute concentrations for Na+ and Cl− are 7 ± 0.58 and 12.5 ± 0.84 mg/L, respectively. The mean molar Na:Cl ratio for all samples is 0.86 ± 0.05, with a range from 0.71 to 0.99 (n = 47), and there is a strong, significant positive correlation between Na+ and Cl− concentrations (r = 0.80; p < 0.001). These values are consistent with previous studies from Marion Island and other Subantarctic islands. Temporal variation in ion concentrations was small. The largest detected change was a decrease in most solute concentrations that coincided with two precipitation events. This decrease was largest at the highest altitude and the shallowest site, suggesting that there was more rainfall at this location. These findings confirm the dominance of the surrounding ocean as the main source of the island’s stream water chemistry and illustrate spatiotemporal patterns that provide an insight into mechanisms affecting their composition on Subantarctic Marion Island. [ABSTRACT FROM AUTHOR]

The catastrophic landslide-dam outburst flood, possibly caused by the same earthquake that destroyed the well-dated Lajia archaeological site, in the upper reaches of the Yellow River in China, may provide an accurate constraint on the age of the first Chinese dynasty (Xia Dynasty), which, according to Chinese ancient documents, has been associated with flood-control activities. The key link between the destructive earthquake and the megaflood is a flood-related blackish sand layer (BSL) covering the Lajia site on terraces high above the Yellow River channel. However, the BSL, which mainly consists of debris of local schist, may have originated from mudflows in local gullies rather than an outburst flood from the Yellow River that swept predominantly schist debris from channel slopes and/or a landslide dam. The composition of the fine particles in the BSL can help to discriminate the provenance of the BSL because an outburst flood would consist of suspended particles from the Yellow River, while a mudflow origin would incorporate fine particles from the local gullies. However, the similar geological origin between the Yellow River sediments and the Quaternary eolian loess and Tertiary reddish clay sediments that feed the local gullies precludes the application of traditional geochemical source tracers. This work shows that the 234U/238U activity ratio, which reflects the comminution age, of the fine particles in the BSL is very similar to that of the Yellow River sediments but not to the sediments in the local gullies, supporting an outburst flood origin of the BSL. Thus, the emergence of the Xia Dynasty can be constrained to be shortly after the sudden destruction of the Lajia site, if the outburst flood is the same event that initiated nationalization as described in the Chinese ancient documents. [ABSTRACT FROM AUTHOR]

Provenance of the silt on the Chinese Loess Plateau (CLP) is essential for the paleo-environmental interpretation of the thick eolian deposits, but is highly debated. The controversy mainly comes from the multi-interpretation of similar geochemical signatures of potential source areas (PSAs). This work applies the (234U/238U) activity ratio as a new source tracer, because it can distinguish particles with different transporting and recycling histories regardless of petrological origin. The (234U/238U) activity ratio of a fine particle decreases progressively after its production because of the increasing fraction of the 234U precursor ejected out of the particle surface, due to the recoiling effect associated with the α decay of 238U. Distinct spatial patterns of (234U/238U) can be found for the sediments in PSAs and the loess on the CLP. When combined with other constraints, the new findings indicate that the CLP loess can be best explained by the mixing of three end-member dust sources on the northwestern transportation trajectory, namely (1) the Gobi Desert, (2) the Ordos Desert, and (3) the Qilian Mountains. A contribution from the Yellow River is also possible but may not be significant. The identified source partition implies that the eolian silt is mainly produced by processes in the 'High Asia' mountains and, partly, by erosion of the exposed clastic rocks. This new constraint on the production and transportation of eolian dust has great implications for the proxy interpretation of loess related to atmospheric circulation, dust accumulation rate, and chemical indexes. [ABSTRACT FROM AUTHOR]