The value of arboreta in South Africa

Significance:• Arboreta are documented, living collections of ligneous species cultivated for research, education and display.• Arboreta are a valuable resource for the forestry industry as gene banks.• Arboreta, together with botanic gardens, form a useful network of sentinel sites for plant pathogens and invasive species.• A survey of the species composition and status     of  arboreta in South Africa would be an important contribution to our botanical knowledge

Remote sensing object-oriented approaches coupled with ecological informatics to map invasive plant species

nvasive alien plants are considered one of the major threats to biodiversity conservation worldwide. Hence, understanding their distribution and abundance is important in order to assess the impact on native ecosystems. It is particularly important to be able to track the spread of invasive species across landscapes; a task best achieved using remotely sensed imagery. The availability of high resolution data, combined with efficient classification methods, can potentially improve early detection of invasive alien species thereby enhancing their management. This study aims to classify woody species with a focus on Melia azedarach (Meliaceae) trees in a moderately invaded coastal belt valley on the east coast of South Africa using WorldView-2 (WV-2) satellite imagery, and to compare the commonly used pixel-based classification with object-oriented approaches. The results show that object-oriented approaches are more suitable for classifying woody species, as well as other land cover classes when using high-resolution WV-2 imagery. The overall accuracy was 90% by object- oriented classification, while the pixel-based classification gave an overall accuracy of 78%. For Melia, a producer accuracy of 92% and user accuracy of 91% was obtained by object-oriented classification and a producer accuracy of 85% and user accuracy of 83% was obtained by pixel-based classification. Hence the combined use of new generation sensor imagery and the employment of object-oriented image classification techniques provided more accurate information on Melia invasion in the study area. This is an encouraging result given the high degree of intermingling of Melia with other plants at the study site. In particular, the vegetation maps produced from this study would aid in gathering accurate knowledge about the distribution and spreading status of Melia, a major invasivespecies over large areas of South Africa and elsewhere in the world

The alignment of projects dealing with wetland restoration and alien control: A challenge for conservation management in South Africa

An inventory of wetland vegetation across the country generated a list of the most common invasive alien plants across South Africa. Many of the plants on that list do not correspond with the priorities in the programmes for alien control across the country, as they are not listed on a government produced list that guides the priorities for alien control. We explore the reasons for this situation. We argue that because wetlands are such important parts of the landscape, invasive aliens in wetlands are of special concern, and there should be more alignment between alien control programmes and wetland rehabilitation programmes. This alignment starts by considering the full number of species that form a threat to wetland habitats, but also considers which pesticides to use, erosion and recolonisation in wetlands, planting indigenous vegetation after aliens have been removed, and strategising by working from upstream to downstream. Existing alien control programmes for specific grasses (some relatively new to the country and in the phase of early detection) and floating aquatic plants may guide how to tackle the invasions of grasses and forbs that have been established in South African wetlands for an extended period of time. Significance:• Wetlands have a distinct set of alien invasive plants that affect their ecology and functioning and many of these plants are not listed as priorities in alien control programmes.• Many restoration projects have an element of removing invasive plants and revegetating. Wetland restoration and alien control need to be integrated to preserve water resources

Corrigendum: The alignment of projects dealing with wetland restoration and alien control: A challenge for conservation management in South Africa

Errors that appear in the Discussion of the Research Article by Sieben et al. are corrected here. Dr Graham Harding (Registered PCO, Invader Plant Specialists (Pty) Ltd) is acknowledged for drawing the authors’ attention to these errors

How to build science-action partnerships for local land-use planning and management: Lessons from Durban, South Africa

The gap between scientific knowledge and implementation in the fields of biodiversity conservation, environmental management, and climate change adaptation has resulted in many calls from practitioners and academics to provide practical solutions responding effectively to the risks and opportunities of global environmental change, e.g., Future Earth. We present a framework to guide the implementation of science-action partnerships based on a real-world case study of a partnership between a local municipality and an academic institution to bridge the science-action gap in the eThekwini Municipal Area, South Africa. This partnership aims to inform the implementation of sustainable land-use planning, biodiversity conservation, environmental management, and climate change adaptation practice and contributes to the development of human capacity in these areas of expertise. Using a transdisciplinary approach, implementation-driven research is being conducted to develop several decision-making products to better inform land-use planning and management. Lessons learned through this partnership are synthesized and presented as a framework of enabling actions operating at different levels, from the individual to the interorganizational. Enabling actions include putting in place enabling organizational preconditions, assembling a functional well-structured team, and actively building interpersonal and individual collaborative capacity. Lessons learned in the case study emphasize the importance of building collaborative capacity and social capital, and paying attention to the process of transdisciplinary research to achieve more tangible science, management, and policy objectives in science-action partnerships. By documenting and reflecting on the process, this case study provides conceptual and practical guidance on bridging the science-action gap through partnerships

How Often Are We in the Here and Now?

There is a conflict between humans’ need to focus on the present circumstances and their ability to plan and reminisce, which often results in mind wandering. Contemporary techniques with ancient roots, such as mindfulness, are useful in solving some of the problems associated with excessive mind wandering but largely fail to recognize the importance of planning and reminiscing. This lack of recognition means that research has by and large ignored the need for a balanced approach, incorporating a focus on both the present local circumstances and elsewhere. Here, I scrutinize time use data to classify contemporary human activities, with an emphasis on leisure but also relevant in a work context. I classify activities according to their temporal and spatial profiles, while also noting any social components involved, which may further remove the activity focus from the self. A visual summary of this classification indicates that our activities, whether societally imposed on us or performed by choice, cover the full range of time-and-place focus profiles available to the human mind more or less evenly. This contradicts the prevalent paradigm, suggesting a dichotomy between present time-and-place focus and mind wandering. I suggest that individual differences in temporal and spatial focus profiles require both broad and in-depth study, such differences having the potential to help optimize not only individual well-being but also the functioning of society, and that mind wandering may be (at least partly) unnecessarily vilified

Analyses towards determining Madagascar’s place in global biogeography

The relationships of Madagascan plant and animal taxa have been the object of much fascination, Madagascar sharing numerous lineages with Africa, others with Asia, Australia, or the Americas, and many others being of uncertain relationships. In commonly accepted global regionalization schemata, Madagascar is treated together with Africa for animals, and with Africa, tropical Asia and the Pacific islands in the case of plants. Here we examine the similarities between the biotic assemblages of (i) tropical Africa, (ii) Madagascar, and (iii) the rest of the world, on a basic taxonomic level, considering the families of vascular plants and vertebrates as analysis units. The percentages of endemic families, families shared pair-wise between regions, or present in all three, are roughly similar between the two broad groups, though plant families with ranges limited to one region are proportionally fewer. In dendrograms and multidimensional scaling plots for different groups, Madagascar clusters together with Africa, Asia or both, and sometimes with smaller Indian Ocean Islands, but quite often (though not in plants) as a convincingly separate cluster. Our results for vertebrates justify the status of full zoogeographic region for Madagascar, though an equally high rank in geobotanical regionalization would mean also treating Africa and Tropical Asia as separate units, which would be debata­ble given the overall greater uniformity of plant assemblages. Beyond the Madagascan focus of this paper, the differences between plant and vertebrate clusters shown here suggest different levels of ecological plasticity at the same taxonomic level, with plant families being much more environmentally-bound, and thus clustering along biome lines rather than regional lines [Current Zoology 58 (3): 363-374, 2012]

Ancient Plant Lineages Endemic to Africa and Its Islands: An Analysis on the Distribution and Diversity

Although Africa and Madagascar host numerous endemic plant families and genera, there has been no attempt to use recent phylogenies in order to summarise information on their age or map their distribution and diversity. Here, we list 35 plant lineages endemic to Africa and its islands deemed to be older than 100 Mya, map their distribution, richness, and weighted endemism, and discuss intrinsic and extrinsic factors that may have facilitated their survival. High concentrations of ancient endemic lineages are found in the Cape and more broadly across southern Africa, in the Congolian rainforests, but also in East Africa and Madagascar, these last two areas sharing surprisingly many lineages. Africa and its islands host a highly distinctive assemblage of unique plant lineages, adapted to humid, mesic, dry, and in several cases fire-prone, environments. A better understanding of their history and ecology will facilitate their conservation in a changing climate