Scielo RSS <![CDATA[Koedoe]]> http://www.scielo.org.za/rss.php?pid=0075-645820130001&lang=en vol. 55 num. 1 lang. en <![CDATA[SciELO Logo]]> http://www.scielo.org.za/img/en/fbpelogp.gif http://www.scielo.org.za <![CDATA[<b>Population ecology of vervet monkeys in a high latitude, semi-arid riparian woodland</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0075-64582013000100001&lng=en&nrm=iso&tlng=en Narrow riparian woodlands along non-perennial streams have made it possible for vervet monkeys to penetrate the semi-arid karoo ecosystem of South Africa, whilst artificial water points have more recently allowed these populations to colonize much more marginal habitat away from natural water sources. In order to better understand the sequelae of life in these narrow, linear woodlands for historically 'natural' populations and to test the prediction that they are ecologically stressed, we determined the size of troops in relation to their reliance on natural and artificial water sources and collected detailed data from two river-centred troops on activity, diet and ranging behaviour over an annual cycle. In comparison to other populations, our data indicate that river-centred troops in the karoo were distinctive primarily both for their large group sizes and, consequently, their large adult cohorts, and in the extent of home range overlap in what is regarded as a territorial species. Whilst large group size carried the corollary of increased day journey length and longer estimated interbirth intervals, there was little other indication of the effects of ecological stress on factors such as body weight and foraging effort. We argue that this was a consequence of the high density of Acacia karroo, which accounted for a third of annual foraging effort in what was a relatively depauperate floristic habitat. We ascribed the large group size and home range overlap to constraints on group fission. Conservation implications: The distribution of group sizes, sampled appropriately across habitats within a conservation area, will be of more relevance to management than average values, which may be nothing more than a statistical artefact, especially when troop sizes are bimodally distributed. <![CDATA[<b>Grassland communities of urban open spaces in Bloemfontein, Free State, South Africa</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0075-64582013000100002&lng=en&nrm=iso&tlng=en Natural vegetation in urban environments is greatly impacted by human activities and it is in constant threat of degradation and destruction as a result of urbanisation. This vegetation, although fragmented, serves an important ecological function and needs to be properly managed and conserved. Studies on urban vegetation are lacking in South Africa, with only a handful having been carried out since the end of the last century. This study was initiated to identify, classify and describe the grassland communities of the urban open spaces in Bloemfontein. Releves were compiled in 61 sample plots, where species present and habitat information were recorded. Care was taken to restrict sample plots to vegetation in pristine condition, wherever possible, and severely degraded stands were avoided. A two-way indicator species analysis (TWINSPAN) classification, refined by Braun-Blanquet procedures, revealed two distinct major communities, seven communities and four sub-communities. Both detrended and canonical correspondence analyses indicated the vegetation units to be associated with soil texture and pH, although biotic factors such as overgrazing, burning and mowing also influence the composition of the vegetation. The proper management and conservation of urban open spaces requires in-depth knowledge of the spatial distribution, floristic, structural and functional compositions within the major vegetation types in this environment. The present study further contributed towards formulating ways for the proper management, utilisation and functioning of the open spaces within the Bloemfontein area. Conservation implications: The Grassland Biome of South Africa is poorly conserved, mainly because of its status as an agricultural hub of the country. The preservation of natural and semi-natural forms of urban vegetation is important because such vegetation, although often disturbed and degraded, could form dispersal corridors between peri-urban and rural vegetation. <![CDATA[<b>Herbaceous species diversity patterns across various treatments of herbivory and fire along the sodic zone of the Nkuhlu exclosures, Kruger National Park</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0075-64582013000100003&lng=en&nrm=iso&tlng=en Understanding relationships between large herbivores and plant species diversity in dynamic riparian zones is critical to biodiversity conservation. The Nkuhlu exclosures in the Kruger National Park (KNP) provided opportunity to investigate spatial heterogeneity patterns within riparian zones, as well as how these patterns are affected by fire and herbivory. A monitoring project was initiated to answer questions about the dynamics of the herbaceous layer and was aimed at determining, (1) whether there exists meaningful variance in herbaceous plant species richness and diversity across different treatments in the ecologically sensitive sodic zone and (2) whether an increase in herbaceous biomass, an artefact of herbivory and fire exclusion, suppresses herbaceous plant species diversity and richness. Herbaceous vegetation was sampled in two 1 m² circular sub-plots in the eastern and western corners of 81 fixed plots. The biomass of each plot was estimated with a disc pasture meter (DPM) diagonally with the plot. DPM-readings were converted to kg/ha, according to the latest conversions for the Lowveld Savanna. Species richness and biomass showed significant variance across treatments, whereas no significant variation in herbaceous species diversity was perceived. Combined treatment of fire absence and herbivore presence contributed to higher forb species richness in the sodic zone. Biomass is significantly higher in fully fenced areas where herbivores are excluded, as opposed to the open and partially fenced areas. Although no significant variation was recorded for diversity across treatments, lowest diversity was recorded in the absence of all herbivores, especially in combination with fire treatment. Therefore herbivores are essential in sustaining herbaceous plant species richness in the sodic zone, whilst no significant results were found with regard to their effect on species diversity. Although statistically non-significant, fire seems to suppress species richness. Conservation implications: This study could be used as framework to advance and develop science-based management strategies for, at least, the sodic zones of the KNP. Research in these exclosures will create better understanding of these landscapes, benefit ecosystem conservation planning of national parks and also provide valuable long-term information on key ecological processes. <![CDATA[<b>Fire regimes in eastern coastal fynbos</b>: <b>Imperatives and thresholds in managing for diversity</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0075-64582013000100004&lng=en&nrm=iso&tlng=en Until recently, fire ecology was poorly understood in the eastern coastal region of the Cape Floral Kingdom (CFK), South Africa. Rainfall in the area is aseasonal and temperatures are milder than in the winter-rainfall and drier inland parts of the CFK, with implications for the management of fire regimes. We synthesised the findings of a research programme focused on informing ecologically sound management of fire in eastern coastal fynbos shrublands and explored potential east-west trends at the scales of study area and CFK in terms of fire return interval (FRI) and fire season. FRIs (8-26 years; 1980-2010) were comparable to those elsewhere in the CFK and appeared to be shorter in the eastern Tsitsikamma than in the western Outeniqua halves of the study area. Proteaceae juvenile periods (4-9 years) and post-fire recruitment success suggested that for biodiversity conservation purposes, FRIs should be > 9 years in eastern coastal fynbos. Collectively, findings on the seasonality of actual fires and the seasonality of fire danger weather, lightning and post-fire proteoid recruitment suggested that fires in eastern coastal fynbos are not limited to any particular season. We articulated these findings into ecological thresholds pertaining to the different elements of the fire regime in eastern coastal fynbos, to guide adaptive management of fire in the Garden Route National Park and elsewhere in the region. Conservation implications: Wildfires are likely to remain dominant in eastern coastal fynbos, whilst large-scale implementation of prescribed burning is unattainable. Fires occurring in any season are not a reason for concern, although other constraints remain: the need for sufficient fire intensity, safety requirements, and integration of fire and invasive alien plant management. <![CDATA[<b>Plant nematodes in South Africa. 11. Checklist of plant nematodes of the protected areas of KwaZulu-Natal</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0075-64582013000100005&lng=en&nrm=iso&tlng=en Nematodes are some of the most abundant soil organisms and are an essential part of soil ecology. These organisms are used as indicator organisms and can be linked to soil health. Biological collections contain vast amounts of data, with the National Collection of Nematodes housed at the Plant Protection Research Institute, Agricultural Research Council being no different. During the digitising of the collection a number of unpublished records of plant nematodes reported from protected areas in KwaZulu-Natal were found in the South African Plant-Parasitic Nematode Survey database. A total of 222 plant nematode species belonging to 39 genera were reported from the province, with only 94 of these species reported from the protected areas and 172 and 159 species reported from uncultivated (outside the protected areas) and cultivated areas, respectively. Only nine species, Criconema silvum, Criconema talanum, Helicotylenchus marethae, Ogma dracomontanum, Ogma louisi, Ogma ueckermanni, Paralongidorus deborae, Trichodorus rinae and Xiphinemella marindae were described from protected areas, whilst O. dracomontanum, P. deborae and T. rinae were subsequently also reported from other provinces. Conservation implications: A higher degree of diversity of nematodes was observed in the unprotected areas of the province. The observation suggests that nematode fauna, and by implication also other invertebrates, are not adequately protected. <![CDATA[<b>Plant communities along the Eerste River, Western Cape, South Africa</b>: <b>Community descriptions and implications for restoration</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0075-64582013000100006&lng=en&nrm=iso&tlng=en Riparian plant communities fulfil many functions, including the provision of corridors linking protected areas and other zones of high conservation value. These habitats across much of South Africa's Cape Floristic Region, especially in the lowlands, have been heavily impacted and degraded by human activities. There is increasing interest in the restoration of degraded riparian zones and the ecosystem services they provide to enhance the conservation value of landscapes. Previous studies of riparian vegetation in the Cape Floristic Region focused on pristine headwater systems, and little is known about human-impacted communities that make up most of the riparian vegetation in downstream areas. More information is needed on the composition of these plant communities to establish a baseline for management intervention. The riparian zone of the Eerste River in South Africa's Western Cape province provides a good opportunity to study the features of riparian vegetation along the entire gradient, from pristine vegetation in a protected area through different levels of human-mediated degradation. Riparian vegetation was surveyed in 150 plots along the entire length of the Eerste River (ca. 40 km). Data were analysed using the vegetation classification and analysis software package JUICE. Final groupings were plotted onto a two-dimensional detrended correspondence analysis plane to check the position of the communities in the reduced multidimensional space. Ten distinct plant communities were identified, including several novel communities dominated by alien plant species. Descriptions of each plant community are presented. Diagnostic, constant and dominant species are listed and the major structural and ecological characteristics of each community are described. Conservation implications: Major changes to hydrological and soil properties, nutrient dynamics and disturbance regimes and plant species composition along sections of the riparian zone mean that restoration of many of these habitats to their historic condition is not feasible. However, several native plant species that provide key ecosystem services persist in and adjacent to transformed communities, offering substantial opportunities for restoration to achieve certain goals. <![CDATA[<b>A perspective on bats (Chiroptera)</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0075-64582013000100007&lng=en&nrm=iso&tlng=en With over 130 species, bats are the most diverse group of mammals almost everywhere in sub-Saharan Africa. Since 2000, two books (Monadjem et al. 2010; Taylor 2000) have made it much easier to appreciate this reality. Species previously unrecognised are frequent discoveries (e.g. Taylor et al. 2012). Whilst most species are mainly insectivorous, some rely more directly on plants, taking fruit and visiting flowers to obtain nectar and pollen. The combination of mobility, long lifespan and diversity of trophic roles makes bats potentially valuable as indicators of ecosystem health (Cumming & Spiesman 2006). Lack of detailed information, however, makes it easy to overlook bats when focusing on issues of conservation.