Distribution by Scientific Domains
Distribution within Life Sciences

Kinds of Park

  • barrier reef marine park
  • bwindi impenetrable national park
  • comoé national park
  • doñana national park
  • elephant park
  • great barrier reef marine park
  • hluhluwe-imfolozi park
  • hwange national park
  • hyde park
  • impenetrable national park
  • island marine park
  • isle royale national park
  • kakadu national park
  • kibale national park
  • kruger national park
  • mahale mountain national park
  • manu national park
  • marine park
  • mountain national park
  • national park
  • natural park
  • ranomafana national park
  • reef marine park
  • royale national park
  • serengeti national park
  • tembe elephant park
  • yasuní national park
  • yellowstone national park
  • yosemite national park
  • zoological park

  • Terms modified by Park

  • park area
  • park cancer institute

  • Selected Abstracts


    JOURNAL OF PHYCOLOGY, Issue 1 2007
    Corinne R. Lehr
    The unicellular eukaryotic algae Cyanidium, Galdieria, and Cyanidioschyzon (herein referred to as "cyanidia") are the only photoautotrophs occurring in acidic (pH<4.0) geothermal environments at temperatures above 40°C. In Yellowstone National Park (YNP), we examined an annual event we refer to as "mat decline," where cyanidial mats undergo a seasonably defined color fading. Monthly sampling of chemical, physical, and biological features revealed that spring aqueous chemistry was essentially invariant over the 1-year sampling period. However, multiple regression analysis suggested that a significant proportion of algal most probable number (MPN) count variation could be explained by water temperature and UV,visible (VIS) light exposure. Irradiance manipulations (filtering) were then coupled with 14CO2 incorporation experiments to directly demonstrate UV inhibition of photosynthesis. Population dynamics were also evident in 18S rDNA PCR clone libraries, which were different in composition at MPN maxima and minima, and again evident in PCR-amplified chloroplast genomic short sequence repeat (SSR) analysis. PCR-cloned SSRs of the YNP isolates and mats were very similar to Cyanidioschyzon merolae Luca, Taddei et Varano, although distance analysis could distinguish the YNP cyanidia from the genome sequenced C. merolae that was isolated in Italy. Unexpectedly, while phylogenetic analysis of 18S rDNA sequences and SSR sequences derived from YNP cyanidial mats and pure cultures suggested these algae are most closely related to C. merolae (99.7% identity), cell morphology was consistent with the genera Galdieria and Cyanidium. [source]


    JOURNAL OF PHYCOLOGY, Issue 1 2001
    Article first published online: 21 DEC 200


    M.S. Bedinger
    ABSTRACT: Devils Hole is a collapse depression connected to the regional carbonate aquifer of the Death Valley ground water flow system. Devils Hole pool is home to an endangered pupfish that was threatened when irrigation pumping in nearby Ash Meadows lowered the pool stage in the 1960s. Pumping at Ash Meadows ultimately ceased, and the stage recovered until 1988, when it began to decline, a trend that continued until at least 2004. Regional ground water pumping and changes in recharge are considered the principal potential stresses causing long term stage changes. A regression was found between pumpage and Devils Hole water levels. Though precipitation in distant mountain ranges is the source of recharge to the flow system, the stage of Devils Hole shows small change in stage from 1937 to 1963, a period during which ground water withdrawals were small and the major stress on stage would have been recharge. Multiple regression analyses, made by including the cumulative departure from normal precipitation with pumpage as independent variables, did not improve the regression. Drawdown at Devils Hole was calculated by the Theis Equation for nearby pumping centers to incorporate time delay and drawdown attenuation. The Theis drawdowns were used as surrogates for pumpage in multiple regression analyses. The model coefficient for the regression, R2= 0.982, indicated that changes in Devils Hole were largely due to effects of pumping at Ash Meadows, Amargosa Desert, and Army 1. [source]

    Haplotype analysis of the PARK 11 gene, GIGYF2, in sporadic Parkinson's disease,

    MOVEMENT DISORDERS, Issue 3 2009
    Greg T. Sutherland PhD
    Abstract Familial Parkinsonism (PARK) genes are strong candidates for conferring susceptibility to common forms of PD. However, most studies to date have provided little evidence that their common variants substantially influence disease risk. Recently, mutations were described in the gene, GIGYF2 (TNRC15), located at the PARK11 locus (2q37.1). Here, we use a haplotype tagging approach to examine common variation in the GIGYF2 gene and PD risk. PD cases (n = 568) and age and gender-matched control subjects (n = 568) were recruited from three specialist movement disorder clinics in Brisbane (Australia) and the Australian electoral roll. Twelve tagging SNPs were assessed in all subjects and haplotype and genotype associations were explored. Overall our findings suggest that common genetic variants of GIGYF2 do not significantly affect sporadic PD risk in Australian Caucasians. © 2008 Movement Disorder Society [source]


    THE HEYTHROP JOURNAL, Issue 3 2007
    T. F. MORRIS
    I offer an exegesis of a few pages of the Concluding Unscientific Postscript and explain how going to Deer Park religiously fits into the general structure of Kierkegaard's thought. Because desiring God requires passion, and passion requires energy, there is a limit to how long any individual person can maintain a continuous desire for God. Kierkegaard discusses how a person who is at that limit can maintain a less intense love of God as he allows himself to desire temporal things. [source]

    Gastrointestinal Bacterial Transmission among Humans, Mountain Gorillas, and Livestock in Bwindi Impenetrable National Park, Uganda

    ecología de enfermedades; Escherichia coli; primates; salud del ecosistema; zoonosis Abstract:,Habitat overlap can increase the risks of anthroponotic and zoonotic pathogen transmission between humans, livestock, and wild apes. We collected Escherichia coli bacteria from humans, livestock, and mountain gorillas (Gorilla gorilla beringei) in Bwindi Impenetrable National Park, Uganda, from May to August 2005 to examine whether habitat overlap influences rates and patterns of pathogen transmission between humans and apes and whether livestock might facilitate transmission. We genotyped 496 E. coli isolates with repetitive extragenic palindromic polymerase chain reaction fingerprinting and measured susceptibility to 11 antibiotics with the disc-diffusion method. We conducted population genetic analyses to examine genetic differences among populations of bacteria from different hosts and locations. Gorilla populations that overlapped in their use of habitat at high rates with people and livestock harbored E. coli that were genetically similar to E. coli from those people and livestock, whereas E. coli from gorillas that did not overlap in their use of habitats with people and livestock were more distantly related to human or livestock bacteria. Thirty-five percent of isolates from humans, 27% of isolates from livestock, and 17% of isolates from gorillas were clinically resistant to at least one antibiotic used by local people, and the proportion of individual gorillas harboring resistant isolates declined across populations in proportion to decreasing degrees of habitat overlap with humans. These patterns of genetic similarity and antibiotic resistance among E. coli from populations of apes, humans, and livestock indicate that habitat overlap between species affects the dynamics of gastrointestinal bacterial transmission, perhaps through domestic animal intermediates and the physical environment. Limiting such transmission would benefit human and domestic animal health and ape conservation. Resumen:,El traslape de hábitats puede incrementar los riesgos de transmisión de patógenos antroponótica y zoonótica entre humanos, ganado y simios silvestres. Recolectamos bacterias Escherichia coli de humanos, ganado y gorilas de montaña (Gorilla gorilla beringei) en el Parque Nacional Bwindi Impenetrable, Uganda, de mayo a agosto 2005 para examinar sí el traslape de hábitat influye en las tasas y patrones de transmisión de patógenos entre humanos y simios y sí el ganado facilita esa transmisión. Determinamos el genotipo de 496 aislados de E. coli con marcaje de reacción en cadena de polimerasa palindrómica extragénica (rep-PCR) y medimos la susceptibilidad a 11 antibióticos con el método de difusión de disco. Realizamos análisis de genética poblacional para examinar las diferencias genéticas entre poblaciones de bacterias de huéspedes y localidades diferentes. Las poblaciones de gorilas con alto grado de traslape en el uso de hábitat con humanos y ganado presentaron E. coli genéticamente similar a E. coli de humanos y ganado, mientras que E. coli de gorilas sin traslape en el uso hábitat con humanos y ganado tuvo relación lejana con las bacterias de humanos y ganado. Treinta y cinco porciento de los aislados de humanos, 27% de los aislados de ganado y 17% de los aislados de gorilas fueron clínicamente resistentes a por lo menos un antibiótico utilizado por habitantes locales, y la proporción de gorilas individuales con presencia de aislados resistentes declinó en las poblaciones proporcionalmente con la disminución en el grado de traslape con humanos. Estos de patrones de similitud genética y resistencia a antibióticos entre E. coli de poblaciones de simios, humanos y ganado indican que el traslape de hábitat entre especies afecta la dinámica de transmisión de bacterias gastrointestinales, probablemente a través de animales domésticos intermediarios y el ambiente físico. La limitación de esa transmisión beneficiaría a la salud de humanos y animales domésticos y a la conservación de simios. [source]

    The Contribution of Long-Term Research at Gombe National Park to Chimpanzee Conservation

    chimpancé; conservación de simios mayores; Parque Nacional Gombe; Tanzania Abstract:,Long-term research projects can provide important conservation benefits, not only through research specifically focused on conservation problems, but also from various incidental benefits, such as increased intensity of monitoring and building support for the protection of an area. At Gombe National Park, Tanzania, long-term research has provided at least four distinct benefits to wildlife conservation. (1) Jane Goodall's groundbreaking discoveries of chimpanzee (Pan troglodytes) tool use, hunting, and complex social relationships in what was then a game reserve drew attention to the area and created support for upgrading Gombe to national park status in 1968. (2) The highly publicized findings have earned Gombe and Tanzania the attention of a worldwide public that includes tourists and donors that provide financial support for Gombe, other parks in Tanzania, and chimpanzee conservation in general. (3) Crucial information on social structure and habitat use has been gathered that is essential for effective conservation of chimpanzees at Gombe and elsewhere. (4) A clear picture of Gombe's chimpanzee population over the past 40 years has been determined, and this has helped identify the greatest threats to the viability of this population, namely disease and habita loss outside the park. These threats are severe and because of the small size of the population it is extremely vulnerable. Research at Gombe has led to the establishment of conservation education and development projects around Gombe, which are needed to build local support for the park and its chimpanzees, but saving these famous chimpanzees will take a larger integrated effort on the part of park managers, researchers, and the local community with financial help from international donors. Resumen:,Los proyectos de investigación de largo plazo pueden proporcionar beneficios importantes a la conservación, no solo a través de investigación enfocada específicamente a problemas de conservación, sino también a través de varios beneficios incidentales, como una mayor intensidad de monitoreo y construcción de soporte para la protección de un área. En el Parque Nacional Gombe, Tanzania, la investigación a largo plazo ha proporcionado por lo menos cuatro beneficios a la conservación de vida silvestre. (1) Los descubrimientos innovadores de Jane Goodall sobre el uso de herramientas, la cacería y las complejas relaciones sociales de chimpancés en lo que entonces era una reserva de caza atrajeron la atención al área y crearon el soporte para cambiar a Gombe a estatus de parque nacional en 1968. (2) Los hallazgos muy publicitados han ganado para Gombe y Tanzania la atención del público en todo el mundo incluyendo turistas y donadores que proporcionan soporte financiero a Gombe, otros parques en Tanzania y a la conservación de chimpancés en general. (3) Se ha reunido información crucial sobre la estructura social y el uso del hábitat que ha sido esencial para la conservación efectiva de chimpancés en Gombe y otros sitios. (4) Se ha determinado un panorama claro de la población de chimpancés en Gombe durante los últimos 40 años, y esto a ayudado a identificar las mayores amenazas a la viabilidad de esta población, a saber enfermedades y pérdida de hábitat fuera del parque. Estas amenazas son severas y la población es extremadamente vulnerable por su tamaño pequeño. La investigación en Gombe ha llevado al establecimiento de proyectos de desarrollo y de educación para la conservación en los alrededores del parque, lo cual es necesario para encontrar soporte local para el parque y sus chimpancés, pero el rescate de estos famosos chimpancés requerirá de un esfuerzo más integrado de parte de los manejadores del parque, investigadores y la comunidad local con la ayuda financiera de donadores internacionales. [source]

    Incorporation of Recreational Fishing Effort into Design of Marine Protected Areas

    consulta pública; modelos de reservas marinas; pesca con caña; suposiciones de poza dinámica Abstract:,Theoretical models of marine protected areas (MPAs) that explore benefits to fisheries or biodiversity conservation often assume a dynamic pool of fishing effort. For instance, effort is homogenously distributed over areas from which subsets of reserves are chosen. I tested this and other model assumptions with a case study of the multiple-use Jervis Bay Marine Park. Prior to zoning of the park I conducted 166 surveys of the park's recreational fisheries, plotting the location of 16,009 anglers. I converted these plots into diagrams of fishing effort and analyzed correlates between fishing and habitat and the effect of two reserve designs,the draft and final zoning plans of the park,on the 15 fisheries observed. Fisheries were strongly correlated with particular habitats and had negatively skewed and often bimodal spatial distribution. The second mode of intensely fished habitat could be 6 SD greater than the fishery's mean allocation of effort by area. In the draft-zoning plan, sanctuary zone (no-take) area and potential subduction of fishing effort were similar. In the final plan, which was altered in response to public comment, the area of sanctuary zone increased, and the impact on fishing effort decreased. In only one case was a fishery's most intensely targeted location closed to fishing. Because of the discriminating manner with which fishers target habitats, if simple percentage targets are used for planning, sanctuary location can be adjusted to avoid existing fishing effort. According to modeled outcomes, the implication of this may be diminished reserve effectiveness. To address this, reserve area should be implicitly linked to subducted fishing effort when promoting or modeling MPAs. Resumen:,Los modelos teóricos de áreas marinas protegidas (AMPs) que exploran los beneficios para las pesquerías o la conservación de la biodiversidad a menudo asumen que hay una poza dinámica en el esfuerzo de pesca. Por ejemplo, el esfuerzo es distribuido homogéneamente en áreas en las que se seleccionan subconjuntos de reservas. Probé esta y otras suposiciones del modelo con un estudio de caso del Parque Marino Jarvis Bay. Antes de la zonificación del parque, realicé 166 muestreos de las pesquerías recreativas del parque, dibujando la localización de 16,009 pescadores con caña. Convertí estos dibujos en diagramas de esfuerzo de pesca y analicé las correlaciones entre la pesca, el hábitat y el efecto de dos diseños de reserva,el anteproyecto y los planes finales de zonificación del parque,sobre las 15 pesquerías observadas. Las pesquerías se correlacionaron fuertemente con los hábitats particulares y tenían una distribución espacial sesgada negativamente y a menudo bimodal. El segundo tipo de hábitat pescado intensivamente podría ser 6 DS mayor que la asignación promedio de esfuerzo de pesquería por unidad de área. En el anteproyecto de plan de zonificación, el área santuario (sin pesca) y la subducción potencial del esfuerzo de pesca eran similares. En el plan final, que fue alterado en respuesta a comentarios del público, el área del santuario fue incrementada, y el impacto del esfuerzo de pesca disminuyó. En solo un caso fue cerrado a la pesca la localidad de pesca más intensiva. Debido a la forma discriminada en que los pescadores eligen los hábitats, si se utilizan objetivos porcentuales simples para la planificación, la localización del santuario puede ser ajustada para evitar el esfuerzo de pesca existente. De acuerdo con los resultados del modelo, la implicación puede ser la disminución de la efectividad de la reserva. Para abordar esto, el área de la reserva debiera estar implícitamente relacionada con la reducción del esfuerzo de pesca cuando se promueven o modelan AMPs. [source]

    The Journal of the Society for Conservation Biology A global community of conservation professionals

    Article first published online: 27 MAR 200
    Cover: Old-growth forest of the Hoh River Valley, Olympic National Park, Washington (U.S.A.). For decades the U.S. Pacific Norwest has been a center of controversy over logging and endangered species. This special section explores progress made by the Northwest Forest Plan,a global example of land-use planning,a decade after it was established to end the stalemate over logging and endangered species. Authors include some of the key architects involved in its creation and implementation. Photo by Kevin Schafer. See pages 274,374. [source]

    The Cost Efficiency of Wild Dog Conservation in South Africa

    crianza de especies cinegéticas; financiamiento de donantes; Lycaon pictus; metapoblación; reintroducción Abstract:,Aside from Kruger National Park, no other suitable reserves of sufficient size exist in South Africa that will hold a viable population of wild dogs (Lycaon pictus). Consequently, conservation efforts have been focused on creating a metapopulation through a series of wild dog reintroductions into isolated fenced reserves. Additional potential exists for conserving wild dogs on private ranch land. Establishing the metapopulation was an expensive process, accounting for approximately 75% of the US$380,000 spent on wild dog conservation in South Africa during 1997-2001. The principal goal of the metapopulation project was to reduce the risk of catastrophic population decline. Now that this has been achieved, we developed a uniform cost-efficiency index to estimate the cost efficiency of current and potential future conservation strategies in South Africa. Conserving wild dogs in large protected areas was predicted to be the most cost-efficient conservation strategy (449 packs/$100,000 expenditure). Establishing the metapopulation has been less cost efficient (23 packs/$100,000), and expansion of the metapopulation was predicted to be even less cost efficient if predation by wild dogs results in additional costs, as is to be expected if private reserves are used for reintroductions (3-13 packs/$100,000). Because of low logistical costs, conserving wild dogs in situ on private ranch land was potentially more cost efficient than reintroducing wild dogs (14-27 packs/$100,000). We recommend that donor funding be used to reintroduce wild dogs into transfrontier parks, when they are established, to maintain the existing metapopulation and to establish conservation programs involving wild dogs on private ranch land. Investing in the expansion of the metapopulation should be limited to state-owned nature reserves willing to carry predation costs without compensation. Resumen:,Además del Parque Nacional Kruger, en África del Sur no existen otras reservas de suficiente tamaño como para mantener una población viable de perros salvajes (Lycaon pictus). En consecuencia, los esfuerzos de conservación se han enfocado en la creación de una metapoblación por medio de una serie de reintroducciones en pequeñas reservas cercadas. Hay un potencial adicional para la conservación de perros salvajes en terrenos privados. El establecimiento de la metapoblación fue un proceso costoso, ,75% de US $380,000 que fueron gastados en la conservación de perros salvajes entre 1997 y 2001 en África del Sur. La meta principal del proyecto de metapoblación fue la reducción del riesgo de una declinación catastrófica de la población. Ya que esto se ha logrado, desarrollamos un índice de rentabilidad uniforme para estimar la rentabilidad de las actuales y potenciales estrategias de conservación en África del Sur. Se predijo que la estrategia de conservación de más rentable (449manadas/$100,000 de gasto) era la conservación de perros salvajes en áreas protegidas grandes. El establecimiento de la metapoblación ha sido menos rentable (23 manadas/$100,000), y se predijo que la expansión de la metapoblación sería aun menos rentable si la depredación por perros salvajes resulta en costos adicionales, como se esperaría si se utilizan reservas privadas para las reintroducciones (3-13 manadas/$100,000). Debido a los bajos costos de logística, la conservación de perros salvajes in situ en terrenos privados fue potencialmente más rentable que reintroducir a los perros salvajes (14-27 manadas/$100,000). Recomendamos que el financiamiento de donantes sea utilizado para reintroducir perros salvajes en parque transfronterizos, cuando sean establecidos, para mantener a la metapoblación existente y para establecer programas de conservación que involucren a perros salvajes en terrenos privados. La inversión en la expansión de la metapoblación deberá limitarse a reservas naturales propiedad del estado que estén dispuestas a absorber los costos de la depredación sin ser compensadas. [source]

    Conservation Alliances with Indigenous Peoples of the Amazon

    The future of Amazonian indigenous reserves is of strategic importance for the fate of biodiversity in the region. We examined the legislation governing resource use on indigenous lands and summarize the history of the Kayapo people's consolidation of their >100,000 km2 territory. Like many Amazonian indigenous peoples, the Kayapo have halted the expansion of the agricultural frontier on their lands but allow selective logging and gold mining. Prospects for long-term conservation and sustainability in these lands depend on indigenous peoples' understandings of their resource base and on available economic alternatives. Although forest conservation is not guaranteed by either tenure security or indigenous knowledge, indigenous societies' relatively egalitarian common-property resource management regimes,along with adequate incentives and long-term partnerships with conservation organizations,can achieve this result. Successful initiatives include Conservation International's long-term project with the A'ukre Kayapo village and incipient large-scale territorial monitoring and control in the Kayapo territory, and the Instituto SocioAmbiental (ISA) 15-year partnership with the peoples of the Xingu Indigenous Park, with projects centered on territorial monitoring and control, education, community organization, and economic alternatives. The recent agreement on ecological restoration of the Xingu River headwaters between ranchers and private companies, indigenous peoples, and environmentalists, brokered by ISA, marks the emergence of an indigenous and conservation alliance of sufficient cohesiveness and legitimacy to negotiate effectively at a regional scale. Resumen:,Las alianzas actuales entre indígenas y organizaciones de conservación en el Amazonas Brasileño han ayudado a obtener el reconocimiento oficial de ,1 millón de km2 en áreas indígenas. El futuro del as reservas indígenas amazónicas es de importancia estratégica para el futuro de la biodiversidad en la región. Examinamos la legislación que rige a la utilización de recursos en zonas indígenas y sintetizamos la historia de la consolidación del territorio > 100,000 km2 de la etnia Kayapo. Como muchos grupos Amazónicos, los Kayapo han detenido la expansión de la frontera agrícola en sus tierras pero permiten actividades madereras y mineras selectivas. Las perspectivas de conservación y sustentabilidad a largo plazo en estas tierras dependen del entendimiento de su base de recursos y de las alternativas económicas disponibles por parte de los grupos indígenas. A pesar de que ni la seguridad en la posesión ni el conocimiento indígena garantizan la conservación de los bosques, los regímenes indígenas de gestión de recursos de propiedad común relativamente igualitarios en conjunto con incentivos adecuados y asociaciones con organizaciones de conservación pueden obtener este resultado. Iniciativas exitosas incluyen el proyecto a largo plazo de Conservation International con el pueblo A'ukre Kayapo y el incipiente monitoreo y control territorial a gran escala en el territorio Kayapo y la asociación durante 15 años del Instituto Socioambiental (ISA) con habitantes del Parque Indígena Xingu, con proyectos enfocados al monitoreo y control territorial, a la educación, a la organización comunitaria y a alternativas económicas. El reciente acuerdo, negociado por ISA, entre rancheros y compañías privadas, grupos indígenas y ambientalistas para la restauración ecológica del Río Xingu marca el surgimiento de una alianza indígena y de conservación con la cohesión y legitimidad suficientes para negociar efectivamente a escala regional. [source]

    Experimental Assessment of Coral Reef Rehabilitation Following Blast Fishing

    arrecifes de Indonesia; recuperación de arrecife de coral; restauración de arrecifes Abstract:,Illegal fishing with explosives has damaged coral reefs throughout Southeast Asia. In addition to killing fish and other organisms, the blasts shatter coral skeletons, leaving fields of broken rubble that shift in the current, abrading or burying new coral recruits, and thereby slowing or preventing reef recovery. Successful restoration and rehabilitation efforts can contribute to coral reef conservation. We used field experiments to assess the effectiveness of different low-cost methods for coral reef rehabilitation in Komodo National Park (KNP), Indonesia. Our experiments were conducted at three different spatial scales. At a scale of 1 × 1 m plots, we tested three different rehabilitation methods: rock piles, cement slabs, and netting pinned to the rubble. Significantly more corals per square meter grew on rocks, followed by cement, netting, and untreated rubble, although many plots were scattered by strong water current or buried by rubble after 2.5 years. To test the benefits of the most successful treatment, rocks, at more realistic scales, we established 10 × 10 m plots of rock piles at each of our nine sites in 2000. Three years after installation, coverage by hard corals on the rocks continued to increase, although rehabilitation in high current areas remained the most difficult. In 2002 rehabilitation efforts in KNP were increased over 6000 m2 to test four rock pile designs at each of four rubble field sites. Assuming that there is an adequate larval supply, using rocks for simple, low-budget, large-scale rehabilitation appears to be a viable option for restoring the structural foundation of damaged reefs. Resumen:,La pesca ilegal con explosivos ha dañado a arrecifes de coral en el sureste de Asia. Además de matar a peces y otros organismos, las explosiones destruyen esqueletos de corales, dejando campos de escombros rotos que se mueven con la corriente, erosionando o enterrando a reclutas de coral nuevos y por lo tanto disminuyen o previenen la recuperación del coral. Esfuerzos exitosos de restauración y rehabilitación pueden contribuir a la conservación de arrecifes de coral. Usamos experimentos de campo para evaluar la efectividad de diferentes métodos de bajo costo para la rehabilitación de arrecifes de coral en el Parque Nacional Komodo (PNK), Indonesia. Desarrollamos nuestros experimentos en tres escalas espaciales diferentes. A una escala de parcelas de 1 x 1 m, probamos tres métodos de rehabilitación: pilas de rocas, losas de cemento y redes sobre el escombro. Crecieron significativamente más corales por metro cuadrado sobre rocas, seguido por el cemento, redes y escombro sin tratamiento, aunque muchas parcelas fueron dispersadas por la fuerte corriente de agua o enterradas por escombros después de 2.5 años. Para probar los beneficios del tratamiento más exitoso, rocas, a escalas más realistas, en 2000 establecimos parcelas de 10 x10 m con pilas de rocas en cada unos de nuestros nueve sitios. Tres años después, la cobertura de corales duros sobre las rocas continuó incrementando, aunque la rehabilitación en áreas con corrientes fuertes fue la más difícil. En 2002, los esfuerzos de rehabilitación en PNK se incrementaron a 6000 m2 para probar cuatro diseños de pilas de rocas en cada uno de los cuatro sitios con escombros. Asumiendo que hay una adecuada existencia de larvas, la utilización de rocas para rehabilitación simple, de bajo costo y gran escala parece ser una opción viable para la restauración de la base estructural de arrecifes dañados. [source]

    An Ecological and Economic Assessment of the Nontimber Forest Product Gaharu Wood in Gunung Palung National Park, West Kalimantan, Indonesia

    Gary D. Paoli
    We studied the demographic effect and economic returns of harvesting aromatic gaharu wood from fungus-infected trees of Aquilaria malaccensis Lam. at Gunung Palung National Park, Indonesia, to evaluate the management potential of gaharu wood. Aquilaria malaccensis trees openface> 20 cm in diameter occurred at low preharvest densities (0.16,0.32 ha) but were distributed across five of six forest types surveyed. During a recent harvest, 75% of trees were felled, with harvest intensities ranging from 50% to 100% among forest types. Overall, 50% of trees contained gaharu wood, but trees at higher elevations contained gaharu wood more frequently ( 73%) than trees at lower elevation (27%). The mean density of regeneration ( juveniles> 15 cm in height) near adult trees (3,7 m away) was 0.2/m2, 200 times greater than at random in the forest (10/ha), but long-term data on growth and survivorship are needed to determine whether regeneration is sufficient for population recovery. Gaharu wood extraction from Gunung Palung was very profitable for collectors, generating an estimated gross financial return per day of US $8.80, triple the mean village wage. Yet, the estimated sustainable harvest of gaharu wood at natural tree densities generates a mean net present value of only $10.83/ha, much lower than that of commercial timber harvesting, the dominant forest use in Kalimantan. Returns per unit area could be improved substantially, however, by implementing known silvicultural methods to increase tree densities, increase the proportion of trees that produce gaharu wood, and shorten the time interval between successive harvests. The economic potential of gaharu wood is unusual among nontimber forest products and justifies experimental trials to develop small-scale cultivation methods. Resumen: Datos ecológicos y económicos son esenciales para la identificación de productos forestales no maderables tropicales con potencial para la extracción sostenible y rentable en un sistema bajo manejo. Estudiamos el efecto demográfico y los beneficios económicos de la cosecha de la madera aromática gaharu de árboles de Aquilaria malaccenis Lam infectados por hongos en el Parque Nacional Gunung Palung Indonesia para evaluar el potencial de manejo de la madera. Arboles de Aquilaria malaccenis> 20 cm de diámetro ocurrieron en bajas densidades precosecha (0.16,0.32 ha,1) pero se distribuyeron en cinco de los seis tipos de bosque muestreados. Durante una cosecha reciente, 75% de los árboles fueron cortados, con intensidades de cosecha entre 50 y 100% en los tipos de bosque. En conjunto, 50% de los árboles contenían madera gaharu, pero árboles de elevaciones mayores contenían madera gaharu más frecuentemente ( 73%) que árboles de elevaciones menores (27%). La densidad promedio de regeneración ( juveniles> 15 cm de altura) cerca de árboles adultos (de 3 a 7 m de distancia) fue de 0.2 m,2, 200 veces mayor que en el bosque (10 ha,1), pero se requieren datos a largo plazo sobre el crecimiento y la supervivencia para determinar si la regeneración es suficiente para la recuperación de la población. La extracción de madera gaharu de Gunung Palung fue muy redituable, generando un rendimiento financiero bruto estimado en US $8.80 diarios, el triple del salario promedio en la zona. Sin embargo, la cosecha sostenible estimada de madera gaharu en densidades naturales de árboles genera un valor presente neto de sólo $10.83 ha,1, mucho menor que el de la cosecha comercial de madera, uso dominante del bosque en Kalimantan. Sin embargo, los rendimientos por unidad de área podrían mejorar sustancialmente mediante la instrumentación de métodos silviculturales para incrementar la densidad de árboles, incrementar la proporción de árboles que producen madera gaharu y reducir el intervalo de tiempo entre cosechas sucesivas. El potencial económico de la madera gaharu es poco usual entre los productos forestales no maderables y justifica la experimentación para desarrollar métodos de cultivo en pequeña escala. [source]

    Noninvasive Stress and Reproductive Measures of Social and Ecological Pressures in Free-Ranging African Elephants

    C. A. H. Foley
    This, coupled with political pressures to delist the elephant, has created a need for noninvasive physiological measures that can quantify the long-term effects of past mortality patterns of this long-lived species. We collected fresh fecal samples from 16 female elephants in three different groups over 23 months at Tarangire National Park, Tanzania, and analyzed them for fecal progesterone and cortisol metabolites. Social and ecological measures were collected concurrently. Fecal progesterone metabolite measures corresponded significantly with stage of gestation, and appear to be able to confirm pregnancy in female elephants from as early as 3 months of gestation. We found that progesterone metabolite concentrations were significantly lower during the dry season than during the wet season after controlling for stage of gestation. Fecal cortisol metabolite concentrations showed the opposite seasonal pattern, being significantly higher in the dry season and inversely correlated with rainfall across seasons. Fecal cortisol metabolite concentrations also increased with group size and were correlated positively with dominance rank in the largest group. Our results suggest that measures of progesterone and cortisol metabolites in feces provide indices of reproductive function and physiological stress that can quantify both natural and human disturbances in African elephants. These measures are ideally suited for monitoring the long-term effects of social disruption from poaching and a variety of other management concerns. Resumen: Debido a la cacería furtiva, la población de elefante africano ( Loxodonta africana) declinó en un 60%, principalmente adultos, entre 1979 y 1988. Esto, aunado a presiones políticas para eliminar al elefante de las listas de especies en peligro, ha creado la necesidad de medidas fisiológicas no invasivas que puedan cuantificar efectos a largo plazo de patrones de mortalidad en el pasado de esta especie longeva. Recolectamos muestras fecales de 16 elefantes hembras en tres grupos diferentes en el Parque Nacional Tarangire, Tanzania a lo largo de 23 meses, y las analizamos para detectar metabolitos de progesterona fecal y de cortisol. Al mismo tiempo se recolectaron medidas sociales y ecológicas. Las medidas de metabolitos de progesterona fecal correspondieron significativamente con la etapa de gestación, y parecen permitir la confirmación de preñez en elefantes hembras tan temprano como a los tres meses de gestación. Las concentraciones de metabolitos de progesterona fueron significativamente menores durante la época de sequía que en la de lluvias después de controlar para la etapa de gestación. Las concentraciones de metabolitos de cortisol fecal mostraron un patrón estacional opuesto, siendo significativamente más altas en la época de sequía e inversamente correlacionados con la precipitación en todas las estaciones. Las concentraciones de metabolitos de cortisol fecal también incrementaron con el tamaño del grupo y se correlacionaron positivamente con el rango de dominancia en el grupo más grande. Nuestros resultados sugieren que las medidas de metabolitos de progesterona y cortisol en las heces proporcionan índices de la función reproductiva y del estrés fisiológico que puede cuantificar perturbaciones, tanto naturales como humanas, en elefantes africanos. Estas medidas son idealmente adecuadas para monitorear efectos a largo plazo de la disrupción social por la cacería furtiva y así como una variedad de aspectos del manejo. [source]

    Factors Affecting Population Assessments of Desert Tortoises

    Jerome E. Freilich
    With a wide geographic range and more living individuals than any other listed land animal, biologists have needed to detect population trends against a "noisy" background of strong annual changes. We obtained annual population estimates of desert tortoises over 6 consecutive years at a 2.59-km2 plot in Joshua Tree National Park, California. Our estimates, based on weekly spring surveys, varied substantially, particularly between wet and dry years. Concurrently, we followed 10 radiotagged animals for 3 years to corroborate the surveys. Population density was determined separately for each year and for all years combined. Our best population estimate was an average of 67 adult tortoises, three times more than the density reported in a 1978 survey of the same site. Annual mortality was low ( <10%), and the animals showed extreme site fidelity. Apparent changes in population size were most strongly related to the animals' varying susceptibility to capture. In dry years, home ranges decreased, captures decreased, and effort required to find each tortoise nearly doubled. Our data confirm that tortoises are likely to be undercounted during dry years and call into question earlier studies conducted during droughts. Resumen: Las tortugas del desierto han sido tema de controversia desde que fueron enlistadas como amenazadas en 1990. Con un amplio rango de distribución geográfica y más individuos vivos que cualquier otro animal terrestre enlistado, los biólogos han necesitado detectar tendencias poblacionales contra un trasfondo "ruidoso" de cambios anuales fuertes. Obtuvimos estimaciones de la población anual de tortugas del desierto por seis años consecutivos en un cuadrante de 2.59 Km2 en el Parque Nacional Joshua Tree de California. Nuestras estimaciones, basadas en sondeos semanales de primavera, variaron sustancialmente, particularmente al comparar años lluviosos con años secos. Al mismo tiempo, monitoreamos por tres años a 10 animales marcados con radiotransmisores para corroborar los sondeos. La densidad poblacional estuvo determinada por separado para cada año y para todos los años combinados. Nuestras mejores estimaciones de densidad poblacional fueron en promedio de 67 adultos, tres veces más que la densidad reportada en un sondeo de 1978 en el mismo sitio. La mortalidad anual fue baja ( <10%) y los animales mostraron una fidelidad extrema por el sitio. Los cambios aparentes en el tamaño poblacional estuvieron más fuertemente relacionados con la variación en la susceptibilidad de captura de los animales. En años secos, el rango de hogar disminuyó, las capturas disminuyeron, y el esfuerzo requerido para encontrar cada tortuga fue de casi el doble. Nuestros datos confirman que las tortugas son probablemente mal contadas ( menos) durante los años de seca y ponen en duda estudios previos realizados durante secas. [source]

    Treatment of erythrodermic psoriasis in HCV+ patient with adalimumab

    Antonio Giovanni Richetta
    ABSTRACT Erythrodermic psoriasis is a severe and disabling variant of psoriasis. The authors present the case of a 48-year-old man with psoriasis and hemophilia presented with a history of hepatitis C virus (HCV) infection treated with pegylated interferon alpha-2a and ribavirin therapy. At the end of antiviral therapy, skin manifestation progressively worsened, becoming erythrodermic, with lack of efficacy of steroid therapy. The authors decided to start biological therapy with induction dose of adalimumab (Humira, Abbott Laboratories, Abbott Park, Chicago, IL) 80 mg at Week 0 and 40 mg weekly. In our case, this resulted in a highly effective and safe treatment. [source]

    ,Model Tribes' and Iconic Conservationists?

    The Makuleke Restitution Case in Kruger National Park
    ABSTRACT This article investigates how the Makuleke community in Limpopo Province achieved iconic status in relation to land reform and community-based conservation discourses in South Africa and beyond. It argues that the situation may be more complex than it first appears, and the ways in which the Makuleke story has been deployed by NGOs, activists, academics, conservationists, the state and business may be too simplistic. The authors discuss historical representations of the Makuleke ,tribe' against the backdrop of their experiences of living in the borderland Pafuri region of the Kruger National Park prior to their forced removal. After investigating the ways in which the chieftaincy, and its relation to communal land, has been strengthened by local mobilizations against threats from the neighbouring Mhinga Tribal Authority, the authors suggest that a central tension in the Makuleke area is the conflict between democratic principles governing the legal entity in control of the land (i.e., the Communal Property Association), and traditionalist patriarchal principles of the Tribal Authority. The article shows how these restitution-linked processes became implicated in the establishment in 2002 of the Great Limpopo Transfrontier Park. The authors also argue that the image of the Makuleke as a ,model tribe' is both a product of changing historical circumstances and a contributor to contemporary discourses on land restitution and conservation. [source]

    Spatiotemporal changes of beetle communities across a tree diversity gradient

    Stephanie Sobek
    Abstract Aim, Plant and arthropod diversity are often related, but data on the role of mature tree diversity on canopy insect communities are fragmentary. We compare species richness of canopy beetles across a tree diversity gradient ranging from mono-dominant beech to mixed stands within a deciduous forest, and analyse community composition changes across space and time. Location, Germany's largest exclusively deciduous forest, the Hainich National Park (Thuringia). Methods, We used flight interception traps to assess the beetle fauna of various tree species, and applied additive partitioning to examine spatiotemporal patterns of diversity. Results, Species richness of beetle communities increased across the tree diversity gradient from 99 to 181 species per forest stand. Intra- and interspecific spatial turnover among trees contributed more than temporal turnover among months to the total ,-beetle diversity of the sampled stands. However, due to parallel increases in the number of habitat generalists and the number of species in each feeding guild (herbivores, predators and fungivores), no proportional changes in community composition could be observed. If only beech trees were analysed across the gradient, patterns were similar but temporal (monthly) species turnover was higher compared to spatial turnover among trees and not related to tree diversity. Main conclusions, The changes in species richness and community composition across the gradient can be explained by habitat heterogeneity, which increased with the mix of tree species. We conclude that understanding temporal and spatial species turnover is the key to understanding biodiversity patterns. Mono-dominant beech stands are insufficient to conserve fully the regional species richness of the remaining semi-natural deciduous forest habitats in Central Europe, and analysing beech alone would have resulted in the misleading conclusion that temporal (monthly) turnover contributes more to beetle diversity than spatial turnover among different tree species or tree individuals. [source]

    Phylogenetic relatedness and plant invader success across two spatial scales

    Marc W. Cadotte
    ABSTRACT Aim, Successful invaders often possess similar ecological traits that contribute to success in new regions, and thus under niche conservatism, invader success should be phylogenetically clustered. We asked if the degree to which non-native plant species are phylogenetically related is a predictor of invasion success at two spatial scales. Location, Australia , the whole continent and Royal National Park (south-eastern Australia). Methods, We used non-native plant species occupancy in Royal National Park, as well as estimated continental occupancy of these species from herbarium records. We then estimated phylogenetic relationships using molecular data from three gene sequences available on GenBank (matK, rbcL and ITS1). We tested for phylogenetic signals in occupancy using Blomberg's K. Results, Whereas most non-native plants were relatively scarce, there was a strong phylogenetic signal for continental occupancy, driven by the clustering of successful species in Asteraceae, Caryophyllaceae, Poaceae and Solanaceae. However, we failed to detect a phylogenetic signal at the park scale. Main Conclusions, Our results reveal that at a large spatial scale, invader success is phylogenetically clustered where ecological traits promoting success appear to be shared among close relatives, indicating that phylogenetic relationships can be useful predictors of invasion success at large spatial scales. At a smaller, landscape scale, there was no evidence of phylogenetic clustering of invasion success, and thus, relatedness plays a much reduced role in determining the relative success of invaders. [source]

    Elephants and water provision: what are the management links?

    I. P. J. Smit
    ABSTRACT In a recent paper we demonstrated that elephant bull groups and mixed herds exhibited spatial and resource segregation across the Kruger National Park. It was found, inter alia, that both bull groups and mixed herds occurred more frequently closer to rivers than expected if they were randomly distributed, but that only bull groups occurred more frequently closer to the artificial waterholes. Although Chamaillé-Jammes et al. (2007) accepted these results, they disagreed with our interpretation regarding the potential effect that closure of artificial waterholes might have. Here we address some of the specific concerns expressed and provide a broader context regarding water provision and elephant management. Although water provision can influence elephant density and distribution, we argue that the effectiveness of surface-water manipulation as a management tool will depend on (1) natural surface-water availability, (2) forage quality, (3) elephant densities, (4) position of a population on its growth trajectory, and (5) management objectives. Even though elephants are water-dependent, the effectiveness of water provision as a management tool will therefore be area- and population-specific and will depend on management objectives. [source]

    Rapid plant diversity assessment using a pixel nested plot design: A case study in Beaver Meadows, Rocky Mountain National Park, Colorado, USA

    Mohammed A. Kalkhan
    ABSTRACT Geospatial statistical modelling and thematic maps have recently emerged as effective tools for the management of natural areas at the landscape scale. Traditional methods for the collection of field data pertaining to questions of landscape were developed without consideration for the parameters of these applications. We introduce an alternative field sampling design based on smaller unbiased random plot and subplot locations called the pixel nested plot (PNP). We demonstrate the applicability of the PNP design of 15 m × 15 m to assess patterns of plant diversity and species richness across the landscape at Rocky Mountain National Park (RMNP), Colorado, USA in a time (cost)-efficient manner for field data collection. Our results produced comparable results to a previous study in the Beaver Meadow study (BMS) area within RMNP, where there was a demonstrated focus of plant diversity. Our study used the smaller PNP sampling design for field data collection which could be linked to geospatial information data and could be used for landscape-scale analyses and assessment applications. In 2003, we established 61 PNP in the eastern region of RMNP. We present a comparison between this approach using a sub-sample of 19 PNP from this data set and 20 of Modified Whittaker nested plots (MWNP) of 20 m × 50 m that were collected in the BMS area. The PNP captured 266 unique plant species while the MWNP captured 275 unique species. Based on a comparison of PNP and MWNP in the Beaver Meadows area, RMNP, the PNP required less time and area sampled to achieve a similar number of species sampled. Using the PNP approach for data collection can facilitate the ecological monitoring of these vulnerable areas at the landscape scale in a time- and therefore cost-effective manner. [source]

    The role of environmental gradients in non-native plant invasion into burnt areas of Yosemite National Park, California

    Rob Klinger
    ABSTRACT Fire is known to facilitate the invasion of many non-native plant species, but how invasion into burnt areas varies along environmental gradients is not well-understood. We used two pre-existing data sets to analyse patterns of invasion by non-native plant species into burnt areas along gradients of topography, soil and vegetation structure in Yosemite National Park, California, USA. A total of 46 non-native species (all herbaceous) were recorded in the two data sets. They occurred in all seven of the major plant formations in the park, but were least common in subalpine and upper montane conifer forests. There was no significant difference in species richness or cover of non-natives between burnt and unburnt areas for either data set, and environmental gradients had a stronger effect on patterns of non-native species distribution, abundance and species composition than burning. Cover and species richness of non-natives had significant positive correlations with slope (steepness) and herbaceous cover, while species richness had significant negative correlations with elevation, the number of years post-burn, and cover of woody vegetation. Non-native species comprised a relatively minor component of the vegetation in both burnt and unburnt areas in Yosemite (percentage species = 4%, mean cover < 6.0%), and those species that did occur in burnt areas tended not to persist over time. The results indicate that in many western montane ecosystems, fire alone will not necessarily result in increased rates of invasion into burnt areas. However, it would be premature to conclude that non-native species could not affect post-fire succession patterns in these systems. Short fire-return intervals and high fire severity coupled with increased propagule pressure from areas used heavily by humans could still lead to high rates of invasion, establishment and spread even in highly protected areas such as Yosemite. [source]

    Regional differences in kelp-associated algal assemblages on temperate limestone reefs in south-western Australia

    Thomas Wernberg
    Abstract.,Ecklonia radiata (C. Agardh) J. Agardh kelp beds , a characteristic feature of the nearshore environment along the south-west Australian coastline , contribute significantly to the coastal biodiversity in temperate Australia, yet, little is known about the organization of these macroalgal assemblages. By compiling existing and new data sets from habitat surveys, we have characterized and compared the structure of kelp-associated macroalgal assemblages in three regions (Marmion Lagoon, Hamelin Bay and the marine environment neighbouring the Fitzgerald River National Park) across more than 1000 kilometres of the south-west Australian coastline. 152 macroalgal taxa had been recognized within the three regions and this is in the range of species richness reported from other Australian and African kelp beds. The kelp-associated algal assemblages were regionally distinct, 66% of all taxa were only found in one region and only 17 taxa were found in all three regions. Adjacent regions shared an additional 13,15 taxa. The regional shifts in assemblage structure were evident in species composition of both canopy and understorey. The organization of assemblages followed a spatial hierarchy where differences in assemblage structure were larger among regions (hundreds of kilometres apart) than among sites within regions (kilometres apart) and differences among sites within region were larger than differences among quadrats within sites (metres apart). Despite this hierarchy each level of nesting contributed approximately the same to total variation in assemblage structure and these spatial patterns were stronger than temporal differences from seasons to 2,3 years. Our results suggest that local and small-scale processes contribute considerably to heterogeneity in macroalgal assemblages throughout south-western Australia, and, in particular, our results are consistent with E. radiata exerting a strong influence on macroalgal assemblage structure. Further, our study contradicts the existence of a general south-west Australian kelp assemblage, although a few species may form the core of E. radiata associations across regions. [source]

    Diversity, distinctiveness and conservation status of the Mediterranean coastal dung beetle assemblage in the Regional Natural Park of the Camargue (France)

    Jorge Miguel Lobo
    Abstract. The Mediterranean region as a whole has the highest dung beetle species richness within Europe. Natural coastal habitats in this region are among those which have suffered severe human disturbance. We studied dung beetle diversity and distinctiveness within one of the most important coastal protected areas in the west Euro-Mediterranean region (the regional Park of Camargue, southern France) and made comparisons of dung beetle assemblages with other nearby Mediterranean localities, as well as with other coastal protected area (Doñana National Park, Spain). Our finding showed that: (1) The species richness of coastal habitats in the Camargue is low and only grasslands showed a similar level of species richness and abundance to inland habitats of other Mediterranean localities. The unique habitats of the coastal area (beaches, dunes and marshes) are largely colonized by species widely distributed in the hinterland. (2) In spite of their low general distinctiveness, dune and marsh edges are characterized by the occurrence of two rare, vulnerable, specialized and large roller dung beetle species of the genus Scarabaeus. As with other Mediterranean localities, current findings suggest a recent decline of Scarabaeus populations and the general loss of coastal dung beetle communities in Camargue. (3) The comparison of dung beetle assemblages between the Camargue and Doñana shows that, in spite of the low local dung beetle species richness in the Camargue, the regional dung beetle diversity is similar between both protected areas. Unique historical and geographical factors can explain the convergence in regional diversity as well as the striking divergence in the composition of dung beetle assemblages between both territories. [source]

    A new approach of selecting real input ground motions for seismic design: The most unfavourable real seismic design ground motions

    Chang-Hai Zhai
    Abstract This paper presents a new way of selecting real input ground motions for seismic design and analysis of structures based on a comprehensive method for estimating the damage potential of ground motions, which takes into consideration of various ground motion parameters and structural seismic damage criteria in terms of strength, deformation, hysteretic energy and dual damage of Park & Ang damage index. The proposed comprehensive method fully involves the effects of the intensity, frequency content and duration of ground motions and the dynamic characteristics of structures. Then, the concept of the most unfavourable real seismic design ground motion is introduced. Based on the concept, the most unfavourable real seismic design ground motions for rock, stiff soil, medium soil and soft soil site conditions are selected in terms of three typical period ranges of structures. The selected real strong motion records are suitable for seismic analysis of important structures whose failure or collapse will be avoided at a higher level of confidence during the strong earthquake, as they can cause the greatest damage to structures and thereby result in the highest damage potential from an extended real ground motion database for a given site. In addition, this paper also presents the real input design ground motions with medium damage potential, which can be used for the seismic analysis of structures located at the area with low and moderate seismicity. The most unfavourable real seismic design ground motions are verified by analysing the seismic response of structures. It is concluded that the most unfavourable real seismic design ground motion approach can select the real ground motions that can result in the highest damage potential for a given structure and site condition, and the real ground motions can be mainly used for structures whose failure or collapse will be avoided at a higher level of confidence during the strong earthquake. Copyright © 2007 John Wiley & Sons, Ltd. [source]

    Spatial and temporal hotspots of termite-driven decomposition in the Serengeti

    ECOGRAPHY, Issue 3 2010
    Bernd P. Freymann
    Ecosystem engineers are organisms that directly or indirectly control the availability of resources to other organisms by causing physical state changes in biotic or abiotic materials. Termites (Insecta, Isoptera) are among the most important ecosystem engineers in tropical ecosystems. We used a field experiment in the tall grasslands of Serengeti National Park, Tanzania, to investigate 1) the consumption by termites of grass litter and dung baits along the landscape gradient of catena position, and 2) seasonal variation in litter and dung removal. Our maps of termitaria and patterns of bait removal revealed clear spatial and temporal hotspots of termite activity. In the dry season termites removed more baits at the top-catena positions than at the bottom positions, but there was no effect of catena position in the wet season. Spatial hotspots of termite activity overlapped with those of both mammalian herbivores and predators. Within the framework of ecosystem engineering, this study suggests that intraspecific aspects of spatial heterogeneity and temporal variability deserve much greater consideration. [source]

    Integrating physiology, population dynamics and climate to make multi-scale predictions for the spread of an invasive insect: the Argentine ant at Haleakala National Park, Hawaii

    ECOGRAPHY, Issue 1 2010
    Stephen Hartley
    Mechanistic models for predicting species' distribution patterns present particular advantages and challenges relative to models developed from statistical correlations between distribution and climate. They can be especially useful for predicting the range of invasive species whose distribution has not yet reached equilibrium. Here, we illustrate how a physiological model of development for the invasive Argentine ant can be connected to differences in micro-site suitability, population dynamics and climatic gradients; processes operating at quite different spatial scales. Our study is located in the subalpine shrubland of Haleakala National Park, Hawaii, where the spread of Argentine ants Linepithema humile has been documented for the past twenty-five years. We report four main results. First, at a microsite level, the accumulation of degree-days recorded in potential ant nest sites under bare ground or rocks was significantly greater than under a groundcover of grassy vegetation. Second, annual degree-days measured where population boundaries have not expanded (456,521,degree-days), were just above the developmental requirements identified from earlier laboratory studies (445,degree-days above 15.9°C). Third, rates of population expansion showed a strong linear relationship with annual degree-days. Finally, an empirical relationship between soil degree-days and climate variables mapped at a broader scale predicts the potential for future range expansion of Argentine ants at Haleakala, particularly to the west of the lower colony and the east of the upper colony. Variation in the availability of suitable microsites, driven by changes in vegetation cover and ultimately climate, provide a hierarchical understanding of the distribution of Argentine ants close to their cold-wet limit of climatic tolerances. We conclude that the integration of physiology, population dynamics and climate mapping holds much promise for making more robust predictions about the potential spread of invasive species. [source]

    Genetic pattern of the recent recovery of European otters in southern France

    ECOGRAPHY, Issue 2 2008
    Xavier Janssens
    We investigated how landscape affects the population genetic structure and the dispersal of the elusive European otter Lutra lutra in a contemporary colonization context, over several generations and at the level of hydrographic basins. Our study area included 10 basins located in the Cévennes National Park (CNP), at the southern front of the natural otter recovery in France. Each basin comprised 50 to 300 km of permanent rivers that were surveyed for otter presence from 1991 to 2005. Faecal samples collected in 2004 and 2005 in this area were genotyped at 9 microsatellite loci, resulting in the identification of 70 genetically distinct individuals. Bayesian clustering methods were used to infer genetic structure of the populations and to compare recent gene flow to the observed colonization. At the regional level, we identified 2 distinct genetic clusters (NE and SW; FST=0.102) partially separated by ridges, suggesting that the CNP was recolonized by 2 genetically distinct otter populations. At the basin level, the genetic distance between groups of individuals in different basins was positively correlated to the mean slope separating these basins. The probable origins and directions of individual movements (i.e. migration between clusters and basin colonization inside clusters) were inferred from assignment tests. This approach shows that steep and dry lands can stop, impede or divert the dispersal of a mobile carnivore such as the otter. [source]

    Spatial distribution and environmental correlates of Australian snubfin and Indo-Pacific humpback dolphins

    ECOGRAPHY, Issue 3 2006
    Guido J. Parra
    We present data on the spatial distribution of Australian snubfin and humpback dolphins using boat-based line transect surveys in three adjacent bays located in the Far Northern Section of the Great Barrier Reef Marine Park, northeast Queensland. We used Geographic Information Systems (GIS), and both randomization and Mantel tests to examine the relationship between the spatial distribution of the dolphins and three simple, readily quantified, environmental variables: distance to land, distance to river mouth, and water depth. Mantel tests allowed us to make clear inferences about the correlation of the species' distributions with environmental variables, while taking into account spatial autocorrelation and intercorrelation among variables. Randomization tests indicated snubfin and humpback dolphins occur closer to land than would be expected at random. Two-sample randomization tests indicated snubfin dolphins were found closer to river mouths than were humpback dolphins. Taking spatial autocorrelation into account, Mantel tests indicated all environmental variables were correlated with the spatial distribution of snubfin and humpback dolphins. Interspecific differences in spatial distribution appeared to be related to proximity to river mouths. Preference by snubfin and humpback dolphins for nearshore, estuarine waters is likely related to the productivity of these tropical coastal areas. This spatial analysis suggests that existing protected areas in this region may not include the most critical habitats for snubfin and humpback dolphins. The techniques used here shown relationships between the spatial distribution of the dolphins and environmental features that should facilitate their management and conservation. [source]

    The influence of scale and patchiness on spider diversity in a semi-arid environment

    ECOGRAPHY, Issue 4 2002
    Mary E. A. Whitehouse
    Semi-arid scrubland in the Middle East consists of a soil crust matrix overlain with patches of perennial shrubs. To understand factors influencing biodiversity in this vulnerable landscape we need to understand how this mosaic of habitats influences associated fauna. Spiders are particularly abundant in this habitat so we asked if spider diversity differed between habitat patches and if different patch types contained either a subset of the regional species pool or specific species guilds. We also asked whether changes in the fractal nature of the microphytic and macrophytic patch mosaic altered spider diversity in this habitat. We found that the semi-arid scrubland at Sayeret Shaked Park (Israel) contains different spider communities that require patches of a certain quality to develop fully. Different patch types contain communities of different species, but the community structure of the patches is similar. We suggest that large-scale environmental factors typical of the site as a whole influence coarse-grained community structure, while small-scale differences between patch types result in the specialisation of species to different patch types. [source]