Wildfire selectivity for land cover type: does size matter ?

Previous research has shown that fires burn certain land cover types disproportionally to their abundance. We used quantile regression to study land cover proneness to fire as a function of fire size, under the hypothesis that they are inversely related, for all land cover types. Using five years of fire perimeters, we estimated conditional quantile functions for lower (avoidance) and upper (preference) quantiles of fire selectivity for five land cover types - annual crops, evergreen oak woodlands, eucalypt forests, pine forests and shrublands. The slope of significant regression quantiles describes the rate of change in fire selectivity (avoidance or preference) as a function of fire size. We used Monte-Carlo methods to randomly permutate fires in order to obtain a distribution of fire selectivity due to chance. This distribution was used to test the null hypotheses that 1) mean fire selectivity does not differ from that obtained by randomly relocating observed fire perimeters; 2) that land cover proneness to fire does not vary with fire size. Our results show that land cover proneness to fire is higher for shrublands and pine forests than for annual crops and evergreen oak woodlands. As fire size increases, selectivity decreases for all land cover types tested. Moreover, the rate of change in selectivity with fire size is higher for preference than for avoidance. Comparison between observed and randomized data led us to reject both null hypotheses tested (a = 0.05) and to conclude it is very unlikely the observed values of fire selectivity and change in selectivity with fire size are due to chance.Funding: This paper was supported by the Fundação para a Ciência e Tecnologia Ph.D. Grant SFRH/BD/40398/2007. JMCP participated in this research under the framework of research projects ‘‘Forest fire under climate, social and economic changes in Europe, the Mediterranean and other fire-affected areas of the world (FUME)’’, EC FP7 Grant Agreement No. 243888. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscrip

Nonrenewable Resources, Strategic Behavior and the Hotelling Rule: An Experiment

This study uses the methods of experimental economics to investigate possible causes for the failure of the Hotelling rule for nonrenewable resources. We argue that as long as resource stocks are large enough, producers may choose to (partially) ignore the dynamic component of their production decision, shifting production to the present and focusing more on strategic behavior. We experimentally vary stock size in a nonrenewable resource duopoly setting and find that producers with large stocks indeed pay significantly less attention to variables related to dynamic optimization,leading to a failure of the Hotelling rule

Disequilibrium, adaptation and the Norse settlement of Greenland

This research was supported by the University of Edinburgh ExEDE Doctoral Training Studentship and NSF grant numbers 1202692 and 1140106.There is increasing evidence to suggest that arctic cultures and ecosystems have followed non-linear responses to climate change. Norse Scandinavian farmers introduced agriculture to sub-arctic Greenland in the late tenth century, creating synanthropic landscapes and utilising seasonally abundant marine and terrestrial resources. Using a niche-construction framework and data from recent survey work, studies of diet, and regional-scale climate proxies we examine the potential mismatch between this imported agricultural niche and the constraints of the environment from the tenth to the fifteenth centuries. We argue that landscape modification conformed the Norse to a Scandinavian style of agriculture throughout settlement, structuring and limiting the efficacy of seasonal hunting strategies. Recent climate data provide evidence of sustained cooling from the mid thirteenth century and climate variation from the early fifteenth century. Archaeological evidence suggests that the Norse made incremental adjustments to the changing sub-arctic environment, but were limited by cultural adaptations made in past environments.Publisher PDFPeer reviewe

La aspiración y elisión de /s/ en el español porteño

En este informe se ofrecerán los datos preliminares recopilados hasta la fecha en el estudio sobre fonología del hablade la clase "media-alta" de Buenos Aires, Los datos se basan en la transcripción de 24 cintas grabadas en Buenos Aires como parte del "Proyeco del estudio coordinado de la norma lingüística culta de las principales ciudades de Iberoamérica y de la -Península Ibérica." La selecciónde los informantes se hizo de acuerdo con los principios metodológicos del Proyecto original; así, los entrevistados poseen educación formal superior, son porteños de nacimiento, y tienen entre 25 y 75 años de edad

The Cartesian Model and Dependency in Mitterrand's African Policy: the Case of Senegal

Senegal's relationship with France from the very beginning was marked by dependency. Economic, political and cultural life in Senegal revolved around the metropole — the highly centralized administrative and political institutions of France located in Paris dominated the Senegalese periphery. But Senegal's dependency was not merely economic or political. French policies towards Senegal primarily aimed at intellectual and cultural goals and were in some cases economic and political liabilities to the metropole. In this respect, the Senegalese case did not correspond to traditional theories of dependency which stress the overall importance of economic interests. Furthermore, the nature of this dependency does not appear to have significantly altered, although the political orientation of the French government has changed greatly since the colonization of Senegal. The character and development of this phenomenon, along with its implications for current French policy, will be considered here in light of the French world view, with particular reference to the Cartesian ideal.</jats:p

La nasal implosiva y final en el español de Cuba

Este trabajo forma parte del "Proyecto de estudio coordinado de la norma lingüística culta de las principales ciudades de Hispanoamérica y de la Península Ibérica". Su propósito general es ofrecer una explicación de los datos obtenidos en términos de procesos fonológicos generales, que puedan servir como base decomparación diacrónica y sincrónica con otros dialectos hispánicos y que, asimismo, puedan contribuir a mejorar nuestro conocimientode la operación de procesos fonológicos en el lenguaje humano. Así pues, mi estudio intenta ser una aportacióna una teoría fonológica, tanto dialectal como general

The Natural Approach

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Number Bracelets: A Study in Patterns

If you are interested in a novel approach to number patterns, an experience in following an algorithmic procedure different from the usual one, some practice in systematic search techniques, and something that provides students with significant amounts of practice with the basic facts—all this in one activity—we would urge you to consider number bracelets.</jats:p