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Increased air pollution in a number of developing African countries, together with the reports of vegetation damage typically associated with acid precipitation in commercial forests in South Africa, has raised concerns over the potential impacts of acid rain on natural vegetation in these countries. Recalcitrant (i.e. desiccation sensitive) seeds of many indigenous African species, e.g. must germinate shortly after shedding and hence, may not be able to avoid exposure to acid rain in polluted areas. This study investigated the effects of simulated acid rain (rainwater with pH adjusted to pH 3.0 and 4.5 with 70:30, H2SO4: HNO3) on germination, seedling growth and oxidative metabolism in a recalcitrant-seeded African tree species Trichilia dregeana Sond., growing in its natural seed bank. The results suggest that acid rain did not compromise T. dregeana seed germination and seedling establishment significantly, relative to the control (non-acidified rainwater). However, pH 3.0 treated seedlings exhibited signs of stress typically associated with acid rain: leaf tip necrosis, abnormal bilobed leaf tips, leaf necrotic spots and chlorosis, reduced leaf chlorophyll concentration, increased stomatal density and indications of oxidative stress. This may explain why total and root biomass of pH 3.0 treated seedlings were significantly lower than the control. Acid rain also induced changes in the species composition and relative abundance of the different life forms emerging from T. dregeana's natural seed bank and in this way could indirectly impact on T. dregeana seedling establishment success. [ABSTRACT FROM AUTHOR]

Aim While there is a huge macroecological and biogeographical literature addressing endemism, very little has been done to systematically study lineages that are widely distributed across the globe. Our aim here was to list and analyse those lineages of terrestrial tetrapod vertebrates found in 60-90% of the world, loosely termed here as cosmopolitan. Location Global. Methods Two sets of geographical units and three occupancy criteria were used to list, analyse and map cosmopolitan lineages and their sister lineages. Results Among the 83 lineages identified, 2 were represented by amphibians, 9 by reptiles, 13 by mammals, and the remainder by birds, of which 12 were passerines and 47 were non-passerines. All these lineages are present in parts of Southeast Asia, most of them throughout much of Eurasia and Africa, but fewer in South America and very few in Australia. Only three of the lineages (all reptiles) are likely to exemplify vicariance or early dispersal-driven cosmopolitanism, the rest having attained world-wide distribution via extensive, geologically recent dispersal. The distribution of sister lineages indicates that many cosmopolitan lineages probably originated in the savanna regions of Africa, some in Southeast Asia, and fewer in tropical America. Main conclusions Cosmopolitan distributions in tetrapods are primarily the result of dispersal, with large body size and the ability to fly being two key correlates of rapid global colonization. We argue that a cosmopolitan lineage framework in biogeographical and ecological studies could add great depth to the understanding of evolutionary success, and would be highly relevant to the field of invasion biology. [ABSTRACT FROM AUTHOR]

Molecular phylogenetic reconstructions have indicated that Haworthia is not monophyletic. Here we show, using considerably expanded datasets of both chloroplast (trnL-trnF and psbA-trnH intergenic spacers) and nuclear (ITS1) markers that the issue of a polyphyletic Haworthia is more complicated than previously reported. Both parsimony and bayesian analyses of cpDNA and ITS1 produced poorly resolved phylogenies, with little or no support for deeper nodes. Species of Haworthia are placed in three of the four main lineages in the cpDNA phylogeny, while in the ITS1 phylogeny Haworthia species were placed in two of the four main lineages retrieved. The cpDNA phylogeny was incongruent with that obtained from the ITS1 data, and the topology of the combined dataset reflected that obtained from the ITS1 dataset. As species of H. subg. Hexangulares and subg. Robustipedunculares have been reportedly involved in intergeneric hybridizations with other Alooideae, it is postulated that a history of ancient hybridization may account for a polyphyletic Haworthia. Hybridization is also ongoing between species within H. subg. Haworthia, and may be responsible for results indicating that some species in this subgenus are not monophyletic. This hybridization may be facilitated by the lack of effective reproductive barriers. We hypothesize that Haworthia is undergoing a contemporary and explosive radiation in southern Africa, driven in part by local adaptation to relatively fine-grained ecological heterogeneity of soils and microclimate. [ABSTRACT FROM AUTHOR]

The genus Kniphofia, comprising 71 species, has an African-Malagasy distribution, with one species from Yemen. The genus is found predominantly in moist temperate montane grassland and has its centre of diversity in the Drakensberg region of southern Africa. The genus has a complex alpha taxonomy and species relationships are poorly understood. Using a multiple exemplar approach, DNA sequence data from the chloroplast trnT-L spacer and the nuclear internal transcribed spacer region were used in an attempt to resolve phylogenetic relationships: Five cpDNA lineages were recovered, the geographic distributions of which correspond well with previously identified Afromontane centres of diversity and endemism. The data revealed that several morpho-species were non-monophyletic, and this, together with short branch lengths and many identical sequences within each of the five lineages, suggests a recent radiation. We additionally propose that hybridisation and! or incomplete lineage sorting may also account for this result. The nrlTS region was largely uninformative as many taxa and samples had identical sequences. We hypothesise that Kniphofia experienced periods of range expansion, secondary contact and hybridisation during Pleistocene glacial periods, followed by contraction, fragmentation and isolation in montane refugia during the warmer interglacial periods. [ABSTRACT FROM AUTHOR]

Aim The genus Kniphofia contains 71 species with an African–Malagasy distribution, including one species from Yemen. The genus has a general Afromontane distribution. Here we explore whether Kniphofia is a floristic indicator of the Afromontane centre of endemism and diversity. The South Africa Centre of diversity and endemism was explored in greater detail to understand biogeographical patterns. Location Africa, Afromontane Region, southern Africa, Madagascar and Yemen. Methods Diversity and endemism for the genus were examined at the continental scale using a chorological approach. Biogeographical patterns and endemism in the South Africa Centre were examined in greater detail using chorology, phenetics, parsimony analysis of endemicity (PAE) and mapping of range-restricted taxa. Results Six centres of diversity were recovered, five of which are also centres of endemism. Eight subcentres of diversity are proposed, of which only two are considered subcentres of endemism. The South Africa Centre is the most species-rich region and the largest centre of endemism for Kniphofia. The phenetic analysis of the South Africa Centre at the full degree square scale recovered three biogeographical areas that correspond with the subcentres obtained from the chorological analysis. The PAE (at the full degree square scale) and the mapping of range-restricted taxa recovered two and six areas of endemism (AOEs), respectively. These latter two approaches produced results of limited value, possibly as a result of inadequate collecting of Kniphofia species. Only two AOEs were identified by PAE and these are embedded within two of the six AOEs recovered by the mapping of range-restricted taxa. All the above AOEs are within the three subcentres found by chorological and phenetic analysis (at the full degree square scale) for the South Africa Centre. Main conclusions The centres for Kniphofia broadly correspond to the Afromontane regional mountain systems, but with some notable differences. We regard Kniphofia as a floristic indicator of the Afromontane Region sensu lato. In southern Africa, the phenetic approach at the full-degree scale retrieved areas that correlate well with those obtained by the chorological approach. [ABSTRACT FROM AUTHOR]

Herbivory is ubiquitous. Despite being a potential driver of plant distribution and performance, herbivory remains largely undocumented. Some early attempts have been made to review, globally, how much leaf area is removed through insect feeding. Kozlov et al., in one of the most comprehensive reviews regarding global patterns of herbivory, have compiled published studies regarding foliar removal and sampled data on global herbivory levels using a standardized protocol. However, in the review by Kozlov et al., only 15 sampling sites, comprising 33 plant species, were evaluated in tropical areas around the globe. In Brazil, which ranks first in terms of plant biodiversity, with a total of 46,097 species, almost half (43%) being endemic, a single data point was sampled, covering only two plant species. In an attempt to increase knowledge regarding herbivory in tropical plant species and to provide the raw data needed to test general hypotheses related to plant–herbivore interactions across large spatial scales, we proposed a joint, collaborative network to evaluate tropical herbivory. This network allowed us to update and expand the data on insect herbivory in tropical and temperate plant species. Our data set, collected with a standardized protocol, covers 45 sampling sites from nine countries and includes leaf herbivory measurements of 57,239 leaves from 209 species of vascular plants belonging to 65 families from tropical and temperate regions. They expand previous data sets by including a total of 32 sampling sites from tropical areas around the globe, comprising 152 species, 146 of them being sampled in Brazil. For temperate areas, it includes 13 sampling sites, comprising 59 species. Thus, when compared to the most recent comprehensive review of insect herbivory (Kozlov et al.), our data set has increased the base of available data for the tropical plants more than 460% (from 33 to 152 species) and the Brazilian sampling was increased 7,300% (from 2 to 146 species). Data on precise levels of herbivory are presented for more than 57,000 leaves worldwide. There are no copyright restrictions. Please cite this paper when using the current data in publications; the authors request to be informed how the data is used in the publications. [ABSTRACT FROM AUTHOR]