24 research outputs found

    Consistent patterns of common species across tropical tree communities

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    Trees structure the Earth’s most biodiverse ecosystem, tropical forests. The vast number of tree species presents a formidable challenge to understanding these forests, including their response to environmental change, as very little is known about most tropical tree species. A focus on the common species may circumvent this challenge. Here we investigate abundance patterns of common tree species using inventory data on 1,003,805 trees with trunk diameters of at least 10 cm across 1,568 locations1,2,3,4,5,6 in closed-canopy, structurally intact old-growth tropical forests in Africa, Amazonia and Southeast Asia. We estimate that 2.2%, 2.2% and 2.3% of species comprise 50% of the tropical trees in these regions, respectively. Extrapolating across all closed-canopy tropical forests, we estimate that just 1,053 species comprise half of Earth’s 800 billion tropical trees with trunk diameters of at least 10 cm. Despite differing biogeographic, climatic and anthropogenic histories7, we find notably consistent patterns of common species and species abundance distributions across the continents. This suggests that fundamental mechanisms of tree community assembly may apply to all tropical forests. Resampling analyses show that the most common species are likely to belong to a manageable list of known species, enabling targeted efforts to understand their ecology. Although they do not detract from the importance of rare species, our results open new opportunities to understand the world’s most diverse forests, including modelling their response to environmental change, by focusing on the common species that constitute the majority of their trees

    Catálogo Taxonômico da Fauna do Brasil: setting the baseline knowledge on the animal diversity in Brazil

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    The limited temporal completeness and taxonomic accuracy of species lists, made available in a traditional manner in scientific publications, has always represented a problem. These lists are invariably limited to a few taxonomic groups and do not represent up-to-date knowledge of all species and classifications. In this context, the Brazilian megadiverse fauna is no exception, and the Catálogo Taxonômico da Fauna do Brasil (CTFB) (http://fauna.jbrj.gov.br/), made public in 2015, represents a database on biodiversity anchored on a list of valid and expertly recognized scientific names of animals in Brazil. The CTFB is updated in near real time by a team of more than 800 specialists. By January 1, 2024, the CTFB compiled 133,691 nominal species, with 125,138 that were considered valid. Most of the valid species were arthropods (82.3%, with more than 102,000 species) and chordates (7.69%, with over 11,000 species). These taxa were followed by a cluster composed of Mollusca (3,567 species), Platyhelminthes (2,292 species), Annelida (1,833 species), and Nematoda (1,447 species). All remaining groups had less than 1,000 species reported in Brazil, with Cnidaria (831 species), Porifera (628 species), Rotifera (606 species), and Bryozoa (520 species) representing those with more than 500 species. Analysis of the CTFB database can facilitate and direct efforts towards the discovery of new species in Brazil, but it is also fundamental in providing the best available list of valid nominal species to users, including those in science, health, conservation efforts, and any initiative involving animals. The importance of the CTFB is evidenced by the elevated number of citations in the scientific literature in diverse areas of biology, law, anthropology, education, forensic science, and veterinary science, among others

    Consistent patterns of common species across tropical tree communities

    Get PDF
    Trees structure the Earth's most biodiverse ecosystem, tropical forests. The vast number of tree species presents a formidable challenge to understanding these forests, including their response to environmental change, as very little is known about most tropical tree species. A focus on the common species may circumvent this challenge. Here we investigate abundance patterns of common tree species using inventory data on 1,003,805 trees with trunk diameters of at least 10 cm across 1,568 locations1-6 in closed-canopy, structurally intact old-growth tropical forests in Africa, Amazonia and Southeast Asia. We estimate that 2.2%, 2.2% and 2.3% of species comprise 50% of the tropical trees in these regions, respectively. Extrapolating across all closed-canopy tropical forests, we estimate that just 1,053 species comprise half of Earth's 800 billion tropical trees with trunk diameters of at least 10 cm. Despite differing biogeographic, climatic and anthropogenic histories7, we find notably consistent patterns of common species and species abundance distributions across the continents. This suggests that fundamental mechanisms of tree community assembly may apply to all tropical forests. Resampling analyses show that the most common species are likely to belong to a manageable list of known species, enabling targeted efforts to understand their ecology. Although they do not detract from the importance of rare species, our results open new opportunities to understand the world's most diverse forests, including modelling their response to environmental change, by focusing on the common species that constitute the majority of their trees

    Fiber Bragg Based Sensors for Foot Plantar Pressure Analysis

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    Gait analysis is of major importance in physical rehabilitation scenarios, lower limbs diseases diagnosis and prevention. Foot plantar pressure is a key parameter in the gait analysis and its dynamic monitoring is crucial for an accurate assessment of gait related pathologies and/or rehabilitation status evolution. It is therefore critical to invest effort in research for foot plantar analysis technologies. From that perspective, optical fiber sensors appear to be an excellent solution, given their sensing advantages for medical applications, when compared with their electronic counterparts. This chapter explores the use of optical fiber Bragg grating (FBG) sensors, both in plastic and silica optical fiber, to dynamically monitor the foot plantar pressure. An array of FBGs was integrated in a specially designed cork insole, with the optical sensors placed at key pressure points for analysis. Both insoles, containing plastic and silica optical fiber sensors, were tested for dynamic gait monitoring and body center of mass displacement, showing the reliability of this sensing technology for foot plantar pressure monitoring during gait motion

    Strategies for Embedding Optical Fiber Sensors in Additive Manufacturing Structures

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    The use of optical fiber sensors (OFS) has spread in the Structural Health Monitoring (SHM) community for their ability to detect many different physical quantities, robustness against electromagnetic disturbances, light weight and embedding possibilities. The last point has been widely investigated for different types of materials, but only recently researchers considered the possibility to embed optical fibers in 3D printed structures. Additive Manufacturing (AM) offers new opportunities in terms of design, for the manufacturing of structures with complex geometries in a relatively low amount of time. However, new challenges must be considered, including innovative embedding solutions for different types of sensors. As a first step, this work discusses current embedding strategies for optical fiber sensors in structures produced with the Fused Deposition Modeling (FDM) technique. A novel methodology to embed OFS is introduced and then tested through the production of specimens at three different filling densities and six different loads. The experimental results, where both distributed OFS and strain gauges were used, were also compared with the data obtained from a numerical model developed in Abaqus/CAE in which the filling pattern of the specimens was accurately reproduced. Finally, the results were critically discussed, highlighting both agreements and discrepancies with respect to the expected data
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