Shower water usage in Kruger National Park tourist accommodation : effectiveness of technology and information intervention to reduce use

Human freshwater consumption continues to be a growing global concern. Research and implementation of interventions on multiple fronts are required to safeguard this critical resource. Household water consumption is a significant contributor to overall freshwater use. Such indoor water use in nature-based tourism presents a challenge to this industry, but also provides opportunities to influence human behaviour and experimenting with, and mainstreaming, new technologies promoting water conservation and sustainability. Here we assess interventions to one significant source of water use (showers) in tourist accommodation in a popular nature-based tourism destination, the Kruger National Park, South Africa. Control trials utilizing information interventions (to induce behavioural change), and a novel shower technology, are implemented to identify water saving opportunities. We show that technological intervention (installation of Triton Xerophyte®) results in ∼30% overall water saving as compared to control showers. Adding water-saving infographics slightly enhances this saving, but is shown to have limited success when implemented in isolation (i.e. without the technology). In addition, we show how shower duration and water usage is related to ambient temperature, with the Triton Xerophyte® resulting in increasing water savings under cooler ambient conditions (up to ∼50% water reduction for ambient temperatures <5 °C). Encouragingly, visitors to this national park are shown to use less shower water and shower for shorter, even in control units, as compared to the general public, suggesting that these nature-based tourists may already be more mindful of water usage. Nature-based tourism agencies have a responsibility to promote water saving behaviour, and implementing technology and providing information and awareness in aid thereof may act as a catalyst for broader water-conservation in society.https://pubs.rsc.org/en/journals/journal/ewhj2023Mammal Research InstituteZoology and Entomolog

Probabilistic Mapping and Spatial Pattern Analysis of Grazing Lawns in Southern African Savannahs Using WorldView-3 Imagery and Machine Learning Techniques

Savannah grazing lawns are a key food resource for large herbivores such as blue wildebeest (Connochaetes taurinus), hippopotamus (Hippopotamus amphibius) and white rhino (Ceratotherium simum), and impact herbivore densities, movement and recruitment rates. They also exert a strong influence on fire behaviour including frequency, intensity and spread. Thus, variation in grazing lawn cover can have a profound impact on broader savannah ecosystem dynamics. However, knowledge of their present cover and distribution is limited. Importantly, we lack a robust, broad-scale approach for detecting and monitoring grazing lawns, which is critical to enhancing understanding of the ecology of these vital grassland systems. We selected two sites in the Lower Sabie and Satara regions of Kruger National Park, South Africa with mesic and semiarid conditions, respectively. Using spectral and texture features derived from WorldView-3 imagery, we (i) parameterised and assessed the quality of Random Forest (RF), Support Vector Machines (SVM), Classification and Regression Trees (CART) and Multilayer Perceptron (MLP) models for general discrimination of plant functional types (PFTs) within a sub-area of the Lower Sabie landscape, and (ii) compared model performance for probabilistic mapping of grazing lawns in the broader Lower Sabie and Satara landscapes. Further, we used spatial metrics to analyse spatial patterns in grazing lawn distribution in both landscapes along a gradient of distance from waterbodies. All machine learning models achieved high F-scores (F1) and overall accuracy (OA) scores in general savannah PFTs classification, with RF (F1 = 95.73±0.004%, OA = 94.16±0.004%), SVM (F1 = 95.64±0.002%, OA = 94.02±0.002%) and MLP (F1 = 95.71±0.003%, OA = 94.27±0.003%) forming a cluster of the better performing models and marginally outperforming CART (F1 = 92.74±0.006%, OA = 90.93±0.003%). Grazing lawn detection accuracy followed a similar trend within the Lower Sabie landscape, with RF, SVM, MLP and CART achieving F-scores of 0.89, 0.93, 0.94 and 0.81, respectively. Transferring models to the Satara landscape however resulted in relatively lower but high grazing lawn detection accuracies across models (RF = 0.87, SVM = 0.88, MLP = 0.85 and CART = 0.75). Results from spatial pattern analysis revealed a relatively higher proportion of grazing lawn cover under semiarid savannah conditions (Satara) compared to the mesic savannah landscape (Lower Sabie). Additionally, the results show strong negative correlation between grazing lawn spatial structure (fractional cover, patch size and connectivity) and distance from waterbodies, with larger and contiguous grazing lawn patches occurring in close proximity to waterbodies in both landscapes. The proposed machine learning approach provides a novel and robust workflow for accurate and consistent landscape-scale monitoring of grazing lawns, while our findings and research outputs provide timely information critical for understanding habitat heterogeneity in southern African savannah

The impacts of artificial light at night in Africa : prospects for a research agenda

Artificial light at night (ALAN) has increasingly been recognised as one of the world’s most pernicious global change drivers that can negatively impact both human and environmental health. However, when compared to work elsewhere, the dearth of research into the mapping, expansion trajectories and consequences of ALAN in Africa is a surprising oversight by its research community. Here, we outline the scope of ALAN research and elucidate key areas in which the African research community could usefully accelerate work in this field. These areas particularly relate to how African conditions present underappreciated caveats to the quantification of ALAN, that the continent experiences unique challenges associated with ALAN, and that these also pose scientific opportunities to understanding its health and environmental impacts. As Africa is still relatively free from the high levels of ALAN found elsewhere, exciting possibilities exist to shape the continent’s developmental trajectories to mitigate ALAN impacts and help ensure the prosperity of its people and environment. SIGNIFICANCE : We show that the African research community can usefully accelerate work into understudied aspects of ALAN, which demonstrably impacts human and environmental health. Africa presents a unique, and in places challenging, research environment to advance understanding of this global change driver.Jennifer Ward Oppenheimer Research Grant.http://www.sajs.co.zahj2023Zoology and Entomolog

Research, monitoring, and reflection as a guide to the management of complex ecosystems : the case of fire in the Kruger National Park, South Africa

Conservation managers frequently set goals and monitor progress toward them. This often becomes a routine annual exercise, and periodic reflection over longer periods is done less often, if at all. We report on the annual monitoring of fire patterns in the Kruger National Park between 2012 and 2020, and examine how these compared with desired thresholds of spatial extent and intensity. These thresholds were based on decades of research and were aimed at achieving specific ecological outcomes. The patterns were outside of thresholds in two out of five fire management zones. In one (Zone 1), the goal was to encourage frequent burning, and this was marginally not achieved due to a severe drought during the period assessed. In Zone 3, a reduction in extent and intensity was desired, but thresholds for both were substantially exceeded. An exceedance in any given year might not trigger a management response, but if this occurs over multiple years it should trigger an examination of whether these exceedances affected the desired ecological outcomes. On reflection, we recommend that current management in four zones need not change, but that Zone 3 would require appropriate interventions. The available options can simultaneously produce positive and negative conservation outcomes, so trade-offs become necessary. By reflecting on research findings and management challenges, the advantages and disadvantages of available options have become clear, providing a basis for prioritization and compromise.The Centre for Invasion Biology, Stellenbosch University, and Scientific Services, South African National Parks.http://wileyonlinelibrary.com/journal/csp2am2023Zoology and Entomolog

Differential climatic conditions drive growth of Acacia tortilis tree in its range edges in Africa and Asia

DATA AVAILABILITY STATEMENT : The full data are available on Figshare at https://doi.org/10.6084/m9.figshare.21779819.SUPPORTING INFORMATION : APPENDIX S1. Supplementary tables. APPENDIX S2. Supplementary figures.PREMISE : Tree growth is a fundamental biological process that is essential to ecosystem functioning and water and element cycling. Climate exerts a major impact on tree growth, with tree species often requiring a unique set of conditions to initiate and maintain growth throughout the growing season. Still, little is known about the specific climatic factors that enable tree growth in savannah and desert tree species. Among the global tree species, Acacia tortilis occupies one of the largest distribution ranges (crossing 6500 km and 54 latitudes), spanning large parts of Africa and into the Middle East and Asia. METHODS : Here we collected climate data and monitored Acacia tortilis tree growth (continuous measurements of stem circumference) in its southern and northern range edges in South Africa (SA) and Israel (IL), respectively, to elucidate whether the growth–climate interactions were similar in both edges. RESULTS : Growth occurred during the summer (between December and March) in SA and in IL during early summer and autumn (April–June and October–November, respectively). Surprisingly, annual growth was 40% higher in IL than in SA. Within the wide distribution range of Acacia tortilis, our statistical model showed that climatic drivers of tree growth differed between the two sites. CPNCLUSIONS : High temperatures facilitated growth at the hot and arid IL site, while high humidity permitted growth at the more humid SA site. Our results confer an additional understanding of tree growth adaptation to extreme conditions in Acacia's world range edges, a major point of interest with ongoing climate change.http://wileyonlinelibrary.com/journal/AJBZoology and Entomolog

Linking scales and disciplines : an interdisciplinary cross-scale approach to supporting climate-relevant ecosystem management

CITATION: Berger, C. et al. 2019. Linking scales and disciplines : an interdisciplinary cross-scale approach to supporting climate-relevant ecosystem management. Climatic Change, 156:139–150, doi:10.1007/s10584-019-02544-0.The original publication is available at https://www.springer.com/journal/10584Southern Africa is particularly sensitive to climate change, due to both ecological and socioeconomic factors, with rural land users among the most vulnerable groups. The provision of information to support climate-relevant decision-making requires an understanding of the projected impacts of change and complex feedbacks within the local ecosystems, as well as local demands on ecosystem services. In this paper, we address the limitation of current approaches for developing management relevant socio-ecological information on the projected impacts of climate change and human activities.We emphasise the need for linking disciplines and approaches by expounding the methodology followed in our two consecutive projects. These projects combine disciplines and levels of measurements from the leaf level (ecophysiology) to the local landscape level (flux measurements) and from the local household level (socio-economic surveys) to the regional level (remote sensing), feeding into a variety of models at multiple scales. Interdisciplinary, multi-scaled, and integrated socio-ecological approaches, as proposed here, are needed to compliment reductionist and linear, scalespecific approaches. Decision support systems are used to integrate and communicate the data and models to the local decision-makers.https://link.springer.com/article/10.1007/s10584-019-02544-0Publisher's versio

Predicting the Effects of Woody Encroachment on Mammal Communities, Grazing Biomass and Fire Frequency in African Savannas.

With grasslands and savannas covering 20% of the world's land surface, accounting for 30-35% of worldwide Net Primary Productivity and supporting hundreds of millions of people, predicting changes in tree/grass systems is priority. Inappropriate land management and rising atmospheric CO2 levels result in increased woody cover in savannas. Although woody encroachment occurs world-wide, Africa's tourism and livestock grazing industries may be particularly vulnerable. Forecasts of responses of African wildlife and available grazing biomass to increases in woody cover are thus urgently needed. These predictions are hard to make due to non-linear responses and poorly understood feedback mechanisms between woody cover and other ecological responders, problems further amplified by the lack of long-term and large-scale datasets. We propose that a space-for-time analysis along an existing woody cover gradient overcomes some of these forecasting problems. Here we show, using an existing woody cover gradient (0-65%) across the Kruger National Park, South Africa, that increased woody cover is associated with (i) changed herbivore assemblage composition, (ii) reduced grass biomass, and (iii) reduced fire frequency. Furthermore, although increased woody cover is associated with reduced livestock production, we found indigenous herbivore biomass (excluding elephants) remains unchanged between 20-65% woody cover. This is due to a significant reorganization in the herbivore assemblage composition, mostly as a result of meso-grazers being substituted by browsers at increasing woody cover. Our results suggest that woody encroachment will have cascading consequences for Africa's grazing systems, fire regimes and iconic wildlife. These effects will pose challenges and require adaptation of livelihoods and industries dependent on conditions currently prevailing

Average adult body mass of herbivore species included in analysis (body mass from [56,57]) (arranged from smallest to largest).

<p>Average adult body mass of herbivore species included in analysis (body mass from [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0137857#pone.0137857.ref056" target="_blank">56</a>,<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0137857#pone.0137857.ref057" target="_blank">57</a>]) (arranged from smallest to largest).</p

Average Total Herbivore Biomass (THB) (kg.km^-2) observed for 12 large herbivore species along a woody cover gradient.

<p>(basalts: solid circles; granites: open squares) (standard error bars included). As expected the nutrient-rich basalts support higher biomass than the nutrient-poor granites. Surprisingly, even though nine of the 12 individual species studied show significant directional increases or decreases along the woody cover gradient (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0137857#pone.0137857.g002" target="_blank">Fig 2</a> and <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0137857#pone.0137857.t002" target="_blank">Table 2</a>), when all species are combined the average THB stays constant between 20–65% woody cover with no change in productivity (refer to <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0137857#pone.0137857.t003" target="_blank">Table 3</a> for slope coefficients).</p