A collaborative project using narratives: What happens when pupils work on mathematical investigations?

Mathematical investigations involve searching for patterns, formulating, testing, and justifying conjectures, reflecting, and generalising. Doing investigations in the classroom is a powerful activity for students’ learning but poses many challenges to the teacher. To study the professional knowledge involved in this kind of work was the aim of a collaborative action-research project that involved one classroom teacher and two university teacher educators. We used narratives to depict relevant elements of teachers’ activity and to show key aspects of their dilemmas and uncertainties. This paper discusses the role of the collaborative work undertaken by the participants in the project as they reflected about classroom practices and curriculum issues, based on a narrative of a class where sixth grade students worked on a mathematical investigation.Investigações matemáticas envolvem a procura de regularidades, a formulação, teste e justificação de conjecturas, reflexão e generalização. Fazer investigações na sala de aula é uma actividade poderosa para a aprendizagem dos alunos mas coloca muitos desafios ao professor. O estudo do conhecimento profissional envolvido neste tipo de trabalho constituiu o objectivo de um projecto colaborativo de investigação-acção que envolveu uma professora de Matemática e dois educadores matemáticos universitários. Usámos narrativas para ilustrar aspectos relevantes da actividade da professora e para mostrar elementos importantes dos seus dilemas e incertezas. Tendo por base uma aula do 6.º ano de escolaridade em que os alunos trabalharam numa investigação matemática, o artigo discute o papel do trabalho colaborativo realizado pelos participantes no projecto enquanto reflectem sobre as práticas lectivas e as questões curriculares

Filling gaps in a large reserve network to address freshwater conservation needs

Freshwater ecosystems and biodiversity are among the most threatened at global scale, but efforts for their conservation have been mostly peripheral to terrestrial conservation. For example, Natura 2000, the world's largest network of protected areas, fails to cover adequately the distribution of rare and endangered aquatic species, and lacks of appropriate spatial design to make conservation for freshwater biodiversity effective. Here, we develop a framework to identify a complementary set of priority areas and enhance the conservation opportunities of Natura 2000 for freshwater biodiversity, using the Iberian Peninsula as a case study. We use a systematic planning approach to identify a minimum set of additional areas that would help i) adequately represent all freshwater fish, amphibians and aquatic reptiles at three different target levels, ii) account for key ecological processes derived from riverscape connectivity, and iii) minimize the impact of threats, both within protected areas and propagated from upstream unprotected areas. Addressing all these goals would need an increase in area between 7 and 46%, depending on the conservation target used and strength of connectivity required. These new priority areas correspond to subcatchments inhabited by endangered and range restricted species, as well as additional subcatchments required to improve connectivity among existing protected areas and to increase protection against upstream threats. Our study should help guide future revisions of the design of Natura 2000, while providing a framework to address deficiencies in reserve networks for adequately protecting freshwater biodiversity elsewhere.We acknowledge funding support provided by Griffith University and Ramon y Cajal Program (RYC-2013-13979) to VH. PB and AFF were supported by EDP Biodiversity Chair. PS was supported by a grant funded by FCT (SFRH/BPD/39067/2007)

Predicting the ecological status of rivers and streams under different climatic and socioeconomic scenarios using Bayesian Belief Networks

Freshwater systems have increasingly been subjected to a multitude of human pressures and the re-establishment of their ecological integrity is currently a major worldwide challenge. Expected future climate and socioeconomic changes will most probably further exacerbate such challenges. Modelling techniques may provide useful tools to help facing these demands, but their use is still limited within ecological quality assessment of water resources due to its technical complexity. We developed a Bayesian Belief Network (BBN) framework for modelling the ecological quality of rivers and streams in two European river basins located in two distinct European climatic regions: the Odense Fjord basin (Denmark) and the Sorraia basin (Portugal). This method enabled us to integrate different data sources into a single framework to model the effect of multiple stressors on several biological indicators of river water quality and, subsequently, on their ecological status. The BBN provided a simple interactive user interface with which we simulated combined climate and socioeconomic changes scenarios to assess their impacts on river ecological status. According to the resulting BBNs the scenarios demonstrated small impacts of climate and socioeconomic changes on the biological quality elements analysed. This yield a final ecological status similar to the baseline in the Odense case, and slightly worse in Sorraia. Since the present situation already depicts a high percentage of rivers and streams with moderate or worse ecological status in both basins, this means that many of them would not fulfil the Water Framework Directive target in the future. Results also showed that macrophytes and fish indices were mainly responsible for a non-desirable overall ecological status in Odense and Sorraia, respectively. The approach followed in this study is novel, since BBN modelling is used for the first time for assessing the ecological status of rivers and streams under future scenarios, using an ensemble of biological quality elements. An important advantage of this tool is that it may easily be updated with new knowledge on the nature of relationships already established in the BBN or even by introducing new causal links. By encompassing two case studies of very different characteristics, these BBN may be more easily adapted as decision-making tools for water management of other river basinsinfo:eu-repo/semantics/publishedVersio

Mathematical investigations in the classroom: A collaborative project

This paper presents some work developed through a collaborative project involving mathematics teachers and teacher educators, aimed at the development of classroom tasks involving students in mathematical investigations and the study of related teaching styles. We give a general overview of the project and present one task dealing with the concepts of powers and exponents. Then, we describe how it was used in the classroom (grade levels 5-7), and present our experience about the role and the activity of the teacher in the process of organizing, conducting and reflecting about this kind of activity

Aquatic biodiversity and quality of streams in certified eucalypt plantations in central Portugal

Em Portugal, mais de 150.000 ha de plantações de eucalipto (Eucalyptus globulus) são já geridas em conformidade com os sistemas internacionais de certificação. O objetivo deste trabalho foi o de avaliar a biodiversidade e a qualidade ecológica de pequenos rios associados a este tipo de povoamentos, usando diversas comunidades aquáticas – peixes, anfíbios e macroinvertebrados – bem como um índice de condição morfológica fluvial (qualidade do leito e margens). Este estudo foi conduzido em dois cursos de água localizados na zona centro de Portugal, a ribeira da Foz (média dimensão e regime hidrológico permanente) e a ribeira dos Rouxinóis (pequena dimensão e regime intermitente), com envolventes dominadas por plantações certificadas de eucalipto, e por isso com zonas ripícolas bem conservadas. A ribeira da Foz revelou associações piscícolas com elevada riqueza específica e que, embora dominadas por uma espécie exótica (Gobio lozanoi), incluíram várias espécies ameaçadas. A anfíbiofauna apresentou‑se contudo pouco abundante, muito provavelmente devido à grande diversidade e densidade piscícola e à presença significativa do lagostim-vermelho-do-Louisiana (Procambarus clarkii). Neste sistema, registou-se ainda uma boa qualidade da condição morfológica, bem como uma elevada diversidade da comunidade de macroinvertebrados, reflexo de boa qualidade da água. Na ribeira dos Rouxinóis a comunidade piscícola foi próxima da potencial para este tipo de rios, e a anfíbiofauna apresentou-se diversa e abundante. No entanto, a comunidade de macroinvertebrados revelou-se muito pouco diversa, provavelmente devido à menor riqueza de habitats ou às elevadas condutividades aí verificadas. Os resultados demonstraram que rios associados a eucaliptais certificados podem apresentar boa qualidade ecológica e uma significativa biodiversidade aquáticainfo:eu-repo/semantics/publishedVersio

Concepções sobre a matemática e trabalho investigativo

As actividades de investigação proporcionam aos alunos uma experiência viva e gratificante – levando-os a aprender processos como generalizar, considerar casos particulares, simbolizar, comunicar, analisar, explorar, conjecturar e provar. Investigação anterior, embora escassa, mostra as suas potencialidades mas t6ambém os seus problemas, resultantes dos alunos manifestarem, frequentemente, concepções incorrectas sobre a Matemática e a sua aprendizagem. Este estudo procura saber como é que eles trabalham nestas actividades e de que forma podem evoluir as suas concepções. Para isso – tendo por base a realização de quatro tarefas de investigação em aulas de Matemática e usando um estudo de caso – analisamos o modo como um alunos do 6º ano de escolaridade se envolve em actividades deste tipo. O aluno em causa, Francisco, mostra grande interesse nas actividades propostas. Nas primeiras não vai além da formulação de conjecturas. Progressivamente, realiza testes, refina conjecturas e ensaia justificações. Revela crescente autonomia, confiança e ousadia nos seus raciocínios. De início, integra-se pouco no grupo, mas por fim já interage bastante com os colegas. Inicialmente muito dependente da professora para a validação dos resultados, vai reconhecendo que também é uma autoridade matemática. Estas actividades contribuem para que ele adquira uma nova visão da Matemática como ciência em desenvolvimento, do papel do professor como orientador e do carácter desejavelmente estimulante das tarefas. O estudo conclui que a natureza desafiante e aberta das tarefas, o modo de trabalho usado pela professora e a dinâmica da aula proporcionaram oportunidades de raciocínio e interacção que foram aproveitadas por este aluno. Mostra também que é possível um significativo enriquecimento de aspectos cruciais das concepções dos alunos e sugere que o trabalho investigativo na sala de aula merece uma grande atenção na pesquisa educacional, indiciando novas pistas para trabalho futuro

Favourable areas for co-occurrence of parapatric species: niche conservatism and niche divergence in Iberian tree frogs and midwife toads

Aim Predicting species responses to global change is one of the most pressing issues in conservation biogeography. A key part of the problem is understanding how organisms have reacted to climatic changes in the past. Here we use species distribution modelling to infer the effects of climate changes since the Last Interglacial (LIG, about 130,000 ybp) on patterns of genetic structure and diversity in the Western Spadefoot toad (Pelobates cultripes) in combination with spatially-explicit phylogeographic analyses. Location Iberian Peninsula and mainland France. Methods 524 individuals from 54 populations across the species range were sampled to document patterns of genetic diversity and infer their evolutionary history based on data from mtDNA and fourteen polymorphic microsatellites. Generalized linear models based on distribution data were used to infer climatic favourability for the species in the present and in paleoclimatic simulations for the LIG, the Mid Holocene and the last glacial maximum (LGM). Results Estimates of genetic diversity show a decreasing trend from south to north, suggesting persistence of high historical population sizes in the southern Iberian Peninsula. Species distribution models show differences in climatic favourability through time, with significant correlations between historically stable favourable areas and current patterns of genetic diversity. These results are corroborated by Bayesian Skyline Plots and continuous diffusion phylogeographic analyses. Main conclusions The results indicate the presence of southern refugia, with moderate recent expansions at the northern end of the species’ range. Toads at the northern range margin exhibit the lowest genetic diversity and occupy areas of high past climate variability, classified as marginal in terms of favourability, rendering these populations most vulnerable to climate-mediated changes in the long term

Water quantity and quality under future climate and societal scenarios: a basin-wide approach applied to the Sorraia river, Portugal

Water resources are impacted by several stressors like over-population and over consumption that compromises their availability. These stressors are expected to progressively intensify due to climate change in most regions of the world, with direct impact on watersheds and river systems. This study investigates the effect of different watershed pressure scenarios due to climate change in the hydrological regime of the Sorraia River basin, Portugal. This catchment includes one of the largest irrigated areas in the country, thus being strongly influenced by anthropogenic activities, associated to hydrological (irrigation, flow regulation, damming) and nutrient stressors. The SoilWater Assessment Tool has been used to simulate water flow and nutrient dynamics in the watershed while considering inputs from two climate models and three societal scenarios. Results have shown that the predicted rainfall reductions will have a significant impact on river flow and nutrient concentrations when compared to baseline conditions. River flow will expectably decrease by 75%, while nitrogen and phosphorus concentrations in river water will expectably increase by 500% and 200%, respectively. These differences are more evident for storylines that consider increasing pressures such as population growth and agricultural expansion marked with unsustainable practices and increased reliance on technology. The results of this study indicate a possible future outcome and provide effective guidelines for the formulation of water management policies to counter the impacts of climate change and corresponding environmental pressures in the Sorraia River basininfo:eu-repo/semantics/publishedVersio

One millennium of historical freshwater fish occurrence data for Portuguese rivers and streams

The insights that historical evidence of human presence and man-made documents provide are unique. For example, using historical data may be critical to adequately understand the ecological requirements of species. However, historical information about freshwater species distribution remains largely a knowledge gap. In this Data Descriptor, we present the Portuguese Historical Fish Database (PHish–DB), a compilation of 2214 records (557 at the basin scale, 184 at the sub-basin scale and 1473 at the segment scale) resulting from a survey of 194 historical documents. The database was developed using a three-scale approach that maximises the inclusion of information by allowing different degrees of spatial acuity. PHish database contains records of 25 taxonomical groups and covers a time span of one millennium, from the 11th until the 20th century. This database has already proven useful for two scientific studies, and PHish further use will contribute to correctly assess the full range of conditions tolerated by species, by establishing adequate benchmark conditions, and/or to improve existing knowledge of the species distribution limits.info:eu-repo/semantics/publishedVersio

Modelling stream-fish functional traits in reference conditions: regional and local environmental correlates

Identifying the environmental gradients that control the functional structure of biological assemblages in reference conditions is fundamental to help river management and predict the consequences of anthropogenic stressors. Fish metrics (density of ecological guilds, and species richness) from 117 least disturbed stream reaches in several western Iberia river basins were modelled with generalized linear models in order to investigate the importance of regional- and local-scale abiotic gradients to variation in functional structure of fish assemblages. Functional patterns were primarily associated with regional features, such as catchment elevation and slope, rainfall, and drainage area. Spatial variations of fish guilds were thus associated with broad geographic gradients, showing (1) pronounced latitudinal patterns, affected mainly by climatic factors and topography, or (2) at the basin level, strong upstream-downstream patterns related to stream position in the longitudinal gradient. Maximum native species richness was observed in midsize streams in accordance with the river continuum concept. The findings of our study emphasized the need to use a multi-scale approach in order to fully assess the factors that govern the functional organization of biotic assemblages in ‘natural’ streams, as well as to improve biomonitoring and restoration of fluvial ecosystems