24 research outputs found
FReD: the Floral Reflectance Database - a web portal for analyses of flower colour
Background: Flower colour is of great importance in various fields relating to floral biology and pollinator behaviour. However, subjective human judgements of flower colour may be inaccurate and are irrelevant to the ecology and vision of the flower's pollinators. For precise, detailed information about the colours of flowers, a full reflectance spectrum for the flower of interest should be used rather than relying on such human assessments.
Methodology/Principal Findings: The Floral Reflectance Database (FReD) has been developed to make an extensive collection of such data available to researchers. It is freely available at http://www.reflectance.co.uk. The database allows users to download spectral reflectance data for flower species collected from all over the world. These could, for example, be used in modelling interactions between pollinator vision and plant signals, or analyses of flower colours in various habitats. The database contains functions for calculating flower colour loci according to widely-used models of bee colour space, reflectance graphs of the spectra and an option to search for flowers with similar colours in bee colour space.
Conclusions/Significance: The Floral Reflectance Database is a valuable new tool for researchers interested in the colours of flowers and their association with pollinator colour vision, containing raw spectral reflectance data for a large number of flower species
Gene-flow through space and time: dispersal, dormancy and adaptation to changing environments
Defining the Low End of Primate Social Complexity: The Social Organization of the Nocturnal White-Footed Sportive Lemur (Lepilemur leucopus)
Graphene nanostructures for memristive devices
Memristive nanoscale devices can generate intense fields by the application of relatively low voltages. This peculiar property allows fast, nonvolatile, and low-energy electrical switching as well as the possibility of retaining the internal resistance state according to the history of applied voltage and current. Memristors are predicted to revolutionize the current approaches in computer electronic architecture with their application, for instance, as resistive random access memory and for neuromorphic artificial intelligence. The use of graphene nanostructures for memristive switching systems offers an exciting alternative to other classes of materials, such as transition metal oxide and organic thin film
Dawn chorusing in guereza colobus monkeys
Dawn chorusing by guereza black-and-white colobus monkeys is one of the most impressive spectacles of African rainforests. This vocal behaviour is highly contagious, travelling from one neighbouring group to the next, until a wide forest area is covered by calling monkeys. Chorusing usually occurs up to 2 h before dawn, sometimes more than once, unless the preceding night was cold and wet. We conducted a series of playback experiments, which showed that guerezas' chorusing was difficult to elicit experimentally, suggesting that callers took several variables into account before responding to other monkeys' predawn calls. Acoustic analyses showed that morning calls were individually distinct, but we found no evidence that callers took individual identity into account in their decision to participate in chorusing. The only way to reliably elicit chorusing in our study area was to broadcast recordings of morning choruses for longer than 30 s and at a time when a chorus simultaneously emerged in a distant part of the forest.</p
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Establishment of a Cross-European Field Site Network in the ALARM Project for Assessing Large-Scale Changes in Biodiversity
The field site network (FSN) plays a central role in conducting joint research within all Assessing Large-scale Risks for biodiversity with tested Methods (ALARM) modules and provides a mechanism for integrating research on different topics in ALARM on the same site for measuring multiple impacts on biodiversity. The network covers most European climates and biogeographic regions, from Mediterranean through central European and boreal to subarctic. The project links databases with the European-wide field site network FSN, including geographic information system (GIS)-based information to characterise the test location for ALARM researchers for joint on-site research. Maps are provided in a standardised way and merged with other site-specific information. The application of GIS for these field sites and the information management promotes the use of the FSN for research and to disseminate the results. We conclude that ALARM FSN sites together with other research sites in Europe jointly could be used as a future backbone for research proposal
Combining WV-2 images and tree physiological factors to detect damage stages of Populus gansuensis by Asian longhorned beetle (Anoplophora glabripennis) at the tree level
Improved methods for measuring forest landscape structure: LiDAR complements field-based habitat assessment
Conservation and monitoring of forest biodiversity requires reliable information about forest structure and composition at multiple spatial scales. However, detailed data about forest habitat characteristics across large areas are often incomplete due to difficulties associated with field sampling methods. To overcome this limitation we employed a nationally available light detection and ranging (LiDAR) remote sensing dataset to develop variables describing forest landscape structure across a large environmental gradient in Switzerland. Using a model species indicative of structurally rich mountain forests (hazel grouse Bonasa bonasia), we tested the potential of such variables to predict species occurrence and evaluated the additional benefit of LiDAR data when used in combination with traditional, sample plot-based field variables. We calibrated boosted regression trees (BRT) models for both variable sets separately and in combination, and compared the models’ accuracies. While both field-based and LiDAR models performed well, combining the two data sources improved the accuracy of the species’ habitat model. The variables retained from the two datasets held different types of information: field variables mostly quantified food resources and cover in the field and shrub layer, LiDAR variables characterized heterogeneity of vegetation structure which correlated with field variables describing the understory and ground vegetation. When combined with data on forest vegetation composition from field surveys, LiDAR provides valuable complementary information for encompassing species niches more comprehensively. Thus, LiDAR bridges the gap between precise, locally restricted field-data and coarse digital land cover information by reliably identifying habitat structure and quality across large areas
Obtaining Height Information Using a 2-D Top View UAV Image with the Help of Spherical Astronomy
Assessing habitats and organism-habitat relationships by airborne laser scanning
Three-dimensional structure is a fundamental physical element of habitat. Because of the well-recognised link between vegetation structure and organism-habitat associations, many published studies that make use of airborne LiDAR for forest applications have results of potential relevance for habitat assessment. This chapter reviews those published studies that have made direct use of airborne LiDAR data for habitat assessment of individual species or groups of species in a woodland or forest context. This is followed by a case study of the authors’ own work at a study site in eastern England, Monks Wood National Nature Reserve. We conclude that airborne LiDAR has the capability for supplying a range of forest structural measures that are key elements of an organism’s habitat at the meso-scale. Examined in combination with detailed field ecology data on species distributions, abundances or biological activity, airborne LiDAR data can be used as an exploratory tool to advance ecological understanding by quantifying how forest structure impacts habitat use and thereby influences habitat quality