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Aleks Terauds Steven L. Chown Fraser Morgan Helen J. Peat David J. Watts Harry Keys Peter Convey Dana M. Bergstrom 《Diversity & distributions》2012,18(7):726-741
Aim
To present a synthesis of past biogeographic analyses and a new approach based on spatially explicit biodiversity information for the Antarctic region to identify biologically distinct areas in need of representation in a protected area network.Location
Antarctica and the sub‐Antarctic.Methods
We reviewed and summarized published biogeographic studies of the Antarctic. We then developed a biogeographic classification for terrestrial conservation planning in Antarctica by combining the most comprehensive source of Antarctic biodiversity data available with three spatial frameworks: (1) a 200‐km grid, (2) a set of areas based on physical parameters known as the environmental domains of Antarctica and (3) expert‐defined bioregions. We used these frameworks, or combinations thereof, together with multivariate techniques to identify biologically distinct areas.Results
Early studies of continental Antarctica typically described broad bioregions, with the Antarctic Peninsula usually identified as biologically distinct from continental Antarctica; later studies suggested a more complex biogeography. Increasing complexity also characterizes the sub‐Antarctic and marine realms, with differences among studies often attributable to the focal taxa. Using the most comprehensive terrestrial data available and by combining the groups formed by the environmental domains and expert‐defined bioregions, we were able to identify 15 biologically distinct, ice‐free, Antarctic Conservation Biogeographic Regions (ACBRs), encompassing the continent and close lying islands.Main conclusions
Ice‐free terrestrial Antarctica comprises several distinct bioregions that are not fully represented in the current Antarctic Specially Protected Area network. Biosecurity measures between these ACBRs should also be developed to prevent biotic homogenization in the region. 相似文献65.
ABSTRACT: Malaria affects large parts of the developing world and is responsible for almost 800,000 deaths annually. As climates change, concerns have arisen as to how this vector-borne disease will be impacted by changing rainfall patterns and warming temperatures. Despite the importance and controversy surrounding the impact of climate change on the potential spread of this disease, little information exists on the tolerances of several of the vector species themselves. METHODS: Using a ramping protocol (to assess critical thermal limits - CT) and plunge protocol (to assess lethal temperature limits - LT) information on the thermal tolerance of two of Africa's important malaria vectors, Anopheles arabiensis and Anopheles funestus was collected. The effects of age, thermal acclimation treatment, sex and strain (laboratory versus wild adults) were investigated for CT determinations for each species. The effects of age and sex for adults and life stage (larvae, pupae, adults) were investigated for LT determinations. RESULTS: In both species, females are more tolerant to low and high temperatures than males; larvae and pupae have higher upper lethal limits than do adults. Thermal acclimation of adults has large effects in some instances but small effects in others. Younger adults tend to be more tolerant of temperature changes than older age groups. Long-standing laboratory colonies are sufficiently similar in thermal tolerance to field-collected animals to provide reasonable surrogates when making inferences about wild population responses. Differences between these two vectors in their thermal tolerances, especially in larvae and pupae, are plausibly a consequence of different habitat utilization. CONCLUSIONS: Limited plasticity is characteristic of the adults of these vector species relative to others examined to date, suggesting limited scope for within-generation change in thermal tolerance. These findings and the greater tolerance of females to thermal extremes may have significant implications for future malaria transmission, especially in areas of current seasonal transmission and in areas on the boundaries of current vector distribution. 相似文献
66.
White CR Frappell PB Chown SL 《Proceedings. Biological sciences / The Royal Society》2012,279(1742):3616-3621
The effects of body mass and temperature on metabolic rate (MR) are among the most widely examined physiological relationships. Recently, these relationships have been incorporated into the metabolic theory of ecology (MTE) that links the ecology of populations, communities and ecosystems to the MR of individual organisms. The fundamental equation of MTE derives the relation between mass and MR using first principles and predicts the temperature dependence of MR based on biochemical kinetics. It is a deliberately simple, zeroth-order approximation that represents a baseline against which variation in real biological systems can be examined. In the present study, we evaluate the fundamental equation of MTE against other more parameter-rich models for MR using an information-theoretic approach to penalize the inclusion of additional parameters. Using a comparative database of MR measurements for 1359 species, from 11 groups ranging from prokaryotes to mammals, and spanning 16 orders of magnitude in mass and a 59°C range in body temperature, we show that differences between taxa in the mass and temperature dependence of MR are sufficiently large as to be retained in the best model for MR despite the requirement for estimation of 22 more parameters than the fundamental equation of MTE. 相似文献
67.
Procheş S Forest F Veldtman R Chown SL Cowling RM Johnson SD Richardson DM Savolainen V 《Molecular phylogenetics and evolution》2009,51(1):94-99
It has been argued that insect diversity in the Cape is disproportionately low, considering the unusually high plant diversity in this region. Recent studies have shown that this is not the case, but the precise mechanisms linking plant diversity and insect diversity in the Cape are still poorly understood. Here we use a dated genus-level phylogenetic tree of the Cape plants to assess how plant phylogenetic diversity compares with taxonomic diversity at various levels in predicting insect diversity. We find that plant phylogenetic diversity (PD) is a better predictor of insect species diversity that plant species diversity, but the number of plant genera is overall as good a predictor as PD, and much easier to calculate. The relationship is strongest between biomes, suggesting that the relationship between plant diversity and insect diversity is to a large extent indirect, both variables being driven by the same abiotic factors and possibly by common diversification, immigration and extinction histories. However, a direct relationship between plant diversity and insect diversity can be detected at fine scales, at least within certain biomes. Diversity accumulation curves also indicate that the way plant phylogenetic diversity and the number of plant genera increase over spatial scales is most similar to that for insect species; plant species show a greater increase at large spatial scales due to high numbers of local endemics. 相似文献
68.
Air flow rates may confound the investigation and classification of insect gas exchange patterns. Here we report the effects of flow rates (50, 100, 200, 400 ml min−1) on gas exchange patterns in wild-caught Glossina morsitans morsitans from Zambia. At rest, G. m. morsitans generally showed continuous or cyclic gas exchange (CGE) but no evidence of discontinuous gas exchange (DGE). Flow rates had little influence on the ability to detect CGE in tsetse, at least in the present experimental setup and under these laboratory conditions. Importantly, faster flow rates resulted in similar gas exchange patterns to those identified at lower flower rates suggesting that G. m. morsitans did not show DGE which had been incorrectly identified as CGE at lower flow rates. While CGE cycle frequency was significantly different among the four flow rates (p < 0.05), the direction of effects was inconsistent. Indeed, inter-individual variation in CGE cycle frequency exceeded flow rate treatment variation. Using a laboratory colony of closely related, similar-sized G. morsitans centralis we subsequently investigated the effects of temperature, gender and feeding status on CGE pattern variation since these factors can influence insect metabolic rates. At 100 ml min−1 CGE was typical of G. m. centralis at rest, although it was significantly more common in females than in males (57% vs. 43% of 14 individuals tested per gender). In either sex, temperature (20, 24, 28 and 32 °C) had little influence on the number of individuals showing CGE. However, increases in metabolic rate with temperature were modulated largely by increases in burst volume and cycle frequency. This is unusual among insects showing CGE or DGE patterns because increases in metabolic rate are usually modulated by increases in frequency, but either no change or a decline in burst volume. 相似文献
69.
Ricardo Guerra Peixe Marcela Santana Bastos Boechat Alba Lucinia Peixoto Rangel Rh?nia Fran?a Gomes Rosa Maria Luiza Petzl-Erler Lilian MG Bahia-Oliveira 《Memórias do Instituto Oswaldo Cruz》2014,109(1):99-107
The association of single nucleotide polymorphisms (SNPs) in the interferon (IFN)-γ
gene ( IFNG ) with different types of retinal scar lesions
presumably caused by toxoplasmosis were investigated in a cross-sectional
population-based genetic study. Ten SNPs were investigated and after Bonferroni
correction, only the associations between SNPs rs2069718 and
rs3181035 with retinal/retinochoroidal scar lesions type A (most
severe scar lesions) and C (least severe scar lesions), respectively, remained
significant. The associations of two different IFNG SNPs with two
different types of retinal lesions attributable to toxoplasmosis support the
hypothesis that different inflammatory mechanisms underlie the development of these
lesions. The in vitro analysis of IFN-γ secretion by peripheral blood mononuclear
cells stimulated with Toxoplasma gondii antigens was also
investigated. The association between SNP rs2069718 and type A scar
lesions revealed that differential IFN-γ levels are correlated with distinct
genotypes. However, no correlation was observed with IFN-γ secretion levels and the
SNP rs3181035 , which was significantly associated with type C scar
lesions. Our findings strongly suggest that immunogenetic studies of individuals with
congenital or postnatally acquired infection are needed to better understand the role
of IFN-γ and its polymorphisms in the pathogenesis of ocular toxoplasmosis. 相似文献
70.