Refugia, dispersal and divergence in a forest archipelago: a study of Streptocarpus in eastern South Africa

We describe a scenario of plant speciation across a relict forest archipelago in South Africa involving Pleistocene habitat expansion-contraction cycles, dispersal and adaptation to lower temperatures. This is the first population level study using molecular data in South African forests and has significant implications for conservation efforts in this area. Populations of the mesophytic forest floor herbs Streptocarpus primulifolius sensu lato and Streptocarpus rexii were sampled throughout their range in the naturally fragmented forests of eastern South Africa in order to investigate population genetic and phylogenetic patterns within the species complex, using nuclear microsatellites, nuclear ribosomal ITS (internal transcribed spacer) sequences and chloroplast genome sequences. S. primulifolius harbours high levels of genetic diversity at both the nuclear (mean HE = 0.50) and the chloroplast level (each population fixed for a unique haplotype). This is consistent with populations of these coastal species being Pleistocene relicts. In contrast, populations of S. rexii in cooler habitats at higher altitudes and lower latitudes harbour little or no nuclear genetic diversity (mean HE = 0.09) and most share a common chloroplast haplotype. The split of S. rexii from populations intermediate between the two species (S. cf. primulifolius) occurred between 0 and 0.44 million years ago according to the calibrated ITS phylogeny of the taxa. The low genetic diversity and homogeneity of S. rexii is congruent with this species having reached its current range during the Holocene. We found no evidence of monophyly of any of the taxa in this study, which we consider a consequence of recent evolution in a fragmented habitat.     

GPS telemetry of forest elephants in Central Africa: results of a preliminary study

Few data exist on the ranging behaviour of forest elephants. A feasibility study on the use of GPS telemetry as a tool to study ranging, seasonal movements and distribution was implemented in the Dzanga‐Sangha and Nouabalé‐Ndoki National Parks Complex of Central African Republic and Congo. The study consisted of two parts – a thorough hand‐held testing of an elephant GPS telemetry collar under tropical forest conditions and the deployment of collars on two elephants. During the feasibility study the system performance was satisfactory; GPS fix acquisition success rate, VHF and UHF collar–researcher communications were adequate. Two elephants, a mature bull and an adult female, were immobilized and fitted with GPS collars in October 1998. After deployment, the female's GPS collar performed well initially, but in less than a month the GPS within the collar stopped acquiring fixes. She was subsequently located using VHF tracking. The male was never relocated strongly suggesting complete failure of the collar. Despite these setbacks, the small amount of data retrieved provide an important first insight into forest elephant ranging and daily activity patterns, with significant conservation implications. When technical difficulties of reliability are overcome, GPS telemetry will provide an exceptionally useful tool in forest elephant research and management.     

Rural change and nature conservation in Africa: A case study from Swaziland

High population growth and deteriorating economic conditions imperil Africa's natural environment. Conservationists are trying to cope with the threat by working in rural communities. Yet it is unclear whether they can be effective when social and economic change in rural areas is so rapid. Northeast Swaziland provides a case study. The landscape has been transformed since the 1950s, and conservationists are the only people now giving nature conservation a high priority. Land uses incompatible with local nature reserves are supported because they provide jobs. Thus, conservationists find themselves facing a world where wildlife is increasingly devalued as the forces of change accelerate. This paper concludes: (1) conservationists must expand their influence into rural communities, (2) an integrated development and conservation plan is required for northeastern Swaziland, and (3) only the alleviation of poverty will secure the future of nature conservation in Swaziland as well as the rest of Africa.     

Priority areas of intraspecific diversity: Larzac, a global hotspot for facultative paedomorphosis in amphibians

Although the designation of biodiversity hotspots is a valuable tool to improve conservation efforts, this is a concept primarily based on species diversity. In consequence, another component of biodiversity, adaptive variation, is often ignored in conservation and to my knowledge no attempt has been made to identify hotspots of remarkable intraspecific patterns. My aim was to focus on the process of facultative paedomorphosis (i.e. the retention of larval traits such as gills in adult variants), a rare developmental pathway. One hundred and seventy-four ponds were inventoried in Larzac (France) to determine the distribution and abundance of paedomorphic palmate newts Triturus helveticus (Amphibia, Caudata) and to compare these results with the current distribution of paedomorphs in this and other species. During this study, paedomorphic newts were found in 46 ponds, 32 of which were described here for the first time. Seventy-nine per cent of known paedomorphic populations of this species were found there, whereas this area covers only 0.5% of the distribution area of the species. This represents the highest known density of facultatively paedomorphic populations, all species being considered. Because these populations face a high threat of disappearance, Larzac should be designated as an intraspecific biodiversity hotspot in order to protect adaptive intraspecific variation. Future conservation-oriented work should focus not only on species distributions but also on phenotypically diverse but spatially localized variation.     

甘肃省中国种子植物特有属物种多样性保护优先地区分析

以甘肃省境内11个主要天然林区作为基本的地理单元,选择天然分布在各林区的中国种子植物特有属的物种丰富度、相对特有性和等级性作为评价指标,对各林区中国种子植物特有属物种多样性进行综合评价,确定出甘肃省中国种子植物特有属物种多样性保护的关键林区,并且运用互补性原理设计出最低保护区域组合及其优先序。分析得出关键保护林区为白龙江下游（白水江）林区、白龙江中上游林区和小陇山林区;最低保护区域组合按其优先序依次为白龙江下游（白水江）林区、白龙江中上游林区、东祁连山林区、小陇山林区和太子山,大夏河林区。     

The selection and design of marine protected areas: Australia as a case study

Recently there has been increased interest in the use of Marine Protected Areas (MPAs) as tools for the conservation of marine habitats and species. This has resulted in the declaration of many MPAs around the world. Despite this activity there have been few tests of hypotheses about the design criteria for selection and management of these areas, resulting in a haphazard and ad hoc selection of protected areas, with conflicting and inconsistent terminology and objectives. The application of appropriately tested scientific information to the design of MPAs will increase the likelihood of success in the future.To 1st January 1992, 267 MPAs had been declared in Australia, covering a total area of ca 400 019 km². The history of their declaration has been sporadic and uneven. Conflicts over State and Federal legislation and, within states, conflicts over jurisdiction among agencies caused by overlapping responsibilities, have at times slowed the declaration of MPAs. In this paper, the history of MPAs in Australia is used as a case study to discuss the problems, both biological and administrative, of declaring MPAs.     

Searching for potential wintering and migration areas of a Danish Barn Swallow population in South Africa by correlating NDVI with survival estimates

On the basis of correlation analyses between annual Normalised Difference Vegetation Index (NDVI) values in Africa and the annual survival rate estimated for a breeding population of barn swallows Hirundo rustica from Denmark, we identified potential wintering and migration areas in South Africa during December–February and March–May, when barn swallows commonly occur in South Africa. During December–February we identified potential wintering areas only in the western part of South Africa, in the Karoo. Potential areas in the central and eastern parts of the country were only identified during March–May. NDVI values in the Karoo during March–May explained most of the variance in annual adult survival rate of the population. The high ratio of European ringed barn swallows among controlled individuals in the Karoo was similar to the ratio that would be expected based on the number of ringed barn swallows and the population sizes of barn swallows in north-western European breeding populations. The level of this ratio in the Karoo was higher than in any other locality in the central and eastern parts of South Africa and Botswana, indicating that ringed birds from the eastern flyway are absent to a much smaller extent than ringed birds from the western flyway. This approach shows that the NDVI and survival method can focus ringing efforts to regions and areas that are likely to harbour specific breeding populations, thereby helping to identify potential wintering and migration areas for breeding populations of migratory birds.     

A sediment-based history of medium altitude forest in central Africa: a record from Kabata Swamp, Ndale volcanic field, Uganda

1 Sedimentary data from a 6-m long core from Kabata Swamp, an in-filled crater in the Ndale volcanic field of western Uganda, provided evidence for a number of cycles of disturbance and recovery of medium altitude forest.
2 The date of formation of the crater was earlier than an Accelerator Mass Spectrometry (AMS) radiocarbon date of 11 460 ± 90  bp (11 699–11 209 bc cal.) and thus appears to predate volcanism farther north in the Fort Portal area.
3 A form of medium altitude forest was already present in western Uganda by the later stages of the last ice age. A more diverse form of medium altitude forest was present from 11 460 ± 90  bp .
4 Some phases of disturbance of this forest during the Holocene could be correlated with established political–economic changes in the study area. One dated c. 2500  bp (768–542 bc cal.) could be associated with the entry of Bantu-speaking people. A second at 400 ± 60  bp ( ad  1419–1648 cal.) coincides with significant shifts in the focus of settlement from drier grassland to wetter, more forested parts.
5 Levels of biodiversity in forests in western Uganda remain relatively high, even after substantial modifications of vegetation cover over an extended period of time. Many central African forest taxa may therefore be able to cope with environmental change, including prolonged human impact.     

Conservation strategies for poorly surveyed taxa: a dung beetle (Coleoptera, Scarabaeidae) case study from southern Africa

Despite being the focus of an international research effort spanning decades, the spatial distribution of southern African scarab beetles remains poorly documented. As well as reinforcing the magnitude of the challenge facing biodiversity scientists, this raises real concerns about best practice conservation strategies in the absence of detailed distribution information. However, dung beetles appear to be well represented in established conservation areas. This apparent contradiction could be ascribed to anthropogenic transformation, successful conservation efforts, the presence of dung generalists and reserve-biased or mesic-biased dung beetle collection efforts. It is suggested that all of the above contribute to the observed pattern to varying degrees. The implications of selecting areas that are either rich in species, contain rare species or contain taxonomically distinct species from a group whose taxonomy is well known but for which inadequate distribution data exist are explored. Best practice, in the face of inadequate data, appears to revolve around a subtle interplay between advantages and disadvantages associated with data interpolation techniques, reserve selection algorithms that use criteria more robust than database rarity (such as taxonomic distinctiveness) and the long-term economic costs of proceeding with the data at hand versus investing in biological surveys.     

Black Jews in the Northern Province: a study of ethnic identity in South Africa

The article examines ways in which the Lemba people of the Northern Province of South Africa have used their oral history and traditional customs associated with distant Semitic origins in Yemen, to claim a modern Jewish identity in racially divided South Africa. While Lemba live in Mozambique and Zimbabwe as well as in South Africa, it is only in the latter that belief in a Jewish origin is found. The article seeks to show that early white missionaries and colonial officials propagated a Semitic identity for the Lemba and in their writings emphasized the differences between the Lemba and their African neighbours through comparisons of Lemba customs with Jewish communities in Europe. Such writings contributed to an ethos of a distinct identity, through which, via the establishment of the Lemba Cultural Association, middle-class Lemba intellectuals sought to promote the Lemba. This was achieved in a situation where the apartheid regime in South Africa pursued a divide and rule policy which allowed the Bantustans to discriminate against ethnic minorities under their control.     

Priority areas for the conservation of South African vegetation: a coarse-filter approach

Abstract.  South Africa has an important responsibility to global biodiversity conservation, but a largely inadequate conservation area network for addressing this responsibility. This study employs a coarse-filter approach based on 68 potential vegetation units to identify areas that are largely transformed, degraded or impacted upon by road-effects. The assessment highlights broad vegetation types that face high biodiversity losses currently or in the near future due to human impacts. Most vegetation types contain large tracts of natural vegetation, with little degradation, transformation or impacts from road networks. Regions in the grasslands, fynbos and forest biomes are worst affected. Very few of the vegetation types are adequately protected according to the IUCN's 10% protected area conservation target, with the fynbos and savanna biomes containing a few vegetation types that do achieve this arbitrary goal. This investigation identifies areas where limited conservation resources should be concentrated by identifying vegetation types with high levels of anthropogenic land use threats and associated current and potential biodiversity loss.     

Conservation of temperate forest birds in Chile: implications from the study of an isolated forest relict

We characterize the bird assemblage of an isolated relict temperaterainforest (Santa Inés) in terms of its structure, composition anddynamics. The relict character and long-term isolation of this forest remnant,immersed in a matrix of semiarid scrub, provide a natural experiment to assessthe consequences of long-term isolation and forest area reduction for temperatebird species. Bird surveys were conducted in a forest fragment and thesurrounding scrub matrix between April 1999 (austral autumn) and October 2000(austral spring) on a seasonal basis. Within the forest fragment wedistinguished two microhabitat types: creeks and areas far from creeks (i.e.slopes). A total of 36 species were recorded in the study site, of which 21were inside the relict forest. Highest bird abundance and richness wererecorded during winter and spring, and these were always higher in creek plotsrather than slope plots. Comparisons between this assemblage and thosedistributed in the continuous temperate forest (located more than 900km southwards) indicate that this bird assemblage shares moresimilarities, with regard to bird species composition, to southern temperateforest localities and to other relict forests, than to nearer scrub habitats.However, there are eight species, endemic to temperate forests in southern SouthAmerica, missing from our system. In this regard, our analyses indicate thatthese eight endemic species should be of great conservation concern and willlikely be the ones that will go extinct first if the fragmentation of thetemperate forest continues.     

Mountain forest islands and Holocene environmental changes in Central Asia: A case study from the southern Gobi Altay, Mongolia

A multi-proxy case study conducted on Central Asia's most isolated mountain forest sheds light on the apparent decline of forest in the Subboreal time period and the incisive environmental changes from dark taiga to steppe in the Gobi Altay of Southern Mongolia over the last 5000 yr.

New vegetation records from the ‘Gobi Gurvan Saykhan’ (43°30′ N/103°10′ E) reveal long distance disjunctions of birch–willow forests as well as a number of herbaceous forest plants. Thus the question arises as to whether long-distance dispersal or fragmentation, following climatic changes and human interference, are more plausible explanations for such a pattern. Analysis of current plant distribution patterns lead to conclusions which are corroborated by zoological surveys of the Gobi Altay: During the Holocene, dark taiga forests apparently existed approximately 600 km to the southeast of their present range, and pollen analysis and charcoal remains provide evidence of a forest decline during the Subboreal time period. The presence of humans during these environmental changes is highly probable as pollen indicating human presence was found. Thus, it is assumed that humans at least contributed to the subboreal forest decline and the spreading of sagebrush and pastures. Moreover we cannot rule out with certainty that disjunctions of forest flora between the Gobi Altay and the forests of north-eastern Tibet are indicative of migration through the present North China desert, as forests may have partly replaced deserts during the moister periods of the Holocene. This multidisciplinary approach implies a mid-Holocene and subboreal scenario, which is new for Central Asia and more in accordance with the environmental history of the Holocene in the western desert belt of the Old World.     

Integrating conservation and development: effective trade-offs between biodiversity and cost in the selection of protected areas

Strategies are needed for reconciling competing demands at the regional level when areas are to be selected for protection and there are associated costs, possibly equivalent to forgone development opportunties. As an alternative to the fixed scaling (or weighting) of costs and benefits required by cost-benefit analysis, multi-criteria analyses allow the exploration of alternative weightings and a summary trade-off curve to determine preferred solutions. For alternative sets of areas, total cost could be plotted against total represented biodiversity, but a more consistent approach should look at trade-off space at the level of individual areas. For a given weighting, an area is assigned protection if and only if its contribution to total biodiversity, CB, exceeds its equivalent cost, EC (in biodiversity units). Because CB for a given area depends on which other areas are also protected, it can be more or less than EC. Here we develop an iterative strategy for selecting areas, such that, for a given weighting, an area is in the final protected set if and only if its final CB value is greater than its EC value. Sensitivity analysis is used to identify those areas that: (1) are assigned protection even when low weight is given to biodiversity, or (2) are not assigned protection even when high weight is given to biodiversity. This approach is applicable in principle to any surrogate measure for biodiversity; here examples are presented in which environmental data are summarized as an environmental space.     

Chilling damage in a changing climate in coastal landscapes of the subtropical zone: a case study from south Florida

Freeze events significantly influence landscape structure and community composition along subtropical coastlines. This is particularly true in south Florida, where such disturbances have historically contributed to patch diversity within the mangrove forest, and have played a part in limiting its inland transgression. With projected increases in mean global temperatures, such instances are likely to become much less frequent in the region, contributing to a reduction in heterogeneity within the mangrove forest itself. To understand the process more clearly, we explored the dynamics of a Dwarf mangrove forest following two chilling events that produced freeze‐like symptoms, i.e., leaf browning, desiccation, and mortality, and interpreted the resulting changes within the context of current winter temperatures and projected future scenarios. Structural effects from a 1996 chilling event were dramatic, with mortality and tissue damage concentrated among individuals comprising the Dwarf forest's low canopy. This disturbance promoted understory plant development and provided an opportunity for Laguncularia racemosa to share dominance with Rhizophora mangle. Mortality due to the less severe 2001 event was greatest in the understory, probably because recovery of the protective canopy following the earlier freeze was still incomplete. Stand dynamics were static over the same period in nearby unimpacted sites. The probability of reaching temperatures as low as those recorded at a nearby meteorological station (≤3 °C) under several warming scenarios was simulated by applying 1° incremental temperature increases to a model developed from a 42‐year temperature record. According to the model, the frequency of similar chilling events decreased from once every 1.9 years at present to once every 3.4 and 32.5 years with 1 and 4 °C warming, respectively. The large decrease in the frequency of these events would eliminate an important mechanism that maintains Dwarf forest structure, and promotes compositional diversity.     

Floral divergence and convergence in the genusPelargonium (Geraniaceae) in southern Africa: Ecological and evolutionary considerations

Based on field observations and a survey of the available literature, the functional and evolutionary significance of floral characters ofPelargonium is investigated in relation to a recent infrageneric re-classification. Most of the 208Pelargonium taxa (recognized as species, subspecies or varieties) involved show bee and long-proboscid hovering fly pollination syndromes (about 60% and 25%, respectively), only 7% of the taxa are pollinated by butterflies, some 2 to 4% by hawkmoths and presumably 1% by birds. The heterogeneity ofPelargonium in terms of structural blossom types and pollination syndromes indicates an independent and repeated evolution of convergent flower morphs in the genus and even in sections.     

Buffer zones for forest reserves: opinions of land owners and conservation value of their forest around nature reserves in southern Sweden

Buffer zones around reserves are often suggested, but have rarely been evaluated. We examined their design for small forest reserves (5–225 ha), where buffer zones (200 m wide) would protect the reserves and reduce negative edge effects. The potential buffer zones could be partly protected, but remain as private land. Alternatively, the state may buy land outside reserves (to be included in reserves). To consider opinions of forest owners, we interviewed 33 private forest owners in potential buffer zones of reserves. The respondents were weakly positive to conservation, but disliked a state reserve on their land, or a buffer zone where 50% of the forest would be protected without compensation; however, with compensation the majority of them were neutral or positive to such a buffer zone. In a choice between buffer zone or reserve bought by the state, the great majority of the respondents chose the buffer zone (compensation paid, land still private). We found no relationships between opinions of respondents and conservation values of their forests (densities of old and dead trees), but older owners had forests of higher value. The forest in the potential buffer zones had higher conservation value than other non-protected forests in southern Sweden. Thus, buffer zones may be valuable, and we suggest they are created in cooperation with local residents where this is possible.     

Anurans of a subtropical montane forest in northwestern Argentina: ecological survey and a proposed list of species of conservation concern

The species composition, reproductive ecology, and patterns of activitywere determined for an anuran assemblage of an area of subtropical montaneforest in northwest Argentina. Twenty-four species were recorded at ParqueNacional Calilegua, Province of Jujuy. This study reflects a 75% increase in thenumber of species reported in previous surveys. Most species inhabiting the parkare mainly from adjacent Chacoan regions and only six taxa are known to beendemic from montane forest areas. Most species are aquatic breeders, and theabsence of many forest reproductive modes is noticeable. Although baselineinformation to compare former community composition was lacking, comparisonsbased on museum specimens revealed no evidence of local population extinctions.Immediate intensive monitoring is needed to quantitatively address amphibianpopulation fluctuations and to examine the effectiveness of present-day montaneforest protection. Although long-term population monitoring and documentation ofspecies declines is lacking, I propose a list of seven species of conservationconcern in order to assist and promote future monitoring programs.     

Avian rarity in ten cloud-forest communities in the Andes of Ecuador: implications for conservation

Avian rarity was investigated in ten high-altitude cloud forests in the Andes of Ecuador. Data on species compositions and abundances were obtained by a fully standardized method (standardization for area, altitude, habitat, effort and seasonality). The rare species were isolated from rank-abundance plots on the basis of the quartile definition of rarity. A positive correlation between mean abundances of species and number of sites occupied suggests that high-altitude bird species classified rare by abundance generally can also be classified rare by range. However, it is necessary to be cautious using this result in ranking conservation priorities since the generality is not obeyed by all species. Within the two abundance classes (contains one and two individuals, respectively) represented among the rare species, the one-individual class had significantly more species than the two-individual class. The quantitative rarity of taxa and ecological groupings produced similar results for all sites, while pairwise similarity of rare species between sites was very low. Together with the difficulty of identifying species that are truly rare by abundance, these results imply that sites selected for conservation preferably should be based upon a qualitative evaluation of lists of species referred to vulnerability categories such as endemic, restricted-range, CITES or IUCN threatened/near-threatened species. However, it is necessary also to incorporate other aspects of biodiversity to cover a full range of biotic diversity.