Patterns of distribution and conservation status of freshwater fishes in South Africa

The combined fish collection databases of the Albany Museum and the J.L.B. Smith Institute of Ichthyology are used to identify hotspots of endemism and threatened fish distributions in South Africa. Hotspots of fish species richness occur in the north-eastern lowveld sectors of South Africa and along the ecotone between the tropical/ subtropical and temperate faunal zones. Hotspots of endemic fish richness occur within both the tropical and temperate faunal regions, notably in the Olifants River system, Western Cape and in areas of high relief such as the Cape Fold Mountains, the Amatola-Wrnterberg (Eastern Cape), and the Drakensberg Escarpment {Kwazulu/ Natal-Eastern Transvaal). Threatened taxa are concentrated in the hotspots of endemic species richness which coincide largely with areas of major river conservation concern. There is limited scope for fish conservation within the ambit of formal (or informal) declared reserves, and the survival of the fauna depends on the success of river catchment conservation management. The value of museum collections in identifying areas of conservation concern for freshwater fishes is emphasized, and highlights the importance of well-preserved voucher specimens for biodiversity conservation.     

Patterns of distribution and current protection status of the Carnivora,Chiroptera and Insectivora in South Africa

Geographic patterns of species richness and endemism in three mammalian orders (Chiroptera, Insectivora and Carnivora) were studied in relation to the biomes and existing protected areas of greater South Africa (including Lesotho and Swaziland). Locality data for 21500 specimens representing 124 species were analysed with a geographical information system. Species richness of Chiroptera is high in the savanna biome, particularly in the north-east of the country, owing to the marginal intrusion of 14 tropical species. Endemism in Chiroptera is low, however, with only two endemic species in the fynbos and Karoo biomes. The Carnivora display less biome specificity and endemism than the Chiroptera. Whereas the north-eastern savannas have the highest species richness, the transition between the Nama-Karoo and grassland biomes is an important southern African centre of endemism for the Carnivora, particularly the smaller species. In addition to being an important centre for species richness in the Carnivora and Chiroptera, the Kruger National Park is also particularly important for Red Dala Book species in both orders. The Insectivora display both high species richness and endemism. Species richness of the Insectivora is greatest in the mesic south-east of the country, whereas endemism is most pronounced in the forest and grassland biomes. Differences in biome specificity and endemism between these orders reflect not only phylogenetic divergence, but also variation in body size, vagility and life-history strategies. Most of South Africa's endemics are small mammals and many of them are listed in the Red Data Book. Distributions, life-history strategies and trends in man-induced habitat degradation were used to re-evaluale the protection status of the 124 species. We conclude that at least 11 endemic species are not adequately protected by existing publicly owned protected areas and consequently identify several areas which need to be added to the existing protected area system.     

Livestock grazing has minimal effect on the species richness and diversity of semi-arid shrubland in the Western Little Karoo,South Africa

The Succulent Karoo, one of two arid biodiversity hotspots in the world, is known for its high plant species richness, but little is known about the influence of topography and how it mediates the potentially deleterious effects of grazing. Changes in vegetation species composition, cover and species diversity were examined along piosphere gradients on northerly slopes, bottomlands and low-lying plains on 45 farms. Landscapes differed in the plant speciesand life-form composition, species richness and cover, with the more species-rich, heterogeneous grassy northerly slopes distinct from the plains and bottomlands, which were dominated by Pteronia pallens, Psilocaulon junceum and Drosanthenum spp. with more annual and ephemeral species. Overall, species richness declined linearly with decreasing rangeland condition. A weak grazing effect was detected only on the north-facing slopes, where shrubs and grass decreased with intense grazing. Years of overgrazing have resulted in the widespread dominance of P. pallens, especially on the plains and bottomlands, rendering them insensitive to grazing. The current condition of the northern slopes should be maintained and managed such that palatable species can spread to more degraded areas of the landscape.     

The potential drivers in forming avian biodiversity hotspots in the East Himalaya Mountains of Southwest China

Little has been published to describe or interpret Asian biodiversity hotspots, including those in the East Himalayan Mountains of Southwest China (HMSC), thus making necessary a review of the current knowledge. The Pliocene and Pleistocene geological and glacial histories of the Asian continent differ from those of Europe and North America, suggesting different mechanisms of speciation and extinction, and, thus, different responses to climate changes during the Quaternary glaciations. This short review summarizes potential drivers in shaping and maintaining high species richness and endemism of birds in the HMSC. The geographical location at the junction of different biogeographical realms, the wide range of habitats and climates along the extensive elevational range, the complex topography and the distinct geological history of this region have probably contributed to the evolution of an exceptionally species‐rich and endemic‐rich, specialized montane avian fauna. The Mountain systems in the HMSC may have provided refugia where species survived during the glacial periods and barriers for preventing species dispersal after the glacial periods. More studies are required to further test this refugia hypothesis by comparing more cold‐tolerent and warm‐tolerent species.     

Anuran distribution,diversity and conservation in South Africa,Lesotho and Swaziland

The distributions of 96 anuran species in South Africa were mapped using published locality records, and the collections of the South African and Port Elizabeth museums. Centres of richness, endemism and Red Data Book (RDB) richness were identified, and compared with currently protected areas, using a geographical information system (GIS). Maputaland and the Kwazulu/Natal coast were identified as centres of species richness. Endemic ‘hotspots’ occur in the vicinity of Pietermaritzburg, Durban and Ihe fynbos region of the Western Cape, The Western Cape was also identified as a centre of RDB species richness. A large portion (95,8%) of South African anuran species are found in protected areas. The effective long-term viability of populations of many of these species within these areas, must be assessed. Currently four South African frog species are not found within protected areas. The Karoo biomes were identified as being under-represented, both in the species database and in the proportion of conserved areas. While a large proportion of the fynbos biome is contained in reserve areas, the low-lying fynbos habitats have almost disappeared as a result of urbanization and agriculture. Remnants of the sandy coastal fynbos and renosterveld veld types require urgent conservation. Several areas in the Western and Eastern Cape were identified as requiring additional research and conservation measures. A GIS proves a useful tool in the analysis of species distributions and the prioritization of areas and species for conservation. The importance of accurate collection data, for incorporation into species databases, and the regular publication of reserve species lists is emphasized.     

Vegetation responses to seasonal weather conditions and decreasing grazing pressure in the arid Succulent Karoo of South Africa§

The Succulent Karoo biome is a renowned centre of biodiversity and endemism in the arid winter rainfall region of South Africa that is threatened by climate change. On 20 permanently marked plots within a biodiversity observatory, species richness and cover were assessed annually from 2002 to 2017 during the growing season. We were interested, firstly, in whether the vegetation showed any trends in response to the strong decrease in grazing pressure, which occurred at the beginning of the monitoring period, and secondly, in the effect of seasonal climate on the vegetation. We analysed the responses of species richness and cover in four life forms to seasonal rainfall and the standardised precipitation–evapotranspiration index (SPEI) using linear mixed-effect models. Time had a positive effect on richness of annual species and a negative effect on cover of shrubs and annuals, which increased in response to SPEI and less strongly to rainfall during autumn and winter. Habitat did not have any effect and geophytes and perennial herbs did not show any significant response. The importance of SPEI during autumn and winter is discussed in relation to potential germination cues and the projected decrease in rainfall and increase in temperature during these seasons.     

Distribution pattern of endangered bird species in China

In this study, we determined six “hotspots” for avian biodiversity conservation in China. We analyzed the distribution patterns of 183 threatened bird species in China in conjunction with geographical data to produce a distribution map that shows the concentrations of threatened species. The six biodiversity hotspots are: the western Tianshan Mountains; the Qilian and Hengduan mountains; southern Anhui, southern Jiangsu, and the Zhejiang Hills; the Songliao Plain and the northern region of the North China Plain; the island of Taiwan; and the island of Hainan. Based on our analysis of a species–habitat matrix, species were determined to be distributed mainly in broadleaved forest, grassland and meadows, urban and agricultural areas, wetlands, and bush. Most species were commonly found to have a range of three to five different habitat types. Apart from the six biodiversity hotspots, six ecological clusters were determined. Protection strategies indicating different levels of habitat priority among the biodiversity hotspots were also recommended.     

Variation in mammal species richness and relative abundance in the Karoo§

Understanding how climate change and land transformation may impact the distribution and diversity of wildlife species requires landscape-level foundational biodiversity surveys. The Karoo BioGaps Project aims to provide such data and to support the scientific assessment for shale gas development projects in the Karoo basin. In this paper we present the findings of the BioGaps mammal survey, which recorded medium and large mammals across twenty-five 1 km × 1 km sampling sites within the proposed fracking footprint using camera trapping techniques. We use sample rarefaction curves, non-parametric species richness estimators and non-metric multidimensional scaling plots to explore both species richness and community structure. We also used a generalised linear model to investigate how species diversity varies with both site-specific and landscape-level predictors. A total of 38 species were recorded at the majority of sites. Longitude (z = 4.018, p = 0.0005) emerged as the best predictor of species diversity across the study area, which we suggest is linked to the clear east–west aridity gradient. Together these results reveal the cosmopolitan distribution of the mammal taxa in the Karoo and could be used to inform decision-making linked to mining activities in the area.     

Introduction to an evaluation of the protection status of South Africa's vertebrates

During the Zoological Society of Southern Africa's 1994 Symposium in Pietermaritzburg, a theme session was convened to evaluate the protection status of selected groups of South African vertebrates (viz. freshwater fish, frogs, tortoises and terrapins, snakes, birds, and various mammal orders). The research papers presented during that session are reported in this number of the South African Journal of Zoology. The rationale behind the research, and the data and methods used, are described in this introductory paper. South Africa's national and international contractual obligations to conserve its biodiversity, and the urgent need for a national conservation strategy and national conservation information networks and databases, are also discussed.     

Bird diversity and the conservation value of a new Ramsar site: Guangdong Haifeng Wetlands,China

Wetlands are critical habitats for birds. However, wetlands are being degraded at an accelerating rate due to global human activity, and a disproportionate fraction of wetland‐dependent bird species are in decline. We evaluated the conservation value of a new Ramsar site, Guangdong Haifeng Wetlands, China, for birds, by comparing bird communities (using line transect data) in 3 different districts: Gongping, Dongguan Lian'anwei and Dahu. We recorded 139 species of birds, including 26 species that are protected at a national level. Dahu had the highest species richness and diversity, whereas Dongguan Lian'anwei had the highest abundance of birds and the lowest species diversity. Finally, Gongping had both the lowest species richness and the lowest abundance. The endemism of constituent species differed among districts, and the bird communities were complementary. There were significant seasonal differences in the species richness and the number of individuals. Spring had the highest species richness and diversity. The present study identifies the high conservation value of Haifeng Wetlands for both waterbirds and terrestrial birds. Our findings suggest that conservation efforts in Haifeng Wetlands and other wetlands should focus not only on wintering migratory birds, but also on resident birds. To accomplish effective conservation, we should consider the reserve and surrounding wetlands as a whole, incorporating ecological research, education and local economic development.     

Southeast Asian primate communities: the effects of ecology and Pleistocene refuges on species richness

We examined historical and ecological factors affecting current primate biodiversity in Southeast Asia. In Africa, Madagascar and South America, but not Southeast Asia, primate species richness is positively associated with average rainfall and distance from the equator (latitude). We predicted that Southeast Asia's non‐conformance may be due to the effect of dispersed Pleistocene refuges (locations of constricted tropical forests during glacial maxima which today are at least 305 m in altitude). Based on 45 forested sites (13 on large islands; 32 on the mainland) of at least 100 km² to minimize recent human impact, we determined correlations between extant primate species richness and rainfall, latitude and supplementary ecological variables, while controlling for refuges and islands. We found that refuge sites had significantly higher primate species richness than non‐refuges (t = –2.76, P < 0.05), and distance from the nearest Pleistocene refuge was negatively correlated with species richness for non‐refuge sites (r = –0.51, P < 0.05). There was no difference in species richness between sites on large islands and the mainland (t = –1.4, P = 0.16). The expected positive relationship between rainfall and species richness was not found (r = 0.17, P = 0.28). As predicted, primate species richness was negatively correlated with latitude (r = –0.39, P < 0.05) and positively correlated with mean temperature (r = 0.45, P < 0.05). General linear models indicated that a site's latitude (F_1,38 = 6.18, P < 0.05) and Pleistocene refuge classification (F_1,42 = 5.96, P < 0.05) were the best predictors of species richness. Both ecological and historical factors contribute to present day primate species richness in Southeast Asia, making its biodiversity less of an outlier than previously believed.     

大花金鸡菊入侵对植物多样性的影响

采用样方法研究了青岛市5个不同生境下大花金鸡菊（Coreopsis grandiflora）入侵地植物的种类和数量,分析了其物种丰富度、多样性指数和均匀度指数,并计算出每种植物的重要值。5个样地共采集本地植物92种,隶属16科,以菊科和禾本科最多,其中出现频率较高或植株数量较多的植物共33种。大花金鸡菊入侵地物种丰富度、Simpson指数、Shannon Wiener指数和Pielou指数较对照均有下降,最大下降幅度分别为34.75%、60.53%、58.22%和41.98%。大花金鸡菊的平均重要值高达56.92%,远大于群落中其他植物的重要值,并且和群落的物种丰富度有显著相关性(R2=0.907),当大花金鸡菊重要值高于20.25%时,样方内物种丰富度随着重要值的增加而减少,对入侵地的植物多样性产生不利的影响。     

Ecotourist trail-use affects the taxonomic,functional and phylogenetic diversity of mammals in a protected area: lessons for conservation management

Ecotourism, by definition, aims to engage peoples’ interest in wildlife and the environment. The use of tourist roads and trails to access sites within protected areas (PAs) can detrimentally affect the behavior and distribution of species. The way mammals respond to anthropogenic pressures may differ across taxonomic, functional, and phylogenetic groups; nevertheless, how ecotourist trail-use affects these different diversity remains under-investigated. Here, we assessed 6 metrics of taxonomic, phylogenetic, and functional diversity for a mammal community in a PA in central China, recording how Trail use (using Trail type as a proxy) and habitat variables affected sightings and signs of mammals across 60 replicate 0.5 km transects. We then examined how Trail use affected the taxonomic, functional, and phylogenetic diversity indices of species (>1 kg). Using generalized liner mixed modeling, we identified that more used trail types had a greater adverse effect on all diversity richness indices than did less used trail types. Consequently, tourist pressure was associated with a general tendency to homogenize the site's mammal community. In contrast, the effects of Trail Types on all diversity evenness indices were non-significant. Furthermore, more developed and more heavily used trail types had a greater, significant negative effect on taxonomic, functional, and phylogenetic richness, whereas these richness indices were unaffected by minor trail types, used less intensively. As a general principle, lower biodiversity indices reduce ecosystem resilience, and so it is vital to better understand these responses to balance public access against biodiversity management in PAs.     

The Rise of Conservation in South Africa: Settlers,Livestock and the Environment 1770–1950 — William Beinart 2003

The hump-back relationship between species diversity and productivity predicts highest species richness at intermediate levels of biomass, and low species numbers in least and most productive habitats. Sodic patches of semi-arid savannas are considered ‘nutrient hotspots’ by producing high-quality forage. The impact of biomass reduction (due to overgrazing) and accumulation (in the absence of herbivores) on herbaceous species richness and diversity is still unknown for these hotspots. We tested the relationship between biomass and herbaceous species richness/diversity in savanna sodic sites across varying biomass levels obtained through different herbivore exclosures. LOWESS and quadratic regression analyses revealed a unimodal species richness/ diversity–biomass relationship for biomass <2 500?kg ha?1. Species richness and diversity in the sodic zone peaked at 1 300?kg ha?1, followed by a steady decline. At biomass levels exceeding 2 500?kg ha?1, i.e. where herbivores have been excluded for 10 years, the decline in species richness and diversity stabilised. Despite many debates surrounding unimodal relationships and the intermediate disturbance hypothesis, this study confirmed a peak in species richness and diversity at intermediate biomass levels in a herbivory-adapted ecosystem. Herbivores drive ecosystem heterogeneity and enhance herbaceous species richness and diversity by keeping biomass at intermediate levels (i.e. <2 500?kg ha?1 for this sodic site).     

青藏高原高寒草甸群落特征对氮沉降和增水的响应

试验选择高寒草甸为研究对象,通过连续两年定位观测,采用模拟氮沉降与增水及其交互作用对高寒草地群落特征的影响,为高寒草地生产力功能提升提供科学依据。结果表明:模拟氮沉降和增水及其交互处理,当年均能够显著增加高寒草甸地上总生物量、禾本科植物、豆科植物生物量,但显著降低莎草科植物生物量;而在第2年,增水处理并未明显增加地上生物量,氮沉降与增水交互作用可以稳定地提高高寒草地生产力,各处理均能够明显提高禾本科和莎草科生物量、降低杂类草生物量。增水当年能够显著提高高寒草甸物种丰富度和生物多样性指数,但氮沉降和增水交互降低物种多样性指数;而在第2年,各处理物种数目和多样性指数均降低,且氮沉降与增水的交互作用影响效应达到极显著性检验水平。综合分析,氮沉降和增水及其交互作用在提升草地生产力、优良牧草生物量的同时,也可能造成高寒草甸物种丰富度和多样性指数降低,在草地的适应性管理方面需要引起足够的关注。     

刈割和封育对松嫩草原碱化羊草草地土壤跳虫群落的影响

应用类群数、个体密度和多样性指数等多个群落参数,研究刈割活动和围栏封育对松嫩草原碱化羊草草地土壤跳虫群落特征的影响.本研究共捕获土壤跳虫1 086只,分别隶属于8科18属.研究结果表明,围栏封育能够提高草地土壤跳虫的类群数、个体密度和多样性,其中个体密度提高最为迅速和显著;但长期刈割活动造成恶化的土壤理化环境对跳虫类群数量增长和群落食物网的复杂性与稳定性的提高制约是长期的;凋落物的存在与否对草地土壤跳虫群落有较大的影响,其中凋落物的累积有助于退化草地土壤跳虫群落的恢复,而凋落物的流失可能会使草地土壤跳虫群落进一步退化.     

拉萨河谷植物物种丰富度空间分布格局及其环境解释

为研究拉萨河谷植物物种丰富度的空间分布格局,按不同植被类型设置47个样地,每个样地随机设置3个样方,共141个样方。记录维管植物247种,隶属47科、134属。运用基于距离的Moran特征向量图(MEM)和方差分解, 分析环境因子和空间变量对植物物种丰富度空间分布的影响;运用广义可加模型(GAM)对各环境因子与转换物种丰富度(TSR)进行回归分析,同时对各环境因子之间进行相关分析;运用除趋势对应分析(DCA)对样地和物种进行非约束排序,并将环境因子与排序轴之间进行相关分析。结果表明空间结构对拉萨河谷植物物种丰富度分布具有重要作用,而环境因子的空间格局是影响物种丰富度空间分布格局的重要因素;各环境因子与TSR的GAM拟合结果发现气候因子、经纬度和海拔对TSR存在显著的影响;DCA排序结果表明干扰可能是影响物种丰富度空间格局的未测环境因子,DCA第二轴反映了湿度梯度。干扰和湿度可能是拉萨河谷植物物种丰富度空间分布格局的主要影响因素。     

Gill Ectoparasites of Juvenile Rainbow Trout and Brown Trout in the Upper Colorado River

Abstract

During 1996 and 1997, 112 rainbow trout Oncorhynchus mykiss and 204 brown trout Salmo trutta, all young of the year, were sampled from a 40-km study area of the upper Colorado River and were examined for gill parasites. Ambiphrya, Chilodonella, Ichthyobodo, Apiosoma, Trichodina, Trichodinella, Tripartiella, Epistylis, and an unidentified cochliopodid amoeba were the representative protozoan genera observed on fish examined. Significant month–year–species interactions (P = 0.0295) were revealed, reflecting the changes in infestation prevalence among months, years, and species of salmonid. Greater ectoparasite richness was observed in downstream sections of the study area, most notably near Hot Sulphur Springs, Colorado. Peaks of infestation intensity and ectoparasite richness occurred in August and September of both years, presumably because of high mean water temperatures and low flows during that time.     

Meso-zooplankton movement through the newly constructed Mfolozi channel into and out of the St Lucia Estuary,South Africa

The historical canalization of the Mfolozi River resulted in the St Lucia Estuary losing its main freshwater source. This, combined with the recent drought, led to low water levels, hypersaline conditions and dramatic losses in biodiversity. The excavation of a beach spillway between the estuary and the Mfolozi River mouth in 2012, combined with the commencement of a wet phase in the preceding year, has alleviated the freshwater deprivation crisis. This study compares the meso-zooplankton composition within the channel on both flood and ebb tides, providing a preliminary understanding of the role of the Mfolozi channel in the migration and recruitment of organisms. Abundance was higher on ebb tides, while species richness was higher on flood tides. A total of 53 zooplankton taxa were recorded in the channel. Of these, one had never been recorded in St Lucia before, namely the gastropod Pterotrachea cf. hippocampus. Additionally, the ctenophore Pleurobrachia cf. pileus and the mysid Gastrosaccus gordonae were again recorded for the first time since the late 1970s. Results show that the beach spillway has facilitated recruitment into St Lucia from the ocean and the Mfolozi River. Further research is needed to ascertain what effect this recruitment has on long-term zooplankton community structure.     

Incorporating Biodiversity Into Rangeland Health: Plant Species Richness and Diversity in Great Plains Grasslands

Indicators of rangeland health generally do not include a measure of biodiversity. Increasing attention to maintaining biodiversity in rangelands suggests that this omission should be reconsidered, and plant species richness and diversity are two metrics that may be useful and appropriate. Ideally, their response to a variety of anthropogenic and natural drivers in the ecosystem of interest would be clearly understood, thereby providing a means to diagnose the cause of decline in an ecosystem. Conceptual ecological models based on ecological principles and hypotheses provide a framework for this understanding, but these models must be supported by empirical evidence if they are to be used for decision making. To that end, we synthesize results from published studies regarding the responses of plant species richness and diversity to drivers that are of management concern in Great Plains grasslands, one of North America's most imperiled ecosystems. In the published literature, moderate grazing generally has a positive effect on these metrics in tallgrass prairie and a neutral to negative effect in shortgrass prairie. The largest published effects on richness and diversity were caused by moderate grazing in tallgrass prairies and nitrogen fertilization in shortgrass prairies. Although weather is often cited as the reason for considerable annual fluctuations in richness and diversity, little information about the responses of these metrics to weather is available. Responses of the two metrics often diverged, reflecting differences in their sensitivity to different types of changes in the plant community. Although sufficient information has not yet been published for these metrics to meet all the criteria of a good indicator in Great Plains Grasslands, augmenting current methods of evaluating rangeland health with a measure of plant species richness would reduce these shortcomings and provide information critical to managing for biodiversity.