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Restricted Distribution (restricted + distribution)
Selected AbstractsStatus of the crucian carp, Carassius carassius (L.), in the UKFISHERIES MANAGEMENT & ECOLOGY, Issue 4 2000A. Wheeler Summary The crucian carp, Carassius carassius (L.), is a small fish of restricted distribution in the UK, which is probably only native to central and eastern England. The crucian carp is endemic to northern Europe. It has been widely confused with the introduced and congeneric goldfish, Carassius auratus (L.), and forms hybrids with that species and the introduced Cyprinus carpio L. The status of this fish has become confused with the presence of the congener and its hybrids, and it is now thought to be less frequent in occurrence than formerly. [source] Is competition important to arctic zooplankton community structure?FRESHWATER BIOLOGY, Issue 9 2004Andrew R. Dzialowski Summary 1. Daphnia pulex and Daphnia middendorffiana are commonly found in the Toolik Lake region of arctic Alaska. These two species are very similar morphologically, although their natural distributions differ markedly: D. pulex is restricted to shallow ponds, while D. middendorffiana is widely distributed and found in a variety of ponds and lakes. We compared the reproductive capabilities of D. pulex and D. middendorffiana grown under similar resource conditions and in the absence of the invertebrate predator Heterocope septentrionalis. In situ life table and mesocosm experiments were conducted in Toolik Lake and Dam Pond, habitats that have historically contained natural populations of D. middendorffiana, but never D. pulex. 2. Daphnia pulex exhibited a significantly higher net growth rate than D. middendorffiana in both life table and mesocosm experiments although D. pulex has never been found in either Toolik Lake or Dam Pond. Daphnia middendorffiana exhibited a negative net growth rate in Dam Pond, which had lower resource levels then Toolik Lake. Therefore, the smaller D. pulex appears to have a lower food threshold concentration than the larger D. middendorffiana. 3. Our results indicate that D. pulex is a superior resource competitor in the Toolik Lake region. These results combined with distributional patterns suggest that the restricted distribution of D. pulex in these arctic lakes and ponds cannot be explained by resource competition alone. We suggest that in the presence of H. septentrionalis, predation is an important factor structuring arctic zooplankton communities in the Toolik Lake region. [source] Aquatic Coleoptera Distribution and Environmental Relationships in a Large Patagonian RiverINTERNATIONAL REVIEW OF HYDROBIOLOGY, Issue 5 2006María Laura Miserendino Abstract The benthic coleopteran assemblages of the Chubut River basin were studied in order to assess the main factors affecting species composition and distribution along the upper, middle and lower catchments. A total of 13 sampling sites were selected and sampled seasonally. Eight taxa and 1,601 individuals were collected during the study. Richness was higher in the main channel of Chubut River at the upper basin than at the middle basin. Beetles were completely absent at the lower basin. Mean monthly density per sites varied from 0 to 85 ind m,2. Stethelmis kaszabi had a more restricted distribution whereas Hemiosus dejeanii, Austrelmis sp. and Austrolimnius spp. were more frequent and abundant. Austrelmis sp. appears as the most tolerant species, especially to higher TSS, ammonia, and conductivity values. Luchoelmis cekalovici was absent in stations associated with urban areas. A Canonical Correspondence Analysis shows that conductivity, total suspended solids, wet width, water temperature and pH were the most important variables structuring beetle assemblages. Land use related variables such as NH4, TP, and NO3 were less important but still significant. An increase in TSS affected negatively the coleopteran community; this could be related to both hydrogeological characteristics and agricultural activities (including overgrazing). This is the first approach to the knowledge of the ecological range of distribution of the coleopteran species in Patagonian rivers. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Australian biogeographical connections and the phylogeny of large genera in the plant family MyrtaceaeJOURNAL OF BIOGEOGRAPHY, Issue 7 2003Pauline Y. Ladiges Abstract Aim To compare the phylogeny of the eucalypt and melaleuca groups with geological events and ages of fossils to discover the time frame of clade divergences. Location Australia, New Caledonia, New Guinea, Indonesian Archipelago. Methods We compare published molecular phylogenies of the eucalypt and melaleuca groups of the plant family Myrtaceae with geological history and known fossil records from the Cretaceous and Cenozoic. Results The Australasian eucalypt group includes seven genera, of which some are relictual rain forest taxa of restricted distribution and others are species-rich and widespread in drier environments. Based on molecular and morphological data, phylogenetic analyses of the eucalypt group have identified two major clades. The monotypic Arillastrum endemic to New Caledonia is related in one clade to the more species-rich Angophora, Corymbia and Eucalyptus that dominate the sclerophyll vegetation of Australia. Based on the time of rifting of New Caledonia from eastern Gondwana and the age of fossil eucalypt pollen, we argue that this clade extends back to the Late Cretaceous. The second clade includes three relictual rain forest taxa, with Allosyncarpia from Arnhem Land the sister taxon to Eucalyptopsis of New Guinea and the eastern Indonesian archipelago, and Stockwellia from the Atherton Tableland in north-east Queensland. As monsoonal, drier conditions evolved in northern Australia, Arnhem Land was isolated from the wet tropics to the east and north during the Oligocene, segregating ancestral rain forest biota. It is argued also that the distribution of species in Eucalyptopsis and Eucalyptus subgenus Symphyomyrtus endemic in areas north of the stable edge of the Australian continent, as far as Sulawesi and the southern Philippines, is related to the geological history of south-east Asia-Australasia. Colonization (dispersal) may have been aided by rafting on micro-continental fragments, by accretion of arc terranes onto New Guinea and by land brought into closer proximity during periods of low sea-level, from the Late Miocene and Pliocene. The phylogenetic position of the few northern, non-Australian species of Eucalyptus subgenus Symphyomyrtus suggests rapid radiation in the large Australian sister group(s) during this time frame. A similar pattern, connecting Australia and New Caledonia, is emerging from phylogenetic analysis of the Melaleuca group (Beaufortia suballiance) within Myrtaceae, with Melaleuca being polyphyletic. Main conclusion The eucalypt group is an old lineage extending back to the Late Cretaceous. Differentiation of clades is related to major geological and climatic events, including rifting of New Caledonia from eastern Gondwana, development of monsoonal and drier climates, collision of the northern edge of the Australian craton with island arcs and periods of low sea level. Vicariance events involve dispersal of biota. [source] Immunohistological analysis of transglutaminase factor XIIIA expression in mouse embryonic growth plateJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 3 2002M. V. Nurminskaya Abstract Previously we demonstrated the expression of Factor XIIIA (FXIIIA), a coagulation transglutaminase, in avian embryonic growth plate. To explore whether FXIIIA is also expressed by chondrocytes of the mammalian cartilage anlagen of bones, we analyzed the mouse embryonic growth plate by immunostaining using anti-FXIIIA antibodies developed against human and chicken proteins. We revealed the expression of FXIIIA in the epiphyseal growth plate, where FXIIIA appears first intracellularly in the zone of proliferation/maturation, and remains intra- and extracellularly throughout the hypertrophic zone. Externalization of FXIIIA occurs before mineralization. Transglutaminase activity was assayed in organ cultures using rhodamine-labeled synthetic substrate Pro,Val,Lys,Gly. Enzymatic activity shows a restricted distribution in cartilage and correlates with FXIIIA expression pattern, suggesting that cartilagenous transglutaminase activity is due, at least partially, to the FXIIIA isoform. We conclude, that coagulation factor FXIIIA is expressed by chondrocytes of embryonic mouse long bone cartilages in a strictly regulated pattern, which correlates with chondrocyte differentiation and matrix mineralization. © 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved. [source] DEPOSITIONAL ENVIRONMENT AND DIAGENESIS OF THE EOCENE JDEIR FORMATION, GABES-TRIPOLI BASIN, WESTERN OFFSHORE, LIBYAJOURNAL OF PETROLEUM GEOLOGY, Issue 4 2000J. M. Anketell The late Ypresian (early Eocene) Jdeir Formation was deposited in the Mesozoic-Cenozoic Gabes-Tripoli Basin, offshore Libya. The basin developed on the northern passive margin of the African Plate and was relatively unstable being affected by syn-sedimentary tectonic movements. Deposition was coeval with a relative rise of sea-level and the subsequent highstand. A lower, thinly-developed nummulitic bank facies with restricted distribution records the transgressive event and is succeeded by more micritic sediments that record the time of maximum flooding. The succeeding sea-level highstand is represented by a thick, and widely developed, progradational-aggradational nummulitic sequence that displays lateral changes across WE-ESE trending facies belts. Three major lithofacies are recognized in the Jdeir Formation: Nummulites packstone-grainstone, Alveolina-Orbitoliteswackestone-packtone, andFragmental-Discocyclina-Assilina wackestone-packstone, depositedin bank, back-bank, and fore-bank environments, respectively. The formation passes to the NNE into the pelagic lithofacies of the Hallab Formation; landward, to the south, it passes into shoreline evaporitic facies of the Taljah Formation. The lithofacies were structurally controlled by contemporaneous and/or syndepositional tectonic movements, with nummulitic facies tending to develop on uplifted areas. Petrographic and petrophysical studies indicate that porosity in the Jdeir Formation is controlled by depositional environment, tectonic setting and diagenesis. The combined effects of salt tectonics, a major unconformity at the top of the formation and meteoric diagenesis have produced excellent-quality reservoir facies at the Bouri oilfield and in other areas. Porosity is highest in the nummulitic bank facies and lowest in the Alveolina-Orbitolites micrite facies. Good to excellent reservoir quality occurs in the upper part of the nummulitic packstone-grainstone facies, especially where these sediments overlie structurally high areas. High rates of dissolution found at the crests of domes and anticlines suggest that early diagenetic processes and features are, in part, structurally controlled. Future exploration success will depend on investigation of similar structures within the Gabes-Tripoli Basin. Both porosity initiation and preservation are related to early depositional and diagenetic processes. The wide time-gap between hydrocarbon generation and reservoir formation points to the role of the seal in porosity preservation and rules out the assumption that early emplacement of oil had preserved the porosity. [source] Endemic regions of the vascular flora of the peninsula of Baja California, MexicoJOURNAL OF VEGETATION SCIENCE, Issue 3 2007Hugo Riemann Abstract Question: Can we recognize areas of high endemism and high endemic richness, using data from collections, and what are the ecological variables that best explain these areas? Location: Peninsula of Baja California, Mexico. Methods: We analysed the distribution of 723 endemic vascular plants species along the peninsula of Baja California and neighbouring islands distributed in 218 cartographic cells 15' x 20' in size. By means of a residual analysis, we identified areas of significantly high endemic species richness, and we calculated the degree of endemicity (or rarity) in each cell by giving to each species a weight factor inversely proportional to the land area it covers. Results: Nine regions of high-endemicity and/or high endemic species richness were found. Discussion and conclusions: The analyses of rarity and endemic species richness showed two contrasting scenarios: High endemicity values in oceanic and sky islands accounts for a high number of species with a restricted distribution, promoted most likely by genetic isolation and high environmental heterogeneity. High endemic richness along the peninsular coast is related to ecotonal transition along vegetation types. After correcting for collection effort (i.e. the number of specimens collected within a cell), we found the phytogeographic region and altitudinal heterogeneity to be the variables that best predicted endemic richness. Both high endemism and high endemic richness have distinct geographic patterns within our study region. The nine endemic regions provide elements for priority definitions in future conservation programs. [source] Molecular phylogenetics of the Macaronesian-endemic genus Bystropogon (Lamiaceae): palaeo-islands, ecological shifts and interisland colonizationsMOLECULAR ECOLOGY, Issue 4 2005JENNIFER L. TRUSTY Abstract A molecular phylogenetic study of Bystropogon L'Hèr. (Lamiaceae) is presented. We performed a cladistic analysis of nucleotide sequences of the internal transcribed spacers (ITS), of the nuclear ribosomal DNA, and of the trnL gene and trnL-trnF intergenic spacer of the chloroplast DNA. Bystropogon odoratissimus is the only species endemic to the Canary Islands that occurs in the three palaeo-islands of Tenerife. This species is not part of an early diverging lineage of Bystropogon and we suggest that it has a recent origin. This phylogenetic pattern is followed by most of the species endemic to the palaeo-islands of Tenerife. The two sections currently recognized in Bystropogon form two monophyletic groups. Taxa belonging to the section Bystropogon clade show interisland colonization limited to the Canary Islands with ecological shifts among three ecological zones. Taxa from the section Canariense clade show interisland colonization both within the Canary Islands and between the Canary Islands and Madeira. Speciation events within this clade are mostly limited to the laurel forest. The genus has followed a colonization route from the Canaries towards Madeira. This route has also been followed by at least five other plant genera with species endemic to Macaronesia. Major incongruences were found between the current infrasectional classification and the molecular phylogeny, because the varieties of Bystropogon origanifolius and Bystropogon canariensis do not form two monophyletic groups. The widespread B. origanifolius appears as progenitor of the other species in section Bystropogon with a more restricted distribution. [source] Phylogeography and population structure of an ecotonal marsupial, Bettongia tropica, determined using mtDNA and microsatellitesMOLECULAR ECOLOGY, Issue 12 2000L. C. Pope Abstract The northern bettong, Bettongia tropica, is an endangered species of Potoroidae with a restricted distribution in the wet tropics of north Queensland, Australia. The species is only found within a thin strip of sclerophyll forest along the western margin of rainforest. This tight association with rainforest boundaries is predicted to have resulted in population isolation as rainforest contracted during the Pleistocene, though some have proposed that the northern bettong was not present in the wet tropics until the late Pleistocene. The dispersal ability of the species, and of the family, is not known. This study examined gene flow among populations within areas of continuous habitat complemented by a broader analysis of phylogeography. Individuals trapped at each of the four known regions (one region was subsampled at three different sites), were sequenced for 547 base pairs of the mitochondrial DNA (mtDNA) control region and typed for seven microsatellite loci. The mtDNA phylogeny showed congruence with a biogeographical hypothesis, a relatively deep split suggesting historical isolation in separate northern and southern refugia. The two divergent clades were both present within the Lamb Range, indicating an expansion from these refuges and subsequent admixture at one site. mtDNA allele frequencies indicated relatively limited gene flow within the Lamb Range over distances as short as nine km. Tests of population divergence using microsatellites (FST and assignment tests) strongly supported this result. A molecular signal indicative of a recent bottleneck was unexpectedly detected in one of the Lamb Range subpopulations. This lead us to examine the behaviour of the statistics used in this bottleneck test under a linear stepping-stone model with varying migration rates. We found that it may be more difficult to detect molecular signatures for recent bottlenecks under conditions of very low migration rates than for isolated populations and, conversely, that ,false' bottleneck signatures may be observed at higher migration rates. The Lamb Range FST estimate clearly fell within the category of potentially ,false' bottleneck signals. Despite relatively limited gene flow, evidence for asymmetric dispersal suggests more complicated population dynamics than a simple linear stepping-stone model. [source] Eighteen microsatellite loci in Salix arbutifolia (Salicaceae) and cross-species amplification in Salix and Populus speciesMOLECULAR ECOLOGY RESOURCES, Issue 4 2009TAKESHI HOSHIKAWA Abstract Salix arbutifolia is a riparian dioecious tree species that is of conservation concern in Japan because of its highly restricted distribution. Eighteen polymorphic loci of dinucleotide microsatellites were isolated and characterized. Among these, estimates of the expected heterozygosity ranged from 0.350 to 0.879. Cross-species amplification was successful at 9,13 loci among six Salix species and at three loci in one Populus species. [source] The genus Leptophytum (Melobesioideae, Corallinales, Rhodophyta) in NW SpitsbergenNORDIC JOURNAL OF BOTANY, Issue 4 2004Athanasios Athanasiadis Three species of the genus Leptophytum, viz. the generitype L. laeve, L. foecundum and the new Arctic endemic L. jenneborgii nov. sp. are described from localities in NW Spitsbergen. A fourth species, related to L. laeve, may also be present and its status requires further comparative studies with Lithothamnion tenue described from western Greenland. Leptophytum jenneborgii is restricted to sublittoral sites around Vasahalvøya, between 8 and 30 m depth growing on hard substrates (usually on Lithothamnion glaciale) and forming encrusting to foliose thalli up to 10 cm in diameter. New lamellae develop in an unattached-superimposed pattern, overgrowing the parent thallus, so that individuals can reach at least 1.5 cm in thickness. Thallus organization is dorsiventral, with a noncoaxial hypothallium (producing rare patches of coaxial cells) and an ascending perithallium with short subepithallial and flattened epithallial cells. Multiporate conceptacles have convex or flattened roof and develop specialized (thinner-wider) pore cells lining the canals. This character combination supports a position in the genus Leptophytum, as recently emended by Athanasiadis & Adey (2006), and simultaneously distinguishes L. jenneborgii from its Arctic and North Atlantic congeners. Like Leptophytum arcticum nov. comb., that is only known from Uddebay on the east coast of Novaja Zemlya, L. jenneborgii shows a restricted distribution on the presumed north periphery of maximum ice cover during the latest glaciation. It is suggested that these two species represent the first evidence of algal glacial survivals in this part of the Arctic. [source] Characterization of cis elements of the probasin promoter necessary for prostate-specific gene expression,THE PROSTATE, Issue 9 2010JianFeng Zhang Abstract BACKGROUND The androgen-regulated probasin (PB) promoter has been used extensively to target transgenes to the prostate in transgenic mice; however, limited data exist on the mechanism that dictates prostate-specific gene expression. Tissue-specific gene expression involves synergistic effects among transcription factors associated in a complex bound to cis -acting DNA elements. METHODS Using comprehensive linker scan mutagenesis, enzyme mobility shift and supershift assays, chromatin immunoprecipitation, and transgenic animal studies, we have extensively characterized the prostate-specific PB promoter. RESULTS We identified a series of nonreceptor transcription factors that are bound to the prostate-specific rat PB promoter. These factors include several ubiquitously distributed proteins known to participate in steroid receptor-mediated transcription. In addition, we identified two tissue-specific DNA elements that are crucial in directing prostate-specific PB expression, and confirmed the functional importance of both elements in transgenic animal studies. These two elements are functionally interchangeable and can be bound by multiple protein complexes, including the forkhead transcription factor FoxA1, a "pioneer factor" that has a restricted distribution to some cells type that are ectoderm and endoderm in origin. Using transgenic mice, we further demonstrate that the minimal PB promoter region (,244/,96,bp) that encompasses these tissue-specific elements results in prostate-specific gene expression in transgenic mice, contains androgen receptor and FoxA1-binding sites, as well as ubiquitous transcription factor binding sites. CONCLUSION We propose that these sequence-specific DNA-binding proteins, including tissue-restricted and ubiquitous factors, create the first level of transcriptional control, which responds to intracellular pathways that directs prostate-specific gene expression. Prostate 70: 934,951, 2010. © 2010 Wiley-Liss, Inc. [source] Complex habitat requirements and conservation needs of the only extant Baroniinae swallowtail butterflyANIMAL CONSERVATION, Issue 3 2004Jorge L. León-Cortés The unique butterfly species, Baronia brevicornis, perhaps the oldest taxon in the Papilionidae, is known to have a very restricted distribution in Mexico. Populations are restricted to southern Mexico in deciduous scrub forest where its host-plants, Acacia trees (Leguminosae), are common and widespread. Little is known of the conservation implications of its relationship with its host trees. We recorded fine scale population data for larval and adult B. brevicornis in 22 km2 of fragmented landscape in southern Mexico. Habitat associations determined from over 1319 transect walks reveal that B. brevicornis exhibited an extremely localised distribution, occupying < 1% of the study area and being mostly associated with Acacia woodlots. Detailed analyses of habitat requirements for larva and/or adult B. brevicornis suggest that it lays its eggs on Acacia pennatula and A. macracantha (two newly recorded larval host-plants), that eggs were laid disproportionately on Acacia trees with long branches (,2= 17.7, P < 0.001) and that the probability of finding adult B. brevicornis between occupied and un-occupied Acacia woodlots increased with host-plant density (,2= 18.4, P < 0.001). The results of this study suggest that conservation recommendations for B. brevicornis must consider the condition of the Acacia habitat network, given that Acacia is mostly associated with human-managed grazing systems. Effective conservation will require the establishment of connected networks of patches where natural dynamics can produce new habitats, as well as the creation of new habitats within colonisation distance. This research provides a rare case study of conservation biology of a Neotropical insect, emphasising the importance of using ecological information to provide management recommendations. [source] ,Damsel in distress'- The tale of Miss Kerala, Puntius denisonii (Day), an endemic and endangered cyprinid of the Western Ghats biodiversity hotspot (South India)AQUATIC CONSERVATION: MARINE AND FRESHWATER ECOSYSTEMS, Issue 1 2009Rajeev Raghavan Abstract 1.Denison's Barb, Puntius denisonii (Day) is an endemic and endangered cyprinid fish of the Western Ghats biodiversity hotspot in peninsular India, which is the focus of an organized yet undocumented fishery targeting juveniles for the international aquarium trade. 2.Research on P. denisonii has been very limited and there has been no systematic effort to assess and monitor their abundance, distribution and populations. 3.Anecdotal and circumstantial evidence indicates a highly restricted distribution, low abundance, declining populations, low catch per unit effort and increasing market prices, providing evidence of an impending conservation crisis and the need for urgent management of wild stocks. 4.This paper reviews current knowledge, provides results from the authors' field study and suggests priorities for conservation and management actions for P. denisonii in the streams of Kerala. Copyright © 2008 John Wiley & Sons, Ltd. [source] Inhibition of fatty acid amide hydrolase by kaempferol and related naturally occurring flavonoidsBRITISH JOURNAL OF PHARMACOLOGY, Issue 2 2008L Thors Background and purpose: Recent studies have demonstrated that the naturally occurring isoflavone compounds genistein and daidzein inhibit the hydrolysis of anandamide by fatty acid amide hydrolase (FAAH) in the low micromolar concentration range. The purpose of the present study was to determine whether this property is shared by flavonoids. Experimental approach: The hydrolysis of anandamide in homogenates and intact cells was measured using the substrate labelled in the ethanolamine part of the molecule. Key results: Twenty compounds were tested. Among the commonly occurring flavonoids, kaempferol was the most potent, inhibiting FAAH in a competitive manner with a Ki value of 5 ,M. Among flavonoids with a more restricted distribution in nature, the two most active toward FAAH were 7-hydroxyflavone (IC50 value of 0.5,1 ,M depending on the solvent used) and 3,7-dihydroxyflavone (IC50 value 2.2 ,M). All three compounds reduced the FAAH-dependent uptake of anandamide and its metabolism by intact RBL2H3 basophilic leukaemia cells. Conclusions and implications: Inhibition of FAAH is an additional in vitro biochemical property of flavonoids. Kaempferol, 7-hydroxyflavone and 3,7-dihydroxyflavone may be useful as templates for the synthesis of novel compounds, which target several systems that are involved in the control of inflammation and cancer. British Journal of Pharmacology (2008) 155, 244,252; doi:10.1038/bjp.2008.237; published online 16 June 2008 [source] Projection of diffusions on submanifolds: Application to mean force computationCOMMUNICATIONS ON PURE & APPLIED MATHEMATICS, Issue 3 2008Giovanni Ciccotti We consider the problem of sampling a Boltzmann-Gibbs probability distribution when this distribution is restricted (in some suitable sense) on a submanifold , of ,n implicitly defined by N constraints q1(x) = , = qN(x) = 0 (N < n). This problem arises, for example, in systems subject to hard constraints or in the context of free energy calculations. We prove that the constrained stochastic differential equations (i.e., diffusions) proposed in [7, 13] are ergodic with respect to this restricted distribution. We also construct numerical schemes for the integration of the constrained diffusions. Finally, we show how these schemes can be used to compute the gradient of the free energy associated with the constraints. © 2007 Wiley Periodicals, Inc. [source] Range size, taxon age and hotspots of neoendemism in the California floraDIVERSITY AND DISTRIBUTIONS, Issue 3 2010Nathan J. B. Kraft Abstract Aim, Sustaining biological diversity requires the protection of the ecological, evolutionary and landscape-level processes that generate it. Here, we identify areas of high neoendemism in a global diversity hotspot, the California flora, using range size data and molecular-based estimates of taxon age. Location, California, USA. Methods, We compiled distribution and range size data for all plant taxa endemic to California and internal transcribed spacer (ITS)-based age estimates for 337 putative neoendemics (15% of the endemic flora). This information was combined to identify areas in the state with high proportions of young and restricted-range taxa. We overlaid the distribution of neoendemic hotspots on maps of currently protected lands and also explored correlations between our diversity measures and climate. Results, The central coast of California, the Sierra Nevada and the San Bernardino Range contained endemics with the most restricted distributions on average, while areas in the Desert and Great Basin provinces found within the state were composed of the youngest neoendemics on average. Diversity measures that took age and range size into account shifted the estimate of highest endemic diversity in the state towards the Desert and Great Basin regions relative to simple counts of endemic species richness. Our diversity measures were poorly correlated with climate and topographic heterogeneity. Main conclusions, Substantial portions of California with high levels of plant neoendemism fall outside of protected lands, indicating that additional action will be needed to preserve the geographic areas apparently associated with high rates of plant diversification. The neoendemic flora of the deserts appears particularly young in our analyses, which may reflect the relatively recent origin of desert environments within the state. [source] Testing abundance-range size relationships in European carabid beetles (Coleoptera, Carabidae)ECOGRAPHY, Issue 5 2003D. Johan Kotze Four of the eight hypotheses proposed in the literature for explaining the relationship between abundance and range size (the sampling artifact, phylogenetic non-independence, range position and resource breadth hypotheses) were tested by using atlas data for carabid beetles (Coleoptera, Carabidae) from Belgium, Denmark and the Netherlands. A positive relationship between abundance and partial range size was found in all three countries, and the variation in abundance was lower for widespread species. Analysis of the data did not support three of the proposed hypotheses, but did support the resource breadth hypothesis (species having broader environmental tolerances and being able to use a wider range or resources will have higher local densities and be more widely distributed than more specialised species). Examination of species' characteristics revealed that widespread species are generally large bodied, generalists (species with wide niche breadths occurring in a variety of habitat types) and are little influenced by human-altered landscapes, while species with restricted distributions are smaller bodied, specialists (species with small niche breadths occurring in only one or two habitat types), and favour natural habitat. Landscape alteration may be an important factor influencing carabid abundance and range size in these three countries with a long history of human-induced environmental changes. [source] Taxonomic revision of Mecyclothorax Sharp (Coleoptera, Carabidae) of Hawaii Island: abundant genitalic variation in a nascent island radiationMITTEILUNGEN AUS DEM MUSEUM FUER NATURKUNDE IN BERLIN-DEUTSCHE ENTOMOLOGISCHE ZEITSCHRIFT, Issue 1 2008James K. Liebherr Abstract The Hawaii Island fauna of Mecyclothorax Sharp, 1903 is taxonomically revised and found to comprise 30 species, 18 newly described: M. gagnei sp. n., M. nitidus sp. n., M. maunakukini sp. n., M. punakukini sp. n., M. kaukukini sp. n., M. perivariipes sp. n., M. aa sp. n., M. giffini sp. n., M. hephaestus sp. n., M. funebris sp. n., M. granulipennis sp. n., M. rufipennis sp. n., M. blackburnianus sp. n., M. swezeyi sp. n., M. sinuosus sp. n., M. williamsi sp. n., M. purpuripennis sp. n., and M. footei sp. n. New synonymies include: Mecyclothorax parvus Britton, 1948 = M. subunctus (Perkins), 1917; Thriscothorax munroi Perkins, 1937 = M. karschi (Blackburn), 1882; Thriscothorax gracilis Sharp, 1903 and Mecyclothorax proximus Britton, 1948 = M. konanus Sharp, 1903; Mecyclothorax terminalis Britton, 1948 = M. discedens (Sharp) 1903. Mecyclothorax vulcanus (Blackburn) was described from a mixed series, with the cryptic sibling species M. hephaestus newly described to correct the partial misidentification. Species delimitation for the highly variable M. konanus is achieved using a hierarchical analysis based on infraspecifically variable attributes. Extensive male genitalic variation is documented within M. konanus and M. deverilli (Blackburn), and also among the cryptic sibling species pair M. variipes (Blackburn) and M. perivariipes. The observed variation is consistent with various hypotheses of sexual selection, but not with the genitalic lock and key hypothesis. Areas of endemism are tentatively proposed based on the most restricted distributions of Hawaii Island Mecyclothorax, with various flanks of Mauna Kea and Mauna Loa volcanoes identified as distinctive areas. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Rules for macroorganisms applied to microorganisms: patterns of endemism in benthic freshwater diatomsOIKOS, Issue 4 2007Cathy Kilroy Ecological theory based on the dynamic equilibrium model (DEM) suggests that maintenance of endemic taxa is most likely in stable, unproductive environments. We tested whether this hypothesis, which was developed mainly using terrestrial plant examples, held when applied to distributions of benthic freshwater diatoms in New Zealand. Given current arguments for the ubiquity of microbial organisms, with distributions determined mainly by environmental tolerances, demonstration that distinctive taxa with evidently restricted distributions conform to theory applicable to larger organisms would lend support to the opposite point of view, that barriers to dispersal do exist. We examined diatom communities from over 320 sites representing the entire spectrum of freshwater habitats in New Zealand and assessed relative abundances of the main taxa present. Each taxon distinguished was assigned to one of five distribution categories ranging from cosmopolitan to endemic. We derived indices of disturbance and productivity for each site using the River Environment Classification (REC), a GIS-based classification system developed for New Zealand rivers. Diatom taxa assigned to endemic or distinctive potential endemic categories were significantly more abundant in low disturbance sites but occurred across a range of productivities. However, bogs and tarns, both of which fell mainly into low disturbance and productivity classes, were distinctive in supporting relatively high proportions of endemic and potential endemic diatoms. Thus our findings in general conformed to the patterns predicted by the DEM, thereby supporting the role of dispersal limitation in diatoms. At the same time, conformity with the DEM helps to explain the continued coexistence in New Zealand freshwaters of many common and apparently cosmopolitan taxa with endemic diatoms, since the DEM explanation for maintenance of endemism does not rely on geographic isolation of species. [source] Status of galaxiid fishes in Tasmania, Australia: conservation listings, threats and management issuesAQUATIC CONSERVATION: MARINE AND FRESHWATER ECOSYSTEMS, Issue 3 2006Scott A. Hardie Abstract 1.Fish of the family Galaxiidae are restricted to the southern hemisphere where they occupy a diverse array of habitats ranging from over 2000 m in elevation to sea level. Some species are diadromous and, hence, freshwater, estuarine and marine habitats are used during their life-cycle; other species complete their entire life-cycles in freshwater environments. 2.Tasmania has a diverse galaxiid fauna that accounts for 64% of native freshwater fish species found on the island. The Tasmanian galaxiid fauna is characterized by high species richness (5 genera and 16 species), endemism (11 species), restricted distributions, and non-diadromous life histories (11 species). 3.The galaxiid fauna of Tasmania has significant conservation status with 69% of species considered ,threatened'. The conservation status of the fauna is recognized at State, national and international levels. 4.The key threats to galaxiids in Tasmania are exotic species, hydrological manipulations, restricted distributions, general habitat degradation and exploitation of stocks. 5.Although work has recently been undertaken to conserve and manage Tasmanian galaxiid populations, the fauna is still thought to be imperilled. Knowledge gaps that need to be addressed include the biology and ecology of most species (e.g. reproductive biology, life histories, habitat use and requirements) and impacts of habitat manipulations, as well as mechanisms and impacts of interactions with exotic species. Techniques to monitor accurately the status of galaxiid species and their populations need to be developed and the coexistence of some galaxiids with introduced salmonids should also be examined. Copyright © 2005 John Wiley & Sons, Ltd. [source] | |||||||||||||||||||||||||||||||