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Taxonomic Order (taxonomic + order)
Selected AbstractsTrade-Offs between Species Conservation and the Size of Marine Protected AreasCONSERVATION BIOLOGY, Issue 1 2010P. M. CHITTARO áreas marinas protegidas; conservación de la biodiversidad; relaciones especies,área Abstract:,Moving from single-species- to ecosystem-based management requires an understanding of how community-level attributes such as diversity change with area. We used survey data from bottom trawls to examine spatial patterns of species richness in U.S. Pacific coastal fishes. Specifically, we generated and compared species,area relationships (SARs) for species classified into several groups on the basis of maximum body size, trophic level, diet, maximum depth, geographic affinity, and taxonomic order. Because SARs among groups were not parallel and z values varied significantly for several groups, groups of species were under- or overrepresented (depending on the size of the area) relative to their proportions in the entire community (i.e., entire U.S. Pacific coast). In this way, differences in SARs help demonstrate trade-offs between species representation and coastal area and suggest strategies (such as targeting the protection of habitats and locations where a particular species or groups of species are maximized) that may minimize the size of marine protected areas (MPAs) but protect diversity at the level of the community and functional group. Resumen:,El traslado del manejo de una sola especie al manejo basado en ecosistemas requiere del entendimiento de los cambios en atributos de la comunidad como el cambio de diversidad con el área. Utilizamos datos de muestreo de redes de arrastre para examinar patrones espaciales de la riqueza de especies en peces costeros del Pacífico en E. U. A. Específicamente, generamos y comparamos relaciones especies,área (REAs) para especies clasificadas en varios grupos con base en la talla máxima, nivel trófico, profundidad máxima, afinidad geográfica y orden taxonómico. Debido a que las REAs entre grupos no fueron paralelas y que los valores de z variaron significativamente para varios grupos, los grupos de especies estuvieron sub- o sobre- representados (dependiendo del tamaño del área) en relación con sus proporciones en toda la comunidad (i.e., toda la costa del Pacífico en E. U. A.). De esta manera, las diferencias en REAs ayudan a demostrar el balance entre la representación de especies y el área costera y sugieren estrategias (como la protección de hábitats y localidades donde se maximiza una especie o grupo de especies) que pueden minimizar el tamaño de áreas marinas protegidas pero proteger la diversidad al nivel de la comunidad y grupo funcional. [source] Non-random patterns in the Yellowstone ecosystem: inferences from mammalian body size, order and biogeographical affinityGLOBAL ECOLOGY, Issue 2 2007Judsen E. Bruzgul ABSTRACT Aim, Our aim was to investigate how the environment, species characteristics and historical factors at the subcontinental scale affect patterns of diversity. We used the assembly of the Yellowstone biota over the past 10,000 years as a natural experiment for investigating the processes that generate a modern non-volant mammal species pool. Location, The data represent species from throughout North America with special attention to the non-volant mammals of Yellowstone National Park, USA. Methods, We used digitized range maps to determine biogeographical affinity for all non-volant mammals in the Rocky Mountains, Deserts and Great Plains biogeographical regions of North America. This biogeographical affinity, along with taxonomic order and body size class, was used to test whether non-random patterns exist in the assemblage of Yellowstone non-volant mammals. These characteristics were also used to investigate the strength of non-random processes, such as habitat or taxon filtering, on particular groups of species or individual species. Results, Our results indicated that the Yellowstone fauna is composed of a non-random subset of mammals from specific body size classes and with particular biogeographical affinities. Analyses by taxonomic order found significantly more Carnivora from the Rocky Mountains region and significantly fewer Rodentia from the Deserts region than expected from random assembly. Analyses using body size classes revealed deviations from expectations, including several significant differences between the frequency distribution of regional body sizes and the distribution of those species found within Yellowstone. Main conclusions, Our novel approach explores processes affecting species pool assembly in the Yellowstone region and elsewhere, and particularly identifies unique properties of species that may contribute to non-random assembly. Focusing on the mechanisms generating diversity, not just current diversity patterns, will assist the design of conservation strategies given future environmental change scenarios. [source] Ecosystem functioning in stream assemblages from different regions: contrasting responses to variation in detritivore richness, evenness and densityJOURNAL OF ANIMAL ECOLOGY, Issue 3 2008B. G. McKie Summary 1The diversity of species traits in a biological assemblage varies not only with species richness, but also with species evenness and organism density, which together influence the concentration of traits within functional guilds. Potential trait diversity at local scales is also constrained by the regional species pool. Implications of such variation for spatio-temporal variability in biodiversity,ecosystem functioning relationships are likely to be complex, but are poorly understood. 2In microcosm experiments conducted at laboratories in Sweden, Ireland and Romania, we investigated effects of species richness, evenness and density of stream-living detritivores on two related processes: detritivore leaf-processing efficiency (LPE) and growth. Assemblage composition varied among laboratories: one taxonomic order (Plecoptera) was studied in Sweden, whereas two orders, encompassing wider trait variation, were studied in Romania (Trichoptera and Plecoptera) and Ireland (Trichoptera and Isopoda). 3Relationships between density and both LPE and growth ranged from negative to positive across the study species, highlighting the potential for density-dependent variation in process rates to alter ecosystem functioning, but indicating that such effects depend on species identity. 4LPE varied with species diversity in the two more heterogeneous assemblages, but whereas LPE in the Romanian study was generally enhanced as richness increased, LPE in the Irish study increased only in less-even polycultures dominated by particular species. Transgressive overyielding was detected in the Irish experiment, indicating complementary resource use and/or facilitation (complementarity). These mechanisms could not be distinguished from the selection effect in the Romanian study. 5Growth was elevated in Romanian species mixtures, reflecting positive complementarity, but lower than expected growth in some Swedish mixtures was associated with negative complementarity, indicating interspecific interference competition. 6Our results emphasize the potential importance of detritivore diversity for stream ecosystem functioning, but both the effects of diversity on the studied processes, and the mechanisms underlying those effects, were specific to each assemblage and process. Such variability highlights challenges in generalizing impacts of diversity change for functional integrity in streams and other ecosystems in which the occurrence of important species traits fluctuates over relatively small spatio-temporal scales. [source] Egg mass and incubation period allometry in birds and reptiles: effects of phylogenyJOURNAL OF ZOOLOGY, Issue 2 2006D. C. Deeming Abstract Here we test the hypothesis that the relationship between egg mass at oviposition (IEM) and incubation period (Ip) is a function of the taxonomic relatedness of bird and reptile species. Allometric relationships between IEM and Ip were examined for 1525 bird species and 201 reptilian species. Treating species as independent data revealed the allometric exponent linking Ip to IEM to be 0.234 for birds and 0.138 for reptiles. However, ANCOVA revealed that within both birds and reptiles the elevation and slope of the regression lines were dependent on the taxonomic order studied, indicating that the exponents were confounded by the phylogenetic relatedness of species. Thus, allometric exponents were recalculated based on the method of comparative analysis using independent contrasts. This technique revealed that the allometric exponent in both birds and reptiles was confounded by phylogeny. In birds the allometric relationship between Ip and IEM was almost halved to 0.122, whereas in reptiles the exponent increased to 0.185. Importantly, the results demonstrate that some results of allometric analyses can be artefacts of the method of analysis of the dataset. That for bird eggs Ip is not determined in large part by egg mass allows new questions to be posed regarding the ecological and physiological factors affecting the length of incubation, and hence rates of embryonic growth, for different taxa and habitats. [source] Profiling invasive fish species: the importance of phylogeny and human useDIVERSITY AND DISTRIBUTIONS, Issue 4 2005Carles Alcaraz ABSTRACT Understanding the ecological differences between native and invasive species is of considerable scientific and practical interest. We examined such differences between native and invasive inland fish species from the Iberian Peninsula in order to analyse the importance of phylogenetic correction and variability (in addition to central tendency). We collected 26 quantitative and qualitative variables on the ecology, life-history traits and human use of the 69 inland fish species of the Iberian Peninsula, including native, invasive and migratory species. The taxonomic distribution of invasive fish species deviated significantly from world freshwater richness and in contrast to native species, invasive fish belongs to only five taxonomic orders but to a wide spectrum of families not native to the Iberian Peninsula. Because the life-history traits were highly dependent on taxonomy, the results, with or without applying phylogenetic methods, differed and after accounting for phylogeny, invasive species displayed higher and wider latitude in general and a different reproductive season mainly among salmonids and cyprinids. Human use was also significantly different between native and invasive fish species and produced more variability in life-history traits of invasive species and uneven taxonomic distribution because of the high diversity of species introduced. We show that accounting for taxonomy and studying variability in addition to central tendency is important in the comparison of life-history traits between native and invasive species. [source] Community effects of praying mantids: a meta-analysis of the influences of species identity and experimental designECOLOGICAL ENTOMOLOGY, Issue 4 2002William F. Fagan Abstract ,1. Generalist arthropod predators are ubiquitous in terrestrial ecosystems but experimental studies have yielded little agreement as to their effects on prey assemblages. Drawing on results from a suite of experimental field studies, a meta-analysis was conducted of the impact of praying mantids (Mantodea: Mantidae) on arthropod assemblages in order to identify predictable and unpredictable effects of these extremely generalised predators. 2. Results across different experiments were synthesised using the log response ratio framework, with a focus on quantifying net mantid impacts on arthropod density across taxonomic orders and trophic levels of arthropods, paying special attention to the contribution of mantid species identity and experimental design variables, such as the use of cages, length of experiment, and manipulated mantid density. 3. Calculated on a per mantid-day basis, the net impacts of Tenodera sinensis on arthropod density were generally weaker but more predictable than the effects of Mantis religiosa. Mantids in general had weak negative effects on density for most taxa but exhibited strong negative and positive effects on some taxa. Tenodera sinensis tended to have negative effects on Homoptera, Diptera, and Hemiptera and herbivores as a group, however M. religiosa exhibited greater variation in response of different taxa that appeared to be affected more strongly by experimental design. The effects of Stagmomantis carolina tended to be negative or non-significant. 4. Experimental cages had little influence on either the sign or magnitude of net community impacts for T. sinensis, however cage experiments reversed the sign of the mean effect for two of six taxonomic orders when the experimental predator was M. religiosa. Cages also increased the variability of effect size greatly for M. religiosa but not for T. sinensis. 5. It was concluded that it is possible to use log response ratios to determine general, predictable trends in a well-studied system. Similar meta-analyses of generalist predator effects in other systems should produce predictions of how these predators influence food webs, an important step towards defining more clearly the influences of generalist predators on community structure and dynamics. [source] Extent and possible conservation implications of fish use for research, testing and education in North AmericaAQUATIC CONSERVATION: MARINE AND FRESHWATER ECOSYSTEMS, Issue 6 2006Melissa Grey Abstract 1.Fish species are used globally for fundamental research, product and environmental testing, and education, but this use has not hitherto been documented. The number of fish used for research and education in North America currently represents approximately one-quarter of all animal use for these purposes; only mice are used in higher numbers. Data from the Canadian Council on Animal Care, various animal care committees from Canadian universities, and the United States Fish and Wildlife Service are collated and summarized. 2.In Canada nearly a half a million fish were used for research and education each year from 1996 to 2001. We estimated that the United States used over four times that amount for the same purposes, totalling approximately 2.8 million fish each year. 3.At least 100 fish species, representing 27 taxonomic orders, were used for research and education in North America from 1996 to 2001. Close to one-third of the species had life-history characteristics that might make them particularly susceptible to over-exploitation. This potential vulnerability, coupled with data from animal care facilities in Canada suggesting that nearly half of all fish used for research and education were wild-caught, should prompt further documentation of such fish uses in order to assess their sustainability. Copyright © 2006 John Wiley & Sons, Ltd. [source] Embryonic development of verongid demosponges supports the independent acquisition of spongin skeletons as an alternative to the siliceous skeleton of spongesBIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 2 2009MANUEL MALDONADO Approximately 85% of extant sponges (phylum Porifera) belong to the class Demospongiae, which contains 14 taxonomic orders. In the orders Verongida, Dictyoceratida, and Dendroceratida, jointly referred to as ,keratose demosponges', the skeleton does not contain siliceous spicules but only spongin fibres. This shared trait has encouraged placement of these orders together within Demospongiae, although their relationships remain uncertain. The present study documents for the first time embryo development in the order Verongida (Aplysina aerophoba), providing some clues for phylogenetic inference. Spawned eggs were enveloped by a follicle of maternal cells. Embryos and larvae were chimeric organisms, the blastocoel of which was filled with symbionts and maternal cells migrated from the follicle. The ultrastructure of epithelial larval cells revealed: (1) a basal apparatus characterized by a peculiar, angling accessory centriole; (2) a pear-shaped nucleus with a protruding beak connected to the rootlets of the basal body; and (3) a distinctive Golgi apparatus encircling the nuclear apex. Developmental and ultrastructural findings support the concept, in congruence with recent molecular studies, that Verongida are more closely related to Halisarcida (askeletal sponges) and Chondrosida (askeletal sponges + sponges with spongin + spiculate sponges) than to the remaining ,keratose' orders, making a monophyletic ,supra-ordinal unit' equivalent to a subclass (Myxospongia, new subclass). Hence, spongin skeletons have evolved at least twice in Demospongiae. Independent acquisition of ,corneous' materials as an alternative to silica could have been stimulated by the radiation of diatoms at the Cretaceous,Tertiary boundary (approximately 65 Mya), which depleted silicon in the photic zone of the world's ocean. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 97, 427,447. [source] | ||||||||||