The relative impact of forest patch and landscape attributes on black howler monkey populations in the fragmented Lacandona rainforest, Mexico     

Víctor Arroyo-Rodríguez  Iraida M. González-Perez  Adriana Garmendia  Mireia Solà  Alejandro Estrada 《Landscape Ecology》2013,28(9):1717-1727

Land-use change is forcing many animal populations to inhabit forest patches in which different processes can threaten their survival. Some threatening processes are mainly related to forest patch characteristics, but others depend principally on the landscape spatial context. Thus, the impact of both patch and landscape spatial attributes needs to be assessed to have a better understanding of the habitat spatial attributes that constraint the maintenance of populations in fragmented landscapes. Here, we evaluated the relative effect of three patch-scale (i.e., patch size, shape, and isolation) and five landscape-scale metrics (i.e., forest cover, fragmentation, edge density, mean inter-patch isolation distance, and matrix permeability) on population composition and structure of black howler monkeys (Alouatta pigra) in the Lacandona rainforest, Mexico. We measured the landscape-scale metrics at two spatial scales: within 100 and 500 ha landscapes. Our findings revealed that howler monkeys were more strongly affected by local-scale metrics. Smaller and more isolated forest patches showed a lower number of individuals but at higher densities. Population density also tended to be positively associated to matrices with higher proportion of secondary forests and arboreal crops (i.e. with greater permeability), most probably because these matrices can offer supplementary foods. The immature-to-female ratio also increased with matrix permeability, shape complexity, and edge density; habitat characteristics that can increase landscape connectivity and sources availability. The prevention of habitat loss and isolation, and the increment of matrix permeability are therefore needed for the conservation of this endangered Neotropical mammal.  相似文献   

Science for action at the local landscape scale   总被引：4，自引：4，他引：0  

Paul Opdam  Joan Iverson Nassauer  Zhifang Wang  Christian Albert  Gary Bentrup  Jean-Christophe Castella  Clive McAlpine  Jianguo Liu  Stephen Sheppard  Simon Swaffield 《Landscape Ecology》2013,28(8):1439-1445

For landscape ecology to produce knowledge relevant to society, it must include considerations of human culture and behavior, extending beyond the natural sciences to synthesize with many other disciplines. Furthermore, it needs to be able to support landscape change processes which increasingly take the shape of deliberative and collaborative decision making by local stakeholder groups. Landscape ecology as described by Wu (Landscape Ecol 28:1–11, 2013) therefore needs three additional topics of investigation: (1) the local landscape as a boundary object that builds communication among disciplines and between science and local communities, (2) iterative and collaborative methods for generating transdisciplinary approaches to sustainable change, and (3) the effect of scientific knowledge and tools on local landscape policy and landscape change. Collectively, these topics could empower landscape ecology to be a science for action at the local scale.  相似文献   

Helpful hints in the cutting and planting of seed potatoes     

Albert G. Fradkin  George F. Dow  M. W. Parker 《American Journal of Potato Research》1963,40(3):103-107

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An instructional model for training competence in solving clinical problems     

Ramaekers SP  van Beukelen P  Kremer WD  van Keulen H  Pilot A 《Journal of veterinary medical education》2011,38(4):360-372

We examined the design of a course that aims to ease the transition from pre-clinical learning into clinical work. This course is based on the premise that many of the difficulties with which students are confronted in this transition result from a lack of experience in applying knowledge in real practice situations. It is focused on the development of competence in solving clinical problems; uses an instructional model with alternating clinical practicals, demonstrations, and tutorials; and extends throughout the last pre-clinical year. We used a "proof-of-concept" approach to establish whether the core principles of the course design are feasible with regard to achieving the intended results. With the learning functions and processes as a frame of reference, retrospective analysis of the course's design features shows that this design matches the conditions from theories of the development of competence in solving clinical problems and instructional design. Three areas of uncertainty in the design are identified: the quality of the cases (information, openness), effective teaching (student and teacher roles), and adjustment to the development of competence (progress, coherence).  相似文献   

Controls of infiltration–runoff processes in Mediterranean karst rangelands in SE Spain     

Xiao-Yan Li  Sergio Contreras  Albert Solé-Benet  Yolanda Cantón  Francisco Domingo  Roberto Lázaro  Henry Lin  Bas Van Wesemael  Juan Puigdefábregas 《CATENA》2011

Semiarid karst landscapes represent an important ecosystem surrounding the Mediterranean Basin for which little is known on runoff generation. Knowledge of the sources and patterns of variation in infiltration–runoff processes and their controls is important for understanding and modelling the hydrological functions of such ecosystems. The objectives of this paper are to determine the infiltration rates and their controls in a representative mountain karst area (Sierra de Gádor, SE Spain) at micro-plots and to investigate the integrated response of rainfall on a typical hillslope. Rainfall simulations in micro-plots and natural rainfall-runoff monitoring on a hillslope were carried out complementarily. We investigated the role of soil surface components (vegetation, rock outcrop, fracture, and soil crust), topographic position, antecedent soil moisture, and rainfall characteristics in regulating infiltration–runoff processes. Results of rainfall simulation revealed the importance of vegetation cover and the presence of rock fractures in promoting the infiltration in the limestone karst landscape, while bare patches and rock outcrops acted as sources for runoff. All plots with > 50% vegetation cover had no runoff with up to 55 mm h^− 1 of simulated rain. In contrast, nearly all bare plots had runoff under the same simulated rain, with runoff coefficients ranging from 3.1 to 20.6% on dry soil surface conditions, and from 2.0 to 65.4% on wet soil surfaces. Runoff coefficients amounted to 59.0–79.5% for rock outcrops without cracks, but were drastically reduced by the presence of cracks. The surfaces with rock fragments resting on the soil (generally located in the middle of the slopes) prevented more effectively the runoff generation than those surfaces where rock fragments were embedded in the top soil. Antecedent soil moisture had significant impact on runoff generation, with wet soil having doubled runoff coefficient, shortened time to runoff, and increased runoff rate compared to the same but dry soil. Linear regressions indicated that the main controls for constant infiltration rate were the cover percentages of vegetation and litter, plus rainfall intensity; while the major controls for runoff coefficient were the bare soil and vegetation coverage, plus rainfall intensity. High infiltration rates measured at the micro-plots agreed with low intra-event runoff coefficients (mostly below 1%) observed under natural rainfalls at the hillslope. Runoff depth and coefficient at the hillslope was significantly correlated with rainfall depth, maximum hourly rainfall intensity and antecedent precipitation over 20 days (AP₂₀). During the 1.5-year monitoring period from Sep-2003 to Mar-2005, the overall infiltration was 41% of the total rainfall amount and the maximum infiltration rate was almost 94% of the largest single rainfall event. The results from this study contribute to improved understanding of the magnitude and controls of the surface runoff in semiarid karst mountain areas.  相似文献   

New Bruce-ladder multiplex PCR assay for the biovar typing of Brucella suis and the discrimination of Brucella suis and Brucella canis     

López-Goñi I  García-Yoldi D  Marín CM  de Miguel MJ  Barquero-Calvo E  Guzmán-Verri C  Albert D  Garin-Bastuji B 《Veterinary microbiology》2011,154(1-2):152-155

Rapid and specific identification of Brucella suis at the biovar level is necessary because some of the biovars that infect animals are pathogenic for humans. None of the molecular typing methods described so far are able to discriminate B. suis biovars in a single test and differentiation of B. suis from Brucella canis by molecular approaches can be difficult. This article describes a new multiplex PCR assay, Suis-ladder, for fast and accurate identification of B. suis at the biovar level and the differentiation of B. suis, B. canis and Brucella microti. An advancement of the original Bruce-ladder PCR protocol which allows the correct discrimination of all known Brucella species is also described.  相似文献   

Genetic instability of Campylobacter coli in the digestive tract of experimentally infected pigs     

Leblanc-Maridor M  Denis M  Chidaine B  Rossero A  Seegers H  Beaudeau F  Belloc C 《Veterinary microbiology》2011,154(1-2):171-179

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Full-Scale Remediation of a Jet Fuel-Contaminated Soil: Assessment of Biodegradation, Volatilization, and Bioavailability     

Jos�� Luis R. Gallego  Carlos Sierra  Albert Permanyer  Ana I. Pel��ez  Demelza Men��ndez-Vega  Jes��s S��nchez 《Water, air, and soil pollution》2011,217(1-4):197-211

Here, we addressed biodegradation vs. volatilization processes, and also bioavailability limitations during biopile remediation of soil initially contaminated by more than 5,000 mg/kg of hydrocarbons. In order to select bioremediation strategies, we first conducted a biotreatability study, which included geochemical, textural, and microbiological characterization of the soil matrix. Next, we implemented five bioremediation approaches onsite in real-scale biopiles. In order to monitor hydrocarbon depletion and to distinguish between biological and non-biological processes, we analyzed chemical biomarkers by means of gas chromatography?Cmass spectrometry. In addition, a comprehensive study of soil grain size and its implications on bioavailability were studied. Furthermore, the evolution of microbial populations was also examined. Two of the strategies implemented in the biopiles (the combination of a slow-release fertilizer and a surfactant, and the use of an oleophilic fertilizer respectively) reduced the soil hydrocarbon content to under 500 mg/kg in 5 months. Additional results from this study indicate that volatilization was the predominant degradation process for light hydrocarbons (below 12 carbon atoms), whereas heavier compounds were mainly biodegraded. However, even in the most favorable situation, a residual concentration of hydrocarbons linked to the finer fraction of the soil was found.  相似文献   

Genome-wide association study for insect bite hypersensitivity susceptibility in horses revealed novel associated loci on chromosome 1     

Merina Shrestha  Marina Solé  Bart J. Ducro  Marie Sundquist  Ruth Thomas  Anouk Schurink  Susanne Eriksson  Gabriella Lindgren 《Zeitschrift für Tierzüchtung und Züchtungsbiologie》2020,137(2):223-233

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Exploring the genetics underpinning dynamic laryngeal collapse associated with poll flexion in Norwegian-Swedish Coldblooded Trotter racehorses     

B. D. Velie  P. M. Smith  C. T. Fjordbakk  M. Solé  K. Jäderkvist Fegraeus  M. K. Rosengren  K. H. Røed  C. F. Ihler  G. Lindgren  E. Strand 《Equine veterinary journal》2020,52(2):174-180

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