Ecology

This paper describes an ontology network that will serve as the basis for publishing and linking data about wood plant communities of the Brazilian Cerrado biome, obtained from scientific studies, meteorological and environmental data and geographical information (maps). Data Cube, Meteorological, GeoSPARQL and Time ontologies were used as infrastructure ontologies. In addition, two domain ontologies Cerrado Concepts and Wood Plant Dynamics Ontology (Ccon) and Fire Ontology (Fire) were developed to represent scientific knowledge about vegetation ecology focused on vegetation dynamics under different burning regimes. Datasets provided by Brazilian government agencies and those obtained from scientific literature, found in different formats, were transformed into RDF using Open Refine along with its RDF extension or, for shape files, using the geometry2RDF tool. A web-based application was deployed using Map4RDF, so as to provide a proper visualization of aggregated information, integ...

The present work describes an interdisciplinary evaluation activity of learning by modelling involving secondary school teachers. DynaLearn software functionalities (www.dynalearn.eu) were presented to teachers in a course. They created their own models integrating knowledge from different areas by developing interdisciplinary projects. During the course, the teachers discussed difficulties and facilities found during the modelling activities; aspects related to motivation and support in the context of the teacher-student interaction; how the software can be brought into the classroom; and educational activities that could be developed in their disciplines. The results suggest an improvement in the identification of causal inferences after modelling activities performed by the secondary school teachers. The teachers were positively motivated to explore models, to engage in a modelling activity and to learn more about the phenomena being studied with DynaLearn support. Initiatives of this type may become the basis for preparing teachers to work out scientific concepts with the support of QR models.

Knowledge about the natural dynamics of wind resources and the advantages of its exploration as energy source has a high value for implementing sustainable and integrated environmental management. The present work aims to explain the mechanism of wind formation in coastal zone, its capacity to produce energy, and the conversion of wind power in to energy for domestic use by human activities. The model shows changes of the wind direction in the coast zone due to changes of the air temperature caused by differences of water and land specific heat, leading to variations of air pressure. The result is a sea-land breezes that creates an adequate scenario to place wind farms for energy production. The model was built using Qualitative Reasoning techniques, and implemented in the DynaLearn workbench (www.dynalearn.eu), software which is being tested and evaluated.

Tendências atuais na educação científica mediada por computadores apontam para a importância da construção do conhecimento pelos alunos através de uma interação ativa com o ambiente de aprendizagem. Atividades de modelagem farão parte das atividades escolares regulares e contribuirão para desenvolver o raciocínio científico dos alunos. Enquanto estão envolvidos em tarefas de modelagem, os estudantes adquirem maior compreensão dos conceitos apresentados e desenvolvem outras habilidades cognitivas, explorando, construindo, utilizando e testando modelos no computador. O trabalho aqui descrito tem como objetivo apresentar os resultados de um estudo de avaliação de DynaLearn, um software que compreende um ambiente de aprendizagem que combina raciocínio qualitativo, agentes pedagógicos virtuais e tecnologia semântica (www.dynalearn.eu). Esse software foi projetado para ser usado principalmente por estudantes do ensino médio e universitários em disciplinas nas quais se adota a dinâmica de sistemas. O presente estudo explora princípios da biologia da conservação como parte de um currículo de ciências ambientais. Na atividade de avaliação com alunos de ensino médio aqui descrita, observou-se que melhorou o entendimento de conceitos do conteúdo trabalhado nas atividades de modelagem, os alunos se sentiram motivados com essas tarefas , e consideram que modelagem em DynaLearn é uma abordagem interessante para ser incorporada às atividades em sala de aula.

A better understanding of population dynamics is needed in the face of accelerating changes and modifications of natural landscapes. Qualitative Reasoning based models have been considered as a tool for integration and exploration of conceptual knowledge in ecological systems and population dynamics. The objective of the present work is to develop a set of qualitative models in order to capture, formalize, summarize, and compare knowledge about different approaches to metapopulation theory. Three types of approaches were modelled: 1) the classical concepts developed by Levins; 2) Pulliam’s view on source and sink populations; and 3) an integrated model of conservation, based on Hanski’s ideas. The models proved to be effective to summarize the central aspects of metapopulation theory and useful for comparing hypotheses and assumptions involved in the three approaches. The results show that qualitative models are a valuable tool for exploring theories and concepts and may provide a b...

This work aims to link data about wood plant communities obtained from scientific studies about the Brazilian Cerrado biome, meteorological and environmental data, geographical information (maps) and Qualitative Reasoning (QR) conceptual models. An ontology network was developed in order to integrate data from different sources. Data Cube, AEMET, GeoSPARQL, and Time ontologies and QR formalism were used as general ontologies. In addition, two domain ontologies Cerrado Concepts and Wood Plant Dynamics Ontology (Ccon) and Fire Ontology (Fire) were developed to represent scientific knowledge about vegetation ecology focused on vegetation dynamics under different burning regimens. Datasets provided by Brazilian government agencies and those obtained from scientific literature were transformed into RDF using LOD Refine and visualized in Map4RDF. The interface integrates map visualization using Google Maps API with facet browsing. Given the aggregated information, the application selects ...

Knowledge about the natural dynamics of wind resources and the advantages of its exploration as energy source has a high value for implementing sustainable and integrated environmental management. The present work aims to explain the mechanism of wind formation in coastal zone, its capacity to produce energy, and the conversion of wind power in to energy for domestic use by human activities. The model shows changes of the wind direction in the coast zone due to changes of the air temperature caused by differences of water and land specific heat, leading to variations of air pressure. The result is a sea-land breezes that creates an adequate scenario to place wind farms for energy production. The model was built using Qualitative Reasoning techniques, and implemented in the DynaLearn workbench (www.dynalearn.eu), software which is being tested and evaluated. Introduction Wind is an indirect form of solar power and has emerged as a preeminent option of energy sources, in part because ...

The composition of phytoplankton and the concentration of pigments in their cells make their absorption and specific absorption coefficients key parameters for bio-optical modeling. This study investigated whether the multispectral vertical diffuse attenuation coefficient of downward irradiance (Kd) gradients could be a good framework for accessing phytoplankton genera. In situ measurements of remote sensing reflectance (Rrs), obtained in an Amazon Floodplain Lake (Lago Grande do Curuai), were used to invert Kd, focusing on Sentinel-3/Ocean and Land Color Instrument (OLCI) sensor bands. After that, an analysis based on the organization of three-way tables (STATICO) was applied to evaluate the relationships between phytoplankton genera and Kd at different OLCI bands. Our results indicate that phytoplankton genera are organized according to their ability to use light intensity and different spectral ranges of visible light (400 to 700 nm). As the light availability changes seasonally,...

In the Amazonian floodplains, the local populations living from agricultural activities and fishing, have always coped natural variations, between flood and dry seasons. However, the rhythm and the amplitude of these floods are disturbed nowadays, resulting in great uncertainty for these populations. Biophysics and social scientists have joined hands to help these populations better improve their resilience to such changes. Our initial goal aims to better understand and discuss the impacts of current practices in the long term. To ad dress this, we first turned the perspective around the preoccupations and strategies of local populations and collectively discussed possible future scenarios. Using a role-playing game (RPG) as a dialogue interface, an agent-based model (ABM) was progressively built. This is a hybrid model allowing the users to interact with the simulation: they take seasonal decisions on agriculture, fishing and animal husbandry, which are virtually performed by the m...

The processes in tropical floodplain lakes enable maintaining phytoplankton nutrient requirements over a hydrological year. The nutrients such as nitrogen, phosphorus and carbon compounds play an essential role in phytoplankton growth. However, the way that nutrients and phytoplankton interact and how this relationship varies seasonally in tropical freshwater ecosystems is not clear. In this study, we evaluate the relationship between phytoplankton–nutrients over the hydrological cycle in Amazonian floodplain lakes and verify if this relationship influences the biomass of cyanobacteria. We also check what factors linked to nutrients act in structuring phytoplankton community. Using the phytoplankton functional approach, we verified how their ability to respond to hydrological and environmental variations reflects the ecological conditions and investigated how these interactions work. The results show that the Amazonian floodplain lakes could maintain long-term nutrient enrichment st...

This study focuses on determining how many samples are needed to effectively assess the species richness of a community. Zooplankton samples at 40 sampling sites distributed among four lakes in the floodplain of the middle Araguaia River (Central-West region of Brazil) were evaluated to determine the effect of the accumulation of collecting points by lake on species richness estimates. The results indicated the zooplankton community has high spatial heterogeneity. Thus, using a single sampling unit per lake would not be sufficient to accurately estimate their diversity (i.e. the zooplankton composition in these cases would be represented mainly by abundant species). Sampling designs that include a minimum of seven sampling sites in each lake are needed to record 70% of the total species richness. It is recommended, therefore, that researchers use a larger number of sampling sites per lake or, alternatively, that the water obtained and filtered through plankton nets is extracted from a wide area and in different lake compartments, rather than from a single site.

River floodplains are subject to different inundation scenarios, mainly related to the flood pulse. Moreover, the ecology of floodplain lakes is modulated by exchanges of water with the main stream. On Amazonian floodplains, the water level fluctuates seasonally, with four distinct stages during the year: rising, high, falling, and low water. This study evaluated how/which three functional approaches to phytoplankton (FG, functional groups; MFG, morphofunctional groups; and MBFG, morphology-based functional groups) showed the largest relation to the environmental variations in response to rising and falling water periods, using data of the seven lakes sampled during rising and falling water periods, on the Curuaí Floodplain system, Pará state, Brazil. We used a Principal Coordinates Analysis to check for differences in phytoplankton species composition between the rising and falling water periods and a Redundancy Analysis to evaluate the relationship between functional approaches and environmental. Electrical conductivity, silica, and pH were the most important environmental variables to structuring the phytoplankton. The biological dissimilarity was computed using Bray-Curtis index for species biovolume and indicated greater similarity among the species compositions in the lakes during the falling water period. During rising water species is adapted in almost all lentic ecosystems (FG Y) and autotrophic organisms typical from the meroplanktonic that can be found in phytoplankton samples of the shallow lakes (FG MP); cryptomonads (MFG 2d), large centrics (MFG 6a), and large pennates (MFG 6b); and nonflagellated organisms with siliceous exoskeletons (MBFG VI) and unicellular flagellates of medium to large size (MBFG V) were predominant. During falling water, species that tolerate eutrophic to hypertrophic environments with low nitrogen content predominated all shallow lakes (FGs H1 and M; MFGs 5e and 5b; and MBFGs III and VII) and Dolichospermum spp. formed blooms. Morphology-based functional groups were the larger relation with the environmental variations than did functional groups and morphofunctional groups. MBFGs provides a relatively simple and objective classification and were the best in characterizing phytoplankton dynamics on the Curuaí floodplain. Therefore, we recommend using these groups to study phytoplankton ecology in shallow floodplain lakes.

Amazonian aquatic environments are complex, and their interaction promotes heterogeneous environments that turn difficult the development of patterns to describe them. We evaluated if interannual variation in the physical-chemical structure and the phytoplankton community promote environmental and biological contrasted conditions between similar hydrological periods. Amazonian floodplain lakes have different environmental and biological responses in similar water periods due to the interannual variation. Phytoplankton community structure has differences between periods, but these differences do not necessary promote dissimilarities. Most of the phytoplankton species belong to the same functional groups. The composition of species and functional groups between sample units inside lakes is variable and may have or not significant differences in dissimilarity, but both periods are equally heterogeneous. Beta diversity has shown that the replacement of species and functional groups causes a great level of variation between sites, which maintain a high heterogeneity between periods. These variations have different responses for different scales turning a difficult task the interpretation of patterns for these environments. Hence, scale and interannual variability are factors that need to be carefully considered when setting standards to describe the ecological dynamics of floodplain lakes in the Amazonian system.

Aim This study aimed to answer: (i) can phytoplankton communities be used as surrogate of zooplankton communities?; (ii) can we use ecological approaches like functional groups (FG) or morphofunctional classification (MBFG) as surrogate for phytoplankton species?; (iii) can we use substitute groups (cladocera, copepod, rotifer or testate amoebae) as surrogate for zooplankton species?; (iv) are the environmental variables’ ordination standards concordant with the ordering patterns of phytoplankton and zooplankton species?; and (v) for both communities, is the spatial pattern of ordination maintained using density data or presence/absence of individuals or lower taxonomic resolutions? Methods The study was conducted in 25 water bodies that supply central-pivot irrigation in the Federal District - Brazil (Rio Preto Basin), in October 2012. We evaluated some physical and chemical variables as well as phytoplankton and zooplankton samples. To evaluate correlation among biological groups,...

Many trophic indices have been constructed for temperate aquatic environments, but few have proved reliable for tropical environments. Indices constructed on the basis of nutrients may not be effective for describing the trophic state because the fractions of nitrogen and phosphorus differ in their potential to predict the nutrient limitation in tropical aquatic environments. We developed an index based on the phytoplankton Reynolds functional groups for an Amazonian floodplain lake from samples collected during 2 contrasting hydrological periods (rising and flushing) and compared it with the index initially proposed by Carlson in 1977 and further adapted to tropical environments by Toledo in 1990. The functional group and Carlson indices matched only 37% and 56% of the sample units collected during the rising and flushing periods, respectively. Our study confirms the difficulty of assessing trophic states using only phosphorus and chlorophyll a in tropical floodplain lakes. In this environment (1) nitrogen may significantly limit phytoplankton growth and (2) complex phytoplankton-nutrient relationships occur during the hydrological cycle that cannot be accounted for through a simple phosphorus and chlorophyll a formula.

The Amazonian floodplain is among the most productive and diversified ecosystems in the world. The moving littoral enables a rapid nutrient recycling, explaining the large productivity and biodiversity of the system. Attracted by such favourable conditions for agricultural activities and fishing, populations have settled in the floodplains and developed complementary activities to cope with important variations in their environment, between the flood season and the dry season. However, in the past decades, the rhythm of these floodplains has changed, obliging the actors to deal with great uncertainty. Based on several years of hydrological and biogeochemical studies to understand the reasons of these environmental changes, the “life scientists” of our team invited the “social scientists” with the following question: Can the results about the dynamics of these floodplains help local populations better anticipate the future fluctuations of the river and adapt their activities to be le...

This study aimed to answer: (i) can phytoplankton communities be used as surrogate of zooplankton communities?; (ii) can we use ecological approaches like functional groups (FG) or morphofunctional classification (MBFG) as surrogate for phytoplankton species?; (iii) can we use substitute groups (cladocera, copepod, rotifer or testate amoebae) as surrogate for zooplankton species?; (iv) are the environmental variables' ordination standards concordant with the ordering patterns of phytoplankton and zooplankton species?; and (v) for both communities, is the spatial pattern of ordination maintained using density data or presence/absence of individuals or lower taxonomic resolutions? Methods: The study was conducted in 25 water bodies that supply central-pivot irrigation in the Federal District-Brazil (Rio Preto Basin), in October 2012. We evaluated some physical and chemical variables as well as phytoplankton and zooplankton samples. To evaluate correlation among biological groups, numerical and higher taxonomic resolutions, we performed some Mantel and Procrustes analyses. Results: Evaluating the use of substitute groups, comparisons between phytoplankton and zooplankton, FG and MBFG classifications and almost all the comparisons between zooplankton groups suggested concordant patterns. However, the values of r were low, all below 0.70. Biological analyses with phytoplankton and zooplankton can be performed using presence/ absence of individuals without significant loss of information, except for MBFG classification and copepods. Data may also be used at genus or family level for copepods and testate amoebae and only data at genus level for cladocerans and rotifers. Different results were found concerning taxonomic resolution for phytoplankton considering that, while being significant, the r value was less than 0.70. Conclusions: For environmental monitoring purposes, it is important to sample both phytoplankton

This study focuses on determining how many samples are needed to effectively assess the species richness of a community. Zooplankton samples at 40 sampling sites distributed among four lakes in the floodplain of the middle Araguaia River (Central-West region of Brazil) were evaluated to determine the effect of the accumulation of collecting points by lake on species richness estimates. The results indicated the zooplankton community has high spatial heterogeneity. Thus, using a single sampling unit per lake would not be sufficient to accurately estimate their diversity (i.e. the zooplankton composition in these cases would be represented mainly by abundant species). Sampling designs that include a minimum of seven sampling sites in each lake are needed to record 70% of the total species richness. It is recommended, therefore, that researchers use a larger number of sampling sites per lake or, alternatively, that the water obtained and filtered through plankton nets is extracted from a wide area and in different lake compartments, rather than from a single site.

Canadian Water Quality Index (CWQI) provides protection for freshwater life promoting healthy ecosystems and safeguarding human health. Biological Diatom Index (BDI) was developed to indicate the ecological status and water quality of freshwater systems. This paper evaluates the relations between the two different indices. During rising and falling, water samples were taken in the Curuai Floodplain, Brazil. CWQI was calculated using 14 physicochemical parameters and 1 microbiological parameter. The limits were established according to freshwater quality conditions and standards based on water use classes 1 and 2 determined in CONAMA 357 legislation and British Columbia. Canadian Water Quality Index categorization ranged from "marginal" to "excellent," most sampling units were "good" (71%), followed by "fair" (12%) and "excellent" (12%) water quality. Total phosphorus (38 times), chlorophyll a (20), dissolved oxygen (10), and total organic carbon (10) were the parameters that presented the most noncompliance values. Encyonema silesiacum (14%), Gomphonema parvulum (13%), and Navicula cryptotenella (12%) were the main taxa in the rising period, while G. lagenula, E. silesiacum, and Fragilaria capucina were the main taxa during the falling period. BDI ranges from I to V water quality classes. We observed "poor" to "very good" ecological status, with most sampling units "moderate" (52%) and "good" (29%). Water quality for class 2 was better than water quality for class 1, as the limits of the parameters evaluated were more restrictive in class 1 than in class 2 and the predominant uses of water require a higher degree of water purity. The biological index based on diatoms was the most restrictive index whose water classes and categorizations have shown an ecological status that could threaten the protection of aquatic communities on the Curuai floodplain. We suggest the combined use of both indices-physicochemical and biological for water quality assessment in this type of environment.