ABSTRACT
RESUMEN Los suelos degradados y sin plantas de la Mixteca Alta de Oaxaca (México) fueron, por un largo tiempo, como el paisaje habitual de la región; sin embargo, la organización de los campesinos y las intervenciones de los programas de reforestación configuraron un nuevo paisaje con bosques. Desde 1935, la Mixteca Alta experimenta reforestaciones en su territorio, lo que originó una paulatina mejoría del paisaje. Para estudiar esta transformación, se aplicó una metodología cualitativa, la cual, se apoyó en la planeación de escenarios y de entrevistas semiestructuradas con las autoridades comunales. Los resultados muestran que los entrevistados perciben a las forestaciones como el factor que cambió su paisaje y, al mismo tiempo, identifican los servicios ecosistémicos que les brindan, como un clima local más agradable, la aparición de pequeños arroyos y fauna silvestre. Los resultados del estudio muestran la intención que tienen los entrevistados para hacer uso y aprovechamiento de las plantaciones.
ABSTRACT The degraded and deforested soils of the Mixteca Alta of Oaxaca (Mexico) were for a long time the usual landscape of the region. However, the organization of the farmers and the interventions of reforestation programs configured a new forested landscape. Since 1935, the Mixteca Alta has been subject to reforestation processes in its territory, which has led to a gradual improvement of the landscape. To study this transformation, a qualitative methodology was applied, based on scenario planning and semi-structured interviews with community authorities. The results show that the interviewees perceive the forestations as the factor that changed their landscape and at the same time identify the ecosystem services they provide, such as a more pleasant local climate, the appearance of small streams and wildlife. The results of the study show the intention of the interviewees to use and take advantage of the plantations.
ABSTRACT
Introduction: Migration of people from rural environments to cities has accelerated urbanization and modified the landscape as well as the ecological processes and communities in these areas. The Costa Rican endemic Cabanis´s Ground-Sparrow (Melozone cabanisi) is a species of limited distribution restricted to the "Gran Area Metropolitana", which is the biggest urban settlement of the country. This area has experimented and still experiment an ongoing fragmentation and loss of habitat used by this species (coffee plantations, shrubs, and thickets). Objective: To determine the effects of urbanization on habitat abundance and spatial pattern for the occurrence of Melozone cabanisi. Methods: We modeled the area of potentially suitable habitat for this species in Costa Rica using occurrence and bioclimatic data. Then, we estimated the actual suitable habitat using land cover type layers. Finally, we analyzed the connectivity among the actual suitable habitat patches using single-patch and multi-patch approaches. Results: From the area of potentially suitable habitat estimated by the bioclimatic model, 74 % were urban areas that are unsuitable for Melozone cabanisi. The largest suitable patches within urban areas were coffee plantations; which also were crucial for maintaining connectivity between habitat patches along the species' range. Conclusions: To preserve and protect the Melozone cabanisi, these areas must be taken into consideration by decision-makers in the present and future management plans. We recommend avoiding change shrubs and thickets to urban cover to preserve the occurrence of Melozone cabanisi, and implement a program for the payment of environmental services to landholders, supported by the local governments, to protect those habitats in urban contexts.
Introducción: La migración desde ambientes rurales hacia las ciudades ha incrementado la urbanización. Esto ha modificado el paisaje, así como los procesos ecológicos y comunidades dentro de estas áreas. El Cuatro-ojos de Jupa-roja (Melozone cabanisi) es una especie distribuida principalmente al interior del asentamiento urbano más grande de Costa Rica. Hasta el presente esta área sigue experimentando fragmentación y pérdida del hábitat utilizado por esta especie (plantaciones de café, charrales y tacotales). Objetivo: Determinar los efectos de la urbanización sobre la cantidad de hábitat y su distribución espacial, basada en datos de presencia para M. cabanisi. Métodos: Modelamos el hábitat potencialmente adecuado para M. cabanisi utilizando datos bioclimáticos y de presencia. Luego estimamos el hábitat real utilizando el hábitat potencialmente adecuado y las capas de cobertura del suelo. Finalmente analizamos la conectividad entre los parches de hábitat real utilizando un enfoque multi y mono-parche. Resultados: Del área del hábitat potencialmente adecuado estimada por el modelo bioclimático, 74 % fueron áreas urbanas, lo que consideramos es un porcentaje inadecuado para M. cabanisi. Los parches más grandes de hábitat real dentro de las áreas urbanas fueron plantaciones de café, que a su vez fueron cruciales para mantener la conectividad entre los parches a lo largo del rango de distribución de la especie. Conclusiones: Para conservar y proteger a M. cabanisi, los tomadores de decisiones deben tener en cuenta los charrales, tacotales y cafetales dentro de la distribución de las especies en los planes de gestión presentes y futuros, evitando su cambio a coberturas urbanas.
Subject(s)
Animals , Birds/growth & development , Refugium , Cities , Costa RicaABSTRACT
Abstract INTRODUCTION: The study of the landscape ecology, biological microhabitat, and epidemiological implications for the distribution of the main vectors Aedes aegypti and Aedes albopictus contribute to the prevention and control actions regarding the diseases they transmit. METHODS: This study sought to assess data on positive properties of the vector control program activities from 1998 to 2010. An entomological survey was also carried out on a sample of buildings collecting larvae and pupae from containers between October and April (spring / summer) from 2002 to 2005. We assessed the physico-chemical data of the water in 20% of positive containers. The vegetation and urbanization were assessed with the aid of satellite images and microenvironments were classified as urbanized, woods, and shrubs. The data were analyzed using statistical and geoprocessing software. RESULTS: Ae. aegypti and Ae. albopictus colonized all types of microhabitats and microenvironments, predominantly in the urbanized area, in isolation and in coexistence. The microhabitat of Ae. aegypti showed a temperature gradient greater than that of Ae. albopictus, and there was an association with urbanized areas for the first species and wooded areas for the last species. CONCLUSIONS: Landscape ecology and intra-urban differences favor different microclimates, which contribute to the coexistence of species in the urban environment in an area close to the forest, raising the risk of other arbovirus infections in urban areas. The ecological niche should be considered for Ae. albopictus. Entomological and virologic monitoring are suggested as arbovirus surveillance actions in urban infested centers near preserved forests.
Subject(s)
Animals , Ecosystem , Aedes/physiology , Mosquito Vectors/physiology , Arbovirus Infections/transmission , Seasons , Urban Population , Brazil , Population Density , Aedes/classification , Spatial Analysis , Animal Distribution , Mosquito Vectors/classificationABSTRACT
Este trabajo evalúa el efecto que tienen ciertas variables paisajísticas (ríos, tierras agropecuarias, áreas antrópicas y bosque nativo) en los patrones de presencia del mono araña, Ateles fusciceps, en el noroccidente ecuatoriano. Se utilizaron registros geográficos de Ateles fusciceps tomados en campo y de estudios previos. Se evaluó el efecto de la proximidad de cada variable por medio de la prueba T de Student. Posteriormente mediante regresiones logísticas y por medio del Criterio de Información de Akaike (AIC) se seleccionaron los mejores modelos y se identificaron las variables más importantes. Se observó que tierras agropecuarias y zonas antrópicas tienen un efecto negativo para este primate, pues los puntos de presencia se encontraron alejados de éstas. Se evidencia también que Ateles fusciceps prefiere sitios cercanos a bosque, resultado que corrobora investigaciones previas, sin embargo también se encuentra una asociación con ríos, resultado que no ha sido reportado en estudios anteriores. Se encontraron dos modelos importantes para predecir patrones de presencia de este primate, el primero compuesto por: bosque nativo, ríos y zonas antrópicas (AICw=0.48), mientras que el segundo abarca: bosque nativo, ríos, zonas antrópicas y tierras agropecuarias (AICw=0.34). Estos resultados servirán de base para futuros análisis, dirigidos a la conservación de A. fusciceps.
In this work, I investigate the effect of some landscape variables (rivers, agricultural lands, anthropic areas and native forest) on the presence patterns of spider monkey, Ateles fusciceps, in the northwestern Ecuador. Geographical records collected in field and others from previous studies were used to conduct this study. Effects of proximity of each variable to presence of A. fusciceps were assessed with Student T tests. The best model and the most important variables were identified using logistic regressions and the Akaike Information Criterion (AIC). The results showed that agricultural lands and anthropic zones were from the primate presence points, suggesting a negative effect on A. fusciceps. I also found that A. fusciceps prefers sites near rivers, this observation has not been reported in previous studies. Two important models were found to predict the presence of A. fusciceps, the first one was composed by three variables: native forest, rivers and anthropic areas (AICw= 0.48) and the second model was composed by the four variables: native forest, rivers, anthropic areas and agricultural lands (AICw= 0.34). The results of this work will contribute a basis for future studies aimed on A. fusciceps conservation.
ABSTRACT
Abstract: Habitat loss and fragmentation are the main threats to the conservation of Cerrado biodiversity. The objective of this study was to evaluate the implications of habitat loss on the persistence of medium and large mammal species, considering the spatial and temporal changes (years 1985, 2000 and 2014) to the evaluated fragments. The study was carried out in 14 fragments (10.5 - 618 ha), located in Southeastern Goiás, Brazil. Records for 24 mammal species were obtained and revealed the two sites with the largest habitat amount in the landscape contained higher species richness than the remaining sites. The three mammal groups based on body mass (weight < 5 kg; weight between 5 and 20 kg; and weight > 20 kg) analyzed in this study showed different responses regarding landscape changes. For larger mammals (between 5 - 20 kg and > 20 kg), there was significant association between current species richness and the amount of habitat in 2014, while the species richness of smaller mammals did not significantly correlate with any of the variables assessed for any of the years. Therefore, the amount of habitat present within the current landscape was the most important variable regarding mammal species richness, especially for the larger species. The time lag was not evident at the time scale evaluated, and this delay in response may have occurred in a relatively short time (< 15 years). For the remaining fragments in the studied landscapes, most are too small to support populations of some larger mammal species and may also leave individuals more vulnerable to anthropogenic actions (e.g. hunting), whose effects may accelerate local extinctions.
Resumo: A perda e a fragmentação de habitats são as principais ameaças à conservação da biodiversidade no bioma Cerrado. O presente estudo objetivou avaliar as implicações da perda de habitat na persistência de espécies de mamíferos de médio e grande porte, levando em consideração as alterações espaciais e temporais dos fragmentos avaliados. O estudo foi realizado em 14 fragmentos (10,5 - 618 ha), localizados na região sudeste de Goiás, Brasil. Foram obtidos registros de 24 espécies de mamíferos, sendo que os dois locais com as maiores quantidades de habitat na paisagem apresentaram maior riqueza de espécies que as demais áreas. Os três grupos de mamíferos baseados na massa corporal criados neste estudo (peso < 5 kg; peso entre 5 e 20 kg; e peso > 20 kg) apresentaram respostas diferentes em relação às mudanças na paisagem. Para os mamíferos de maior porte, houve significativa associação entre a riqueza atual de espécies e a quantidade de habitat na paisagem de 2014, mas a riqueza de espécies de mamíferos de menor porte não apresentou relação significativa com nenhuma das variáveis das paisagens analisadas. Portanto, a quantidade de habitat presente na paisagem atual foi a variável mais importante para a riqueza de espécies de mamíferos, principalmente para as espécies de maior porte. O tempo de latência não ficou evidente na escala temporal avaliada, sendo que esse atraso na resposta pode ter ocorrido em tempo relativamente curto (< 15 anos), pois os fragmentos remanescentes nas paisagens estudadas em sua maioria são pequenos para suportar populações de mamíferos de maior porte e também podem deixar os indivíduos mais vulneráveis às ações antrópicas (e.g. caça), cujos efeitos podem acelerar as extinções locais.
ABSTRACT
AbstractAnts have been considered useful for bioindication because of their ecological characteristics. Nonetheless, among the characteristics of a bioindicator group, there must be a consistent and replicable response to disturbance. In this sense, divergent reactions have been found, even between taxons narrowly related. The objective of this work was to compare the diversity of the ant communities in three different temperate forests with different levels of disturbance, and to correlate their abundance and diversity of species, with that found in other arthropod communities of the same forests. The work was carried out in three municipalities in the North of the State of Mexico, where three types of different forests were identified by their degree of disturbance. These types include: 1) primary forest (PF), with typical species of a conserved forest; 2) mixed forest (MF), with species of a conserved forest and a reforestation effort; and 3) reforested forest (RF), with species used in reforestation efforts and indicative of disturbance. In each sample, an area of 2 500 m2 was selected. Each area had 16 pitfalls apiece and they were placed 10 m away from each other. Samples were collected twice; one from February through March 2009 (dry season) and another from August through September 2010 (rainy season), which produced a total of 192 traps. Obtained specimens were identified at the most taxonomically specific level. All data captured was transformed to √n + 0.5 and diversity index levels of Shannon and Simpson were calculated, as well as richness of species for ants, beetles, grasshoppers, true bugs, and spiders. The values of richness, diversity, and abundance were correlated with the Pearson coefficient, and to evaluate possible causal relationships between these, a path analysis was performed. Results suggested an important influence of the site over ant communities, and values of richness, abundance and diversity were correlated with the communities of spiders, beetles, grasshoppers and true bugs, but not for all the sites studied. Responses to environmental changes are not only on the numeric proportions of abundance, richness and diversity, but also in the indirect and casual ecological interactions. Finally, the data seems to indicate that the responses of the ants to the environmental changes are not necessarily reflected on other organisms’ communities, so the ants’ role as bioindicators can be limited. Rev. Biol. Trop. 64 (2): 571-585. Epub 2016 June 01.
ResumenPor sus características ecológicas las hormigas se han considerado útiles para la bioindicación. Sin embargo, entre los rasgos de un grupo bioindicador, debe haber una respuesta consistente y repetible a la perturbación. En este sentido, se han encontrado respuestas divergentes, incluso entre taxones estrechamente relacionados. El objetivo de este trabajo fue comparar la diversidad de las comunidades de hormigas en tres tipos de bosque templado con diferente nivel de perturbación y correlacionar su abundancia, riqueza de especies y la diversidad con aquella que se encuentra en otras comunidades de artrópodos en los mismos bosques. El trabajo se realizó en tres localidades del norte del Estado de México donde fueron identificados tres tipos de bosque diferenciados por grado de disturbio: 1) bosque primario (PF), con especies típicas de un bosque conservado; 2) bosque mixto (MF) con especies de bosque conservado y propias de reforestación y 3) bosque reforestado (RF) con especies utilizadas en reforestación e indicadoras de pertubación. En cada tipo de bosque se seleccionó un área de 2 500 m2 donde fueron colocadas 16 trampas de caída con una separación de 10 m. Fueron realizadas dos recolectas una de febrero a marzo 2009 (estación seca) y otra de agosto a septiembre 2010 (estación lluviosa), lo que dio un total de 192 trampas. Los especímenes obtenidos fueron identificados al nivel taxonómico más específico posible. Todos los datos de las capturas fueron transformados a √n+0.5 y fueron calculados los índices de diversidad de Shannon y Simpson y riqueza de especies tanto para hormigas como para escarabajos, chapulines, chiches y arañas. Los valores de riqueza, diversidad y abundancia fueron correlacionados con el coeficiente de Pearson y para evaluar posibles relaciones causales entre estos se realizó un análisis de sendero. Los resultados sugieren una influencia importante del sitio sobre las comunidades de hormigas y sus valores de riqueza, abundancia y diversidad están correlacionadas con las comunidades de arañas, escarabajos, chapulines y chinches, pero no para todos los sitios estudiados. Las respuestas a los cambios ambientales no sólo están en las proporciones numéricas de la abundancia, riqueza y diversidad sino también en las interacciones ecológicas indirectas y causales. Los resultados sugieren que las respuestas de las hormigas a los cambios ambientales no necesariamente se reflejan sobre comunidades de otros organismos por lo que su papel como bioindicadores puede ser limitado.
Subject(s)
Animals , Ants/classification , Biodiversity , Sentinel Species/classification , Ants/physiology , Temperature , Forests , Sentinel Species/physiology , MexicoABSTRACT
ResumenLos pastos marinos son ambientes costeros que se han visto amenazados por el incremento de las actividades humanas. Alterando de forma negativa los procesos y servicios ambientales que presentan, así como la disminución de praderas. El objetivo es generar conocimiento de la distribución, estado de la estructura y nivel de fragmentación en dos arrecifes del Parque Nacional Sistema Arrecifal Veracruzano (PNSAV). Se eligieron dos praderas en arrecifes con características distintas: Sacrificios en el Norte que se encuentra cerca de la costa y Cabezo en el Sur que está alejado de la costa. Se determinaron las características específicas de haz y área de las praderas de macrófitas sumergidas presentes e identificaron cuatro grupos de cobertura morfofuncionales. Se comprobaron diferencias significativas entre coberturas (ANOVA no paramétrico, prueba de Kruskal-Wallis). Se realizó una clasificación supervisada de una imagen espacial de alta resolución verificada con datos de campo (55 Sacrificios y 290 Cabezo). El nivel de fragmentación se calculó usando métricas de paisaje a nivel de clase y se realizaron mapas temáticos en función de las cuatro coberturas. Las praderas se encuentran dominadas por Thalassia testudinum; se tuvieron densidades máximas de 208 haces/m2 para Cabezo y 176 haces/m2 en Sacrificios. Cabezo presentó pastos de hojas cortas (9 cm) y delgadas (0.55 cm) en promedio; Sacrificios tuvo hojas más largas (23.5 cm) y gruesas (1 cm). Sacrificios mostró menor grado de fragmentación que Cabezo; en ambos casos la fragmentación de la cobertura vegetal corresponde a menos del 50 %. Aunque el arrecife Cabezo presenta una mayor fragmentación, que crea un gran número de microambientes, siendo reconocido por su importancia como zona de reclutamiento. Este trabajo sirve como una línea de base para la creación de un plan de manejo adecuado (formación de una zona núcleo de Cabezo). Es necesario complementar este trabajo con nuevos esfuerzos del reconocimiento de las praderas de pastos marinos en todos los arrecifes del PNSAV, así como de monitoreos periódicos y reconocimiento de sus servicios ecosistémicos.
AbstractSeagrasses in coastal environments have been threatened by increased human activities; these have negatively altered processes and environmental services, and have decreased grassland areas. The aim of this study was to generate knowledge of Thalassia testudinum distribution, state of the structure and fragmentation level in two reefs of the Veracruz Reef System National Park (PNSAV). Two different reefs were selected: Sacrificios in the North and near the coast, and Cabezo in the South and away from the coast. Shoot-specific and area-specific characteristics of submerged macrophytes meadows present were determined, and four morpho-functional groups were identified. Significant differences between plant coverage were tested through nonparametric ANOVA, Kruskal-Wallis test. A supervised classification of spatial high-resolution image verified with field data was performed (55 Sacrificios and 290 Cabezo). The fragmentation level was calculated using landscape metrics, class level and thematic maps were made based on four covers. The meadows were dominated by Thalassia testudinum; maximum densities were 208 shoot/m2 in Cabezo, and 176 shoot/m2 in Sacrificios. Cabezo presented grasses with short (9 cm) and thin leaves (0.55 cm) on average; while Sacrificios showed longer (23.5 cm) and thicker (1 cm) leaves. Sacrificios showed lower fragmentation degree than Cabezo; in both cases, the vegetation cover fragmentation corresponded to less than 50 %. Although Cabezo reef presents further fragmentation, which creates a large number of microenvironments, being recognized for its importance as recruitment area. This work serves as a baseline for the creation of an adequate management plan (formation of a core area of Cabezo). It is necessary to complement this work with new efforts for the recognition of seagrass prairies in all PNSAV reefs, as well as periodic monitoring and recognition of ecosystem services. Rev. Biol. Trop. 64 (2): 427-448. Epub 2016 June 01.
Subject(s)
Hydrocharitaceae/classification , Population Dynamics , Population Density , Conservation of Natural Resources , Coral Reefs , MexicoABSTRACT
Abstract We believe that in tropics we need a community approach to evaluate road impacts on wildlife, and thus, suggest mitigation measures for groups of species instead a focal-species approach. Understanding which landscape characteristics indicate road-kill events may also provide models that can be applied in other regions. We intend to evaluate if habitat or matrix is more relevant to predict road-kill events for a group of species. Our hypothesis is: more permeable matrix is the most relevant factor to explain road-kill events. To test this hypothesis, we chose vertebrates as the studied assemblage and a highway crossing in an Atlantic Forest region in southeastern Brazil as the study site. Logistic regression models were designed using presence/absence of road-kill events as dependent variables and landscape characteristics as independent variables, which were selected by Akaikes Information Criterion. We considered a set of candidate models containing four types of simple regression models: Habitat effect model; Matrix types effect models; Highway effect model; and, Reference models (intercept and buffer distance). Almost three hundred road-kills and 70 species were recorded. River proximity and herbaceous vegetation cover, both matrix effect models, were associated to most road-killed vertebrate groups. Matrix was more relevant than habitat to predict road-kill of vertebrates. The association between river proximity and road-kill indicates that rivers may be a preferential route for most species. We discuss multi-species mitigation measures and implications to movement ecology and conservation strategies.
Resumo Nós acreditamos que nos trópicos, precisamos de uma abordagem de comunidade para avaliar os impactos das estradas sobre a vida silvestre, e então, sugerir medidas de mitigação para grupos de espécies ao invés da abordagem de espécie-foco. Compreender quais características da paisagem indicam eventos de atropelamento podem também fornecer modelos que podem ser aplicados em outras regiões. Nós pretendemos avaliar se habitat ou matriz é mais relevante para prever eventos de atropelamento para grupos de espécies. Nossa hipótese é: matriz mais permeável é o fator mais relevante para explicar os eventos de atropelamentos. Para testar essa hipótese, escolhemos vertebrados como a assembléia estudada e uma rodovia cruzando uma região de Mata Atlântica no sudeste do Brasil como área de estudo. Modelos de regressão logística foram criados usando presença/ausência de eventos de atropelamentos como variáveis dependentes e características da paisagem como variáveis independentes, os quais foram selecionados pelo Critério de Informação de Akaike. Nós consideramos um conjunto de modelos candidatos contendo quatro tipos de modelos de regressão simples: modelo de efeito de habitat; modelos de efeito de tipos de matriz; modelo de efeito da rodovia; e, modelos de referência (intercepto e distância da faixa de influência). Quase 300 atropelamentos e 70 espécies foram registradas. Proximidade do rio e cobertura da vegetação herbácea, ambos modelos de efeito da matriz, foram associadas à maioria dos grupos de vertebrados atropelados. Matriz foi mais relevante do que habitat para prever atropelamentos de vertebrados. A associação entre proximidade do rio e atropelamentos indica que rios podem ser a rota preferencial para a maioria das espécies. Nós discutimos medidas de mitigação multi-espécies e implicações para a ecologia do movimento e estratégias de conservação.
ABSTRACT
Abstract We believe that in tropics we need a community approach to evaluate road impacts on wildlife, and thus, suggest mitigation measures for groups of species instead a focal-species approach. Understanding which landscape characteristics indicate road-kill events may also provide models that can be applied in other regions. We intend to evaluate if habitat or matrix is more relevant to predict road-kill events for a group of species. Our hypothesis is: more permeable matrix is the most relevant factor to explain road-kill events. To test this hypothesis, we chose vertebrates as the studied assemblage and a highway crossing in an Atlantic Forest region in southeastern Brazil as the study site. Logistic regression models were designed using presence/absence of road-kill events as dependent variables and landscape characteristics as independent variables, which were selected by Akaike’s Information Criterion. We considered a set of candidate models containing four types of simple regression models: Habitat effect model; Matrix types effect models; Highway effect model; and, Reference models (intercept and buffer distance). Almost three hundred road-kills and 70 species were recorded. River proximity and herbaceous vegetation cover, both matrix effect models, were associated to most road-killed vertebrate groups. Matrix was more relevant than habitat to predict road-kill of vertebrates. The association between river proximity and road-kill indicates that rivers may be a preferential route for most species. We discuss multi-species mitigation measures and implications to movement ecology and conservation strategies.
Resumo Nós acreditamos que nos trópicos, precisamos de uma abordagem de comunidade para avaliar os impactos das estradas sobre a vida silvestre, e então, sugerir medidas de mitigação para grupos de espécies ao invés da abordagem de espécie-foco. Compreender quais características da paisagem indicam eventos de atropelamento podem também fornecer modelos que podem ser aplicados em outras regiões. Nós pretendemos avaliar se habitat ou matriz é mais relevante para prever eventos de atropelamento para grupos de espécies. Nossa hipótese é: matriz mais permeável é o fator mais relevante para explicar os eventos de atropelamentos. Para testar essa hipótese, escolhemos vertebrados como a assembléia estudada e uma rodovia cruzando uma região de Mata Atlântica no sudeste do Brasil como área de estudo. Modelos de regressão logística foram criados usando presença/ausência de eventos de atropelamentos como variáveis dependentes e características da paisagem como variáveis independentes, os quais foram selecionados pelo Critério de Informação de Akaike. Nós consideramos um conjunto de modelos candidatos contendo quatro tipos de modelos de regressão simples: modelo de efeito de habitat; modelos de efeito de tipos de matriz; modelo de efeito da rodovia; e, modelos de referência (intercepto e distância da faixa de influência). Quase 300 atropelamentos e 70 espécies foram registradas. Proximidade do rio e cobertura da vegetação herbácea, ambos modelos de efeito da matriz, foram associadas à maioria dos grupos de vertebrados atropelados. Matriz foi mais relevante do que habitat para prever atropelamentos de vertebrados. A associação entre proximidade do rio e atropelamentos indica que rios podem ser a rota preferencial para a maioria das espécies. Nós discutimos medidas de mitigação multi-espécies e implicações para a ecologia do movimento e estratégias de conservação.
Subject(s)
Animals , Conservation of Natural Resources/methods , Ecosystem , Motor Vehicles , Vertebrates , Brazil , Forests , Mortality , MovementABSTRACT
Resumen:Cambios en el uso del suelo son principalmente consecuencia de las acciones antropogénicas. La actual transformación agrícola y urbana en Costa Rica ha generado preguntas acerca de la efectividad de la conservación y restauración dentro de las áreas protegidas. En este documento nosotros analizamos los patrones de cambio del uso del suelo entre tres periodos: 1997, 2005 y 2010 en términos de magnitud, dirección y velocidad a través de mapas categóricos generados por la foto-interpretación para dos áreas silvestres protegidas y sus áreas aledañas: Parque Nacional La Cangreja (LCNP), el Refugio de Vida Silvestre Rancho Mastatal (RMWR) y sus áreas aledañas (SA), esta última compuesta por área de un kilómetro de radio fuera de los límites de las áreas protegidas. La matriz que describe el paisaje dentro de las áreas protegidas es la cobertura natural, compuesta principalmente por la cobertura forestal y tacotales. Encontramos que la cobertura natural más abundante para ambas áreas protegidas fue cubierta forestal en todos los años estudiados. La estabilidad y las grandes áreas de la cubierta forestal en LCNP y RMWR para 2005 y 2010 reflejan que las políticas, las acciones de manejo y vigilancia tienen un impacto positivo en la conservación y restauración de los hábitats naturales en esta zona del Pacifico Central Costarricense. Sin embargo, la alta complejidad del paisaje de SA en 1997, 2005 y 2010 son una prueba de presión antropogénica sobre estas áreas protegidas y sugieren una ineficacia de los gobiernos locales para monitorear y disminuir los cambios de uso del suelo que podrían obstaculizar la gestión, conservación y restauración de especies dentro de las áreas protegidas.
Abstract:Changes in land use are mainly a consequence of anthropogenic actions. The current agricultural and urban transformations in Costa Rica have raised questions about the effectiveness of conservation and restoration within protected areas. Herein we analyzed the patterns of land use change between three periods: 1997, 2005 and 2010 in terms of magnitude, direction, and pace through categorical maps generated by the photo-interpretation for La Cangreja National Park (LCNP), Rancho Mastatal Wildlife Refuge (RMWR), and their surrounding areas (SA), this last compound of one kilometer radius outside the protected areas' boundaries. The matrix which describes the landscape within the protected areas is natural coverage, composed mainly by forest cover and thickets. We found that the most abundant natural cover for both protected areas was forest cover for all years tested. The stability and large areas of forest cover in LCNP and RMWR for 2005 and 2010, reflected that policies, management actions and vigilance, have a positive impact on the conservation and restoration of natural habitats in these Costa Rican Central Pacific areas. However, the high landscape complexity of the SA in 1997, 2005 and 2010 was an evidence of the anthropogenic pressure on these protected areas, and suggested the ineffectiveness of local governments to monitor and abate land use changes, that could hinder the management, conservation and restoration of species in the protected areas.
Subject(s)
Conservation of Natural Resources , Forests , Agriculture , Costa Rica , Ecosystem , Environmental Restoration and Remediation , Geographic Information SystemsABSTRACT
Landscape Ecology is a contemporary approach in conservation studies in which, coupled to the development and use of GIS-based tools, provides new methods for the analysis of forest fragments. Based on these new approaches, the environmental assessment of ground use in the Iguatemi river basin Mato Grosso do Sul State, Brazil is provided through conservation-based flora and ecology aspects. A regional map of ground use with field -collected data using Rapid Ecological Assessment methodology and digital satellite images was prepared. AER analysis showed a highly impacted region featuring intense transformation in ground use with a conversion of 87% of native forest into grazing and agriculture land. The general situation is inconsistent with APA guidelines, the conservationist unit which operates in the river basin. PPAs' recovery, erosion control and adjustment to current environmental regulations are mandatory.
A Ecologia de Paisagem é uma abordagem atual nos estudos conservacionistas que, aliada ao desenvolvimento e uso de ferramentas baseadas em SIG, proporciona novas metodologias de análise de fragmentos florestais. Baseado nessas novas abordagens, o objetivo do estudo foi realizar o diagnóstico ambiental do uso do solo na bacia do rio Iguatemi, Estado do Mato Grosso do Sul, utilizando aspectos florísticos e ecológicos com um foco conservacionista. Pelos dados coletados, em campo utilizando metodologia da Avaliação Ecológica Rápida e imagens de satélite tratadas digitalmente, foi elaborado um mapa de uso do solo da região. A análise da AER indicou uma região intensamente antropizada com a conversão de 87% de floresta nativa em área de uso antrópico, como pastagem e agricultura. A situação geral não condiz com as diretrizes de uma APA, unidade de conservação na qual está inserida toda a bacia. Há necessidade de recuperação de APPs, controle de erosão e adequação quanto à legislação ambiental vigente.
Subject(s)
Forests , EcologyABSTRACT
The composition of local orchid-bee faunas (Hymenoptera, Apidae, Euglossina) in open-vegetation domains is poorly known, making the ecology and biogeography of the group difficult to understand. The aim of this work was to answer the following questions: i) Is the orchid-bee fauna composition, species richness and abundance in the cerrado (Brazilian savanna) sensu stricto similar to that of riparian forests immersed in that domain? ii) Do species from neighboring forest domains use riparian forests as mesic corridors into the Cerrado? Two sites in cerrado s.s. and two in riparian forests were sampled monthly, one day per month, during one year (Nov/2003-Oct/2004) in northwestern Minas Gerais state, Brazil. Six aromatic compounds (β-ionone, 1,8-cineole, eugenol, methyl trans-cinnamate, methyl salicilate and vanillin) were exposed from 8:00 AM to 4:00 PM to attract orchid bees. The results suggest that: i) The composition of the orchid bee fauna in the two kinds of environments is the same; ii) Riparian forests apparently have no role as mesic corridors for penetration of forest-dependent euglossine species into the core of the Cerrado Domain.
A composição das faunas locais de Euglossina (Hymenoptera, Apidae) em formações vegetais abertas é pouco conhecida, o que dificulta o entendimento da ecologia e biogeografia do grupo. O objetivo deste trabalho foi responder às seguintes perguntas: i) No domínio do Cerrado, a composição da fauna, riqueza em espécies e abundância de euglossinas em áreas de cerrado s.s. e em mata ciliar são semelhantes entre si? ii) Espécies de domínios florestais adjacentes utilizam as matas ciliares como corredores mésicos para dentro do Cerrado? Duas áreas de cerrado s.s. e duas de mata ciliar foram amostradas mensalmente, um dia por mês, durante um ano (nov/2003-out/2004), no noroeste do estado de Minas Gerais, Brasil. Seis compostos aromáticos (β-ionona, cineol, cinamato de metila, eugenol, salicilato de metila e vanilina) eram expostos das 8 às 16 horas para atrair as euglossinas. Os resultados encontrados sugerem que: i) As composições das faunas em áreas de cerrado s.s. e matas ciliares são iguais; ii) As matas ciliares aparentemente não atuam como corredores mésicos para a penetração, em áreas centrais do Cerrado, de espécies de euglossinas dependentes de florestas.
ABSTRACT
Hurricane impact on Thalassia testudinum (Hydrocharitaceae) beds in the Mexican Caribbean. Hurricanes have increased in strength and frequency as a result of global climate change. This research was conducted to study the spatio-temporal distribution and changes of Thalassia testudinum, the dominant species in Bahia de la Ascension (Quintana Roo, Mexico), when affected by heavy weather conditions. To complete this objective, a 2001 Landsat ETM+ image and the information from 525 sampling stations on morpho-functional and coverage of T. testudinum were used, and the seeds generated for the classification of eight benthic habitats. To quantify the changes caused by two hurricanes, we used two images, one of 1988 (Gilberto) and another of 1995 (Roxanne); other three data sets (2003, 2005 and 2007) were also used to describe the study area without major weather effects. Six categorial maps were obtained and subjected to analysis by 8 Landscape Ecology indexes, that describe the spatial characteristics, structure, function, change of the elements (matrix-patch-corridor), effects on ecosystems, connectivity, edges, shape and patch habitat fragmentation. Models indicate that T. testudinum may be classified as a continuum (matrix), since the fragments were not observed intermittently, but as a progression from minimum to maximum areas in reference to their coverage (ecological corridors). The fragments do not have a regular shape, indicating that the impacts are recent and may be due to direct effects (high-intensity hurricanes) or indirect (sediment). Fragments of type "bare soils" have a discontinuous distribution, and are considered to be the sites that have remained stable over a long timescale. While more dense coverage areas ("beds", "medium prairie" and "prairie") have low fragmentation and high connection of fragments. Features have an irregular perimeter and radial growth of formal; suggesting that the impact of meteors has no effect on the resilience of T. testudinum in this ecosystem, indicating good environmental quality to grow in this bay. Rev. Biol. Trop. 59 (1): 385-401. Epub 2011 March 01.
Thalassia testudinum es la macrófita dominante en Bahía de la Ascensión (Quintana Roo, México), se estudió para conocer su distribución espacio- temporal y determinar si fue afectada por el paso de huracanes que se han visto incrementados en fuerza y frecuencia por el cambio climático. Partiendo de una imagen Landsat ETM+de 2001 y usando información de grandes grupos morfofuncionales y de cobertura de T. testudinum adquiridas en 525 estaciones de muestreo, se obtienen las semillas para la clasificación supervisada de los hábitats bénticos (8 clases). Con el fin de cuantificar los cambios ocasionados por dos huracanes, se usaron dos imágenes, una de 1988 (Gilberto) y 1995 (Roxanne) y tres más (2003, 2005 y 2007) para monitoreo sin efectos meteorológicos mayores; a estos 6 mapas categóricos se les aplicó un análisis de Ecología del Paisaje usando 8 índices que describen las características espaciales, de estructura, función, cambio de los elementos (matriz-mancha-corredor), efectos sobre el ecosistema, conectividad, bordes, forma del parche y fragmentación del hábitat. Los modelos indican que T. testudinum puede clasificarse como un continuo (matriz), pues los fragmentos no se observan de forma intermitente, sino como una progresión de zonas mínimas a máximas en referencia a su cobertura (corredores ecológicos). No poseen una forma regular, indicando que los impactos son recientes y pueden ser debidos a efectos directos (huracanes de alta intensidad) e indirectos (aporte de sedimentos). Los fragmentos de tipo "suelos desnudos" presentan una distribución discontinua, considerándose sitios que han permanecido estables en una larga escala de tiempo; las zonas con coberturas más densas ("camas", "praderas medias" y "praderas") presentan baja fragmentación y alta conexión de sus fragmentos. Las características de poseer un perímetro irregular y crecimiento de formal radial, sugieren que el impacto de los meteoros no tiene efecto en la capacidad de resiliencia de T. testudinum en este ecosistema, indicando el buen estado de la calidad ambiental de la bahía para su crecimiento.
Subject(s)
Cyclonic Storms , Ecosystem , Environmental Monitoring/methods , Hydrocharitaceae/growth & development , Caribbean Region , Mexico , Population DensityABSTRACT
The aim of this work was to propose a methodology for quantifying the environmental compensation through the spatial analysis of vulnerability indicators. A case study was applied for the analysis of sand extraction enterprises, in the region of Descalvado and Analândia, inland of São Paulo State, Brazil. Environmental vulnerability scores were attributed for the indicators related to erosion, hydrological resources and biodiversity loss. This methodological proposal allowed analyzing the local alternatives of certain enterprise with the objective of reducing impacts and at the same time reducing the costs of environmental compensation. The application of the methodology significantly reduced the subjectivity degree usually associated to the most of the methodologies of impact evaluation.
O termo compensação ambiental refere-se à obrigação do empreendedor em apoiar a implantação e manutenção de Unidades de Conservação, aplicável a empreendimentos de significativo impacto ambiental, de acordo com a Lei 9.986/2000. Esta lei estabelece que o volume de recursos a ser aplicado pelo empreendedor deve ser de no mínimo 0,5 por cento dos custos totais previstos para a implantação do empreendimento, sendo que este percentual deve ser fixado pelo órgão ambiental competente, de acordo com o grau de impacto ambiental. Sendo assim, o presente artigo tem o objetivo de propor uma metodologia para quantificação da compensação ambiental através da análise espacial de indicadores de vulnerabilidade ambiental. A proposta foi aplicada através de um estudo de caso em empreendimentos de mineração de areia, na região de Descalvado/Analândia, interior do Estado de São Paulo. Índices de vulnerabilidade ambiental foram atribuídos a indicadores de impactos relacionados à erosão, recursos hídricos e perda de biodiversidade. Esta metodologia representa importante instrumento de planejamento ambiental e econômico, podendo ser adaptada a diversos tipos de empreendimentos e realidades locais, contribuindo para a redução do grau de subjetividade geralmente associado ao processo de avaliação de impacto ambiental.
ABSTRACT
"Restingas" (herbaceous/shrubby coastal sand-dune habitats) used to cover most of Rio de Janeiro State coast, and have suffered extensive degradation over the last five centuries. Using satellite images and field work, we identified the remaining restingas in the State, recording the factors that might cause their degradation. We used two mosaics of Landsat 7 scenes (spatial resolution 15 and 30 m) to map and evaluate preliminarly the remaining areas and conservation status. Each remnant area was checked in the field, degraded areas within it were mapped and subtracted from the remnants. We identified 21 restinga remnants totalling 105,285 ha. The largest and smallest restinga remnants were Jurubatiba (25,141 ha) and Itaipu (23 ha), respectively. We identified 14 causes of degradation. The most important were vegetation removal for housing developments, establishment of exotic plant species, change of original substrate, and selective removal of species of economic importance for the horticultural industry. All restingas had disturbed parts under strong pressure due to human activities. Due to intense habitat loss, and occurrence of endemic/threatened vertebrate species in restinga habitats, we strongly indicate the implementation of new conservation units to protect these fragile remnants. This habitat is steadily decreasing and most remnants lack legal protection. Therefore, under the current human pressure most of this unique habitat is likely to be lost from the State within the next few years.
As restingas, que são hábitats de dunas e planícies arenosas cobertas por vegetação herbáceo-arbustiva e que ocorrem na costa do Brasil, no passado cobriam uma grande extensão da costa do Estado do Rio de Janeiro, mas têm sofrido uma extensiva degradação ao longo dos últimos cinco séculos. Utilizando imagens de satélite e mensurações no campo, identificamos os remanescentes de restinga no estado, registrando os fatores que causam sua degradação. Nós utilizamos dois mosaicos de cenas Landsat 7 ( resolução espacial de 15m e 30m) para localização e avaliação preliminar do estado de conservação dos remanescentes. Cada remanescente de restinga foi analisado no campo, sendo as áreas degradadas no interior da restinga mapeadas mais detalhadamente e subtraídas da área total do remanescente. Identificamos 21 áreas remanescentes de restinga, totalizando 105,285ha. O maior e menor remanescente de restinga foram Jurubatiba (25,141ha) e Itaipu (23ha), respectivamente. Identificamos 14 fontes de degradação, sendo as mais importantes delas: a remoção da vegetação para desenvolvimento imobiliário, o estabelecimento de espécies vegetais exóticas, a alteração do substrato original e a coleta seletiva de espécies vegetais de interesse paisagístico. Todas as áreas de restinga apresentaram porções com áreas degradadas devido à intensa pressão antrópica. Devido à intensa perda de hábitat e ocorrência de espécies endêmicas e/ou ameaçadas de extinção de vertebrados nas restingas, nós fortemente sugerimos a implementação de novas unidades de conservação para proteger estes frágeis remanescentes. Este tipo de hábitat está continuamente decrescendo e a maior parte dos remanescentes carece de proteção legal. Considerando a atual pressão humana sobre estes ambientes, grande parte deste hábitat é provável ser perdido se não forem tomadas medidas para sua proteção.
Subject(s)
Ecosystem , Environmental Monitoring , Trees , Brazil , Population Density , Risk Factors , Satellite CommunicationsABSTRACT
Con base en información obtenida sobre los nombres de todas las plantas con DAP > 2.5 cm (Diámetro a la Altura del Pecho, medido a una altura de 1.3 m) dentro de 30 parcelas de 0.1 ha cada una, y sobre los suelos, la vegetación y el paisaje a lo largo de 8 transectos (entre 2 y 5 km de longitud cada uno), se describen los aspectos más importantes sobre la taxonomía botánica y el ordenamiento o jerarquización del medio ambiente desde la perspectiva de los Indígenas Miraña de la Amazonía central colombiana. A pesar de la pérdida cultural, algunos pocos ancianos guardan como parte de su tradición oral, los elementos básicos de un sistema complejo de conocimiento de su ambiente natural. Se detectó un alto grado de conocimiento sobre las especies vegetales silvestres, la existencia de sistemas nomenclaturales para éstas y para los suelos, y un reconocimiento organizado de paisajes fisiográficos y tipos de vegetación.
We describe the most important aspects of Miraña's plant taxonomy, and landscape categorization. Data about plants' names (in 30 plots of 0.1 ha), was gathered from all individual plants with DBH > 2.5 cm (Diameter at Breast High, or 1.3 m above ground), and data about soils, forest types and landscapes was (in 8 transects of 2-5 km long each) was gathered from 8 transects of 2-5 km long each. In spite of cultural lost, complex knowledge about natural environment classification, it is present into the oral tradition keep in some elders' mind. We detected a high level of knowledge about wild plants, the presence of nomenclatural systems for plants and soil types, and organized landscapes and forest types systems.
Subject(s)
Ethnicity , Classification , Human Ecology , EcologyABSTRACT
Understanding the transmission ecology of parasites involves the challenge of studying the complexity of life-cycles at multiple levels of biological organisation and at various space-time scales. We think that a single field of science alone cannot fully address this issue and that a way to understand such complexity is to connect various fields of science, to consider the whole transmission system, and to identify which are the variables reasonably accessible to measurement and the relevant scales at which they may provide information about transmission processes and indicate a higher risk of transmission⁄emergence. Based on ongoing studies carried out in Europe and in China, the aim of the present paper is to discuss this approach and to show how results obtained from mass-screening of human populations may be combined to those obtained from small mammal and landscape ecology studies and modelling to promote an understanding of <I>Echinococcus multilocularis</I> transmission and to determine how differences in the time-space scales at which human infection and small mammal population dynamic processes occur may complicate the analysis.