Diatom cooccurrence shows less segregation than predicted from niche modeling

Peer reviewe

Environmental filtering and taxonomic relatedness underlie the species richness-evenness relationship

We examined the relationship between species richness (S) and evenness (J) within a novel, community assembly framework. We hypothesized that environmental stress leads to filtering (increasing the proportional abundance of tolerant species) and taxonomic dispersion (decreasing the number of species within genera and families). Environmental filtering would cause a decline in S by eliminating some stress-sensitive species and a reduction of J by allowing only tolerant species to maintain large populations. Taxonomic relatedness may influence both S and J by controlling the nature of interspecific interactions-positive under taxonomic dispersion versus negative under taxonomic clustering. Therefore, the S-J relationship may be a product of environmental filtering and taxonomic relatedness. We tested this framework with redundancy analyses and structural equation models using continental stream diatom and fish data. We confirmed that (i) environmental stress, defined by watershed forest cover, slope, and temperature, caused filtering (lower sensitive: tolerant species abundance ratios) and taxonomic dispersion (elevated genus: species richness and family: species richness ratios); (ii) S and J, which declined with filtering and taxonomic dispersion, exhibited a positive relationship; and (iii) the role of filtering on J was pronounced only under stressful conditions, while taxonomic dispersion remained an important predictor of J across stressful and favorable environments.Peer reviewe

Les cartes auto-organisatrices de Kohonen appliquées à l'étude des communautés de micro-algues des cours d'eau

Les cartes auto-organisatrices de Kohonen appliquées à l'étude des communautés de micro-algues des cours d'ea

Structure of benthic diatom assemblages in rivers : is environment the only explanation ?

Les diatomées sont des algues microscopiques qui sont largement utilisées pour évaluer la qualité écologique des cours d'eau.Les méthodes utilisées se basent sur des modèles simplifiés de biologie des communautés, dans lesquels seules les réponses individuelles des espèces à l'environnement sont prises en compte.Le test de l'importance de processus complémentaires a montré un impact fort des dynamiques de colonisation des espèces, mais un impact négligeable des phénomènes de compétition ou de facilitation.Ces processus impliquent une structure des assemblages bien plus complexe que celle habituellement assumée par les méthodologies de bioindication.L'adaptation et la mise en oeuvre de méthodes de réseaux de neurones et de logique floue nous ont permis de redéfinir des éco-régions françaises et de décrire des relations générales entre les traits biologiques des espèces et l'environnement, tout en prenant mieux en compte cette complexité.Diatoms are microscopic algae which are widely used to monitor the ecological quality of strems and rivers. The regular methodologies are based on simpllified community models. In these models, only the invidual species responses to environment are accounted for.Testing the importance of complementary processes showed a significant effect of colonization dynamics, but only a slight effect of biotic relationships. These processes led us to considerate a more complex assemblage structure than the one usually assumed by the biomonitoring methodologies.Therefore we implemented both neural networks models and fuzzy logic methodologies, in order to refine French ecoregions and to describe relationships between species traits and environment

Structure of benthic diatom assemblages in rivers : is environment the only explanation ?

Les diatomées sont des algues microscopiques qui sont largement utilisées pour évaluer la qualité écologique des cours d'eau.Les méthodes utilisées se basent sur des modèles simplifiés de biologie des communautés, dans lesquels seules les réponses individuelles des espèces à l'environnement sont prises en compte.Le test de l'importance de processus complémentaires a montré un impact fort des dynamiques de colonisation des espèces, mais un impact négligeable des phénomènes de compétition ou de facilitation.Ces processus impliquent une structure des assemblages bien plus complexe que celle habituellement assumée par les méthodologies de bioindication.L'adaptation et la mise en oeuvre de méthodes de réseaux de neurones et de logique floue nous ont permis de redéfinir des éco-régions françaises et de décrire des relations générales entre les traits biologiques des espèces et l'environnement, tout en prenant mieux en compte cette complexité.Diatoms are microscopic algae which are widely used to monitor the ecological quality of strems and rivers. The regular methodologies are based on simpllified community models. In these models, only the invidual species responses to environment are accounted for.Testing the importance of complementary processes showed a significant effect of colonization dynamics, but only a slight effect of biotic relationships. These processes led us to considerate a more complex assemblage structure than the one usually assumed by the biomonitoring methodologies.Therefore we implemented both neural networks models and fuzzy logic methodologies, in order to refine French ecoregions and to describe relationships between species traits and environment

Structure of benthic diatom assemblages in rivers : is environment the only explanation ?

Les diatomées sont des algues microscopiques qui sont largement utilisées pour évaluer la qualité écologique des cours d’eau.Les méthodes utilisées se basent sur des modèles simplifiés de biologie des communautés, dans lesquels seules les réponses individuelles des espèces à l’environnement sont prises en compte.Le test de l’importance de processus complémentaires a montré un impact fort des dynamiques de colonisation des espèces, mais un impact négligeable les phénomènes de compétition ou de facilitation.Ces processus impliquent une structure des assemblages bien plus complexe que celle habituellement assumée par les méthodologies de bioindication.L’adaptation et la mise en oeuvre de méthodes de réseaux de neurones et de logique floue nous ont permis de redéfinir des éco-régions françaises et de décrire des relations générales entre les traits biologiques des espèces et l’environnement, tout en prenant mieux en compte cette complexité.Diatoms are microscopic algae which are widely used to monitor the ecological quality of streams and rivers. The regular methodologies are based on simpllified community models. In these models, only the invidual species responses to environment are accounted for.Testing the importance of complementary processes showed a significant effect of colonization dynamics, but only a slight effect of biotic relationships. These processes led us to considerate a more complex assemblage structure than the one usually assumed by the biomonitoring methodologies.Therefore we implemented both neural networks models and fuzzy logic methodologies, in order to refine French ecoregions and to describe relationships between species traits and environment

Spatial literacy influences stakeholder’s recognition and mapping of peri-urban and urban ecosystem services

There are several spatial valuation and ecosystem service mapping studies using participatory methods in North America, Australia, Europe and Japan. But, there is much less information from urban areas in the Global South using these approaches, particularly regarding the influence of spatial literacy on such methods. Accordingly, we tested how two-dimensional (2D) maps and three-dimensional models (3DCM) influence the identification of urban and peri-urban ecosystem services by different stakeholders near forested landscapes adjacent to Bogotá, Colombia. We used on-site interviews, quantitative machine-learning statistics, and qualitative methods to identify predictors and assess the ability of different stakeholders to identify: peri-urban forest ecosystem services, threats to forest ecosystems, and in locating points of interest. We found that age, residential proximity to the study sites, and education were the best predictors for estimating the number of ecosystem services. Older and non-local interviewees less than 20 years old recognized a greater number of ecosystem services. Using 2D maps to locate predesignated sites resulted in better results than when using a 3DCM; particularly with younger respondents. However, respondents were able to locate more predesignated sites with the 3DCM when they had a higher level of education. As opposed to other studies, our stakeholders more frequently identified regulating as opposed to cultural ecosystem services. Our study identified socio-demographic predictors that could be used to assess different stakeholder’s abilities in recognizing different processes from landscapes as well as their difficulty in accurately locating areas of interest. Such low cost and participatory approaches can be used to design more context-relevant survey instruments for ecosystem service valuation research and assessments. © 2020, Springer Science+Business Media, LLC, part of Springer Nature

Spatial literacy influences stakeholder’s recognition and mapping of peri-urban and urban ecosystem services

There are several spatial valuation and ecosystem service mapping studies using participatory methods in North America, Australia, Europe and Japan. But, there is much less information from urban areas in the Global South using these approaches, particularly regarding the influence of spatial literacy on such methods. Accordingly, we tested how two-dimensional (2D) maps and three-dimensional models (3DCM) influence the identification of urban and peri-urban ecosystem services by different stakeholders near forested landscapes adjacent to Bogotá, Colombia. We used on-site interviews, quantitative machine-learning statistics, and qualitative methods to identify predictors and assess the ability of different stakeholders to identify: peri-urban forest ecosystem services, threats to forest ecosystems, and in locating points of interest. We found that age, residential proximity to the study sites, and education were the best predictors for estimating the number of ecosystem services. Older and non-local interviewees less than 20 years old recognized a greater number of ecosystem services. Using 2D maps to locate predesignated sites resulted in better results than when using a 3DCM; particularly with younger respondents. However, respondents were able to locate more predesignated sites with the 3DCM when they had a higher level of education. As opposed to other studies, our stakeholders more frequently identified regulating as opposed to cultural ecosystem services. Our study identified socio-demographic predictors that could be used to assess different stakeholder’s abilities in recognizing different processes from landscapes as well as their difficulty in accurately locating areas of interest. Such low cost and participatory approaches can be used to design more context-relevant survey instruments for ecosystem service valuation research and assessments. © 2020, Springer Science+Business Media, LLC, part of Springer Nature

Evaluating the role of spatial landscape literacy in public participation processes and opinions on environmental issues and ecosystem services

Se sabe poco sobre cómo influye la alfabetización espacial en la elaboración de mapas y la toma de decisiones relacionadas con la gestión medioambiental y los servicios ecosistémicos. Evaluamos el papel de la alfabetización espacial del paisaje en la gestión ambiental participativa y las evaluaciones de los servicios ecosistémicos en la Bogotá periurbana, Colombia. La alfabetización paisajística espacial se evaluó poniendo a prueba la capacidad de las partes interesadas para localizar paisajes y puntos de referencia específicos. A continuación, se evaluó si las opiniones sobre las decisiones medioambientales y los servicios ecosistémicos guardaban una relación significativa con la alfabetización paisajística. Se utilizó un instrumento en línea para recoger las características socioeconómicas de 2.397 encuestados, sus conocimientos sobre el paisaje espacial, sus percepciones de los servicios ecosistémicos y sus opiniones sobre cuestiones medioambientales relevantes. Evaluamos y medimos la SL autopercibida de los encuestados y su capacidad para localizar cuatro paisajes en un mapa integrado en línea. La precisión posicional se calculó utilizando un índice de alfabetización espacial del paisaje (SLI). A continuación, se comprobaron los efectos de los datos sociodemográficos en el SLI, se modeló la relación entre los datos sociodemográficos y la SL, y se comprobó la relación entre la SL de los encuestados y sus opiniones sobre cuestiones medioambientales relevantes y servicios ecosistémicos. Descubrimos que alrededor del 75% de los encuestados localizaron correctamente 2 de los 4 paisajes. Las variables sociodemográficas tampoco predijeron bien el modelo SLI. Sin embargo, encontramos relaciones significativas entre el SLI y las opiniones relativas al medio ambiente. No se encontró ninguna relación entre los niveles de participación activa de los encuestados en la gobernanza local y el SLI. En general, la SL se vio poco afectada por los niveles educativos. Lo ideal sería que los procesos participativos que utilizan mapas midieran la LS y no asumieran a priori que los participantes tienen conocimientos espaciales. Es necesario seguir investigando para evaluar cómo las tecnologías espaciales y la comprensión de los valores de las partes interesadas hacia el medio ambiente pueden democratizar la toma de decisiones participativa.Little is known about how spatial literacy influences mapping and decision-making related to environmental management and ecosystem services. We assessed the role of spatial landscape literacy in participatory environmental management and ecosystem service assessments in peri-urban Bogota, Colombia. Spatial landscape literacy (SL) was evaluated by testing stakeholder’s ability to locate specific landscapes and landmarks. We then assessed if opinions on environmental decisions and ecosystem services were significantly related to SL. We used an online instrument to capture 2,397 respondent’s socioeconomic characteristics, SL, ecosystem service perceptions, and opinions concerning relevant environmental issues. We evaluated and measured respondents’ self-perceived SL and ability to locate four landscapes in an integrated online map. Positional accuracy was calculated using a Spatial Landscape Literacy Index (SLI). We then tested for effects of socio-demographics on SLI, modeled the relationship between socio-demographics and SL, and tested the relationship between respondents’ SL and their opinions on relevant environmental issues and ecosystem services. We found that about 75% of the respondents correctly located 2 of the 4 landscapes. The SLI model was also poorly predicted by socio-demographic variables. However, we found significant relationships between SLI and opinions concerning the environment. No relationship was found between respondents’ levels of active participation in local governance and SLI. Overall, SL was little affected by education levels. Participatory processes using maps should ideally measure SL and not assume a priori that participants are spatially literate. Further research is needed to evaluate how spatial technologies and understanding stakeholder’s values towards the environment can democratize participatory-based decision-making

C-scores of pseudo-community matrices, in comparison to the C-score of the real matrix, in the different datasets.

<p>Bold segments represent 95% of the distributions. Perpendicular marks represent the median of distributions. The arrow indicates the value of the real community matrix. The models with names beginning by “NullMod” correspond to standard null models, those with names beginning by “Logit” correspond to environmentally constrained null models based on logistic regression predictions and those beginning by “RandFor” correspond to constrained null models based on Random Forest predictions. At the end of the name “FE” stands for occurrences Fixed and Equiprobable site richnesses, “FF” stands for occurrences and richnesses Fixed, “PF” stands for proportional occurrences (depending on pseudo-probabilities) and fixed richnesses, and “PP” stands for proportional occurrences and richnesses.</p