Remote detection of invasive alien species

The spread of invasive alien species (IAS) is recognized as the most severe threat to biodiversity outside of climate change and anthropogenic habitat destruction. IAS negatively impact ecosystems, local economies, and residents. They are especially problematic because once established, they give rise to positive feedbacks, increasing the likelihood of further invasions and spread. The integration of remote sensing (RS) to the study of invasion, in addition to contributing to our understanding of invasion processes and impacts to biodiversity, has enabled managers to monitor invasions and predict the spread of IAS, thus supporting biodiversity conservation and management action. This chapter focuses on RS capabilities to detect and monitor invasive plant species across terrestrial, riparian, aquatic, and human-modified ecosystems. All of these environments have unique species assemblages and their own optimal methodology for effective detection and mapping, which we discuss in detail

Anuran responses to spatial patterns of agricultural landscapes in Argentina

Context: Amphibians are declining worldwide and land use change to agriculture is recognized as a leading cause. Argentina is undergoing an agriculturalization process with rapid changes in landscape structure. Objectives: We evaluated anuran response to landscape composition and configuration in two landscapes of east-central Argentina with different degrees of agriculturalization. We identified sensitive species and evaluated landscape influence on communities and individual species at two spatial scales. Methods: We compared anuran richness, frequency of occurrence, and activity between landscapes using call surveys data from 120 sampling points from 2007 to 2009. We evaluated anuran responses to landscape structure variables estimated within 250 and 500-m radius buffers using canonical correspondence analysis and multimodel inference from a set of candidate models. Results: Anuran richness was lower in the landscape with greater level of agriculturalization with reduced amount of forest cover and stream length. This pattern was driven by the lower occurrence and calling activity of seven out of the sixteen recorded species. Four species responded positively to the amount of forest cover and stream habitat. Three species responded positively to forest cohesion and negatively to rural housing. Two responded negatively to crop area and diversity of cover classes. Conclusions: Anurans within agricultural landscapes of east-central Argentina are responding to landscape structure. Responses varied depending on species and study scale. Life-history traits contribute to responses differences. Our study offers a better understanding of landscape effects on anurans and can be used for land management in other areas experiencing a similar agriculturalization process.Facultad de Ciencias ExactasCentro de Investigaciones del Medioambient

Fire Regime, Climate, and Vegetation in the Sierras de Córdoba, Argentina

Wildfires are a primary disturbance in the Sierras de Córdoba, Argentina, with approximately 2 152 000 ha burned between 1993 and 2012. However, little is known about the spatial and temporal patterns of fires and their relationship with climate and vegetation in this area. Such information is of great value for fire risk assessment and the development of strategies for fire management. Our main objective was to analyze fire activity in four sierran ranges, assessing which weather and climate conditions were mostly related to fire activity, and which land cover types were mostly burned. We used a fire database of mid-high spatial resolution and a land cover map derived from Landsat imagery. Fire regimes were different among the different sierran ranges. The Sierras Chicas range was the most affected by fires, with the largest number of fire events, burned area, and fire frequency. Although large fires represented 3% to 5% of fire events, they accounted for 60% to 86% of total burned area in different sierran ranges. Sierras of lower elevation had a winter seasonality of fires, while sierras of higher elevation had a winter-spring or spring fire seasonality. The number of fire events was positively correlated with preceding periods that were wetter than normal, while the burned area was mainly associated with midterm weather conditions. Fires occurred mainly in grasslands and shrublands, but the area of burned forests was important, too. Our results will be useful to determine the times and conditions in which fire risk is highest, and also to identify where preventive efforts should be focused.Los incendios constituyen uno de los principales disturbios en las Sierras de Córdoba, Argentina, acumulando aproximadamente 2152000 ha quemadas entre 1993 y 2012. Sin embargo, poco se conoce acerca de los patrones espaciales y temporales del fuego y su relación con el clima y la vegetación del lugar. Esta información es de gran valor para la evaluación del riesgo de incendios y para la implementación de estrategias de manejo del fuego. Nuestro objetivo fue analizar los incendios en cuatro sistemas serranos, evaluando las condiciones meteorológicas y climáticas que favorecen la ocurrencia de incendios y los tipos de vegetación que más se queman. Utilizamos una base de datos de incendios de resolución espacial media-alta y un mapa de cubiertas de suelo obtenido a partir de imágenes Landsat. Los regímenes de fuego fueron diferentes en los distintos sistemas serranos. Las Sierras Chicas fueron las más afectadas por el fuego, presentando el mayor número de eventos, área quemada y frecuencia de incendios. Los grandes incendios representaron entre 3% y 5% de los incendios, sin embargo,quemaron entre 60% y 86% del área quemada total en los diferentes sistemas serranos. Las sierras de menor altitud presentaron una estacionalidad de incendios invernal, mientras que las sierras de mayor altitud presentaron una estacionalidad inverno-primaveral o primaveral. El número de incendios se correlacionó positivamente con periodos precedentes de mayor humedad, mientras que el área quemada se correlacionó con las condiciones meteorológicas ocurrentes en el mediano plazo. Los incendios ocurrieron principalmente en áreas de pastizal y arbustal, aunque la superficie de bosques quemados fue importante también. Nuestros resultados serán de utilidad para determinar los momentos y condiciones de mayor riesgo de incendios y también para identificar las áreas donde se deben concentrar los esfuerzos preventivosInstituto de Recursos BiológicosFil: Argañaraz, Juan Pablo. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Cordoba. Instituto de Diversidad y Ecologia Animal; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; ArgentinaFil: Gavier Pizarro, Gregorio Ignacio. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Recursos Biológicos; ArgentinaFil: Zak, Marcelo Román. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Departamento de Geografia; ArgentinaFil: Bellis, Laura Marisa. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Cordoba. Instituto de Diversidad y Ecologia Animal; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Diversidad y Ecología Animal; Argentin

Integrating biodiversity, remote sensing, and auxiliary information for the study of ecosystem functioning and conservation at large spatial scales

Assessing patterns and processes of plant functional, taxonomic, genetic, and structural biodiversity at large scales is essential across many disciplines, including ecosystem management, agriculture, ecosystem risk and service assessment, conservation science, and forestry. In situ data housed in databases necessary to perform such assessments over large parts of the world are growing steadily. Integrating these in situ data with remote sensing (RS) products helps not only to improve data completeness and quality but also to account for limitations and uncertainties associated with each data product. Here, we outline how auxiliary environmental and socioeconomic data might be integrated with biodiversity and RS data to expand our knowledge about ecosystem functioning and inform the conservation of biodiversity. We discuss concepts, data, and methods necessary to assess plant species and ecosystem properties across scales of space and time and provide a critical discussion of outstanding issues