Air temperatures have increased globally over the past decades, while rainfall changes have been more variable, but are taking place. In South Africa, substantial climate-related impacts are predicted, and protected area management agencies will need to respond actively to impacts. It is critical for management agencies to understand the way in which climate is changing locally to predict impacts and respond appropriately. Here, for the first time, we quantify observable changes in temperature and rainfall in South African national parks over the past five to ten decades. Our results show significant increases in temperatures in most parks, with increases being most rapid in the arid regions of the country. Increases in the frequency of extreme high temperature events were also most pronounced in these regions. These results are consistent with other climate studies conducted in these areas. Similar increases were identified for both minimum and maximum temperatures, though absolute minimum temperatures increased at greater rates than absolute maxima. Overall, rainfall trends were less obvious, but a decrease in rainfall was observed for the southern Cape (in three parks), and an increase was detected in one park. The observed temperature changes over the last 20-50 years have in several instances already reached those predicted for near future scenarios (2035), indicating that change scenarios are conservative. These results provide individual parks with evidence-based direction for managing impacts under current and projected changes in local climate. They also provide the management agency with sub-regional information to tailor policy and impact monitoring. Importantly, our results highlight the critical role that individual weather stations play in informing local land management and the concerns for parks that have no local information on changes in climate.
Aim: Ecosystems face numerous well‐documented threats from climate change. The well‐being of people also is threatened by climate change, most prominently by reduced food security. Human adaptation to food scarcity, including shifting agricultural zones, will create new threats for natural ecosystems. We investigated how shifts in crop suitability because of climate change may overlap currently protected areas (PAs) and priority sites for PA expansion in South Africa. Predicting the locations of suitable climate conditions for crop growth will assist conservationists and decision‐makers in planning for climate change. Location: South Africa. Methods: We modelled climatic suitability in 2055 for maize and wheat cultivation, two extensively planted, staple crops, and overlaid projected changes with PAs and PA expansion priorities. Results: Changes in winter climate could make an additional 2 million ha of land suitable for wheat cultivation, while changes in summer climate could expand maize suitability by up to 3.5 million ha. Conversely, 3 million ha of lands currently suitable for wheat production are predicted to become climatically unsuitable, along with 13 million ha for maize. At least 328 of 834 (39%) PAs are projected to be affected by altered wheat or maize suitability in their buffer zones. Main conclusions: Reduced crop suitability and food scarcity in subsistence areas may lead to the exploitation of PAs for food and fuel. However, if reduced crop suitability leads to agricultural abandonment, this may afford opportunities for ecological restoration. Expanded crop suitability in PA buffer zones could lead to additional isolation of PAs if portions of newly suitable land are converted to agriculture. These results suggest that altered crop suitability will be widespread throughout South Africa, including within and around lands identified as conservation priorities. Assessing how climate change will affect crop suitability near PAs is a first step towards proactively identifying potential conflicts between human adaptation and conservation planning.
The formation of a pronival (protalus) rampart on sub-Antarctic Marion Island is investigated. Morphological attributes show debris at the angle of repose on the rampart's proximal slope and at a lower angle on the distal slope. Relative-age dating, based on the percentage moss cover and weathering rind thickness of the clastic component, indicates accumulation mainly on the proximal slope and rampart crest, implying upslope (retrogressive) accumulation. This contrasts with a previously published model for pronival ramparts, which proposes rampart growth by addition of material to the distal slope. Development of the Marion Island rampart is suggested to result from the control exerted by a relatively low-angled surface and a shrinking snowbed. A small debris step formed on the proximal slope appears to be a response to decreased snowfalls due to changing climate over the last c. 50 years. Growth rate of the rampart is considered to be variable during the Holocene in response to changes in climate and debris supply.
Sediment transport in the scoria areas of Marion Island is primarily the result of needle-ice-induced frost creep associated with diurnal soil frost cycles. Clasts move most rapidly in fine textured areas (532 mm a −1 ; SD 382), more slowly in stony areas (161 mm a −1 ; SD 179), and most slowly in blocky areas (26 mm a −1 ; SD 23). Movement rates increase with increasing frost susceptibility of sediments, slope angle and altitude. The heave of dowels indicates that frost heave is active in all the scoria areas examined. The depth of effective frost heave increases with increasing altitude, with frost heave being restricted to the upper 100 mm of the soil in low altitude areas (<200 m). The heave of 150 mm dowels at the higher altitude sites provides evidence for segregation ice formation at depths greater than those associated with needle ice and diurnal soil frost cycles. Vertical movement profiles show a concave downslope profile, with sediment movement rates being most rapid at the soil surface and decreasing rapidly with depth. This profile shape is typical of areas dominated by diurnal freeze-thaw cycles and needle ice. The capture of sediments moving downslope in troughs and the sampling of material lifted by needle ice, suggest that sediment transport by needle ice under present conditions is extremely effective. Observations suggest that although both fine material and clasts are transported downslope, some preferential transport of clasts occurs.Experiment results and observations of soil frost processes suggest that frost creep associated with needle ice activity is the dominant slope process in the scoria areas of Marion Island. Other slope processes such as slopewash and debris flows appear to play a relatively minor and localized role in sediment transport. It is suggested that needle ice activity is likely to be the dominant geomorphic agent in other areas of the Subantarctic with similar climatic characteristics to Marion Island.
Systematic conservation planning is intended to inform spatially explicit decision making. Doing so requires that it be integrated into complex regulatory and governance processes, and there are limited instances where this has been achieved effectively. South Africa is a global leader in the application of conservation plans, the outputs of which are widely used for spatial planning and decision making in many spheres of government. We aimed to determine how conservation planning in the country progressed from theory to implementation, and to identify practical actions that enabled this transition, by assessing temporal trends in the characteristics of conservation plans (1990–2017, n = 94). Since 2010 conservation planning has entered an operational period characterized by government leadership of plans, administrative rather than ecological planning domains, decreasing size of planning units, increasing emphasis on end‐user products, and scheduled revision of plans. Key actions that enabled this progression include transitioning leadership of plans from scientists to practitioners, building capacity within implementing agencies, creating opportunities to integrate plans in legislative processes, establishing a strong community of practice, adopting implementation‐focused methods, and balancing standardization with innovation. Learning from this model will allow other countries, particularly those with a similar megadiverse, developing context, to operationalize conservation planning into spatial planning and decision making.
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