Academic literature on the topic 'Aridez de habitat'
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Journal articles on the topic "Aridez de habitat"
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Carvalho, Mônica Canaan, Luciano Cavalcante de Jesus França, Isaira Leite e Lopes, Laís Almeida Araújo, José Márcio de Mello, and Lucas Rezende Gomide. "ALGORITMOS DE APRENDIZAGEM DE MÁQUINA NA MODELAGEM DA DISTRIBUIÇÃO POTENCIAL DE HABITATS DE ESPÉCIES ARBÓREAS." Nativa 7, no. 5 (September 12, 2019): 600. http://dx.doi.org/10.31413/nativa.v7i5.7214.
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O estudo teve como objetivo avaliar três métodos de aprendizagem de máquina (árvore de decisão-J48, random forest e redes neurais artificias), na modelagem da distribuição de dez espécies arbóreas mais abundantes em uma sub-bacia do rio São Francisco (MG). Utilizaram-se dados provenientes do Inventário Florestal de Minas, com total de 77 fragmentos amostrados e 2.234 parcelas, nas quais foram computadas a presença/ausência de cada espécie. Empregaram-se 12 variáveis ambientais categóricas procedentes do Zoneamento Ecológico Econômico de Minas Gerais (ZEE/MG), além de variáveis relacionadas ao balanço hídrico do solo (evapotranspiração atual e potencial, aridez e índice alpha). A parametrização dos três algoritmos para as dez espécies selecionadas foi feita com o auxílio do algoritmo cv parameter do software WEKA. Os resultados mostram que os algoritmos testados apresentaram desempenhos estatisticamente iguais em 60% das espécies arbóreas. Os algoritmos random forest e multilayer perceptron foram estatisticamente iguais para a espécie Eugenia dysenterica, sendo superiores ao algoritmo J48. Contudo, o algoritmo random forest foi superior aos demais para as três espécies do gênero Qualea. Conclui-se que o algoritmo random forest apresentou-se como o mais robusto para a modelagem da distribuição potencial de habitat de espécies arbóreas.Palavras-chave: inteligência artificial; árvore de decisão; random forest; redes neurais artificiais. MACHINE LEARNING ALGORITHMS FOR MODELING THE POTENTIAL DISTRIBUTION HABITAT OF TREE SPECIES ABSTRACT: The aim of the present study was to evaluate three methods of machine learning (decision tree-J48, random forest and artificial neural networks) to model the potential habitat distribution of the ten most abundant tree species of the São Francisco river watershed. The presence/absence tree species data were from 77 fragments sampled with 2,234 plots. We used 12 categorical environmental variables from the Economic Ecological Zoning of Minas Gerais (ZEE/MG), as well as variables related to soil water balance (current and potential evapotranspiration, aridity and alpha index). The parameterization of the three algorithms was done with cv parameter algorithm of the WEKA software. The results showed the applied algorithms were statistically similar for 60% of the tree species. The random forest and multilayer perceptron algorithms were statistically similar considering the Eugenia dysenterica and superior to J48 algorithm. However, the random forest algorithm was superior to the other for the three species of Qualea genera. The conclusion is the random forest was the most robust model for the potential distribution habitat of tree species.Keywords: artificial intelligence; decision trees; random forest; artificial neural networks.
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Harris, Peter T., Thomas C. L. Bridge, Robin J. Beaman, Jody M. Webster, Scott L. Nichol, and Brendan P. Brooke. "Submerged banks in the Great Barrier Reef, Australia, greatly increase available coral reef habitat." ICES Journal of Marine Science 70, no. 2 (November 29, 2012): 284–93. http://dx.doi.org/10.1093/icesjms/fss165.
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Abstract Harris, P. T., Bridge, T. C. L., Beaman, R. J., Webster, J. M., Nichol, S. L., and Brooke, B. P. 2013. Submerged banks in the Great Barrier Reef, Australia, greatly increase available coral reef habitat. – ICES Journal of Marine Science, 70: 284–293. Anthropogenic global ocean warming is predicted to cause bleaching of many near-sea-surface (NSS) coral reefs, placing increased importance on deeper reef habitats to maintain coral reef biodiversity and ecosystem function. However, the location and spatial extent of many deep reef habitats is poorly known. The question arises: how common are deep reef habitats in comparison with NSS reefs? We used a dataset from the Great Barrier Reef (GBR) to show that only about 39% of available seabed on submerged banks is capped by NSS coral reefs (16 110 km2); the other 61% of bank area (25 600 km2) is submerged at a mean depth of around 27 m and represents potential deep reef habitat that is spatially distributed along the GBR continental shelf in the same latitudinal distribution as NSS reefs. Out of 25 600 km2 of submerged bank area, predictive habitat modelling indicates that more than half (around 14 000 km2) is suitable habitat for coral communities.
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Lind, P. R., B. J. Robson, B. D. Mitchell, and T. G. Matthews. "Can sand slugs in rivers deliver conservation benefits? The biodiversity value of tributary junction plug wetlands in the Glenelg River, Australia." Marine and Freshwater Research 60, no. 5 (2009): 426. http://dx.doi.org/10.1071/mf08175.
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Restoration works are carried out to alleviate human impacts and improve habitats within ecosystems. However, human impacts may also create new (anthropogenic) habitat for species to exploit. A dilemma arises when proposed restoration works would remove anthropogenic habitat and the assemblages it supports. Sediment input into the Glenelg River has formed tributary junction plug wetlands at confluences. Sand slug removal is proposed as part of river rehabilitation, but would also drain plug wetlands. We sampled four plug wetland, four river run and three river pool sites to determine whether plug wetlands influence water quality and add to the biodiversity of macroinvertebrates in the Glenelg River. Water quality and macroinvertebrate diversity were similar in plug wetlands, river runs and river pools. Assemblages were distinct among all sites, regardless of type, so there was no characteristic ‘plug-wetland fauna’. Therefore, although removal of plug wetlands would not cause a dramatic loss of invertebrate biodiversity, it would destroy anthropogenic habitat that supports a similar range of species to natural habitats in a river subject to multiple degrading processes. Gains from rehabilitation should be weighed against the value of anthropogenic habitat and the extent of similar habitat lost elsewhere in the ecosystem.
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Witt, Jonathan DS, and Paul DN Hebert. "Cryptic species diversity and evolution in the amphipod genus Hyalella within central glaciated North America: a molecular phylogenetic approach." Canadian Journal of Fisheries and Aquatic Sciences 57, no. 4 (April 1, 2000): 687–98. http://dx.doi.org/10.1139/f99-285.
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Many benthic freshwater invertebrates are strong candidates for diversification as a result of their short generation times, the divergent selection pressures that they encounter across habitat gradients, and the insular nature of aquatic environments. We analysed populations of the amphipod crustacean Hyalella azteca s.l. from habitats in Ontario, Wisconsin, New Brunswick, and the Yukon Territory. Combined analysis of allozymes and the mitochondrial cytochrome c oxidase I gene revealed that H. azteca is a complex of at least seven species showing marked genetic, but little morphological divergence. Two or more co-occurring species were detected in at least 15 of the 24 habitats. Evidence suggests that diversification has arisen as a consequence of both isolation in different glacial refugia and habitat specialization. A recent origin for the subgenus Hyalella, following the formation of the Isthmus of Panama, is improbable; the subgenus appears to have originated as early as the mid-Miocene.
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Møller, Anders Pape, Canwei Xia, Bo ZHou, Xianli Che, Xingzhi CHu, Changzhang Feng, Karsten Laursen, et al. "Comparative urbanization of birds in China and Europe based on birds associated with trees." Current Zoology 65, no. 6 (March 4, 2019): 617–25. http://dx.doi.org/10.1093/cz/zoz007.
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AbstractUrbanization effects on living organisms are spatially heterogeneous. Here we quantified the abundance of birds per tree in forested urban and rural habitats for 85,829 trees mainly in China and Europe. A population model was based on the assumption that: 1) birds have a normally distributed habitat preference; 2) an increase in population size linked to the habitat preference; 3) a population size dependent on the habitat preference; and 4) the removal of a certain fraction of individuals giving rise to extinction. We tested for large-scale differences in the impact of urbanization on the frequency distribution of the difference in abundance between urban and rural habitats in China and parts of Europe. The difference in the frequency distribution of urban population density of birds in trees minus rural population density of birds in trees in China and Europe was statistically significant, suggesting that the abundance of birds differed between trees in urban and rural habitats, but more so in China than in Europe. We hypothesize that more pronounced differences in China than in Europe may have arisen due to the Four Pests Campaign in 1958–1962 that resulted in death of hundreds of millions of birds (mainly tree sparrows Passer montanus, but also numerous other less common species that were starting to become urbanized around 1960). Species that were less common in 1960 could not sustain reductions in population size in urban areas and hence these species are still rare or absent in urban areas today 60 years later.
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Crews, Sarah C., Erika L. Garcia, Joseph C. Spagna, Matthew H. Van Dam, and Lauren A. Esposito. "The life aquatic with spiders (Araneae): repeated evolution of aquatic habitat association in Dictynidae and allied taxa." Zoological Journal of the Linnean Society 189, no. 3 (December 17, 2019): 862–920. http://dx.doi.org/10.1093/zoolinnean/zlz139.
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Abstract Despite the dominance of terrestriality in spiders, species across a diverse array of families are associated with aquatic habitats. Many species in the spider family Dictynidae are associated with water, either living near it or, in the case of Argyroneta aquatica, in it. Previous studies have indicated that this association arose once within the family. Here we test the hypothesis of a single origin via the broadest phylogeny of dictynids and related ‘marronoids’ to date, using several taxa that were not previously sampled in molecular analyses to provide the first quantitative test of the hypothesis put forth by Wheeler et al. (2016). We sampled 281 terminal taxa from 14 families, assembling a matrix with 4380 total base pairs of data from most taxa. We also assembled an atlas of morphological traits with potential significance for both ecology and taxonomy. Our resulting trees indicate that an aquatic habitat association has arisen multiple times within dictynids. Dictynidae and the genus Dictyna are polyphyletic and the genera Lathys and Cicurina remain unplaced. A review of aquatic habitat associations in spiders indicates that it occurs in members of at least 21 families. With our morphological atlas, we explore characters that have been implicated in aiding an aquatic lifestyle, which in the past may have caused confusion regarding taxon placement. Our results indicate that not all spiders with traits thought to be useful for aquatic habitat associations occupy such habitats, and that some spider taxa lacking these traits are nonetheless associated with water.
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Lüscher, Beatrice, Lutz Dalbeck, and Dagmar Ohlhoff. "Beaver ponds as habitat of amphibian communities in a central European highland." Amphibia-Reptilia 28, no. 4 (2007): 493–501. http://dx.doi.org/10.1163/156853807782152561.
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Abstract The Eurasian beaver Castor fiber, formerly occurred across the Palaearctic, but was nearly eradicated in the 19th century. Due to reintroductions in the 20th century, beaver populations are increasing and now extend into highland areas. Natural still waters are scarce in highlands of Central Europe. Therefore the question arises, “Are beaver ponds essential habitats for amphibians?”, especially since fishes, predators of amphibian larval stages, also inhabit beaver ponds. We investigated the amphibian fauna of one typical valley in the Eifel, that was colonized by beavers in 1981, and compared areas with and without beaver ponds. All anuran species of the region occupied beaver ponds, including species that were absent (Alytes obstetricans, Bufo bufo and Rana kl. esculenta) or rare (Rana temporaria) in natural waters. Alytes obstetricans obviously benefited from pond construction and the removal of trees by beavers which leads to sunny plots along the slopes of the valley, crucial habitat for this species. The urodelans Salamandra salamandra, Triturus alpestris and Triturus helveticus were widely distributed in beaver ponds. Our results show clearly, that beaver altered landscapes offer high quality habitats for amphibians in our study area. Due to a considerable increase of habitat heterogeneity in impounded streams, the predator Salmo trutta was not able to extirpate the amphibian fauna. We conclude that the historic effects of beavers need to be considered for a proper understanding of patterns of amphibian distribution and habitat requirements in Central European Highlands. Furthermore, beaver-created landscapes will be of future relevance for conservation of endangered species, like Alytes obstetricans.
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Kopps, Anna M., Corinne Y. Ackermann, William B. Sherwin, Simon J. Allen, Lars Bejder, and Michael Krützen. "Cultural transmission of tool use combined with habitat specializations leads to fine-scale genetic structure in bottlenose dolphins." Proceedings of the Royal Society B: Biological Sciences 281, no. 1782 (May 7, 2014): 20133245. http://dx.doi.org/10.1098/rspb.2013.3245.
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Socially learned behaviours leading to genetic population structure have rarely been described outside humans. Here, we provide evidence of fine-scale genetic structure that has probably arisen based on socially transmitted behaviours in bottlenose dolphins ( Tursiops sp.) in western Shark Bay, Western Australia. We argue that vertical social transmission in different habitats has led to significant geographical genetic structure of mitochondrial DNA (mtDNA) haplotypes. Dolphins with mtDNA haplotypes E or F are found predominantly in deep (more than 10 m) channel habitat, while dolphins with a third haplotype (H) are found predominantly in shallow habitat (less than 10 m), indicating a strong haplotype–habitat correlation. Some dolphins in the deep habitat engage in a foraging strategy using tools. These ‘sponging’ dolphins are members of one matriline, carrying haplotype E. This pattern is consistent with what had been demonstrated previously at another research site in Shark Bay, where vertical social transmission of sponging had been shown using multiple lines of evidence. Using an individual-based model, we found support that in western Shark Bay, socially transmitted specializations may have led to the observed genetic structure. The reported genetic structure appears to present an example of cultural hitchhiking of mtDNA haplotypes on socially transmitted foraging strategies, suggesting that, as in humans, genetic structure can be shaped through cultural transmission.
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Osborne, Colin P., and Robert P. Freckleton. "Ecological selection pressures for C 4 photosynthesis in the grasses." Proceedings of the Royal Society B: Biological Sciences 276, no. 1663 (February 25, 2009): 1753–60. http://dx.doi.org/10.1098/rspb.2008.1762.
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Grasses using the C 4 photosynthetic pathway dominate grasslands and savannahs of warm regions, and account for half of the species in this ecologically and economically important plant family. The C 4 pathway increases the potential for high rates of photosynthesis, particularly at high irradiance, and raises water-use efficiency compared with the C 3 type. It is therefore classically viewed as an adaptation to open, arid conditions. Here, we test this adaptive hypothesis using the comparative method, analysing habitat data for 117 genera of grasses, representing 15 C 4 lineages. The evidence from our three complementary analyses is consistent with the hypothesis that evolutionary selection for C 4 photosynthesis requires open environments, but we find an equal likelihood of C 4 evolutionary origins in mesic, arid and saline habitats. However, once the pathway has arisen, evolutionary transitions into arid habitats occur at higher rates in C 4 than C 3 clades. Extant C 4 genera therefore occupy a wider range of drier habitats than their C 3 counterparts because the C 4 pathway represents a pre-adaptation to arid conditions. Our analyses warn against evolutionary inferences based solely upon the high occurrence of extant C 4 species in dry habitats, and provide a novel interpretation of this classic ecological association.
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Tomaŝových, Adam, and Susan M. Kidwell. "Accounting for the effects of biological variability and temporal autocorrelation in assessing the preservation of species abundance." Paleobiology 37, no. 2 (2011): 332–54. http://dx.doi.org/10.1666/09506.1.
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Quantifying the effects of taphonomic processes on species abundances in time-averaged death assemblages (DAs) is pivotal for paleoecological inference. However, fidelity estimates based on conventional “live-dead” comparisons are fundamentally ambiguous: (1) data on living assemblages (LAs) are based on a very short period of sampling and thus do not account for biological variability in the LA, (2) LAs are sampled at the same time as the DA and thus do not necessarily reflect past LAs that contributed to the DA, (3) compositions of LAs and DAs can be autocorrelated owing to shared cohorts, and (4) fidelity estimates are cross-scale estimates because DAs are time-averaged and LAs are not. Some portion of raw (total) live-dead (LD) variation in species composition thus arises from incomplete sampling of LAs and from biological temporal variation among LAs (together = premortem component of LD variation), as contrasted withnewvariation created by interspecific variation in population turnover and preservation rates and by the time-averaging of skeletal input (together = postmortem component of LD variation). To tackle these problems, we introduce a modified test for homogeneity of multivariate dispersions (HMD) in order to (1) account for temporal autocorrelation in composition between LAs and DAs and (2) decompose total LD compositional variation into premortem and postmortem components, and we use simulations to evaluate the contribution of within-habitat time-averaging on the postmortem component. Applying this approach to 31 marine molluscan data sets, each consisting of spatial replicates of LAs and DAs in a single habitat, we find that total LD variation is driven largely by variation among LAs. However, genuinely postmortem processes have significant effects on composition in 25–65% of data sets (depending on the metric) when the effects of temporal autocorrelation are taken into account using HMD. Had we ignored the effects of autocorrelation, the effects of postmortem processes would have been negligible, inflating the similarity between LAs and DAs. Simulations show that within-habitat time-averaging does not increase total LD variation to a large degree—it increases total LD variation mainly via increasing species richness, and decreases total LD variation by reducing dispersion among DAs. The postmortem component of LD variation thus arises from differential turnover and preservation and multi-habitat time-averaging. Moreover, postmortem processes have less effect on the compositions of DAs in habitats characterized by high variability among LAs than they have on DAs in temporally stable habitats, a previously unrecognized first-order factor in estimating postmortem sources of compositional variation in DAs.
Dissertations / Theses on the topic "Aridez de habitat"
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Martins, Fernando de Farias. "Preferência de umidade na oviposição de grilos de serrapilheira (orthoptera: grylloidea): experimentos de campo e laboratório." Universidade Estadual do Oeste do Paraná, 2017. http://tede.unioeste.br/handle/tede/3478.
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For species that do not exhibit parental care such as oviparous insects, choosing a favorable oviposition site is of utmost importance for brood success. Niche theory predicts that crickets should show a bell-shaped oviposition response to substrate humidity. However, at least one lab experiment with mole crickets (Orthoptera: Gryllotalpoidea) indicated a linear oviposition responses to substrate humidity. The house cricket Acheta domesticus (Orthoptera: Grylloidea) also shows a linear juvenile body growth response to substrate humidity, which suggests a positive relationship between humidity and oviposition preference. We evaluated the relationship between oviposition frequency and substrate humidity in forest litter- dwelling species, primarily composed of Ubiquepuella telytokous, using field experiments. We also tested oviposition responses of U. telytokous to substrate humidity in a laboratory experiment. We offered oviposition substrates that varied in humidity from zero percent to maximum substrate water absorption capacity. Oviposition preference was estimated using presence or absence of eggs as a binary response variable, adjusted logistic regression (GAMM) was used to test for non-linear responses, and GLMs were used to test linear responses. We found that oviposition probability increased linearly with substrate humidity for U. telytokous in both field and lab experiments. Our results demonstrate the importance of substrate humidity as an ecological niche requirement for this species. This work bolsters knowledge of litter cricket life history association with humidity, and suggests that litter crickets may be particularly threatened by changes in climate that favor habitat drying.
Para espécies que não apresentam cuidados parentais, tais como insetos ovíparos, a escolha de um local de oviposição favorável é de extrema importância para o sucesso da prole. A teoria do nicho prevê que a oviposição de grilos deve mostrar uma resposta em forma de sino à umidade do substrato. Entretanto, pelo menos um experimento de laboratório com paquinhas (Orthoptera: Gryllotalpoidea) indicou uma resposta de oviposição linear em relação a umidade do substrato. O grilo doméstico Acheta domesticus (Orthoptera: Grylloidea) também apresenta um crescimento corporal dos juvenis linear em relação a umidade do substrato, o que sugere uma relação positiva entre umidade e preferência de oviposição. Aqui testamos a relação entre a frequência de oviposição e a umidade do substrato, em espécies de grilos de serrapilheira florestal, primariamente compostas Ubiquepuella telytokous, utilizando experimentos de campo. Também testamos as respostas de oviposição de U. telytokous em experimentos de laboratório. Oferecemos substratos de oviposção que variaram a umidade de zero porcento até a capacidade máxima de absorção do substrato. A preferência de oviposição foi estimada utilizando presença ou ausência de ovos como uma variável resposta binária, regressão logística ajustada (GAMM) para testar respostas não lineares, e GLMs para testar respostas lineares. Verificamos que a probabilidade de oviposição aumenta linearmente com a umidade do substrato para U. telytokous, nos experimentos de campo e laboratório. Nossos resultados demonstram a importância da umidade do substrato como requisito de nicho ecológico para Ubiquepuella telytokous. Este trabalho reforça o conhecimento da associação de história de vida de grilos com a umidade, e sugere que esses organismos podem ser particularmente ameaçados por mudanças climáticas que tornam habitats áridos.
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Alves, Wagner de Fran?a. "T?rmitas como bioindicadores de qualidade de habitat na caatinga, Brasil: h? uma sintonia entre as vari?veis estruturais dos habitats e as taxocenoses amostradas?" Universidade Federal do Rio Grande do Norte, 2009. http://repositorio.ufrn.br:8080/jspui/handle/123456789/13050.
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Previous issue date: 2009-06-26The composition of termite assemblages was analyzed at three Caatinga sites of the Serid? Ecological Station, located in the municipality of Serra Negra do Norte, in the state of Rio Grande do Norte, Brazil. These sites have been subjected to selective logging, and cleared for pasture and farming. A standardized sampling protocol for termite assemblages (30h/person/site) was conducted between September 2007 and February 2009. At each site we measured environmental variables, such as soil granulometry, pH and organic matter, necromass stock, vegetation height, tree density, stem diameter at ankle height (DAH) and the largest and the smallest crown width. Ten species of termites, belonging to eight genera and three families, were found at the three experimental sites. Four feeding-groups were sampled: wood-feeders, soil-feeders, wood-soil interface feeders and leaf-feeders. The wood-feeders were dominant in number of species and number of encounters at all sites. In general, the sites were not significantly different in relation to the environmental variables measured. The same pattern was observed for termite assemblages, where no significant differences in species richness, relative abundance and taxonomic and functional composition were observed between the three sites. The agreement between the composition of assemblages and environmental variables reinforces the potential of termites as biological indicators of habitat quality
A composi??o das taxocenoses de t?rmitas foi analisada em tr?s ?reas de Caatinga na Esta??o Ecol?gica do Serid?, localizada no munic?pio de Serra Negra do Norte, Estado do Rio Grande do Norte, Brasil. As tr?s ?reas sofreram cortes seletivos e foram utilizadas para atividades de pastagem e agricultura. No per?odo de setembro de 2007 a fevereiro de 2009 foi aplicado um protocolo padronizado de amostragem de t?rmitas e vari?veis ambientais foram mensuradas em cada ?rea, como granulometria, pH e mat?ria org?nica do solo, estoque de necromassa, altura da vegeta??o, densidade de ?rvores, di?metro dos caules ? altura do tornozelo (DAT) e comprimento maior e menor das copas. Foram encontradas 10 esp?cies de t?rmitas pertencentes a oito g?neros nas tr?s ?reas estudadas. Al?m disso, foram identificados quatro grupos alimentares: consumidores de madeira, consumidores de h?mus, consumidores de madeira/h?mus e consumidores de folhas. Os consumidores de madeira foram dominantes em todas as ?reas, tanto em n?mero de esp?cies quanto em n?mero de encontros. No geral, as ?reas n?o foram significativamente diferentes em rela??o ?s vari?veis ambientais mensuradas. O mesmo padr?o foi observado para as taxocenoses de t?rmitas, n?o havendo diferen?a significativa da riqueza de esp?cies, abund?ncia relativa e composi??o dos grupos alimentares e taxon?micos entre as tr?s ?reas. A sintonia entre a composi??o das taxocenoses e as vari?veis ambientais refor?a o potencial dos t?rmitas como indicadores biol?gicos de qualidade de habitat
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Chan, Yu-ki, and 陳裕琪. "Environmental genomic analysis of refuge habitats in hyper-arid deserts." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2011. http://hub.hku.hk/bib/B46917366.
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Pattinson, Nicholas Bruce. "Seasonal physiological and behavioural responses of a small bird in a hot, arid habitat." Thesis, Nelson Mandela Metropolitan University, 2017. http://hdl.handle.net/10948/19728.
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The role that climate plays in the ecology of organisms is perhaps the most pronounced where the earth’s environments are most extreme. In arid-zones, organisms have to deal with large seasonal shifts and/or extremes in temperature and/or moisture levels. As a result, arid-zone species are sensitive to climatic changes. I assessed the physiological and behavioural adjustments of an arid-zone endemic passerine, the rufous-eared warbler (Malcorus pectoralis), to seasonal changes in the Karoo semi-desert of South Africa. Respirometry measurements in the field showed that the warblers’ basal metabolic rate was lower and set point body temperature (Tb) was higher in summer compared to winter. At high air temperatures (Ta) evaporative water loss (EWL) rate was significantly lower in summer compared to winter, while Tb showed a clear pattern of heterothermy that was similar in both seasons. Compared to winter, the warblers in summer were able to remain calm, and tolerate higher Ta’s, before their Tb’s increased to potentially detrimental levels. Behavioural observations showed that free-living warblers exhibited significant temperature-dependence in their behaviour; they increased panting behaviour, and reduced activity levels, time spent preening, and foraging effort at high Ta’s in summer. The warblers also displayed a considerable decrease in foraging success, and a shift in microsite use, at high Ta’s in summer. I hypothesise that the flexible responses the rufous-eared warblers show are aimed at increasing their heat tolerance in summer, and help them balance their energy and water demands in an arid environment that exhibits wide seasonality in Ta, in addition to high summer Ta. My findings emphasise the importance of identifying, as well as understanding, the associated costs of physiological and behavioural responses to environmental variables. This information is valuable in terms of predicting biologically meaningful responses (and hence, vulnerability) of arid-zone avian communities to climactic shifts.
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Bowden, Timothy Scott. "Mexican Spotted Owl reproduction, home range, and habitat associations in Grand Canyon National Park." Thesis, Montana State University, 2008. http://etd.lib.montana.edu/etd/2008/bowden/BowdenT0508.pdf.
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Mexican spotted owls (Strix occidentalis lucida) are nocturnal avian predators that are widely distributed in the southwest U.S. and northern Mexico. In 1993, the lucida subspecies was listed as threatened in response to concern over the loss of forest habitats to which the owl is widely associated. However, in the northwestern corner of their range spotted owls primarily inhabit steep-walled rocky canyons. Owl populations inhabiting this region have received less attention than populations using forests, although, canyon populations are important to the persistence of the subspecies, and are subject to different environmental pressures. I investigated the breeding ecology and home range characteristics of Mexican spotted owls within Grand Canyon which supports both forest and rocky canyon habitat. During the study from 2004 - 2006, female fecundity (mean = 0.86), calculated as the number of female fledglings per paired female, was relatively high compared to values reported previously for Mexican spotted owls. Five adult male owls were radio-tracked during the breeding season. I used minimum convex polygons and fixed kernel estimates to describe home range size (mean = 356 ha and 372 ha, respectively) and generated adaptive kernels to describe areas of concentrated use within home ranges. I used GIS to describe vegetation and geology cover types associated with owl use areas. This information was used to determine if spotted owls used landscape cover types disproportionately to their availability. At a landscape level, spotted owl telemetry locations were positively correlated with piñyon-juniper vegetation that occurred within canyons as well as with the Redwall and Muav geologic layers (p
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Welsh, Daniel. "Selenium in aquatic habitats at Cibola National Wildlife Refuge." Diss., The University of Arizona, 1992. http://hdl.handle.net/10150/186067.
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I studied selenium contamination at Cibola National Wildlife Refuge (Cibola NWR) in the lower Colorado River Valley, California and Arizona. My objectives were to: (1) determine whether local irrigation practices resulted in exposure of fish to toxic levels of selenium; (2) assess the risks to humans of consuming fish from Cibola NWR; (3) assess whether diversity and abundance of fish were related to selenium concentrations or other water quality variables. Water, sediment, fish, crayfish, and aquatic plants were collected from sites which received irrigation return flows and sites which did not. Selenium was below toxic levels at sites receiving irrigation return flows. Selenium was at the toxicity threshhold for fish at two sites receiving water directly from the Colorado River. Concentrations of selenium in fillets of largemouth bass (Micropterus salmoides) from one lake exceeded levels that elicit consumption advisories in California. Most people would be unlikely to consume toxic amounts of fish, but an advisory should be posted to inform people about potential risks. Gill nets were used to determine species diversity and abundance. There were no strong correlations between selenium levels and indices of species richness and equitability. There was a consistent inverse relationship between selenium levels and catch-per-unit-effort for all species combined. This inverse relationship suggested that selenium may be one of a suite of factors limiting abundance of fish. Correlations between indices of species diversity and abundance and values of water quality variables generally were not significant. Temperature and salinity may have limited abundance of some species seasonally. Increases in selenium levels at sites that are already at the toxicity threshhold could impair reproduction of sensitive species. Population declines and concern about edibility of fish could impair the recreational fishery. Therefore, site-specific ways to reduce selenium accumulation should be studied and implemented. Site-specific limnological conditions may play a role in accumulation of selenium to toxic levels, but major sources of selenium appear to be upstream in the Colorado River basin rather than local agricultural practices. Therefore, selenium input to the Colorado River from sources throughout the basin should be monitored and reduced where possible.
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Hirakuri, Valter Levino. "A comunidade e dieta de pequenos mamíferos em uma área de caatinga no Alto Sertão Sergipano." Pós-Graduação em Ecologia e Conservação, 2013. https://ri.ufs.br/handle/riufs/4444.
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Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorConsidering the habitat influence in the occurrence of animal species and feeding ecology as a key factor on community dynamics, the relationship between habitat components and species richness and the abundance of small mammals community were evaluated, as well as the diet characterization of these species at Caatinga‟s area in Sergipe, Brazil. The capture-mark-recapture (CMR) method was applied at the Grota do Angico Natural Monument (MNGA), 100 Sherman‟s® traps were arranged in four sites (dense hiperxerophytic Caatinga) from July 2012 to February 2013. Monthly, the habitat variables and invertebrates availability were measured. Fecal samples were collected for food items identification. Twenty-four individuals belonging to three species, two marsupials (Gracilinanus agilis, N = 17 and Didelphis al-biventris, N = 1) and one rodent (Wiedomys pyrrhorhinus, N = 6) were captured, the recapture rate was 25%. The richness found was lower than other studies described in this biome. High habitat similarity were observed between the study sites, due to the high amount of litter, and the differences among them were influenced by components such as rock, cactus and brome-liads. The only habitat variable that positively influenced the abundance of G. agilis was the amount of bromeliads, there was no such relationship with W. pyrrhorhinus. Thirty seven fecal samples were collected, nine of W. pyrrhorhinus (all male samples) and 28 of G. agilis (11 female samples and 17 male samples). In these two species intake sample were identified eight invertebrates orders (Hymenoptera, Coleoptera, Hemiptera, Lepidoptera, Blattodea, Or-thoptera, Isoptera e Araneae), pulp and seeds were also registered. This is the first study on the feeding habits of W. pyrrhorhinus and G. agilis in Caatinga‟s biome . The two species showed high rates of arthropods intake and the diet composition of marsupial was similar to others studies in Cerrado biome, although in this study the proportions of consumption were higher. There were two food items new records‟ to G. agilis: Blattodea and Pilosocereus gou-nellei (Cactaceae) seeds. No difference was found between the sexes in the diet of G. agilis, however largest consumer of Hymenoptera by males and Orthoptera by females. Besides this study showed that marsupial has opportunistic feeding habits, consuming the more available arthropods orders in the environment.
Considerando a influência do habitat na ocorrência das espécies e a ecologia alimentar como fatores importantes na dinâmica das comunidades, foi avaliada a relação entre os componen-tes do habitat e a riqueza e abundância de pequenos mamíferos e caracterizada a dieta das espécies em uma área de Caatinga no Alto Sertão Sergipano. O estudo foi realizado no Mo-numento Natural Grota do Angico (MNGA), utilizando-se o método de captura-marcação-recaptura (CMR) por meio de 100 armadilhas tipo Sherman®, dispostas em quatro sítios (caa-tinga hiperxerófila densa) de julho de 2012 a fevereiro de 2013. Adicionalmente, mensurou-se mensalmente as variáveis do habitat e a disponibilidade de invertebrados. Além disso, foram coletadas amostras de material fecal para a identificação dos itens alimentares consumidos. Foram capturados 24 indivíduos pertencentes a três espécies, sendo dois marsupiais (Gracili-nanus agilis, N = 17 e Didelphis albiventris, N = 1) e um roedor (Wiedomys pyrrhorhinus, N = 6); com uma taxa de recaptura de 25%. A riqueza desse estudo foi inferior ao descritos em outros trabalhos no bioma. Os sítios apresentaram alta similaridade em relação ao habitat de-vido a elevada quantidade de serrapilheira e as diferenças entre eles foram influenciadas por componentes como rocha, cacto e bromélia. Dentre as variáveis do habitat, apenas a quanti-dade de bromélias influenciou positivamente a abundância de G. agilis e não houve nenhuma relação destas com W. pyrrhorhinus. Foram coletadas 37 amostras de fezes, sendo nove de W. pyrrhorhinus (todas de indivíduos machos) e 28 de G. agilis (11 amostras de fêmeas e 17 de machos). Foram identificadas oito ordens de invertebrados consumidas pelas duas espécies (Hymenoptera, Coleoptera, Hemiptera, Lepidoptera, Blattodea, Orthoptera, Isoptera e Arane-ae), além do registro de polpa e sementes. Esse é o primeiro estudo sobre o hábito alimentar de W. pyrrhorhinus e G. agilis em área de Caatinga. As duas espécies apresentaram elevadas taxas de consumo de artrópodes e a composição da dieta do marsupial se apresentou similar aos demais estudos realizados em Cerrado; porém nesse estudo as proporções de consumo foram superiores. Dois novos registros de itens alimentares para G. agilis foram obtidos: Blat-todea e sementes de Pilosocereus gounellei (Cactaceae). Não constatou-se diferença na dieta entre os sexos de G. agilis, entretanto houve o maior consumo de Hymenoptera por machos e de Orthoptera pelas fêmeas. Além disso, nesse estudo, esse marsupial apresentou um hábito oportunista, consumindo os representantes das ordens que estavam mais disponíveis no ambiente
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Mendez-Estrella, Romeo, Jose Romo-Leon, Alejandro Castellanos, Fabiola Gandarilla-Aizpuro, and Kyle Hartfield. "Analyzing Landscape Trends on Agriculture, Introduced Exotic Grasslands and Riparian Ecosystems in Arid Regions of Mexico." MDPI AG, 2016. http://hdl.handle.net/10150/621492.
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Riparian Zones are considered biodiversity and ecosystem services hotspots. In arid environments, these ecosystems represent key habitats, since water availability makes them unique in terms of fauna, flora and ecological processes. Simple yet powerful remote sensing techniques were used to assess how spatial and temporal land cover dynamics, and water depth reflect distribution of key land cover types in riparian areas. Our study area includes the San Miguel and Zanjon rivers in Northwest Mexico. We used a supervised classification and regression tree (CART) algorithm to produce thematic classifications (with accuracies higher than 78%) for 1993, 2002 and 2011 using Landsat TM scenes. Our results suggest a decline in agriculture (32.5% area decrease) and cultivated grasslands (21.1% area decrease) from 1993 to 2011 in the study area. We found constant fluctuation between adjacent land cover classes and riparian habitat. We also found that water depth restricts Riparian Vegetation distribution but not agricultural lands or induced grasslands. Using remote sensing combined with spatial analysis, we were able to reach a better understanding of how riparian habitats are being modified in arid environments and how they have changed through time.
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Gouat, Patrick. "Etude socioécologique de trois espèces de rongeurs cténodactylides d'Algérie." Lyon 1, 1988. http://www.theses.fr/1988LYO10001.
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Chambers, Joanne. "Terrestrial habitat requirements of a suite of anuran species inhabiting a semi-arid region of South East Queensland." Queensland University of Technology, 2008. http://eprints.qut.edu.au/16610/.
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Hypothesised causes of the observed world-wide decline of amphibian populations are varied and in some cases contentious. Insufficient information relating to the autecology of many amphibian species can cause erroneous speculations regarding critical habitat requirements and hence management programs designed to enhance population viability are often unsuccessful. Most amphibians display a bi-phasic life history that involves occupation of an aquatic breeding habitat and terrestrial habitats that are used for foraging, and shelter from predation and environmental stress. However, the focus of most amphibian research is centred on the breeding habitat, with limited research being conducted into the terrestrial habitat requirements of most amphibian species. Barakula State Forest is a large continuous area of open woodland situated in the semi-arid region of Queensland. The forest supports 21 species of endemic anurans, many of which use ephemeral waterbodies for breeding. This area is, therefore, an ideal location to test the relative importance of terrestrial habitat on the distribution of a suite of frogs that display different morphological and physiological characteristics. On the landscape scale, the attributes of the terrestrial environment at three survey areas within Barakula were similar. However, at the patch scale, ground truthing showed there were considerable variations in vegetation and ground cover attributes within and between each survey site. Measured properties of the soil also tended to vary within and between sites. Soil texture ranged from sandy to heavy clay, soil pH ranged from 3.9 to 6.4 and soil moisture varied considerably. Agar models, used for testing evaporative moisture loss at different microhabitats, retained significantly higher levels of moisture when positioned in the buried microhabitat during summer, but in winter, models that were placed under leaf litter retained higher levels of moisture. Variations in levels of moisture loss at the five different microhabitats were evident within and between the survey sites. Despite a prolonged drought, 1844 native frogs representing 17 species were pitfall trapped. Members from the family Myobatrachidae comprised 94% of these captures, and burrowing species accounted for 75% of total captures. Species were not randomly distributed within or between the survey sites. Vegetation attributes and soil properties played a significant role in influencing the catch rates and traplines that supported similar vegetation and soil attributes also tended to catch similar species. Capture rates of six of the seven burrowing species were significantly influenced by soil properties. When given a choice of four different microhabitats created in enclosures, individuals from five species showed varying responses to habitat choice during night time activity. During daylight all species tended to avoid bare areas and burrowing species tended to burrow under some form of cover. Pseudophryne bibronii metamorphs showed a significant avoidance to soils with high pH. The number of Limnodynastes ornatus metamorphs was significantly and positively correlated with moisture levels surrounding a breeding area. Limnodynastes ornatus metamorphs tended to avoid areas that did not support some form of cover. Embryos from the terrestrial egg laying P. bibronii translocated to sites with varying levels of soil pH, suffered increased mortality where the soil pH was >4.8. In the laboratory, embryonic survival was not significantly different between the four pH treatments. There was a significant influence of fungal infection on survival rates and ranked fungal infection was significantly different between the four pH treatments. The terrestrial environment at the three survey sites has provided sufficient protection from environmental elements to allow a large diversity of anurans to persist for long periods without access to permanent water. Management must consider the importance of the non-breeding habitat when defining buffer zones, restoration programs and conservation strategies to ensure that the complete set of ecological requirements for frog species are provided.
Books on the topic "Aridez de habitat"
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Francesco, Milo, and Bartolozzi Alessandro ill, eds. Animals in hot and cold habitats. Columbus, OH: Waterbird Books, 2003.
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Lazenby, Mark. Caring Matters Most. Oxford University Press, 2017. http://dx.doi.org/10.1093/med/9780199364541.001.0001.
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Through an exploration of the ethical nature of nursing, Caring Matters Most asserts that the act of nursing itself embodies goodness. Nurses can develop this goodness, or moral character, in themselves by cultivating five habits: trustworthiness, imagination, beauty, space, and presence. Practicing these habits will sustain nurses in their everyday work. The habit of trustworthiness can help nurses to meet the demands of the workplace. The habit of imagination is a counterbalance to the threat of automation, and the habit of beauty is a way for nurses to be good to themselves amid the daily difficulties the tasks of nursing present. The habit of space is a remedy to the incivilities that arise within the nursing community. The habit of presence encourages nurses to be grateful, and in turn, gratefulness puts nurses in the presence of the good of nursing. Ultimately, Caring Matters Most offers a vision of the good society that the work of nursing seeks to create—for the community of nurses and for the world.
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Fraser, Ian. Birds in Their Habitats. CSIRO Publishing, 2018. http://dx.doi.org/10.1071/9781486307456.
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Everywhere we go there are birds, and they all have mysteries to be unravelled. These mysteries include the way they look, from bizarre to apparently mundane, why they live where they live, and the things they do, many of which are far too incredible ever to be imagined as fiction.
Birds in Their Habitats is a collection of stories and experiences, which introduce fascinating aspects of birdlife, ecology and behaviour. Informed by a wealth of historical and contemporary research, Ian Fraser takes the reader on a journey through four continents: from places as unfamiliar as the Chonos Archipelago of southern Chile and the arid Sahel woodlands of northern Cameroon to those as familiar as a suburban backyard. This is a book of discovery of birds and the places they live. And with humour and personal insight, it is a book about the sometimes strange world of the people who spend a life absorbed in birds.
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Mills, M. G. L., and M. E. J. Mills. Epilogue. Oxford University Press, 2017. http://dx.doi.org/10.1093/oso/9780198712145.003.0014.
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The main findings from the study, some of which have led to altering perceptions of cheetah biology, are summarized. It is hoped that this will highlight topics for future cheetah research in order to expand knowledge of the species and its role in biodiversity. Comparisons of cheetah ecology and behaviour have been made between the southern Kalahari and other landscapes, especially the Serengeti Plains. These areas are at extremes of the cheetah’s habitat range and therefore differences in the way it has adapted to the southern Kalahari compared with the Serengeti would be expected. The Serengeti Plains, with their vast herds of gazelle and extremely open landscape, might appear to be the ideal habitat for the cheetah. However, it is not that simple and, in some respects cheetahs perform better in the southern Kalahari than they do on the Serengeti Plains. Arid systems are clearly important cheetah habitat.
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Arnaiz, Mabel Gracia. Somos Lo Que Comemos: Estudios de Alimentacion y Cultura En Espa~na (Ariel Antropologia). Ariel, 2002.
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Hewitt, Mason J. The use of satellite remote sensing for the detection, inventory and mapping of riparian habitat within xeric regions. 1989.
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Burton, Derek, and Margaret Burton. Conservation and fish function. Oxford University Press, 2017. http://dx.doi.org/10.1093/oso/9780198785552.003.0016.
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The future for fish is a matter of concern. Individual fish may need specific conditions and are increasingly constrained by habitat changes and destruction, such as the reduction of wetlands. Pollution and temperature change affect fish negatively. It has recently been suggested that extinction rates for freshwater fish are very high. Generally, the wild fishery has no owner, ‘the tragedy of the commons’ may apply with nobody taking adequate responsibility. Increasing awareness is promoting conservation and conservation physiology. This can involve aquaculture, reducing the wild fisheries and captive breeding to rehabilitate stocks. Problems arise with overoptimistic views of bony fish reproductive capacity, a proportion may omit gametogenesis dependent on nutrition or temperature conditions. Conservation measures include establishing ‘marine protected areas’ which help recovery of fish populations. Support for conservation depends on education and knowledge-based decisions rather than inappropriate political compromises, particularly when international groups discuss the problems.
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Plug, Ina. Middle and Later Stone Age hunters and their prey in southern Africa. Edited by Umberto Albarella, Mauro Rizzetto, Hannah Russ, Kim Vickers, and Sarah Viner-Daniels. Oxford University Press, 2017. http://dx.doi.org/10.1093/oxfordhb/9780199686476.013.26.
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Identifications of animal remains from southern African Stone Age sites are complicated by the abundancy of taxa, skeletal differences, a wide variety of habitats, and the fragmented condition of most of the bone samples. Studies in osteomorphology and osteometry are essential. There are regional variations in species sizes combined with changes in bone sizes within and between taxa. Seasonality and animal migrations are demonstrated in the highlands of Lesotho and the semi-arid Karoo. Faunal studies of Sibudu and Bushman Rock Shelter show the contrast between two rock shelters that are geographically separated but overlap in occupation periods.
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Forshaw, Joseph, and Frank Knight. Vanished and Vanishing Parrots. CSIRO Publishing, 2017. http://dx.doi.org/10.1071/9780643106499.
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Joseph M. Forshaw, one of the world’s leading authorities on parrots, calls attention to the threats they face: they are one of the most endangered groups of birds, with a growing number of species nearing extinction. The main threats arise from habitat loss through deforestation and agricultural development and from the taking of birds for the international live-bird trade.
Vanished and Vanishing Parrots brings together information on species that have become extinct in historical times with information on species that are in danger of becoming extinct to increase public awareness of the plight of these magnificent birds. Vivid colour plates by the wildlife artist Frank Knight draw attention to the spectacular species that we have lost or that could be lost. Forshaw’s work gives us fascinating insight into these endangered and extinct parrots.
Vanished and Vanishing Parrots will be a valuable reference for scientific, ornithological and avicultural organisations, as well as individual lovers of birds and of illustrated natural history books.
Announced Highly Commended at the 2018 Whitley Awards
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Kareiva, Peter, Michelle Marvier, and Brian Silliman, eds. Effective Conservation Science. Oxford University Press, 2017. http://dx.doi.org/10.1093/oso/9780198808978.001.0001.
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This book gathers together 28 personal stories told by leading thinkers and practitioners in conservation – all of whom have something to say about the uncomfortable tension that arises when data meet dogma. Together, they make a powerful argument for conservation science that measures effectiveness and evolves in response to new data, rather than clinging to its treasured foundational ideas. Several chapters raise doubts about some of conservation’s core tenets, including the notion that habitat fragmentation is bad for biodiversity, biodiversity declines are threatening ecosystem function, non-native species are a net negative for conservation, and fisheries management is failing. Another set of chapters warns of the potent power of conservation narratives: undeniably useful to inspire conservation action, but potentially dangerous in locking in thinking against contrary data. These chapters challenge iconic stories about GM crops, orangutans in oil palm forests, frog feminization, salmon versus dams, rehabilitating oiled otters, and wolves in Yellowstone. A final set of chapters addresses conceptual and methodological approaches such as environmental tipping points, global assessments, payment for ecosystem service programs, and working with corporations. Throughout, examples of confirmation bias emerge—not as dishonesty, but as a human foible that is a challenge for all science, not just conservation science. Graduate students, in particular, will find a wealth of ideas to inspire their own research. Each chapter points to additional data that could help resolve lingering debates and improve conservation effectiveness.
Book chapters on the topic "Aridez de habitat"
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Pignatti, Erika, and Sandro Pignatti. "Association Tables to the Habitat “Arid and Steppe Grasslands”." In Plant Life of the Dolomites, 77–97. Berlin, Heidelberg: Springer Berlin Heidelberg, 2016. http://dx.doi.org/10.1007/978-3-662-48032-8_5.
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Abed, Raeid M. M., Katharina Kohls, Katarzyna A. Palinska, and Stjepko Golubic. "Diversity and Role of Cyanobacteria and Aerobic Heterotrophic Microorganisms in Carbon Cycling in Arid Cyanobacterial Mats." In Cellular Origin, Life in Extreme Habitats and Astrobiology, 253–73. Dordrecht: Springer Netherlands, 2010. http://dx.doi.org/10.1007/978-90-481-3799-2_13.
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Sánchez-Andrés, R., M. O. Viedma, and S. Sánchez-Carrillo. "The Effects of Anthropogenic Stressors on Wetland Loss and Habitat Quality Deterioration in the Upper Guadiana River Basin: A Long-Term Assessment (1970–2000)." In Ecology of Threatened Semi-Arid Wetlands, 85–107. Dordrecht: Springer Netherlands, 2010. http://dx.doi.org/10.1007/978-90-481-9181-9_4.
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Humphreys, W. F. "Relict stygofaunas living in sea salt, karst and calcrete habitats in arid northwestern Australia contain many ancient lineages." In The Other 99%: The Conservation and Biodiversity of Invertebrates, 219–27. P.O. Box 20, Mosman NSW 2088, Australia: Royal Zoological Society of New South Wales, 1999. http://dx.doi.org/10.7882/rzsnsw.1999.036.
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Herzfeld, Michael. "Ritual and Ritualism in a Contested Sea: Scalar Distortions of Space and Time." In Migrant Hospitalities in the Mediterranean, 105–25. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-56585-5_5.
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AbstractThe ground of mutual understanding between locals and migrants in the Mediterranean Sea emerges through the performance of ritual activities. These should be distinguished from the formalistic or incantatory sense of “ritualism.” They include the socially engaged practices of hospitality—a virtuous tradition that governments, even as they claim it for the nation-state, violate in local eyes by confining migrants to impersonal spaces and uncertain futures. Passages across the sea also partake of a pervasive sense of ritual, which thereby offers rich metaphorical material for considering the scalar shifts at play—shifts that entrain such conversions of social interaction into the asocial frameworks of neoliberal management (which in turn encourage aridly scientistic modes of inquiry) but conversely also domesticate cultural distance through a subtle apperception of shared habits of gesture and generosity, made accessible by the close vision of ethnography as described in these essays.
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Callot, Olivier. "Nouvelles monnaies des marges arides de Syrie du Nord (2010)." In Habitat et environnement, 203–7. MOM Éditions, 2016. http://dx.doi.org/10.4000/books.momeditions.484.
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Al-Dbiyat, Mohamed. "La maison des grands propriétaires dans les marges arides de Syrie centrale." In Habitat et environnement, 267–83. MOM Éditions, 2016. http://dx.doi.org/10.4000/books.momeditions.487.
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Genequand, Denis, and Marie-Odile Rousset. "Résidences aristocratiques byzantines et omeyyades des marges arides du nord de la Syrie." In Habitat et environnement, 207–65. MOM Éditions, 2016. http://dx.doi.org/10.4000/books.momeditions.485.
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Geyer, Bernard, Marie-Odile Rousset, and Jacques Besançon. "Les citernes pluviales des steppes syriennes, éléments de la conquête d’une marge aride." In Habitat et environnement, 45–88. MOM Éditions, 2016. http://dx.doi.org/10.4000/books.momeditions.476.
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Rosenzweig, Michael L., and Robert D. Holt. "SHALOM: A Landscape Simulation Model for Understanding Animal Biodiversity." In Biodiversity in Drylands. Oxford University Press, 2005. http://dx.doi.org/10.1093/oso/9780195139853.003.0010.
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The ecological complexity of landscape components of biodiversity may be understood by examining relatively simple landscapes such as those of arid and semiarid lands. It is believed that such lands provide easy recognition of their components and a relatively simple interaction between their different diversities (Safriel et al. 1989). In general, ecological complexity emerges from the existence of environmental heterogeneity and scaling effects. The effects of scaling include the differential changes in observed patterns produced by processes that operate and interact at different tempospatial scales. For example, interspecific competition may have a strong influence on species coexistence and, therefore, diversity, at a local scale, may be insignificant for determining species diversity compared with a regional scale, where colonization–extinction dynamics may be the major determinant for species diversity. Environmental heterogeneity mainly results from three components: habitat diversity (the number of different habitats), habitat size (the size of each habitat’s patch), and habitat patchiness (the distribution of the different habitats’ patches in the landscape). Each component may affect species diversity by providing specific processes for coexistence, colonization, extinction, and population-size dependent effects. Additionally, as emphasized by Kotliar and Wiens (1990), different scales (Wiens 1989) should introduce different levels of heterogeneity that may influence the way organisms respond to their environment. Morris (1987) suggested that an organism that does not respond to a particular heterogeneity presented at one scale may respond to the heterogeneity presented at another scale. This concept has led ecologists to accept the idea that ecological processes and patterns are not fixed, but rather depend on the scale under study (e.g., Addicott et al. 1987, Kotliar and Wiens 1990, Dunning et al. 1992, Wiens et al. 1993). In this chapter we describe a spatially explicit, multispecies, process-based landscape simulation model, SHALOM (Species-Habitat Arrangement-Landscape-Oriented-Model) that has been designed to explore ecological complexity of large scales. After describing the model, we will present several simulation results to demonstrate the strengths of using such models for understanding biodiversity processes and patterns. We believe that this model can serve an important tool for exploring biodiversity in arid and semiarid lands.
Conference papers on the topic "Aridez de habitat"
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Li, Tiejun, and Weikang Yang. "Environment degeneration affects habitat diversity of Tamarix spp. in arid zone." In Third International Asia-Pacific Environmental Remote Sensing Remote Sensing of the Atmosphere, Ocean, Environment, and Space, edited by Xiaoling Pan, Wei Gao, Michael H. Glantz, and Yoshiaki Honda. SPIE, 2003. http://dx.doi.org/10.1117/12.466529.
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Pérez Rodríguez, Marta. "HABITAR EL AIRE." In LC2015 - Le Corbusier, 50 years later. Valencia: Universitat Politècnica València, 2015. http://dx.doi.org/10.4995/lc2015.2015.668.
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Resumen: Existen en las ideas enunciadas por Le Corbusier dos caminos que partiendo aparentemente de mundos paralelos y opuestos, terminarán convergiéndo en un mismo lugar. Con la construcción del Pavillon de l’Esprit Nouveau, en 1925, se define el nuevo espacio exterior vinculado a la vida moderna. Éste, se dará simultáneamente desde lo colectivo, el immeuble-villa, y desde lo individual, la villa, aunque ambos, se suceden como procesos coexistentes. A este vacío, Le Corbusier lo denominará jardin suspendu, y el orden con el cuál se definirá, será el mismo con el que se constituirá todo el sistema. Desde dentro, este jardin, dejará de ser un exterior para concebirse desde las mismos mecánismos que operan dentro de la casa. Entonces ¿Qué es este espacio?. Simplemente, lo que Le Corbusier trazó, una rica dualidad espacial. Al otro lado, y opuesto a la casa, surge siempre un exterior, como extensión infinita de lo natural. ¿De qué forma ordenarlo?¿cómo vincularlo de nuevo al hombre?. Sólo existe una respuesta posible, un único gesto, el arquitectónico, surgido con la construcción de un plano. Con él, asoma la vertical y la horizontal: Aquellas líneas que vinculan de nuevo al hombre con sus leyes. Con ello, el vacío ya no existe, se ha transformado, constituyendo un nuevo espacio. ¿Qué es este espacio?. De nuevo, una rica ambigüedad. Abstract: Into the ideas enunciated by Le Corbusier there are two paths starting apparently from parallel and opposite worlds, but finally coming to converge in a same place. With the construction of the “Pavillon de l’Esprit Nouveau”, in 1925, it is defined the new outside space linked to modern life. This is given simultaneously from the collective with the “immeuble-villa”, and from the individual, la villa, although both succeed as coexistent processes. This emptiness was called by Le Corbusier “jardin suspendu”, and the order to define it, will be the same used to build the whole system. From inside, this garden will fail to be an outside to be conceived from the same mechanisms that work into the house. So, what is this space? It is simply what Le Corbusier designed, a rich space duality. In the other side, and opposite the house, an outside emerges always, like a boundless extent of the natural. Which way can it be arranged? How can it be linked again to the human? It exists only one possible answer, one unique gesture, the architectonic one, which emerges with the construction of a plan. With it, vertical and horizontal positions arise: those lines that link again the man with his laws. With it, this emptiness doesn’t exists anymore, it has changed becoming in a new space. What is this space? Again, a rich ambiguity. Palabras clave: immeuble-villa, jardin suspendu, interior, exterior, dualidad especial. Keywords: immueble-villa, jardin suspendu, inside, outside, space duality. DOI: http://dx.doi.org/10.4995/LC2015.2015.668
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Young, Michael H., Todd G. Caldwell, John R. Andrews, Douglas J. Merkler, and Kutalmis Saylam. "IDENTIFYING SPECIES HABITATS IN ARID SETTINGS USING REMOTE SENSING AND GEOMORPHIC ATTRIBUTES." In GSA Annual Meeting in Denver, Colorado, USA - 2016. Geological Society of America, 2016. http://dx.doi.org/10.1130/abs/2016am-287623.
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Xiong, Hei-Gang, N. Nurbai, Tashpolat Tiyip, Wei Zhong, Bing-Qi Zhu, and Xiao-Jun Meng. "Restoration and habitat of phytocoenosis in ecotone between oasis and desert in extreme arid zone: a case study in Qira area." In Third International Asia-Pacific Environmental Remote Sensing Remote Sensing of the Atmosphere, Ocean, Environment, and Space, edited by Xiaoling Pan, Wei Gao, Michael H. Glantz, and Yoshiaki Honda. SPIE, 2003. http://dx.doi.org/10.1117/12.466860.
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Carrau Carbonell, Teresa. "La Villa Savoye. Permanencias y transformaciones." In LC2015 - Le Corbusier, 50 years later. Valencia: Universitat Politècnica València, 2015. http://dx.doi.org/10.4995/lc2015.2015.523.
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Resumen: El Patrimonio del Movimiento Moderno y su conservación es un tema de actualidad, no solo desde el punto de vista teórico sino también desde el práctico, ya que la arquitectura de principios del s.XX lleva tiempo necesitando y asumiendo intervenciones para mantenerlas en pie. Se escoge como tema de estudio la vivienda, como arquetipo estudiado por los grandes del Movimiento Moderno y concretamente la villa Savoye como paradigma del Estilo Internacional. Así, con la investigación de este modelo se pretende sacar conclusiones para la conservación de la herencia de Le Corbusier asegurando su permanencia en las generaciones futuras. Se ha realizado un análisis de la villa Savoye por etapas de tiempo. Cada periodo se ha estudiado a través de unos parámetros comunes, obteniéndose una panorámica de la evolución de los elementos que la forman y de su globalidad. Los resultados de este análisis permiten hacer un estudio comparativo entre la villa original, la villa en sus distintas etapas y el estado actual, precisando qué es lo que realmente queda de la villa de 1930. De esta aportación surgen preguntas y reflexiones: ¿importa la conservación de la materia original en la permanencia de un hito? ¿es aceptable una máquina para habitar que no se puede habitar? ¿qué prevalece: la autenticidad arquitectónica o a la autenticidad histórica en la conservación de las obras de Le Corbusier? Abstract: The Heritage of the Modern Movement and its conservation is a current topic, not only from the theoretical point of view but also from the practical, that is because the early twentieth century architecture has been needing and assuming interventions to keep up. It is chosen as a subject of study the housing, as well studied by the great archetype of the modern movement and specifically the Villa Savoye as a paradigm of the International Style. Thus, the investigation of this model is to draw conclusions for the preservation of the heritage of Le Corbusier ensuring its permanence in future generations. It has conducted an analysis of the Villa Savoye through stages of time. Each period has been studied through common parameters, giving an overview of the evolution of the elements that shape it and its entirety. The results of this analysis can make a comparative study between the original villa, the villa in its different stages and the current status, specifying what really remains of the villa of 1930. This contribution questions and thoughts arise: Does it matter the conservation of the original matter in the permanence of a milestone? Is it acceptable to inhabit a machine that you can not live in? Architectural authenticity prevails against the historical authenticity in the conservation of the works of Le Corbusier?Palabras clave: Savoye; evolución; permanencia; intervención; patrimonio. Keywords: Savoye; evolution; permanence; intervention; heritage. DOI: http://dx.doi.org/10.4995/LC2015.2015.523
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Marshall, John, Max Shtein, and Karl Daubmann. "Smartsurfaces: A Multidisciplinary, Hands -on Think Tank." In 2011 ACSA Teachers Conference. ACSA Press, 2011. http://dx.doi.org/10.35483/acsa.teach.2011.5.
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New design practices are emerging that span multiple traditional disciplinary boundaries. As these new models of practice manifest, new pedagogies also become necessary, often challenging both existing educational models and institutional constraints as a result. Gibbons, et al1 questioned the adequacy of traditional disciplinary structures within universities in the context of broader social, technological and economic contexts. The Association of American Colleges and Universities have argued that universities need to change their practices to develop students as “…integrative thinkers who can see connections in seemingly disparate information and draw on a wide range of knowledge to make decisions.”2 The National Academies have recommended, “…students should seek out interdisciplinary experiences, such as courses at the interfaces of traditional disciplines…”3 and that “…schools introduce interdisciplinary learning in the undergraduate environment, rather than having it as an exclusive feature of the graduate programs.”4 As indicated above, there has been much calling for cross-disciplinarity in education but to date there has been little investigation on the impact of cross-disciplinary courses on learning, especially in comparison to teaching that is more discipline-specific. For educators a central question arises: How do we prepare students to be extra-disciplinary thinkers and doers with “habits of mind”5 that prepare them to make the sort of hybrid responses that complex performance problems demand?
Reports on the topic "Aridez de habitat"
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Lichvar, Robert, and Lindsey Dixon. Wetland Plants of Specialized Habitats in the Arid West. Fort Belvoir, VA: Defense Technical Information Center, June 2007. http://dx.doi.org/10.21236/ada469459.
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Brandt, Leslie A., Cait Rottler, Wendy S. Gordon, Stacey L. Clark, Lisa O'Donnell, April Rose, Annamarie Rutledge, and Emily King. Vulnerability of Austin’s urban forest and natural areas: A report from the Urban Forestry Climate Change Response Framework. U.S. Department of Agriculture, Northern Forests Climate Hub, October 2020. http://dx.doi.org/10.32747/2020.7204069.ch.
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The trees, developed green spaces, and natural areas within the City of Austin’s 400,882 acres will face direct and indirect impacts from a changing climate over the 21st century. This assessment evaluates the vulnerability of urban trees and natural and developed landscapes within the City Austin to a range of future climates. We synthesized and summarized information on the contemporary landscape, provided information on past climate trends, and illustrated a range of projected future climates. We used this information to inform models of habitat suitability for trees native to the area. Projected shifts in plant hardiness and heat zones were used to understand how less common native species, nonnative species, and cultivars may tolerate future conditions. We also assessed the adaptability of planted and naturally occurring trees to stressors that may not be accounted for in habitat suitability models such as drought, flooding, wind damage, and air pollution. The summary of the contemporary landscape identifies major stressors currently threatening trees and forests in Austin. Major current threats to the region’s urban forest include invasive species, pests and disease, and development. Austin has been warming at a rate of about 0.4°F per decade since measurements began in 1938 and temperature is expected to increase by 5 to 10°F by the end of this century compared to the most recent 30-year average. Both increases in heavy rain events and severe droughts are projected for the future, and the overall balance of precipitation and temperature may shift Austin’s climate to be more similar to the arid Southwest. Species distribution modeling of native trees suggests that suitable habitat may decrease for 14 primarily northern species, and increase for four more southern species. An analysis of tree species vulnerability that combines model projections, shifts in hardiness and heat zones, and adaptive capacity showed that only 3% of the trees estimated to be present in Austin based on the most recent Urban FIA estimate were considered to have low vulnerability in developed areas. Using a panel of local experts, we also assessed the vulnerability of developed and natural areas. All areas were rated as having moderate to moderate-high vulnerability, but the underlying factors driving that vulnerability differed by natural community and between East and West Austin. These projected changes in climate and their associated impacts and vulnerabilities will have important implications for urban forest management, including the planting and maintenance of street and park trees, management of natural areas, and long-term planning.
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Cairo, Jessica, Iulia Gherman, and Paul Cook. The effects of consumer freezing of food on its use-by date. Food Standards Agency, July 2021. http://dx.doi.org/10.46756/sci.fsa.ret874.
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The current Food Standards Agency consumer guidance states that consumers can freeze pre-packed food right up to the “use-by” date and, once food has been defrosted, it should be consumed within 24 hours. This strategic review has collated relevant data to determine whether there is an increased risk in relation to freezing ready-to-eat and non-ready-to-eat foods on the use-by date compared to the day before the use-by date. The review has focused on how the shelf-life of a food is determined and the effects of freezing, thawing and refrigeration on foodborne pathogens, including Bacillus spp., Campylobacter spp., Clostridium botulinum, Clostridium perfringens, Listeria monocytogenes, Salmonella, pathogenic Escherichia coli and Shigella spp. In the UK, food business operators are responsible for setting the safe shelf-life of a food which, in practice, should take into consideration the consumer habits, as well as the factors affecting shelf-life, such as food product characteristics, food processing techniques, transport, retail and domestic food storage temperatures, and type of packaging. Some countries, such as Ireland, New Zealand and Canada specifically recommend including safety margins within shelf lives. This is used to maintain brand integrity because it ensures that the food is consumed in its optimum condition. The FSA has collaborated with other organisations in the production of several guidance documents; however, there is no explicit requirement for the consideration of a margin of safety when setting shelf-life. There is also no legal requirement in the UK to consider a safety margin when setting shelf-life. According to regulations, pathogens should not be present in sufficient levels to cause foodborne illness on the use-by date, as food should still be safe to eat on that day. Given that these requirements are met, the risk assessed in this report arises from the processes of freezing, thawing and subsequent refrigerated storage for a further 24 hours, and the potential for these to increase pathogen levels. In this review, it was found that there is a risk of additional growth of certain pathogens during the refrigerated storage period although the impact of freezing and thawing on the extent of this growth was not readily evident. This risk would relate specifically to ready-to-eat foods as cooking of non-ready-to-eat foods after defrosting would eliminate pathogens. This report explores the potential issues related to consumer freezing on the use-by date and identifies additional information or research required to understand the risks involved. Overall, there is little evidence to suggest a significant change in risk between consumers freezing ready-to-eat food on the use-by date compared to freezing the food on the day before the use-by date. Specific areas that merit further research include the risks due to low temperature survival and growth of L. monocytogenes. There is also a lack of research on the effects of freezing, defrosting and refrigeration on the growth and toxin production of non-proteolytic C. botulinum, and the growth of Salmonella during domestic freezing and thawing. Finally, more information on how food business operators set shelf-life would enable a better understanding of the process and the extent of the safety margin when determining shelf-life of ready-to-eat and non-ready-to-eat foods.