Kruger's elephants

Prof Rudi van Aarde, Full Professor and Chair of Conservation Biology at the University of Pretoria, delivered this presentation at the Conserving our heritage seminar organized by the Department of Library Services and SANParks, held in the Merensky II auditorium on 30 July 2014Paper presented to University of Pretoria staff and students titled Conserving our heritage seminar organized by the Department of Library Services and SANParks, held in the Merensky II Auditorium on 30 July 2014.eo201

Coastal dune topography as a determinant of abiotic conditions and biological community restoration in northern KwaZulu-Natal, South Africa

Topography is rarely considered as an independent goal of restoration. However, topography determines microenvironmental conditions and hence living conditions for species. Restoring topography may therefore be an important first step in ecological restoration. We aimed at establishing the relative importance of topography where coastal dunes destroyed by mining are rebuilt as part of a rehabilitation program. We assessed the response of (1) microclimatic and soil conditions, and (2) woody plant and millipede species richness and density, to locationspecific topographic profiles. We enumerated the topographic profile using variables of dune morphology (aspect, elevation, and gradient) as well as relative position on a dune (crest, slope, and valley). Temperature, relative humidity, and light intensity varied with aspect, elevation, gradient, and position. However, regeneration age was a better predictor of soil nutrient availability than these topographic variables. Age also interacted with topographic variables to explain tree canopy density and species richness, as well as millipede species richness. The density of keeled millipedes (forest specialists) was best explained by topographic variables alone. The transient nature of these new-growth coastal dune forests likely masks topography-related effects on communities because age-related succession (increasing structural complexity) drives the establishment and persistence of biological communities, not habitat conditions modulated by topography. However, our study has shown that the microhabitats associated with topographic variability influence specialist species more than generalists.Department of Trade and Industry and Richards Bay Minerals and the National Research Foundationhttp://link.springer.com/journal/11355hb2014ab201

The response of bird feeding guilds to forest fragmentation reveals conservation strategies for a critically endangered African eco-region

South African coastal forests form part of two critically endangered eco-regions and harbor an extinction debt. Remainingfragments are small, isolated, and embedded within a range of human land-use types. In this study, we ask: how should we investconservation resources if we want to restore this landscape and prevent predicted extinctions? To answer this question, we use pathanalyses to determine the direct and indirect effects of forest area, forest connectivity, and matrix land-use types on species richnesswithin five bird feeding guilds. We found that forest connectivity had a significant direct effect on insectivores—fragments thatwere more connected had more species of insectivores than those that were isolated. Moreover, forest area had a significant indi-rect effect on insectivores that was mediated through tree species richness. Larg er fragments had more species of trees, which ledto more species of insectivores. Fragment area, connectivity, matrix land-use type, and tree species richness had no significanteffects on the species richness of frugivores, nectarivores, granivores, or generalist feeders. To conserve insectivores in coastal for-ests, conservation efforts should focus on maximizing fragment connectivity across the landscape, but also protect the tree commu-nity within fragments from degradation. This can be achieved by including matrix habitats that adjoin forest fragments withinforest conservation and restoration plans. Natural matrix habitats can increase connectivity, provide supplementary resources, bufferfragments from degradation, and could play an important role in safeguarding diversity and preventing extinctions in this threatenedhuman-modified landscape.Grants from the National Research Foundation, the University of Pretoria, the South African Department of Trade and Industry and Richards Bay Minerals to RVA enabled the study. PO was supported by an Innovation post-doctoral fellowship from the National Research Foundation (Grant No: 88173) and an Ecologist in Africa grant from the British Ecological Society (Grant No: 5169-6211).http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1744-74292018-03-31hb2017Zoology and Entomolog

Fences are more than an issue of aesthetics

Licht and colleagues (BioScience 60: 147–153) identify South Africa’s pioneering efforts to reintroduce top predators to small, fenced protected areas as a conservation model America might be wise to follow. However, South African success at large predator reintroduction is largely the result of ubiquitous fencing that generally prevents predator conflict with people and livestock (see Gusset et al. 2008)

The role of canopy gaps in the regeneration of coastal dune forest

In regenerating coastal dune forest, the canopy consists almost exclusively of a single species, Acacia karroo. When these trees die they create large canopy gaps. If this promotes the persistence of pioneer species to the detriment of other forest species then the end-goal of a restored coastal dune forest may be unobtainable. We wished to ascertain if tree species composition and richness differed significantly between canopy gaps and intact canopy, and across a gradient of gap sizes. In three known-age regenerating coastal dune forest sites, we measured 146 gaps, the species responsible for gap creation, the species most likely to reach the canopy and the composition of adults, seedlings and saplings. We paired each gap with an adjacent plot of the same area that was entirely under intact canopy and sampled in the same way. Most species (15 out of 23) had higher abundance in canopy gaps. The probability of self-replacement was low for A. karroo even in the largest gaps. Despite this predominance of shade intolerant species, regenerating dune forest appears to be in the first phase of succession with “forest pioneers” replacing the dominant canopy species. The nature of these species should lead to successful regeneration of dune forest.The University of Pretoria, Richards Bay Minerals and the South African Department of Trade & Industryhttp://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1365-2028am2013ab201

Resilience of the medicinal plant community of rehabilitating coastal dune forests, KwaZulu-Natal, South Africa

No abstract available.http://www.blackwell-synergy.com/loi/ajehttp://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1365-2028ab201

Amphibian and reptile communities and functional groups over a land-use gradient in a coastal tropical forest landscape of high richness and endemicity

Information on the response of herpetofauna to different land uses is limited though important for land-use planning to support conservation in human-modified landscapes. Though transformation is dogmatically associated with extinction, species respond idiosyncratically to land-use change, and persistence of species in habitat fragments may depend on careful management of the human-modified matrix. We sampled herpetofauna over a vegetation-type gradient representative of regional land uses (old-growth forest, degraded forest, acacia woodland (i.e. new-growth forest), eucalyptus plantation, and sugar cane cultivation) in the forest belt skirting the southeastern coast of Africa, part of a biodiversity hotspot hosting many endemic herpetofaunal species in a highly transformed landscape. We categorized species into trait-derived functional groups, and assessed abundance and richness of groups and compared community metrics along the gradient. We further assessed the capacity of environmental variables to predict richness and abundance. Overall, old-growth forest harbored the highest richness and abundance, and frogs and reptiles responded similarly to the gradient. Richness was low in cultivation and, surprisingly, in degraded forest but substantial in acacia woodland and plantation. Composition differed between natural vegetation types (forest, degraded forest) and anthropogenic types (plantation, cultivation), while acacia woodland grouped with the latter for frogs and the former for reptiles. Functional group richness eroded along the gradient, a pattern driven by sensitivity of fossorial/ground-dependent frogs (F2) and reptiles (R2) and vegetationdwelling frogs (F4) to habitat change. Variables describing temperature, cover, and soil were good predictors of frog abundance, particularly of functional groups, but not for reptiles. Conserving forest and preventing degradation is important for forest herpetofaunal conservation, restoration and plantations have intermediate value, and cultivation is least beneficial. Our study demonstrates the utility of function-related assessments, beyond traditional metrics alone, for understanding community responses to transformation. Particularly, fossorial/ground-dependent frogs and reptiles and vegetation-dwelling frogs should be closely monitored.NSF Graduate Research Fellowship. Research grants to Richards Bay Minerals, the South African Department of Trade & Industry, and the National Research Foundation.http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1469-17952015-10-31hb201

A note on polyvinyl chloride (PVC) pipe traps for sampling vegetation-dwelling frogs in South Africa

No abstract available.http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1365-20282015-09-30hb201

Multi-scale sampling boosts inferences from beta diversity patterns in coastal forests of South Africa

AIM : We used a hierarchical fractal-based sampling design to test how sampling scale influences i) beta diversity and ii) inferences on the modelled contribution of niche- versus dispersal-based assembly processes in structuring tree and bird assemblages. Location Coastal forest fragments, South Africa METHODS : We surveyed 103 tree and 267 bird points within eight forest fragments and partitioned beta diversity (βsor) into its turnover (βsim) and nestedness (βnes) components. We evaluated how sampling at fine, intermediate and coarse scales influenced beta diversity components and compared how tree and bird beta diversity respond to sampling grain variation. We then explored the relative contributions of niche- and dispersal based assembly processes in explaining spatial turnover as a function of sampling grain and/or study taxon by using multiple regression modelling on distance matrices and variance partitioning. RESULTS : Beta diversity (βsor) of trees and birds was mainly explained by spatial turnover (βsim) at all sampling scales. For both taxonomic groups, βsor and βsim decreased as sampling scale increased. Beta diversity differed among trees and birds at fine, but not at coarse sampling scales. Dispersalbased assembly processes were the best predictors of community assembly at fine scales, whereas niche-based assembly processes were the best predictors at coarse scales. Most of the variation in tree community composition was, however, explained at fine scales (by dispersal-based assembly processes), while most of the variation in bird community composition was explained at coarse scales (by niche-based assembly processes). MAIN CONCLUSIONS : Our study shows that inferences from beta diversity are scale dependent. By matching the grain of the data with the grain at which predictor variables and associated processes are likely to operate, multi-scale sampling approaches can improve biodiversity conservation and should be part of incentives directed at ecological sensible conservation plans.National Research Foundation, South African Department of Trade and Industry and Richards Bay Minerals.http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1365-2699hb201

Supporting conservation with biodiversity research in sub-Saharan Africa's human-modified landscapes

Protected areas (PAs) cover 12 % of terrestrial sub-Saharan Africa. However, given the inherent inadequacies of these PAs to cater for all species in conjunction with the effects of climate change and human pressures on PAs, the future of biodiversity depends heavily on the 88 % of land that is unprotected. The study of biodiversity patterns and the processes that maintain them in human-modified landscapes can provide a valuable evidence base to support science-based policy-making that seeks to make land outside of PAs as amenable as possible for biodiversity persistence. We discuss the literature on biodiversity in sub-Saharan Africa’s human-modified landscapes as it relates to four broad ecosystem categorizations (i.e. rangelands, tropical forest, the Cape Floristic Region, and the urban and rural built environment) within which we expect similar patterns of biodiversity persistence in relation to specific human land uses and land management actions. Available research demonstrates the potential contribution of biodiversity conservation in human-modified landscapes within all four ecosystem types and goes some way towards providing general conclusions that could support policy-making. Nonetheless, conservation success in human-modified landscapes is hampered by constraints requiring further scientific investment, e.g. deficiencies in the available research, uncertainties regarding implementation strategies, and difficulties of coexisting with biodiversity. However, information currently available can and should support efforts at individual, community, provincial, national, and international levels to support biodiversity conservation in human-modified landscapes.National Science Foundation Graduate Research Fellowship.Chair in Conservation Ecology at CERU.http://link.springer.com/journal/105312015-08-31hb201