bluuebunny/crossref_metadata_2025 huggingface dataset:
Eddy response to Southern Ocean climate modes
Authors: Morrow R. , Ward Marshall L. , Hogg Andrew McC. , Pasquet S.
Published: October 2010

Interannual variations in Southern Ocean eddy kinetic energy (EKE) are investigated using 16 years of altimetric data. Circumpolar averages show a peak in EKE from 2000 to 2002, 2–3 years after the peak in the Southern Annular Mode (SAM) index. Although the SAM forcing is in phase around the circumpolar band, we find the EKE response varies regionally. The strongest EKE is in the Pacific, with energy peaks occurring progressively later toward the east. We suggest that this is due to the presence of two climate modes: SAM and ENSO. When strong positive SAM events coincide with La Niña periods, as in 1999, anomalous meridional wind forcing is enhanced in the South Pacific Ocean, contributing to the observed increase in EKE 2–3 years later. When positive SAM events coincide with El Niño periods, as in 1993, the climate modes are in opposition in the South Pacific, leading to a weak EKE response during the mid‐1990s. Numerical modeling supports these observations. By applying different combinations of SAM and ENSO, we can reproduce both the elevated Pacific EKE response to SAM as well as an additional amplification/suppression of EKE during La Niña/El Niño. In general, we find that the EKE response depends on the interplay between wind forcing, topography, and mean flow and produces a strongly heterogeneous distribution in the Southern Ocean.
Trend in stratospheric ozone over tropics
Authors: Jain Meena
Published: October 2010

A statistical analysis of zonal monthly average ozone from solar backscatter ultraviolet in 10° latitude bands over 20°S–20°N for the period November 1978 to December 2008 is performed to find heightwise trend in the tropical stratosphere. A turning point (TP) of January 1999 is found for tropics, whereas a TP of January 1997, attributed to the change in equivalent effective stratospheric chlorine (EESC), was found for midlatitudes in previous studies. The introduction of two more TPs corresponding to the beginning and ending of the effect of Mt. Pinatubo volcanic eruption improves the representation of observed behavior of ozone in the lower (20–30 km) and in the upper (>30 km) stratospheres. The trend in total stratospheric ozone column is small compared to those in lower and upper stratospheric ozone columns during the considered subperiods created by TPs. The values of piecewise trend in the lower and upper stratospheres during the periods 1994–1999 and 1999–2008 are significant. The directions of trend (downward/upward) in the upper and lower stratospheres are opposite, and more conspicuously after January 1999 when the trend in the lower stratosphere decreased in contrast to an increase in the upper stratosphere. The trend at Umkehr layer 5 is almost zero at all times during the period 1978–2008. The timewise variation in the trend is comparatively large between Umkehr layers 2–3 and 7–10. The Eliassen‐Palm‐flux gives negative contribution to ozone in the lower stratosphere and positive contribution in the upper stratosphere, indicating that ozone is affected by transport over tropics.
Annual cycle in co‐located in situ, total‐column, and height‐resolved aerosol observations in the Po Valley (Italy): Implications for ground‐level particulate matter mass concentration estimation from remote sensing
Authors: Barnaba F. , Putaud J. P. , Gruening C. , dell'Acqua A. , Dos Santos S.
Published: October 2010

Remote sensing represents a prospective tool to complement in situ measurements for monitoring particulate matter air pollution. The remotely sensed aerosol metric which is generally related to the in situ measured particulate matter mass concentration (PM) is the aerosol optical thickness (AOT), the vertically integrated aerosol extinction that optically quantifies the aerosol load in the whole atmospheric column. Annual variations in AOT and PM can follow very different patterns, indicating that the AOT‐to‐PM conversion is not straightforward. In the Po Valley, northern Italy, AOT and PM seasonal cycles exhibit a marked phase shift. Making use of aerosol extinction vertical profiles derived from continuous aerosol lidar measurements, we further searched through the AOT‐to‐PM10 relationship in this region. On the basis of a 2‐year (2006–2007) multisensor database, including remote sensing observations from ground and space and in situ measurements, this study: (1) discloses for the first time the height‐resolved seasonal variability of the aerosol optical properties in the Po Valley, (2) demonstrates and quantifies the crucial role of the aerosol vertical distribution in the AOT‐to‐PM relationship in this region, (3) suggests a methodology to rescale AOT to ground‐level aerosol extinction values that correlate with PM concentration and from which PM10 annual average and exceedances frequency of daily limit value can be retrieved within a few percentage points, and (4) highlights that the hygroscopic growth of the particles in the atmosphere is a critical factor for comparing in situ‐measured to remotely sensed aerosol properties.
Effects of acidic processing, transport history, and dust and sea salt loadings on the dissolution of iron from Asian dust
Authors: Hsu Shih‐Chieh , Liu Shaw Chen , Arimoto Richard , Shiah Fuh‐Kwo , Gong Gwo‐Ching , Huang Yi‐Tang , Kao Shuh‐Ji , Chen Jen‐Ping , Lin Fei‐Jan , Lin Chun‐Yao , Huang Jr‐Chun , Tsai Fujung , Lung Shih‐Chun Candice
Published: October 2010

Aerosol particles collected over the East China Sea (ECS) were analyzed for water‐soluble Fe (FeS), total Fe (FeT), and other chemical species. Eight samples were classified as high Asian dust (HAD) on the basis of total Al concentrations ≥1500 ng/m3. Comparisons with low Asian dust (LAD) samples showed that unlike FeT or most other substances, the percentage of FeT soluble in deionized water (%FeS) was lower in the HAD samples. The %FeS in the HAD samples varied with transport pattern and air mass history. As the difference in FeS concentrations between HAD and LAD is relatively small and HAD occurs several days each year, the supply of FeS through dry deposition to the surface ocean may be less sporadic than previously thought. Soluble Fe correlated with non‐sea‐salt sulfate, water‐soluble organic carbon, and nitrate, possibly because of an anthropogenic, relatively soluble, form of Fe or enhanced dissolution caused by reactions with anthropogenic acids. Sea salt loadings evidently have a negative effect on %FeS, presumably due to buffering effects of the salts. Dust concentrations and %FeS followed an inverse power law relationship with a moderate correlation, suggesting that the %FeS may be increased by acid processing during transport as dust loadings gradually decrease.
Convective distribution of tropospheric ozone and tracers in the Central American ITCZ region: Evidence from observations during TC4
Authors: Avery Melody , Twohy Cynthia , McCabe David , Joiner Joanna , Severance Kurt , Atlas Eliot , Blake Donald , Bui T. P. , Crounse John , Dibb Jack , Diskin Glenn , Lawson Paul , McGill Matthew , Rogers David , Sachse Glen , Scheuer Eric , Thompson Anne M. , Trepte Charles , Wennberg Paul , Ziemke Jerald
Published: October 2010

During the Tropical Composition, Clouds and Climate Coupling (TC4) experiment that occurred in July and August of 2007, extensive sampling of active convection in the ITCZ region near Central America was performed from multiple aircraft and satellite sensors. As part of a sampling strategy designed to study cloud processes, the NASA ER‐2, WB‐57 and DC‐8 flew in stacked “racetrack patterns” in convective cells. On July 24, 2007, the ER‐2 and DC‐8 probed an actively developing storm and the DC‐8 was hit by lightning. Case studies of this flight, and of convective outflow on August 5, 2007 reveal a significant anti‐correlation between ozone and condensed cloud water content. With little variability in the boundary layer and a vertical gradient, low ozone in the upper troposphere indicates convective transport. Because of the large spatial and temporal variability in surface CO and other pollutants in this region, low ozone is a better convective indicator. Lower tropospheric tracers methyl hydrogen peroxide, total organic bromine and calcium substantiate the ozone results. OMI measurements of mean upper tropospheric ozone near convection show lower ozone in convective outflow. A mass balance estimation of the amount of convective turnover below the tropical tropopause transition layer (TTL) is 50%, with an altitude of maximum convective outflow located between 10 and 11 km, 4 km below the cirrus anvil tops. It appears that convective lofting in this region of the ITCZ is either a two‐stage or a rapid mixing process, because undiluted boundary layer air is never sampled in the convective outflow.
Coral windows onto seasonal climate variability in the northern Caribbean since 1479
Authors: Kilbourne K. H. , Quinn T. M. , Webb R. , Guilderson T. , Nyberg J. , Winter A.
Published: October 2010

Mean surface ocean conditions in the Caribbean were up to ∼2°C cooler than today at times during the Little Ice Age. The seasonal context for such mean state changes is important for determining the mechanisms involved. We reconstructed surface ocean conditions in southwest Puerto Rico at approximately monthly resolution over eight 4–12 year periods during the last ∼520 years to test if the seasonal cycles of temperature or salinity varied with mean state. We carried out paired analyses of Sr/Ca and δ18O for two coral cores. The δ18O data contained clear annual cycles and were significantly correlated to temperature during the 20th century calibration periods (1993–2004 and 1902–1912, r = 0.73). The Sr/Ca data contained high‐frequency noise that obscured the seasonal cycles, although the centennial variability matched that of the coral δ18O, indicating a common forcing that is likely temperature. The seasonal coral δ18O amplitude averaged 0.60 ± 0.17‰, with none of the periods significantly different from the most recent. The simplest explanation is that the amplitudes of seasonal seawater δ18O and temperature variations were not different from today. Previous work in the southern Caribbean indicates that the Intertropical Convergence Zone was shifted southward or weaker during the Little Ice Age, and we speculate about how this could occur with no apparent affect on seasonality in the northern Caribbean.
Effects of open and closed system oxidation on texture and magnetic response of remelted basaltic glass
Authors: Burgess Katherine , Cooper Reid F. , Bowles Julie A. , Gee Jeffrey S. , Cherniak Daniele J.
Published: October 2010

As part of an experimental and observational study of the magnetic response of submarine basaltic glass (SBG), we have examined, using ion backscattering spectrometry (RBS), transmission and scanning electron microscopy, energy dispersive X‐ray spectrometry, and surface X‐ray diffraction, the textures wrought by the controlled, open and closed system oxidation of glasses prepared by the controlled environment remelting and quenching of natural SBG. Initial compositions with ∼9 wt % FeO* were melted at 1430°C with the oxygen fugacity buffered at fayalite‐magnetite‐quartz; melts were cooled at a rate of 200°C min−1 near the glass transition (Tg = 680°C). In open system experiments, where chemical exchange is allowed to occur with the surrounding atmosphere, polished pieces of glass were reheated to temperatures both below and above Tg for times 1–5000 h; undercooled melts were oxidized at 900°C and 1200°C for 18 and 20 h, respectively. RBS demonstrates unequivocally that the dynamics of open system oxidation involves the outward motion of network‐modifying cations. Oxidation results in formation of a Fe‐, Ca‐, and Mg‐enriched surface layer that consists in part of Ti‐free nanometer‐scale ferrites; a divalent‐cation‐depleted layer is observed at depths >1 μm. Specimens annealed/oxidized above Tg have magnetizations elevated by 1–2 orders of magnitude relative to the as‐quenched material; this does not appear to be related to the surface oxidation. Quenched glass (closed system, i.e., no chemical exchange between sample and atmosphere) exhibits very fine scale chemical heterogeneities that coarsen with time under an electron beam; this metastable amorphous immiscibility is the potential source for the nucleation of ferrites with a wide range of Ti contents, ferrites not anticipated from an equilibrium analysis of the bulk basalt composition.
A regional comparison of particle size distributions and the power law approximation in oceanic and estuarine surface waters
Authors: Buonassissi C. J. , Dierssen H. M.
Published: October 2010

The particle size distribution (PSD) is commonly used in studies of sediment fluxes, phytoplankton dynamics, and optical scattering from particulates, but little is known about the spatial and temporal variability of this parameter. Here, we analyze in situ laser diffraction measurements of the PSD from a variety of estuarine and open ocean systems. The power law or “Junge‐type” distribution provided a good fit to surface ocean particle size distributions measured from 6 to 250μm. PSD slopes ranged from 2.7 to 4.7 with a mean of 3.63. Consistent with theory, high particle slopes (3.78) and low particle concentrations characterized the open ocean waters of the Atlantic and the Southern Ocean. Lower PSD slopes (3.63) and high concentrations were characteristic of estuarine waters. River plumes consistently showed the lowest PSD slopes (3.30) and highest particle concentrations characteristic of larger bloom‐forming phytoplankton and production of particle aggregates. In the North Atlantic, an inverse relationship was found between PSD slope and chlorophyll concentration. Such results follow the biological paradigm that larger phytoplankton are prevalent in bloom conditions and smaller phytoplankton dominate in oligotrophic water. Large temporal variability in PSD was observed in near coastal regions prone to sediment resuspension from storms and tidal flow. Dense sea grass beds consistently had lower particle concentrations compared to surrounding waters due to reductions in current flow and sediment resuspension. Simple power law approximations of particle size distributions can be successfully used to describe and assess particle distributions in a wide array of oceanic and estuarine water types.
Measurements of the local energy balance over a coral reef flat, Heron Island, southern Great Barrier Reef, Australia
Authors: McGowan Hamish A. , Sturman Andrew P. , MacKellar Melissa C. , Wiebe Andrew H. , Neil David T.
Published: October 2010

Coral reefs are thought to face significant threat from global warming due to increased water temperatures and ocean acidity. However, research into the surface energy balance of coral reefs and their associated micrometeorology is rare. Here we present, through a case study approach, the first direct in situ measurements of the surface energy balance of Heron Reef, a small platform coral reef in the southern Great Barrier Reef, Australia. Surface energy exchanges were measured using the eddy covariance method and show that during winter and spring an estimated 80–98% of net radiation goes into heating of the water overlaying the reef and reef substrate. As a result, cloud cover is considered the dominant control on heating of the reef flat environment. Change in cloud cover may therefore significantly affect the thermal environment of coral reefs and their ecology. Sensible and latent heat fluxes reached their highest values during wintertime advection of dry and cool continental air blowing from mainland Australia. This resulted in a net loss of energy from the reef flat and a decreasing trend in water temperature. Turbulent fluxes otherwise remained small, with sensible heat flux often close to zero. Results indicate that coral reefs may act as heat sinks during winter and as heat sources during spring, thereby affecting local water and atmosphere heat budgets and associated thermodynamics.
Impact of stratospheric ozone on Southern Hemisphere circulation change: A multimodel assessment
Authors: Son S.‐W. , Gerber E. P. , Perlwitz J. , Polvani L. M. , Gillett N. P. , Seo K.‐H. , Eyring V. , Shepherd T. G. , Waugh D. , Akiyoshi H. , Austin J. , Baumgaertner A. , Bekki S. , Braesicke P. , Brühl C. , Butchart N. , Chipperfield M. P. , Cugnet D. , Dameris M. , Dhomse S. , Frith S. , Garny H. , Garcia R. , Hardiman S. C. , Jöckel P. , Lamarque J. F. , Mancini E. , Marchand M. , Michou M. , Nakamura T. , Morgenstern O. , Pitari G. , Plummer D. A. , Pyle J. , Rozanov E. , Scinocca J. F. , Shibata K. , Smale D. , Teyssèdre H. , Tian W. , Yamashita Y.
Published: October 2010

The impact of stratospheric ozone on the tropospheric general circulation of the Southern Hemisphere (SH) is examined with a set of chemistry‐climate models participating in the Stratospheric Processes and their Role in Climate (SPARC)/Chemistry‐Climate Model Validation project phase 2 (CCMVal‐2). Model integrations of both the past and future climates reveal the crucial role of stratospheric ozone in driving SH circulation change: stronger ozone depletion in late spring generally leads to greater poleward displacement and intensification of the tropospheric midlatitude jet, and greater expansion of the SH Hadley cell in the summer. These circulation changes are systematic as poleward displacement of the jet is typically accompanied by intensification of the jet and expansion of the Hadley cell. Overall results are compared with coupled models participating in the Intergovernmental Panel on Climate Change Fourth Assessment Report (IPCC AR4), and possible mechanisms are discussed. While the tropospheric circulation response appears quasi‐linearly related to stratospheric ozone changes, the quantitative response to a given forcing varies considerably from one model to another. This scatter partly results from differences in model climatology. It is shown that poleward intensification of the westerly jet is generally stronger in models whose climatological jet is biased toward lower latitudes. This result is discussed in the context of quasi‐geostrophic zonal mean dynamics.
Inhibition of lectin‐mediated innate host defences in vivo modulates disease severity during influenza virus infection
Authors: Tate Michelle D , Brooks Andrew G , Reading Patrick C
Published: October 2010

Host‐mediated recognition of mannose‐rich glycans on the surface of pathogens represents an ancient mechanism of innate immune defence. In this study, we demonstrate that the virus strains that differ in the degree of N‐linked glycosylation on the globular head of their hemagglutinin glycoprotein also differed in their (i) sensitivity to neutralization by a mannose‐specific lectin in mouse lung fluids and (ii) ability to infect (and, therefore, to be destroyed) by airway macrophages. Virus strain BJx109 (H3N2), but not PR8 (H1N1), was sensitive to neutralization by mouse lung fluids and infected airway macrophages efficiently in vitro and these antiviral activities were blocked by mannan, a complex polymer of mannose residues. Although intranasal (i.n.) infection of mice with PR8 led to severe disease and mortality, mice infected with an equivalent dose of BJx109 displayed no signs of disease. However, i.n. treatment of BJx109‐infected mice with mannan led to viral pneumonia, severe disease and death characterized by excessive virus replication, pulmonary inflammation, vascular leak and lung edema. Thus, when mannose‐specific innate defences were inhibited in vivo, virus strain BJx109 induced severe viral pneumonia similar to that of PR8. Together, these findings highlight the importance of N‐linked glycans as a target for recognition and destruction of influenza viruses by the innate immune system. Moreover, soluble and cell‐associated lectins coordinate to modulate disease severity following influenza virus infection of mice.
Decoding the intrinsic mechanism that prohibits ALIX interaction with ESCRT and viral proteins
Authors: Zhou Xi , Si Jiali , Corvera Joe , Gallick Gary E. , Kuang Jian
Published: October 2010

The adaptor protein ALIX [ALG-2 (apoptosis-linked-gene-2 product)-interacting protein X] links retroviruses to ESCRT (endosomal sorting complex required for transport) machinery during retroviral budding. This function of ALIX requires its interaction with the ESCRT-III component CHMP4 (charged multivesicular body protein 4) at the N-terminal Bro1 domain and retroviral Gag proteins at the middle V domain. Since cytoplasmic or recombinant ALIX is unable to interact with CHMP4 or retroviral Gag proteins under non-denaturing conditions, we constructed ALIX truncations and mutations to define the intrinsic mechanism through which ALIX interactions with these partner proteins are prohibited. Our results demonstrate that an intramolecular interaction between Patch 2 in the Bro1 domain and the TSG101 (tumour susceptibility gene 101 protein)-docking site in the proline-rich domain locks ALIX into a closed conformation that renders ALIX unable to interact with CHMP4 and retroviral Gag proteins. Relieving the intramolecular interaction of ALIX, by ectopically expressing a binding partner for one of the intramolecular interaction sites or by deleting one of these sites, promotes ALIX interaction with these partner proteins and facilitates ALIX association with the membrane. Ectopic expression of a GFP (green fluorescent protein)–ALIX mutant with a constitutively open conformation, but not the wild-type protein, increases EIAV (equine infectious anaemia virus) budding from HEK (human embryonic kidney)-293 cells. These findings predict that relieving the autoinhibitory intramolecular interaction of ALIX is a critical step for ALIX to participate in retroviral budding.
Enhanced expression of pro-inflammatory mediators and liver X-receptor-regulated lipogenic genes in non-alcoholic fatty liver disease and hepatitis C
Authors: Lima-Cabello Elena , García-Mediavilla María Victoria , Miquilena-Colina María E. , Vargas-Castrillón Javier , Lozano-Rodríguez Tamara , Fernández-Bermejo Miguel , Olcoz José Luis , González-Gallego Javier , García-Monzón Carmelo , Sánchez-Campos Sonia
Published: October 2010

NAFLD (non-alcoholic fatty liver disease) is one of the most frequent chronic liver diseases worldwide. The metabolic factors associated with NAFLD are also determinants of liver disease progression in chronic HCV (hepatitis C virus) infection. It has been reported that, besides inducing hepatic fatty acid biosynthesis, LXR (liver X receptor) regulates a set of inflammatory genes. We aimed to evaluate the hepatic expression of LXRα and its lipogenic and inflammatory targets in 43 patients with NAFLD, 44 with chronic HCV infection and in 22 with histologically normal liver. Real-time PCR and Western blot analysis were used to determine hepatic expression levels of LXRα and related lipogenic and inflammatory mediators in the study population. We found that the LXRα gene and its lipogenic targets PPAR-γ (peroxisome-proliferator-activated receptor-γ), SREBP (sterol-regulatory-element-binding protein)-1c, SREBP-2 and FAS (fatty acid synthase) were overexpressed in the liver of NAFLD and HCV patients who had steatosis. Moreover, up-regulation of inflammatory genes, such as TNF (tumour necrosis factor)-α, IL (interleukin)-6, OPN (osteopontin), iNOS (inducible NO synthase), COX (cyclo-oxygenase)-2 and SOCS (suppressors of cytokine signalling)-3, was observed in NAFLD and HCV patients. Interestingly, TNF-α, IL-6 and osteopontin gene expression was lower in patients with steatohepatitis than in those with steatosis. In conclusion, hepatic expression of LXRα and its related lipogenic and inflammatory genes is abnormally increased in NAFLD and HCV patients with steatosis, suggesting a potential role of LXRα in the pathogenesis of hepatic steatosis in these chronic liver diseases.
Mistakes in the analysis of exotic species establishment: source pool designation and correlates of introduction success among parrots (Aves: Psittaciformes) of the world
Authors: Cassey Phillip , Blackburn Tim M. , Jones Kate E. , Lockwood Julie L.
Published: October 2010

Aim  To evaluate the effect of mis‐specifying the correct comparison of species pools in the study of species characteristics associated with the biological introduction of exotic species.

Methods  We use a high quality data set on biological introductions of parrots (Aves: Psittaciformes). These data allow us to examine relationships between life history traits and probability of successful transition through an introduction stage when the species pool is both correctly and incorrectly specified.

Results  For the establishment of introduced parrot species, nearly half of the predictor variables showed different patterns of significance when an incorrect pool was specified. Multivariate analysis identified entirely different sets of variables as independent predictors of establishment success, depending on the species pool used. Correct pool specification identified that introduced parrot species have been more likely to establish if they have broader diets and are more sedentary.

Main conclusions  Conclusions from the analysis of biological introductions are likely to depend on the specification of the species pool for such analyses. In the analysis of parrot introductions, this was particularly apparent in establishment success following release. Further studies that analyse the introduction pathway need to examine the effects of pool mis‐specification so that the generality of our results can be assessed.
Breeding bird species richness in Taiwan: distribution on gradients of elevation, primary productivity and urbanization
Authors: Lee Pei‐Fen , Ding Tzung‐Su , Hsu Fu‐Hsiung , Geng Shu
Published: October 2010

Aim  To examine the richness of breeding bird species in relation to elevation, primary productivity and urbanization.

Location  The island of Taiwan (120°–122° E, 22°–25° N).

Methods  We arranged bird species richness (BSR) data from 288 bird censuses undertaken in Taiwan into a 2 × 2 km quadrat system and calculated average values of elevation, primary productivity [surrogated by normalized difference vegetation index (NDVI)], and urbanization (surrogated by road density and percentage of built area) for each 2 × 2 km quadrat.

Results  Bird species richness showed a hump‐shaped relationship with elevation. It increased with elevation from sea level (10–64 species per 2 × 2 km quadrat), peaked around 2000 m (43–76 species), and then decreased with elevation towards its minimum at the highest elevation. Road density and percentage of built area decreased with elevation, and NDVI showed a hump‐shaped relationship with elevation and inverse relationships with road density and percentage of built area. BSR increased with NDVI and decreased with road density and percentage of built area. Linear and cubic terms of elevation together explained 31.3% of the variance in BSR, and road density explained additional 3.4%. The explanatory power of NDVI on BSR was insignificant after the effects of elevation and road density had been justified.

Main conclusions  We argue that urbanization plays an important role in the BSR of Taiwan. Urbanization might indirectly decrease BSR through decreasing primary productivity and therefore change the hypothetical inverse relationship between BSR and elevation into a hump‐shaped relationship. We also propose a time hypothesis that the biotic communities in the mid‐elevation zone of Taiwan had relatively longer periods of existence during the Pleistocene glacial cycles, which might be one underlying process of the observed hump‐shaped relationship between species diversity and elevation.
The mismeasure of islands: implications for biogeographical theory and the conservation of nature
Authors: Walter Hartmut S.
Published: October 2010

The focus onplacerather than space provides geography with a powerfulraison d’être. As in human geography, the functional role of place is integral to the understanding of evolution, persistence and extinction of biotic taxa. This paper re‐examines concepts and biogeographical evidence from a geographical rather than ecological or evolutionary perspective. Functional areography provides convincing arguments for a postmoderndeconstructionof major principles of the dynamic Equilibrium Theory of Island Biogeography (ETIB). Endemic oceanic island taxa are functionally insular as a result of long‐term island stability, confinement, isolation, and protection from continental invasion and disturbance. Most continental taxa persist in different, more complex and open spatial systems; their geographical place is therefore fundamentally distinct from the functional insularity of oceanic island taxa. This creates an insular‐continentalpolarityin biogeography that is currently not reflected in conservation theory. The focus on the biogeographical place leads to the development of theeigenplaceconcept defined as thefunctional spatial complex of existence. The application of still popular ETIB concepts in conservation biology is discouraged. The author calls for the integration of functional areography into modern conservation science.
The mid‐domain effect applied to elevational gradients: species richness of small mammals in Costa Rica
Authors: McCain Christy M.
Published: October 2010

Aim  The objective of this study was to comprehensively document and examine the alpha and gamma patterns of species richness in non‐volant, small mammals (rodents, shrews and mouse opossums) along a tropical elevational gradient. These data were used to determine the support for existing hypotheses of species richness encompassing mid‐domain null models, as well as climatic, and community overlap hypotheses.

Location  Field studies were conducted along a Caribbean slope of the Río Peñas Blancas watershed in the north‐eastern region of Costa Rica between 750 and 1850 m at 10 sampling sites.

Methods  Species richness and abundances of small mammals were surveyed for four seasons including three temporal replicates at each of five elevational sites: late wet season (2000), early wet season (2001), and dry season (2002), and one spatial replicate at five different sites within the same elevations during the late wet season (2001). Species richness at elevations below 700 m was compiled from specimen records from 23 US national and international collections. Predictions of a null model based solely on geometric constraints were examined using a Monte Carlo simulation program, Mid‐Domain Null.

Results  In 16,900 trap nights, 1561 individuals from 16 species were captured. Both alpha and gamma species richness peaked at mid‐elevation between 1000 and 1300 m, with richness declining both at higher and lower elevations. Most of the empirical curves of species richness occur within 95% prediction curves of the mid‐domain model, although deviations from the null model exist. Regression of the empirical richness on the null model predictions explained nearly half of the variation observed (r2 = 0.45, P = 0.002).

Main conclusions  The geometric constraints of montane topography appear to influence the diversity pattern of small mammals, although climatic conditions including an intermediate rainfall and temperature regime, and distance from the persistent cloud cap also are correlated with the pattern of species richness. The predictions of productivity, and community overlap hypotheses are not supported with the empirical data.
Geographical gradients in seed mass in relation to climate
Authors: Murray Brad R. , Brown A. H. D. , Dickman C. R. , Crowther M. S.
Published: October 2010

Aim  To determine whether latitudinal and longitudinal gradients in seed mass are related to variation in climatic features including temperature, solar radiation and rainfall.

Location  Australia.

Methods  Seed mass was estimated from over 1600 provenances covering the latitudinal and longitudinal extents of 34 perennial Glycine taxa in Australia. Climatic data were obtained from ANUCLIM 5.1 for collection locations based on long‐term meteorological records across Australia. These climatic data were subject to principal components analysis to extract three components as climatic indices. Generalized linear models were used in three separate sets of analyses to evaluate whether seed mass–latitude and seed mass–longitude relationships persisted after taking climatic variation into account. First, relationships were examined across species in analyses that did not explicitly consider phylogenetic relationships. Secondly, phylogenetic regressions were performed to examine patterns of correlated evolutionary change throughout the Glycine phylogeny. Within‐species analysis was also performed to examine consistency across different taxonomic levels.

Results  Geographical variation in seed mass among species was related primarily to temperature and solar radiation, while rainfall was much less influential upon seed mass. Partialing out the influence of temperature and solar radiation in models resulted in the disappearance of significant seed mass–latitude and seed mass–longitude relationships. Patterns within species were generally consistent with patterns among species. However, in several species, factors additional to these climatic variables may contribute to the origin and maintenance of geographical gradients in seed mass, as significant seed mass–latitude and seed mass–longitude relationships remained after controlling for the influence of climatic variables.

Main conclusions  Our empirical results support the hypotheses that (1) seed mass is larger at low latitudes and in the interior of the Australian continent due to increased metabolic costs at high temperatures, and that (2) higher levels of solar radiation result in an increase in the availability of photosynthate, which in turn leads to an increase in biomass for the production of large seeds. In effect, our findings show that greater energy is available precisely where needed, that is, where high temperatures require large seed mass on the basis of metabolic requirements.
The combined role of glaciation and hybridization in shaping the distribution of genetic variation in a Patagonian southern beech
Authors: Marchelli P. , Gallo L. A.
Published: October 2010

Aim  The distribution of the genetic variation in long‐lived species is a combination of both, historical and current processes. In Nothofagus nervosa (Phil.) Dim. et Mil., the possible existence of multiple glacial refugia, the unidirectional gene flow along fragmented areas and the natural hybridization with the related species Nothofagus obliqua (Mirb.) Oerst. highlights as the most important factors responsible for modelling its genetic structure. The present study aims to find out the relative importance of these evolutionary processes in determining the distribution pattern of the genetic variation in N. nervosa.

Location  The study was carried out in north‐western Patagonia, Argentina. Twenty populations covering the entire distribution range of N. nervosa in Argentina were analysed. For comparison purposes, three populations from Chile were also included.

Methods  Genetic variation was detected using isozyme gene markers; diversity and differentiation parameters were calculated. A cluster analysis was performed and the correlation between genetic and geographical distances was tested.

Results  Levels of genetic variation were relatively high given the small distribution range of the species in Argentina. Genetic and geographical distances were not correlated and a longitudinal trend in the genetic variation was evident. Hotspots of diversity with rare and private alleles were observed among western populations, while hybrid seeds were found almost exclusively among eastern populations.

Main conclusions  The higher level of diversity observed in western populations could be related with the location of glacial refugia. Furthermore, it should also reflect low levels of gene flow given the eastward unidirectional winds. On the contrary, ancient and current interspecific hybridization processes would mainly cause the particular genetic constitution of the eastern populations. Evidence is presented supporting that glaciations and hybridization were the main factors shaping the distribution of the genetic variation in N. nervosa.
Pharaonic Egypt and the origins of plague
Authors: Panagiotakopulu Eva
Published: October 2010

Aim  This paper examines the possibility that bubonic plague was a disease endemic in the wild rodent population of Egypt and East Africa.

Location  The study focuses on Egypt and the Nile Valley during the Pharaonic period.

Methods  This paper presents a hypothesis based on archaeoentomological, archaeozoological and biogeographical information on the insect and small mammal species involved in the spread of plague, as well as relevant information from early literary sources.

Results  The primary host for the rat flea Xenopsylla cheopis is the Nile rat, Arvicanthis niloticus. Urbanization and the Nile floods brought into contact humans and the Nile rat and its ectoparasite, Xenopsylla cheopis, which was able to move to a newly introduced host the synanthropic Rattus rattus. The existence of large numbers of human fleas and squalid conditions from the Workmens’ Village at Amarna, evidence for nile rats and black rats from Pharaonic sites and descriptions of an epidemic disease in the Amarna letters, the Hittitic archives and the Ebers papyrus with references to swelling buboes, present a new scenario for the origins of the disease.

Main conclusions  Most modern researchers have regarded the origins of bubonic plague as a disease of Central Asiatic rodents. Here, I examine the evidence for plague in Egypt, and suggest that the bacillus Yersinia pestis was primarily a disease of the Nile rat, Arvicanthis niloticus, which only achieved epidemic proportions when its vector, the tropical rat flea, Xenopsylla cheopis, was able to make the jump to a new host, the black or ship rat, Rattus rattus, introduced from India or indirectly via Mesopotamia during the Pharaonic period. Synanthropy and a high death rate in the new host lead to frequent transfer to human populations and stochastic waves of pandemics.
The parable of Green Mountain: Ascension Island, ecosystem construction and ecological fitting
Authors: Wilkinson David M.
Published: October 2010

Aims  To use the ecosystem on Green Mountain, Ascension Island, to illustrate aspects of ecosystem construction and function as well as possible mitigation of human caused global environmental change.

Location  Ascension Island, tropical south Atlantic.

Main conclusions  The cloud forest on Green Mountain is a man‐made system that has produced a tropical forest without any coevolution between its constituent species. This has implications for the way we think about ecosystems and provides a striking example of Janzen's idea of ‘ecological fitting’. This system provides ecosystem services, such as carbon sequestration, and illustrates the possible role of man‐made ecosystems in the mitigation of global warming.
The role of landscape history and persistent biogeographical patterns in shaping the responses of Mediterranean land snail communities to recent fire disturbances
Authors: Kiss Laurence , Magnin Frédéric , Torre Franck
Published: October 2010

Aims To assess the impact of various fire regimes over the past 30 years on land snail communities and to analyse the role of recent landscape history and the influence of biogeography in shaping the response patterns of gastropod communities following disturbances by fire.

Location South‐eastern France (Provence) and Mediterranean region.

Methods Stratified sampling within 12 sites was undertaken with regard to fire regime (i.e. number of fires, fire intervals and age of the last fire) occurring over the past 30 years. The study was complemented by a historical analysis using aerial photographs, old maps of vegetation cover and an analysis of the biogeographical composition of malacofaunas. Data were investigated using Correspondence Analysis and Sørensen coefficient of similarity.

Results When a disturbance regime (land use or fire disturbances) has been maintained over decades or centuries, land snail communities appear highly modified and tend to be composed of only Mediterranean and xerophilous species. However, low fire regimes, since the 1970s, do not seem to greatly affect the composition of gastropod communities. Indeed, shade‐loving, mesophilous and European range species persist even after successive fires within some sites. In addition, the malacofaunas have a higher component of European range species with increasing distance from the Mediterranean sea.

Main conclusions Analysis of the response patterns of gastropod communities to fire shows a response to numerous different factors. The composition of current land snail communities is not only the result of (more or less) recent patterns of fire regimes but also of anthropogenic disturbances, of landscape changes over the last centuries and of subsequent structure of the pre‐fire habitat, as well as of the influence of a biogeographical gradient. However, the response patterns observed and the persistence of pre‐fire communities imply the presence of cryptic refuges located within burned areas.
Distribution, endemism and threat status of freshwater fishes in the Western Ghats of India
Authors: Dahanukar Neelesh , Raut Rupesh , Bhat Anuradha
Published: October 2010

Aim  To study (1) the large‐scale distribution patterns of freshwater fishes in the Western Ghats of India; (2) the endemism and uniqueness of the fishes in various zones; and (3) the threat status of fishes by categorizing them under low risk (LR), vulnerable (VU), endangered (EN) and critically endangered (CR).

Location  The Western Ghats of India.

Methods  The scientific literature describing the freshwater fishes of the Western Ghats was reviewed. Data describing the lists of the species were extracted and complied. The species accumulation curve was plotted using Michaelis–Menten‐like equation. The Western Ghats was divided into six zones and similarity of the species was calculated using Jacquard's index.

Results  Literature to date records 288 species belonging to 12 orders, 41 families and 109 genera, of which 118 species are endemic and 51 are unique. However, the species accumulation curve shows that there might be 345 species in this region, indicating that 16% species have not been recorded to date. An analysis of the distribution pattern of fishes in the Western Ghats suggests that the southern region is more diverse than the northern and central regions. The southern region shows high endemism and high uniqueness while the northern region shows high endemism but less uniqueness. The similarity index between the zones indicates that as the distance between the zones increases similarity decreases. The status of 105 of 288 species was not known due to data deficiency but among the remaining 183 species, 58 species were categorized as LR, 41 as VU, 54 as EN, 24 as CR while the remaining six species were introduced.

Conclusions  The distribution patterns of fishes in the Western Ghats are discussed in accordance with the geography of Western Ghats, its climatic conditions and ‘Satpura Hypothesis’. The threat status of fishes found in Western Ghats suggests that at least 41% of fish fauna is threatened by either being VU, EN or CR. Implication of potent conservation measures is necessary to conserve the fish fauna of Western Ghats.
A fine‐resolution Pliocene pollen and charcoal record from Yallalie, south‐western Australia
Authors: Atahan Pia , Dodson John R. , Itzstein‐Davey Freea
Published: October 2010

Aim  This paper aims to reconstruct a high‐resolution fire and vegetation history from a period when humans were absent in Australia. This is then used to comment on the frequency of natural fire in high biodiversity heathland, and to compare this with historical fire regime in the same region.

Methods  A section of varved sediment covering a period of c. 84 years was taken from Palaeolake Yallalie in south‐western Australia. The sediments were separated into approximately single to small multiples of years and then analysed for charcoal, pollen and sediment analysis to reconstruct the environmental conditions at the time.

Results  The charcoal record indicates fire recurrence to have been roughly between 5 and 13 years, a little longer than those of the historical period. The pollen record was dominated by Casuarinaceae, Myrtaceae and a large number of Proteaceae species; these are intermixed with Araucariaceae, Nothofagus and Podocarpus. This suggests there was a mix of sclerophyll woodland and a mosaic of rain forest elements, thus conditions must have been wetter, particularly in the summers, compared with today.

Conclusions  We assume that fire was most likely confined to the sclerophyll vegetation, and that fire has been a significant feature of the environment long before humans entered Australia. The slightly longer fire recurrence times compared with the present result from the intermittent nature of lightning and wetter summers at the time.
The influence of spatial resolution on macroecological patterns of range size variation: a case study using parrots (Aves: Psittaciformes) of the world
Authors: Blackburn Tim M. , Jones Kate E. , Cassey Phillip , Losin Neil
Published: October 2010

Aim To assess the extent to which the resolution at which geographical range sizes are measured influences macroecological patterns in this variable.

Location Global.

Methods Data on the geographical ranges of parrot species were digitized, and a Geographic Information System used to produce nine range size estimates for each species using different degrees of spatial resolution. The inter‐correlation of these estimates was then compared, together with their patterns of covariation with population size, body mass and migratory behaviour (across species and controlling for phylogeny), their pattern of phylogenetic correlation, and the frequency distributions of the different measures.

Results Strong correlations exist among all nine range size measures across species, albeit that measures of similar spatial resolution are more strongly correlated. All measures show similar patterns of covariation with population size, body mass and migratory behaviour, and similar patterns of phylogenetic correlation. The skewness of frequency distributions increases towards zero as the resolution of the range size measure declines.

Main conclusions The results of macroecological analyses are little affected by the resolution with which geographical range sizes are calculated, at least for the parrots of the world. Previously published studies based on crude measures of range size would be unlikely to have produced markedly different conclusions had they used more refined range size metrics.