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Core Areas (core + area)
Selected AbstractsForest landscape pattern in the KwaZulu,Natal midlands, South Africa: 50 years of change or stasis?AUSTRAL ECOLOGY, Issue 6 2004MICHAEL J. LAWES Abstract Understanding patterns and processes of habitat change is essential for managing and conserving forest fragments in anthropogenically altered landscapes. Digitized aerial photographs from 1944 and 1996 were examined for changes to the indigenous forest landscape in the Karkloof-Balgowan archipelago in KwaZulu,Natal, South Africa. Attributes relating to proximate land-use, patch shape, isolation and position in the landscape were used to determine putative causes of forest change. The total change in forest area was ,5.7% (forest covered 6739 ha in 1996). This is contrasted with previous reports for the period 1880,1940 that estimated change in total forest area of up to ,80%. Attrition was the predominant process of forest transformation between 1944 and 1996. Despite little overall change in forest area, 786 mostly small (<0.5 ha) forest patches were lost from the landscape, leaving 1277 forest patches in 1996. An increase in patch isolation, but no change in patch cohesion accompanied the changes in forest area. Ignoring patches that were eliminated, 514 patches decreased in area. This was partly a function of patch size, but the conversion of natural grassland to commercial plantation forestry in the matrix also influenced forest decline. Their small size and irregular shape caused forest patches in the region to be vulnerable to edge effects. Core area declined in a negative exponential way with increasing edge width and the total area of edge habitat exceeded that of core habitat at an edge width of only 50 m. Nevertheless, total core area decreased by only 2% (65 ha) between 1944 and 1996 because most of the eliminated patches were small and contained no core area. The large Karkloof forest (1649 ha) is a conservation priority for forest interior species, but the ecological role and biodiversity value of small forest patches should not be overlooked. [source] Where within a geographical range do species survive best?INSECT CONSERVATION AND DIVERSITY, Issue 1 2008A matter of scale Abstract., 1Opinions differ as to whether declining species are most likely to survive in central or peripheral parts of their distributions. The former pattern is likely to be driven by high extinction risks in peripheral areas; the latter by gradients of extinction risk. 2At a continental scale of analysis, the declining butterfly Euphydryas aurinia survived best in southern and eastern countries within Europe. This was statistically associated with geographical variation in agricultural intensification. At this scale of analysis, there was a gradient of survival, caused by a gradient of agricultural intensification. 3Within England and Wales, survival was greatest in population concentrations, or core areas; that is in 10-km grid squares that were surrounded by other 10-km grid squares that also contained populations of E. aurinia. In the English county of Dorset, populations were also most likely to be found in core areas; that is in habitat patches that were close to other populated habitat patches. 4In this system, there is support for two patterns of decline. At a coarse scale, there is a geographical gradient of habitat degradation, associated with agricultural intensification. But within a region where decline has taken place, populations survive best in core areas, where aggregations of habitat support viable metapopulation dynamics. 5Large-scale geographical patterns of decline towards the periphery (or other locations within) the distribution of a species do not negate the validity of conservation strategies based on core-margin population dynamic principles. Core areas within each country or region represent appropriate targets for conservation action. [source] Threats and biodiversity in the mediterranean biomeDIVERSITY AND DISTRIBUTIONS, Issue 2 2009Emma C. Underwood ABSTRACT Aim, Global conservation assessments recognize the mediterranean biome as a priority for the conservation of the world's biodiversity. To better direct future conservation efforts in the biome, an improved understanding of the location, magnitude and trend of key threats and their relationship with species of conservation importance is needed. Location, Mediterranean-climate regions in California-Baja California, Chile, South Africa, Australia and the Mediterranean Basin. Methods, We undertook a systematic, pan-regional assessment of threats in the mediterranean biome including human population density, urban area and agriculture. To realize the full implications of these threats on mediterranean biodiversity, we examined their relationship with species of conservation concern: threatened mammals at the global scale and threatened plants at the subecoregional scale in California, USA. Results, Across the biome, population density and urban area increased by 13% and agriculture by 1% between 1990 and 2000. Both population density and urban area were greatest in California-Baja California and least in Australia while, in contrast, agriculture was greatest in Australia and least in California-Baja California. In all regions lowlands were most affected by the threats analysed, with the exception of population density in the Chilean matorral. Threatened species richness had a significant positive correlation with population density at global and subecoregional scales, while threatened species were found to increase with the amount of urban area and decrease as the amount of natural area and unfragmented core area increased. Main conclusions, Threats to mediterranean biodiversity have increased from 1990 to 2000, although patterns vary both across and within the five regions. The need for future conservation efforts is further underlined by the positive correlation between species of conservation concern and the increase in population density over the last decade. Challenges to reducing threats extend beyond those analysed to include human,environmental interactions and their synergistic effects, such as urbanization and invasive species and wildfires. [source] Effects of experimental small-scale grassland fragmentation on spatial distribution, density, and persistence of ant nestsECOLOGICAL ENTOMOLOGY, Issue 6 2003Brigitte Braschler Abstract., 1.,Grassland fragmentation is expected to influence the abundance of different invertebrate species to a different extent. Fragmentation-related effects are of particular importance in species that interact with many other species. 2.,The density and spatial distribution of nests of 15 ant species in experimentally fragmented calcareous grasslands at three sites in the Northern Swiss Jura mountains were examined. Fragments of different size (0.25 m2, 2.25 m2, and 20.25 m2) were isolated by a 5-m wide strip of frequently mown vegetation. Control plots of corresponding size were situated in adjacent undisturbed grassland. 3.,Three years after initiation of the experiment, ant nest density did not differ between fragments and control plots. Six years after initiation of the experiment, however, ant nest density and forager abundance were higher in large fragments than in large control plots. Ant nests tended to occur more frequently along the edge of fragments than in the core area. Persistence time of nests of the most abundant species, Lasius paralienus, tended to be shorter in fragments than in control plots. Furthermore, persistence time was longer in nests situated close to the fragment edge than in nests in the core area. 4.,Effects on nest density, edge effects on the spatial distribution of nests, and the relationships between nest density and environmental factors were more pronounced when only nests of L. paralienus were considered. The implications of these findings for plant and other invertebrate species are discussed. [source] Mechanisms of population regulation in the fire ant Solenopsis invicta: an experimental studyJOURNAL OF ANIMAL ECOLOGY, Issue 3 2001Eldridge S. Adams Summary 1We tested for density-dependent regulation of biomass in a population of the fire ant Solenopsis invicta and examined the mechanisms of population recovery following replicated colony removals. 2,All colonies were killed within the core area (1018 m2) of six plots, while six additional plots served as undisturbed controls. Over the next 5 years, colonies were mapped several times per year and the biomass of each colony was estimated from the volume of the nest-mound. 3,The average biomass and density of colonies within the removal areas gradually converged on those of control plots and were no longer detectably different after two years. Thereafter, ant biomass on experimental and control plots showed nearly identical seasonal and yearly fluctuations. 4Territories of colonies surrounding the removal areas rapidly expanded following the deaths of neighbours, while average territory size on control plots showed little short-term change. 5,Significantly more new colonies were established within core areas of experimental plots than within core areas of control plots during the first year following removals. 6,The per-colony probability of movement and the net influx of colony biomass were significantly higher in central regions of the experimental plots than in control plots during the first year. The directions of colony movements were clustered towards the centres of experimental plots in the first 2 years, but did not show significant directional trends on control plots. 7,In all 5 years of the study, annual mortality rates were lower for larger colonies, but the size-specific risk of mortality was not significantly affected by the experimental removal of competitors. 8,The growth rates of colonies, adjusted for initial size, were significantly higher in central regions of experimental plots than in control plots during the first two years of the study. In all years, colony growth rates declined with increasing colony size. 9,These results indicate that populations of S. invicta are regulated by competition among neighbouring colonies. Due to large intraspecific variation in colony size, the dynamics of ant populations are described more accurately by measures of total ant biomass than by colony density alone. [source] Chernozem,Soil of the Year 2005JOURNAL OF PLANT NUTRITION AND SOIL SCIENCE, Issue 6 2005Manfred Altermann Abstract The proclamation of the "Soil of the Year" was made for the first time in Germany in 2005 on occasion of the World Soil Day. Chernozems were selected for this purpose. In this paper an overview of these groups of soils is given. Chernozems are concentrated in the drought region of Central Germany. A standard profile from the core area of Chernozems developed from loess is presented with comprehensive laboratory analysis. Chernozems developed primarily upon carbonatic loess substrates under summer-dry climatic conditions in an open park-like landscape with isolated forest stands. The development of Chernozems began as early as the late glacial period, and they were fully developed by the Atlantikum age. The far-reaching, uniformly thick humus horizons indicate substrate differences in the loess cover, which are partly the result of bioturbation. Within Germany, Chernozems and Chernozem-like soils make up approx. 3% of the surface area and 5% (approx. 11,000 km2) of the arable land. The results of the Static Fertilization Experiment in Bad Lauchstädt, founded in 1902, clarify the high value of Chernozem for biomass production and the environment. Each loss due to erosion or decrease in surface area reduces the fulfillment of soil ecological functions of the soils and is comparable to a loss of animal and plant species. Therefore, soil scientists and the results of soil research must be more comprehensively implemented for soil preservation, protection, and politics. For acceptance of these goals among the general public and the political-decision makers, the campaign "Soil of the Year" should give some thought-provoking impulses. Schwarzerde , Boden des Jahres 2005 Anlässlich des Weltbodentages wurde in Deutschland für 2005 mit der Schwarzerde erstmalig ein ,Boden des Jahres" proklamiert. Damit soll in der Bevölkerung und bei politischen Entscheidungsträgern ein stärkeres Bewusstsein für den Boden und ein höheres Engagement für den Bodenschutz angeregt werden. Im Beitrag wird ein Überblick über diese Bodengruppe gegeben und ein Standardprofil aus dem Kerngebiet der Schwarzerden aus Löss (Mitteldeutsches Trockengebiet) mit umfassenden Laboranalysen exemplarisch präsentiert. Schwarzerden entwickelten sich vorwiegend auf kalkreichen Lössen unter sommertrockenen Klimabedingungen in einer offenen parkähnlichen Landschaft mit Waldinseln. Die Entstehung der Schwarzerden setzte bereits im Spätglazial ein, und im Atlantikum waren sie voll entwickelt. Die weiträumig gleiche Mächtigkeit der Humushorizonte zeichnet primäre Substratunterschiede in der Lössdecke nach; sie sind nicht nur das Ergebnis einer Bioturbation. In Deutschland nehmen die Schwarzerden und schwarzerdeähnlichen Böden etwa 3 % der Bodenfläche bzw. 5 % (ca. 11.000 km2) der landwirtschaftlichen Nutzfläche ein. Die Ergebnisse des seit 1902 bestehenden Statischen Düngungsversuchs Bad Lauchstädt verdeutlichen den hohen Wert der Schwarzerden für Biomasseproduktion und Umwelt. Jeder Verlust durch Erosion oder Flächenentzug mindert die Erfüllung ökologischer Funktionen der Böden und ist dem Artenverlust von Tieren und Pflanzen gleichzustellen. In der Bodenpolitik müssen deshalb die Ergebnisse der Bodenforschung zum Erhalt und Schutz unserer Böden umfassender als bisher umgesetzt und Bodenwissenschaftler stärker in politische Entscheidungen eingebunden werden. Für die Akzeptanz und Umsetzung dieser Ziele in der Öffentlichkeit soll der ,Boden des Jahres" Impulse geben. [source] Home range and habitat selection of pampas deerJOURNAL OF ZOOLOGY, Issue 1 2008A. R. Vila Abstract The southernmost subspecies of pampas deer Ozotocerus bezoarticus celer is an endemic and endangered cervid of the Argentine Pampas. The aim of our study was to describe the habitat use of this deer on the coast of Samborombón Bay. Twelve adult pampas deer (seven female and five male) were radiotracked and their home-range sizes and habitat selection studied from 1995 to 2001. The mean home-range size was 898±181 ha, and the core area was concentrated in 22% of their range. The home-range size of males was three times larger than that of females (1422 vs. 523 ha). Deer home ranges overlapped extensively. No sex differences were found regarding habitat selection. Celtis tala forests and Spartina densiflora grasslands were used more than expected by their availability, while wetlands, coastal grasslands and Salicornia ambigua beaches were avoided. Their habitat selection was affected by cattle presence, suggesting avoidance: they tended to use areas free of cattle, and their home ranges were larger when cattle were absent. An action plan for this endangered population of pampas deer should include initiatives involving private landowners in pampas deer conservation, the use of fire and cattle grazing management tools to improve deer habitat, and studies to provide biological and health data related to pampas deer coexistence with cattle. [source] A review of the historical evidence of the habitat of the Pine Marten in CumbriaMAMMAL REVIEW, Issue 1 2001J. A. Webster ABSTRACT Place names and evidence from the literature show the Pine Marten (Martes martes) to have been well distributed in Cumbria until late in the nineteenth century, with a core area in the central fells. The habitat available to these martens is assessed and the species' status and the reasons for its decline reviewed. Despite the modern emphasis on the absolute importance of woodland to the Pine Marten, it is argued that historical Cumbrian populations survived successfully for many generations in highly fragmented habitats. [source] Exploring barriers to teaching behavioural and social sciences in medical educationMEDICAL EDUCATION, Issue 3 2008Andrea Litva Context,Tomorrow's Doctors provides guidance about what is considered core knowledge for medical graduates. One core area of knowledge identified is the individual in society: graduates are required to understand the social and cultural environments in which medicine is practised in the UK. Yet, despite the presence of the behavioural and social sciences (B&SS) in medical curricula in the UK for the past 30 years, barriers to their implementation in medical education remain. Objective, This study sought to discover medical educators' perceptions of the barriers to the implementation of B&SS. Methods, Medical educationalists in all UK medical schools were asked to complete a survey identifying what they felt were the barriers they had experienced to the implementation of B&SS teaching in medical education. Results, A comparison of our findings with the literature revealed that these barriers have not changed since the implementation of B&SS in medical education. Moreover, the barriers remain similar across medical schools with differing ethos and strategies. Conclusions, Various agendas within the hidden curricula create barriers to effective B&SS learning in medical education and thus need further exploration and attention. [source] A CMOS differential fifth-derivative Gaussian pulse generator for UWB applicationsMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 8 2010Jin He Abstract A CMOS differential fifth-derivative Gaussian pulse generator is presented for Ultrawideband (UWB) applications. The design exhibits low-power consumption, low-circuit complexity, and precise pulse shape to inherently comply with the FCC spectrum mask for indoor UWB applications without the need for a filter. The proposed differential pulse generator was implemented with a 1.8-V, 0.18-,m CMOS process, but only the positive fifth-derivative Gaussian pulse was measured owing to the limitation of the available testing facilities. The measured pulse has peak-to-peak amplitude of 154 mV and a pulse width of 820 ps. Small core area of the differential pulse generator is only 0.028 mm2 because of its all digital circuit design. The average power dissipation is 1.2 mW with a pulse repetition frequency (PRF) of 50 MHz. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1849,1852, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25342 [source] Intra-community coalitionary lethal attack of an adult male southern muriqui (Brachyteles arachnoides)AMERICAN JOURNAL OF PRIMATOLOGY, Issue 10 2009M.G. Talebi Abstract We report on the first evidence of intra-community coalitionary lethal aggression in muriquis (Brachyteles). The event occurred in southern muriquis (Brachyteles arachnoides) during a long-term study (>15 years) of two social groups inhabiting mostly pristine Atlantic forest habitat in the Parque Estadual Carlos Botelho, southern São Paulo State, Brazil. The attack took place deep in the core area of the Group Caetê home range. Tense agonistic behaviors and vocalizations preceded the lethal coalitionary attack, and the tension increased over a 36,48,hr period. One adult female and two unidentified individuals also took part in a coalition led by six adult males. The members of the coalition collectively approached, embraced, immobilized and repeatedly bit the entire body of an adult male, resulting in severe bleeding injuries and the victim's death in less than 1,hr after the attack commenced. Combined ecological, behavioral and spatial data related to the event indicate that this was an intra-community attack and suggest social tensions related to mating competition as the proximate trigger of the coalitionary killing. The attack resembled those reported for chimpanzees, with clear numeric superiority and a low risk of injury to aggressors, resulting in the death of a lone conspecific victim. This observation (n=1) is suggestive of a capacity for escalated aggression in muriquis and reinforces arguments for the potential adaptive significance of intra-community aggression in male philopatric societies, as reported for spider monkeys and chimpanzees. These characteristics challenge the view of the muriquis as a peaceful primate and support the general hypothesis that imbalances of power contribute to intra-specific killing in primates, such as chimpanzees and humans. Am. J. Primatol. 71:860,867, 2009. © 2009 Wiley-Liss, Inc. [source] Internationalising Counseling Psychology in the United States: A SWOT AnalysisAPPLIED PSYCHOLOGY, Issue 1 2007Frederick T.L. Leong Dans le respect des exigences de cette édition spéciale, cet article présente une analyse SWOT du domaine de la psychologie du counseling aux Etats-Unis. Après un bref survol historique, on passe à la description du contexte des tentatives récentes d'internationalisation de la psychologie du counseling aux Etats-Unis au sein du mouvement multiculturaliste. Le premier plaidoyer en faveur du multiculturalisme initié par la division de psychologie du counseling de l'American Psychological Association est certainement l'un de ses points forts. L'ajout du multiculturalisme international au multiculturalisme local semble être une évolution naturelle pour le domaine et ouvre un ensemble de nouvelles perspectives. On peut citer, comme voie prometteuse, notre préoccupation récente pour la justice sociale, autre champ majeur d'investigation et d'intervention. Cependant, le domaine de la psychologie du counseling reste menacé comme le montre notre statut de «rejeton» de la psychologie clinique. On fait remarquer par la même occasion qu'une part de nos faiblesses est due à notre incapacité d'exploiter certaines de nos activités de première importance telles que la réinsertion, la prévention ou la psychologie positive. Des soucis plus récents ont porté sur le déclin organisationnel avec la fermeture d'un nombre important de formations de premier plan en psychologie du counseling. Les raisons de ces disparitions sont toujours sujettes à débat. Consistent with the framework recommended for this special issue, the current article provides a SWOT analysis of the field of counseling psychology within the United States. Beginning with a brief overview of the history of the field, the current analysis moves on to contextualise the recent attempts to internationalise counseling psychology in the United States within the multiculturalism movement. The early advocacy of multiculturalism undertaken by the Division of Counseling Psychology within the American Psychological Association is certainly one of its strengths. The movement to add international multiculturalism to domestic multiculturalism appears to be a natural transition for the field and provides a new set of opportunities. Other opportunities for the field include our recent attention to social justice as another core area of inquiry and intervention. Yet, the field of counseling psychology continues to experience threats as it relates to our "step-child" status vis-a-vis clinical psychology. At the same time, it was noted that part of the weakness of our field has been our failure to capitalise on some of our areas of emphasis such as rehabilitation, prevention, and positive psychology. More recent concerns have centered around organisational decline with the closure of a significant number of the leading counseling psychology training programs in the country. The meaning of these closures continues to be debated. [source] High resolution observations of white-light emissions from the opacity minimum during an X-class flareASTRONOMISCHE NACHRICHTEN, Issue 6 2010Y. Xu Abstract Using high cadence, high resolution near infrared (NIR) observations of the X10 white-light flare (WLF) on 2003 October 29, we investigated the evolution of the core-halo structure of white-light emission during the two-second period flare peak. We found that size and intensity of the halo remained almost constant in the range of 10 Mm2. However, the core area was very compact and expanded rapidly from about 1 Mm2 to 4 Mm2. At the same time, the total emission of the core increased nearly twenty times. This distinct behavior indicates that different heating mechanisms might be responsible for core and halo emissions. In addition to the temporal analysis, we compared the intensity enhancements of the flare core and halo. The result shows that the halo contrast increased by about 8% compared to the flare-quiet region, which could be explained by a combination of direct-heating and backwarming models (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Forest landscape pattern in the KwaZulu,Natal midlands, South Africa: 50 years of change or stasis?AUSTRAL ECOLOGY, Issue 6 2004MICHAEL J. LAWES Abstract Understanding patterns and processes of habitat change is essential for managing and conserving forest fragments in anthropogenically altered landscapes. Digitized aerial photographs from 1944 and 1996 were examined for changes to the indigenous forest landscape in the Karkloof-Balgowan archipelago in KwaZulu,Natal, South Africa. Attributes relating to proximate land-use, patch shape, isolation and position in the landscape were used to determine putative causes of forest change. The total change in forest area was ,5.7% (forest covered 6739 ha in 1996). This is contrasted with previous reports for the period 1880,1940 that estimated change in total forest area of up to ,80%. Attrition was the predominant process of forest transformation between 1944 and 1996. Despite little overall change in forest area, 786 mostly small (<0.5 ha) forest patches were lost from the landscape, leaving 1277 forest patches in 1996. An increase in patch isolation, but no change in patch cohesion accompanied the changes in forest area. Ignoring patches that were eliminated, 514 patches decreased in area. This was partly a function of patch size, but the conversion of natural grassland to commercial plantation forestry in the matrix also influenced forest decline. Their small size and irregular shape caused forest patches in the region to be vulnerable to edge effects. Core area declined in a negative exponential way with increasing edge width and the total area of edge habitat exceeded that of core habitat at an edge width of only 50 m. Nevertheless, total core area decreased by only 2% (65 ha) between 1944 and 1996 because most of the eliminated patches were small and contained no core area. The large Karkloof forest (1649 ha) is a conservation priority for forest interior species, but the ecological role and biodiversity value of small forest patches should not be overlooked. [source] Strength of Habitat and Landscape Metrics in Predicting Golden-Headed Lion Tamarin Presence or Absence in Forest Patches in Southern Bahia, BrazilBIOTROPICA, Issue 3 2010Becky E. Raboy ABSTRACT We investigated the effects of forest fragmentation on golden-headed lion tamarins (Leontopithecus chrysomelas) by qualitatively and quantitatively characterizing the landscape throughout the species range, conducting surveys, and exploring predictive models of presence and absence. We identified 784 forest patches that varied in size, shape, core area, habitat composition, elevation, and distance to neighboring patches and towns. We conducted 284 interviews with local residents and 133 playback experiments in 98 patches. Results indicated a reduction in the western portions of the former species range. We tested whether L. chrysomelas presence or absence was related to the aforementioned fragmentation indices using Monte Carlo logistic regression techniques. The analysis yielded a majority of iterations with a one-term final model of which Core Area Index (percent of total area that is core) was the only significant type. Model concordance ranged between 65 and 90 percent. Area was highlighted for its potential predictive ability. Although final models for area lacked significance, their failure to reach significance was marginal and we discuss potential confounding factors weakening the term's predictive ability. We conclude that lower Core Area Index scores are useful indicators of forest patches at risk for not supporting L. chrysomelas. Taken together, our analyses of the landscape, survey results, and logistic regression modeling indicated that the L. chrysomelas metapopulation is facing substantial threat. The limited vagility of lion tamarins in nonforest matrix may lead to increasingly smaller and inbred populations subject to significant impact from edge effects and small population size. Local extinction is imminent in many forest patches in the L. chrysomelas range. Abstract in Portuguese is available at http://www.blackwell-synergy.com/loi/btp [source] Extent of Nontimber Resource Extraction in Tropical Forests: Accessibility to Game Vertebrates by Hunters in the Amazon BasinCONSERVATION BIOLOGY, Issue 2 2003Carlos A. Peres We conducted a basin-wide geographic information system analysis of the nonmotorized accessibility of Amazonian NTFP extraction and estimated the proportion of the Amazon drainage basin within Brazil ( 3.74 million km 2 ) that can be accessed on foot from the nearest navigable river or functional road. We use a long-term series of standardized line-transect vertebrate censuses conducted throughout the region to illustrate the effects of physical accessibility on wildlife densities in terms of hunting pressure as a function of distance from the nearest point of access. Population abundance in large-bodied, prime-target species preferred by game hunters tended to increase at greater distances from the access matrix, whereas small-bodied species ignored by hunters usually showed the reverse trend. In addition, we estimated the proportion of presumably inviolate core areas within nature, extractive, and indigenous reserves of Brazilian Amazonia that are prohibitively remote and unlikely to be overhunted; for instance, only 1.16% of the basin-wide area is strictly protected on paper and is reasonably safe from extractive activities targeted to game vertebrates and other valuable NTFPs. Finally, we discuss the concept of truly undisturbed wildlands in the last major tropical forest regions by distinguishing potentially overharvested areas from those that remain largely or entirely pristine and that maintain viable populations of a full complement of harvest-sensitive species. Resumen: Las actividades de extracción enfocadas en un amplio rango de productos forestales no maderables ( NTFPs ) son omnipresentes en los bosques tropicales. Sin embargo, la extensión de bosques estructuralmente intactos en una determinada región afectada por esta forma de perturbación críptica ha sido escasamente documentada. Realizamos un análisis GIS del acceso no motorizado para la extracción NTFP en el Amazonas y estimamos la proporción de la desembocadura de la cuenca amazónica ( ,3.74 millones de km2 ) a la cual se puede acceder a pie a partir del río navegable o la carretera funcional más cercana. Utilizamos series de censos de vertebrados a largo plazo empleando transectos en línea estandarizados a lo largo de la región para ejemplificar los efectos del acceso físico sobre las densidades de vida silvestre en términos de presión de caza como función de la distancia al punto de acceso más cercano. La abundancia poblacional de especies de cuerpo grande que son blancos preferidos por los cazadores tendió a crecer a mayores distancias de la matriz de acceso, mientras que las especies de cuerpo pequeño ignoradas por los cazadores generalmente muestran la tendencia inversa. Además, estimamos la proporción de áreas medulares presuntamente inviolables dentro de las reservas naturales, extractivas e indígenas del Amazonas brasileño que son prohibitivamente remotas y poco probables de ser sobreexplotadas: por ejemplo, solo el 1.16% del área de la cuenca estrictamente proyectada en papel está razonablemente a salvo de las actividades extractivas de los vertebrados de caza y otras NTFPs valiosas. Finalmente, discutimos el concepto de tierras silvestres verdaderamente no perturbadas en las grandes regiones de bosque tropical restantes diferenciando las áreas potencialmente sobreexplotadas de aquellas que son en su mayor parte o totalmente prístinas y que mantienen poblaciones viables de un complemento total de especies sensibles a la cosecha. [source] When fish meet fish as determined by physiological sensorsECOLOGY OF FRESHWATER FISH, Issue 4 2009O. Slavík Abstract,,, Electromyogram (EMG) biotelemetry allows a description of the spatial distribution of fish together with a simultaneous measurement of individual energy consumption. Using this technique, we observed behaviour of the largest European freshwater predator, Silurus glanis, in the Elbe River, Central Europe. In total, 52 diurnal cycles and 1248 individual fish positions were recorded with 12,480 EMG records during the period from March to May 2006; 1013 fish positions with 10,130 EMG records were further used for statistical analyses. Energy consumption increased with decreasing mutual distance between specimens, an effect that occurred predominantly when both of them were simultaneously in overlapping preferred areas [core areas (CAs)] appointed within their home ranges (HRs). Furthermore, with increasing energy consumption individual's movement range in longitudinal and lateral profiles decreased; i.e., the fish were positioned within a small area. When the CAs of tested individuals did not overlap, no relationship between EMG signals and mutual distance of conspecifics was found. Our results indicate that movement activity and also social behaviour can be determined with physiological sensors. [source] Are Alaskan trees found in locally more favourable sites in marginal areas?GLOBAL ECOLOGY, Issue 2 2002Jack J. Lennon Abstract Aim Species generally become rarer and more patchily distributed as the margins of their ranges are approached. We predicted that in such marginal sites, tree species would tend to occur where some key environmental factors are at particularly favourable levels, compensating in part for the low overall suitability of marginal sites. Location The article considers the spatial distributions of trees in Southeast Alaska (the Alaskan ,panhandle'). Methods We quantified range marginality using spatial distributions of eight tree species across more than one thousand surveyed sites in Southeast Alaska. For each species we derived a site core/margin index using a three-dimensional trend surface generated from logistic regression on site coordinates. For each species, the relationships between the environmental factors slope, aspect and site marginality were then compared for occupied and unoccupied sets of sites. Results We found that site slope is important for more Alaskan tree species than aspect. Three out of eight had a significant core/margin by occupied/unoccupied interaction, tending to be present in significantly shallower-sloped (more favourable) sites in the marginal areas than the simple core/margin trend predicted. For site aspect, one species had a significant interaction, selecting potentially more favourable northerly aspects in marginal areas. A finer-scale analysis based on the same data came to the same overall conclusions. Conclusions There is evidence that several tree species in Alaska tend to occur in especially favourable sites in marginal areas. In these marginal areas, these species amplify habitat preferences shown in core areas. [source] Innovation and Regional Growth in the Enlarged Europe: The Role of Local Innovative Capabilities, Peripherality, and EducationGROWTH AND CHANGE, Issue 4 2005RICCARDO CRESCENZI ABSTRACT In this paper, a formal model for the relationship between innovation and growth in European Union regions is developed drawing upon the theoretical contribution of the systems of innovation approach. The model combines the analytical approach of the regional growth models with the insights of the systemic approach. The cross-sectional analysis, covering all the Enlarged Europe (EU-25) regions (for which data are available), shows that regional innovative activities (for which a specific measure is developed) play a significant role in determining differential regional growth patterns. Furthermore, the model sheds light on how geographical accessibility and human capital accumulation, by shaping the regional system of innovation, interact (in a statistically significant way) with local innovative activities, thus allowing them to be more (or less) effectively translated into economic growth. The paper shows that an increase in innovative effort is not necessarily likely to produce the same effect in all EU-25 regions. Indeed, the empirical analysis suggests that in order to allow innovative efforts in peripheral regions to be as productive as in core areas, they need to be complemented by huge investments in human capital. [source] Where within a geographical range do species survive best?INSECT CONSERVATION AND DIVERSITY, Issue 1 2008A matter of scale Abstract., 1Opinions differ as to whether declining species are most likely to survive in central or peripheral parts of their distributions. The former pattern is likely to be driven by high extinction risks in peripheral areas; the latter by gradients of extinction risk. 2At a continental scale of analysis, the declining butterfly Euphydryas aurinia survived best in southern and eastern countries within Europe. This was statistically associated with geographical variation in agricultural intensification. At this scale of analysis, there was a gradient of survival, caused by a gradient of agricultural intensification. 3Within England and Wales, survival was greatest in population concentrations, or core areas; that is in 10-km grid squares that were surrounded by other 10-km grid squares that also contained populations of E. aurinia. In the English county of Dorset, populations were also most likely to be found in core areas; that is in habitat patches that were close to other populated habitat patches. 4In this system, there is support for two patterns of decline. At a coarse scale, there is a geographical gradient of habitat degradation, associated with agricultural intensification. But within a region where decline has taken place, populations survive best in core areas, where aggregations of habitat support viable metapopulation dynamics. 5Large-scale geographical patterns of decline towards the periphery (or other locations within) the distribution of a species do not negate the validity of conservation strategies based on core-margin population dynamic principles. Core areas within each country or region represent appropriate targets for conservation action. [source] Mechanisms of population regulation in the fire ant Solenopsis invicta: an experimental studyJOURNAL OF ANIMAL ECOLOGY, Issue 3 2001Eldridge S. Adams Summary 1We tested for density-dependent regulation of biomass in a population of the fire ant Solenopsis invicta and examined the mechanisms of population recovery following replicated colony removals. 2,All colonies were killed within the core area (1018 m2) of six plots, while six additional plots served as undisturbed controls. Over the next 5 years, colonies were mapped several times per year and the biomass of each colony was estimated from the volume of the nest-mound. 3,The average biomass and density of colonies within the removal areas gradually converged on those of control plots and were no longer detectably different after two years. Thereafter, ant biomass on experimental and control plots showed nearly identical seasonal and yearly fluctuations. 4Territories of colonies surrounding the removal areas rapidly expanded following the deaths of neighbours, while average territory size on control plots showed little short-term change. 5,Significantly more new colonies were established within core areas of experimental plots than within core areas of control plots during the first year following removals. 6,The per-colony probability of movement and the net influx of colony biomass were significantly higher in central regions of the experimental plots than in control plots during the first year. The directions of colony movements were clustered towards the centres of experimental plots in the first 2 years, but did not show significant directional trends on control plots. 7,In all 5 years of the study, annual mortality rates were lower for larger colonies, but the size-specific risk of mortality was not significantly affected by the experimental removal of competitors. 8,The growth rates of colonies, adjusted for initial size, were significantly higher in central regions of experimental plots than in control plots during the first two years of the study. In all years, colony growth rates declined with increasing colony size. 9,These results indicate that populations of S. invicta are regulated by competition among neighbouring colonies. Due to large intraspecific variation in colony size, the dynamics of ant populations are described more accurately by measures of total ant biomass than by colony density alone. [source] Home range size, spatial distribution and habitat use of elephants in two enclosed game reserves in the Eastern Cape Province, South AfricaAFRICAN JOURNAL OF ECOLOGY, Issue 2 2009C. Roux Abstract We studied space use and habitat selection by elephants in two enclosed reserves in the Eastern Cape Province (South Africa) that conserve components of the regionally important and poorly conserved Thicket Biome. Home ranges of bulls and herds occupied most of the reserves, and core areas were significantly smaller and centred on permanent water. There was no significant difference in home range size of bulls and herds and both were significantly smaller in winter than summer. Components of the Thicket Biome occurred in the home ranges and core areas of all elephants where it was either used according to its abundance or avoided. However, this should not be interpreted as indicating that elephants will not affect plants of the Thicket Biome since change will be cumulative and monitoring should be ongoing to ensure the conservation of this regionally important Biome. Résumé Nous avons étudié l'utilisation de l'espace et la sélection de l'habitat par les éléphants dans deux réserves clôturées de la Province du Cap Oriental, en Afrique du Sud, qui préservent les composantes d'un Biome important dans la région et cependant mal conservé, le biome de savane broussailleuse. Les domaines vitaux des mâles et des troupeaux occupaient la plus grande part des réserves, et leurs zones centrales étaient significativement plus petites et centrées sur les points d'eau permanents. Il n'y avait pas de différence significative de la taille des domaines vitaux des mâles et des troupeaux, domaines qui étaient significativement plus petits en hiver qu'en été. Des composantes du biome broussailleux étaient présentes dans le domaine vital et dans l'aire centrale de tous les éléphants, où elles étaient soit utilisées selon leur abondance, soit évitées. Cependant, il ne faudrait pas en déduire que cela indique que les éléphants n'affectent pas les plants du Biome à broussailles puisque les changements seront cumulatifs; il faut au contraire poursuivre le monitoring pour assurer la conservation de ce biome important au niveau régional. [source] The Role of Alliance Network Redundancy in the Creation of Core and Non-core TechnologiesJOURNAL OF MANAGEMENT STUDIES, Issue 2 2009Wim Vanhaverbeke abstract This paper studies the effect of a focal firm, and its partners' local alliance actions, on the creation of technological innovations by the former. More specifically, we study how two types of redundancy in a focal firm's ego network affect its ability to create new technologies in its technology core areas (exploitation) and/or non-core areas (exploration). We analyse this empirically in three different industry settings: chemicals, motor vehicles, and pharmaceuticals. One of our key findings is that individual firms can indeed boost both types of innovative output by shaping the degree of redundancy in their local alliance network, but that the way in which this should be done differs between the creation of core and non-core technologies. Next, we find that it is very useful to unpack the rather abstract notion of redundancy into more specific types of redundancy in ego networks. Overall, these findings reflect an action-oriented view on the role of individual firms in collaborative networks, which may complement the dominant view in the alliance literature emphasizing the role of the overall network structure and firms' network position within it. [source] The Phil Hearne course: an evaluation of a multidisciplinary mental health education programme for clinical practitionersJOURNAL OF PSYCHIATRIC & MENTAL HEALTH NURSING, Issue 2 2000S. Parsons CPsychol PhD GDip BSc (Hons) RNM RNG A description and evaluation of the pilot of a 30-week multidisciplinary mental health education programme (The Phil Hearne Course) is presented. The course was based upon the expressed service needs of an NHS Trust and upon the needs of users consulted during the developmental phase of the project. The course was designed to provide core skills, relating to effective assessment, communication, intervention and networking. These skills were thought to be applicable to all mental health disciplines. The course was evaluated positively by students and staff and was found to be effective in improving practice by providing a range of core skills for mental health workers. It was also determined that students tended to over-estimate their skills in core areas, particularly care planning and record-keeping. It is intended to develop the course into a distance learning, skills-based package. [source] Characterization of the spatial distribution of latrines in reintroduced mountain gazelles: do latrines demarcate female group home ranges?JOURNAL OF ZOOLOGY, Issue 1 2010T. Wronski Abstract Mountain gazelle Gazella gazella in Saudi Arabia are listed as ,vulnerable' by the IUCN. At present, the species' survival is secured by extensive captive-breeding programmes and reintroductions into protected areas. Two reintroduction attempts (Ibex Reserve and Uruq Bani Ma'Arid protected areas) in Saudi Arabia have been undertaken in the past two decades. Post-monitoring of released individuals is essential for the success of such reintroduction programmes; however, cryptic species like mountain gazelles are extremely difficult to observe directly. As radio-tracking is a cost-intensive and invasive post-monitoring technique, we asked: how can reintroduced or remnant pockets of natural gazelle populations be monitored indirectly? Here, we propose the use of latrine mapping as an effective, cost-efficient and non-invasive tool to survey the social organization of reintroduced mountain gazelles as an indicator for repatriation success. In this study, we used released radio-collared animals to characterize the spatial distribution of latrines within female group home ranges. Distance to the next latrine, latrine size, as well as numbers of fresh faecal pellet groups per latrine or presence of urination marks were used as dependent variables for step-wise backward multiple regressions and were correlated with various ecological factors. Most dependent variables were correlated with distance or direction from the nearest tree, but not indicative of home-range cores. Only latrine densities were distinctly higher in core areas of female group home ranges, and no pattern of peripheral marking was detected. Hence, latrine density is a good indicator of home-range use in female group home ranges. Mapping latrines and determining latrine densities are therefore the methods of choice to survey mountain gazelle populations. [source] Home-range overlap and spatial organization as indicators for territoriality among male bushbuck (Tragelaphus scriptus)JOURNAL OF ZOOLOGY, Issue 3 2005Torsten Wronski Abstract Many studies have concluded that territoriality is absent in male bushbuck Tragelaphus scriptus but a minority has suggested that some exclusive mechanisms act between adult males. This study provides indirect evidence for the existence of territorial structures between adult male bushbuck by comparing home-range overlap between adult and sub-adult males. The spatial organization of individuals in relation to each other was established by using numerical classification. Location fixes of 52 males, each individual distinguished by a characteristic coat pattern, were taken over a period of 3 years. Home ranges were estimated using the fixed kernel density estimator. Two indices (coefficient of overlap, index of overlap) were applied to compare home-range overlap between the different male age classes. There was a strong home-range overlap up to the 30% home-range core between sub-adult as well as between adult and sub-adult males, while adult male home ranges overlapped up to the 50% home-range core only. It could be shown that home ranges of adult males overlapped significantly less than those of sub-adult males and those between sub-adult and adult males indicating an exclusive use of central core areas (home sites). Sub-adult males form bachelor pools without being permanently associated. With increasing age, sub-adult males challenge territory holders and replace them in order to take over their exclusive areas. These maturing sub-adult males (young adults), often focused on a particular territory holder denoting the young adults as prospects or candidates. [source] Population status and behaviours of the Samoan flying fox (Pteropus samoensis) on Tutuila Island, American SamoaJOURNAL OF ZOOLOGY, Issue 3 2001Anne P. Brooke Abstract The small population and limited range of the Samoan flying fox Pteropus samoensis has generated concern regarding the survival of this large, diurnally active bat. During 1995,96, surveys were conducted monthly in six study valleys on Tutuila Island, American Samoa, to assess population size. The amount of diurnal and nocturnal activity was investigated to gauge the accuracy of diurnal surveys, and territorial behaviours were observed to determine how they influenced local dispersion. Individuals showed long-term fidelity to a series of roosts and small core areas that were used both nocturnally and diurnally. Territorial defence was observed only of temporary feeding territories in fruiting or flowering trees. Bats defended food resources by aerial patrols and extended aerial chases in which intruders were frequently bitten. Foraging movements changed seasonally, with up to 80% of individuals observed bypassing study valleys. The mean density of bats observed within the study valleys was 6.1 bats/km2 (range = 0.9,18.5 bats/km2). Pteropus samoensis were active both nocturnally and diurnally with greatest activity in late afternoon and evening, 16:00,22:00. Because bats were most active at night, it is probable that daytime surveys of flying bats undercount the number of individuals present. Greatest densities were found in valleys that were contiguous with large tracts of forest inaccessible to people. Most observations of roosting bats were of solitary males on dead branches that jutted above the forest canopy, while females and dependant young roosted below the canopy, hidden within vegetation. Adult male,female pairs were rarely seen together other than during the mating period in August,January. The population has increased following a ban on hunting, but reliance on mature forest makes long-term species survival dependant on protection of the limited mature forest remaining and continued hunting restrictions. [source] Is R&D investment in lagging areas of Europe worthwhile?PAPERS IN REGIONAL SCIENCE, Issue 3 2001Theory, empirical evidence R&D, technology; spillovers; economic growth; regions; Western Europe Abstract. Is R&D investment in lagging areas worthwhile? There is no simple answer, nor is there universal theoretical agreement on the question. The Schumpeterian strand of the endogenous growth approach highlights the advantages of spatially concentrating the research and development (R&D) effort in a few areas, in order to maximise external economies and technological spillovers. Innovation is then expected to spill over from these technologically advanced areas into neighbouring regions. The neoclassical view, in contrast, considers that decreasing returns render investment in core areas increasingly less efficient, and makes investment in peripheries more effective. The regional policy view holds that public investment in R&D in lagging regions triggers economic convergence, because it limits congestion in the centre, helps to keep talent, and generates spin-offs in lagging areas. This article surveys these strands and highlights the advantages and disadvantages of investing in R&D in lagging regions. I then turn to the evolution of R&D investment across regions in Western Europe. [source] Mycophagy and its influence on habitat use and ranging patterns in Callimico goeldiiAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 3 2010Leila M. Porter Abstract Mycophagy has been documented in a number of species of marmosets and lion tamarins (Callitrichinae) but its effect on ranging behavior is not known. We present the results of 10 years of research on five groups of Goeldi's monkey (Callimico goeldii) at a field site in northwestern Bolivia. We studied the diet and ranging behavior of two of the groups. On average, groups contained 4.5 individuals (range 2.0,9.0), but they gradually decreased in size until only the breeding female remained in the home range. The annual diet was composed of fungi (31.1,34.9%), fruits (34.0,40.6%), prey (17.4,30.1%), and exudates (1.0,10.9%). They had large home ranges (114,150 ha) and over time individuals tended to shift their core areas of use. They used secondary and bamboo forest and forest with dense understories more than expected based on availability. We suggest that the large home ranges and shifting core areas used by C. goeldii are components of a foraging strategy to track patchy, low density, and ephemeral fungal fruiting bodies. Our results, along with data published on other callitrichines, indicate that groups of Leontopithecus, Callithrix, and Callimico that eat fungi have larger home ranges than those that do not. Mycophagy is one of the several factors that evidently affect home range size in callitrichines. Fungi are clearly an important food source for a number of populations, but additional studies are needed to determine why some eat fungi frequently while others do not. Am J Phys Anthropol, 2010. © 2010 Wiley-Liss, Inc. [source] Male and female range use in a group of white-bellied spider monkeys (Ateles belzebuth) in Yasuní National Park, EcuadorAMERICAN JOURNAL OF PRIMATOLOGY, Issue 2 2010Stephanie N. Spehar Abstract Spider monkeys (Ateles sp.) live in a flexible fission,fusion social system in which members of a social group are not in constant association, but instead form smaller subgroups of varying size and composition. Patterns of range use in spider monkeys have been described as sex-segregated, with males and females often ranging separately, females utilizing core areas that encompass only a fraction of the entire community range, and males using much larger portions of the community range that overlap considerably with the core areas of females and other males. Males are also reported to use the boundary areas of community home ranges more often than females. Spider monkeys thus seem to parallel the "male-bonded" patterns of ranging and association found among some groups of chimpanzees. Over several years of research on one group of spider monkeys (Ateles belzebuth) in Yasuní National Park, Ecuador, we characterized the ranging patterns of adult males and females and evaluated the extent to which they conform to previously reported patterns. In contrast to ranging patterns seen at several other spider monkey sites, the ranges of our study females overlapped considerably, with little evidence of exclusive use of particular areas by individual monkeys. Average male and female home range size was comparable, and males and females were similar in their use of boundary areas. These ranging patterns are similar to those of "bisexually bonded" groups of chimpanzees in West Africa. We suggest that the less sex-segregated ranging patterns seen in this particular group of spider monkeys may be owing to a history of human disturbance in the area and to lower genetic relatedness between males, highlighting the potential for flexibility some aspects of the spider monkeys' fission,fusion social system. Am. J. Primatol. 72:129,141, 2010. © 2009 Wiley-Liss, Inc. [source] | ||||||||||||||||||||||||||||||||||||||||