David Aragonés

• Spanish National Research Council

The long-term monitoring of the plant cover of Doñana shrublands is part of a harmonised protocol for the Long-term Ecological Monitoring Programme of Natural Resources and Processes targeting Terrestrial Vegetation. The general aim of this protocol is to monitor and assess the dynamics and trends of shrubland plant communities in Doñana. For shrub...

The long-term monitoring of the plant cover of Doñana shrublands is part of a harmonised protocol for the Long-term Ecological Monitoring Program of Natural Resources and Processes targeting Terrestrial Vegetation. The general aim of this protocol is to monitor and assess the dynamics and trends of shrubland plant communities in Doñana. For shrubla...

Restored wetlands should be closely monitored to fully evaluate the effectiveness of restoration efforts. However, regular post-restoration monitoring can be time-consuming and expensive, and is often absent or inadequate. Satellite and airborne remote sensing systems have proven to be cost-effective tools in many fields, but they have not been wid...

Soil spectroscopy estimates soil properties using the absorption features in soil spectra. However, modelling soil properties with soil spectroscopy is challenging due to the high dimensionality of spectral data. Feature Selection wrapper methods are promising approaches to reduce the dimensionality but are barely used in soil spectroscopy. The aim...

This work presents the results of an outdoor intercomparison experiment where the reflectance factors from five full-range field spectroradiometers (400-2500 nm) were compared using repeatability, reproducibility, and compatibility metrics. We confronted four Analytical Spectral Devices (ASD) and one Spectravista Corporation (SVC) sensor. Ancillary...

Global change is an important driver of the increase in emerging infectious diseases in recent decades. In parallel, interest in nature has increased, and different citizen science platforms have been developed to record wildlife observations from the general public. Some of these platforms also allow registering the observations of dead or sick bi...

Efforts to conserve the pond network in the Doñana National Park are being threatened by groundwater overexploitation. The dramatic expansion of farming and tourism in nearby areas has caused a severe lowering of the water table, reducing pond hydroperiod length or even instigating pond desiccation. It is important to document the link between grou...

Habitat encroachment can have devastating effects upon biodiversity, especially amphibians. Phyllobates vittatus is an endemic frog from Costa Rica, where land cover has seen significant changes over recent decades. Here we use remote sensing to create a land cover map of the region and carry out ecological niche modelling to identify the main abio...

Wetlands are among the most biodiverse yet endangered ecosystems on Earth. Despite being the most important wetland in Europe, the Doñana National Park (southwestern Spain) is no exception, and the increase of nearby groundwater abstractions for intensive agriculture and human supply has raised international concerns about the conservation of this...

Mountain regions are vital to the provision of ecosystem services. “Cofre de Perote” volcano is the eighth highest mountain in Mexico and provides various goods and services to the people living in the central region of Veracruz. Despite being a protected area as a national park, it shows processes of landscape change in recent years. We mapped lan...

Mediterranean climate regions are facing increased aridity conditions and water scarcity, thus needing integrated management of water resources. Detecting and characterising changes in water resources over time is the natural first step towards identifying the drivers of these changes and understanding the mechanism of change. The aim of this study...

Research on the space use and behaviour of waterbirds yields important insights on human‐wildlife interactions of ecological and societal importance under global change. The extent to which dynamic (within‐season) changes in anthropogenic landscapes affect these interactions is poorly understood. Lesser Black‐backed Gulls (Larus fuscus) are promine...

Eutrophication is a major cause of wetland degradation worldwide. In recent decades, reductions in nutrient inputs have led to improvements in water quality in many rivers and lakes in central and northern Europe, but long-term trends are less clear in southern Europe. We conducted the first comprehensive study of water quality in Doñana (SW Spain)...

En México, los cafetales bajo sombra constituyen parte del paisaje agroforestal y representan el refugio de una alta diversidad biológica. Sin embargo, están sujetos a procesos de transformación derivados de las necesidades de los productores y las demandas del mercado, lo que afecta la configuración del agroecosistema. Este trabajo tuvo como objet...

Background: Research on the space use and behavior of waterbirds—as highly mobile of wetland habitats—yields important insights on human-wildlife interactions of ecological and societal importance under global change. The extent to which dynamic (within-season) changes in anthropogenic landscapes affects these interactions is poorly understood. Les...

Changes in environmental conditions, whether related or not to human activities, are continuously modifying the geographic distribution of vectors, which in turn affects the dynamics and distribution of vector-borne infectious diseases. Determining the main ecological drivers of vector distribution and how predicted changes in these drivers may alt...

The use of soil moisture (SM) measurements from satellites has grown in recent years, fostering the development of new products at high resolution. This opens the possibility of using them for certain applications that were normally carried out using in situ data. We investigated this hypothesis through two main analyses using two high-resolution s...

En México, los cafetales bajo sombra constituyen parte del paisaje agroforestal y representan el refugio de una alta diversidad biológica. Sin embargo, están sujetos a procesos de transformación derivados de las necesidades de los productores y las demandas del mercado, lo que afecta la configuración del agroecosistema. Este trabajo tuvo como objet...

Currently, the wide availability of processing tools allows the automation of practically all procedures, from the downloading of raw images to the publication of products through interoperable services. This paper presents the effort made by the Remote Sensing and GIS Lab of the Doñana Biological Station (LAST-EBD) to automate the entire processin...

Land surface phenology (LSP) can improve the monitoring of forest areas and their change processes. The aim of this study was to characterize the temporal dynamics in Mediterranean pines and evaluate the potential of LSP for species discrimination. We used 661 mono-specific plots for five different Pinus species (Pinus halepensis, P. pinea, P. pina...

Satellite data offer the opportunity for monitoring the temporal flooding dynamics of seasonal wetlands, a parameter that is essential for the ecosystem services these areas provide. This study introduces an unsupervised approach to estimate the extent of flooded areas in a satellite image relying on the physics of light interaction with water, veg...

The use of Pseudoinvariant Areas (PIA) makes it possible to carry out a reasonably robust and automatic radiometric correction for long time series of remote sensing imagery, as shown in previous studies for large data sets of Landsat MSS, TM, and ETM+ imagery. In addition, they can be employed to obtain more coherence among remote sensing data fro...

In this chapter, we present the results of several flight campaigns carried out in 2015 and 2016 using multirotor Unmanned Airborne Vehicles (UAVs) over Slender-billed Gull (Chroicocephalus genei) colonies in the Doñana Nature Space, south west Spain. The images were taken at different times during the breeding season. The requirements for the flig...

Reservoir Digital Terrain Model improvement using Landsat time series Abstract. Delimitation of the flooded areas and documentation of fluctuations in the level of water masses using satellite images can have multiple applications. This study aims to improve the bathymetry of a reservoir by using a time series of low resolution satellite imagery. S...

We test the use of hyperspectral sensors for the early detection of the invasive dense-flowered cordgrass (Spartina densiflora Brongn.) in the Guadalquivir River marshes, Southwestern Spain. We flew in tandem a CASI-1500 (368–1052 nm) and an AHS (430–13,000 nm) airborne sensors in an area with presence of S. densiflora. We simplified the processing...

Mediterranean temporary ponds on Doñana's aeolian sands form an extensive system of small dynamic water bodies, dependent on precipitation and groundwater, of considerable importance for biodiversity conservation. Different areas of the aeolian sands have received different levels of environmental protection since 1969, and this has influenced the...

This paper presents a semi-automatic procedure to discriminate seasonally flooded areas in the shallow temporary marshes of Doñana National Park (SW Spain) by using a radiommetrically normalized long time series of Landsat MSS, TM, and ETM+ images (1974-2014). Extensive field campaigns for ground truth data retrieval were carried out simultaneous t...

In Donana National Park, most aquatic habitats are temporary. Ponds dry up during the summer, and are filled again when phreatic levels rise after heavy rains. Permanent and semipermanent ponds, and a chain of long-hydroperiod ponds are formed in an area of the park where discharges of the dune and regional aquifers coincide. Over the last few deca...

Rice fields are an important habitat for waterbirds. Knowledge of the availability of this habitat is important since the reduction in the area of natural wetlands has converted rice fields into vital refuges. This paper presents a method for mapping habitat availability in rice fields according to different waterbirds’ habitat preferences and exam...

Remote sensing has been used widely, and in many different ways, for wetlands. From simple wetland delineation and mapping to water body characterisation and the extraction of biophysical parameters, remote sensing images have provided useful results. Remote sensing offers synoptic and repetitive views of the same places on Earth. Additionally, rem...

En el periodo 2003-2007 el Laboratorio de SIG y Teledetección de la Estación Biológica de Doñana (LAST-EBD) realizó trabajo de campo simultáneo con la adquisición de datos de satélite, Landsat TM y ETM+, en el río Guadalquivir con el objetivo de estudiar, entre otros parámetros, la evolución histórica de su turbidez entre 1984 y 2008. Se ajustaron...

El número disponible de imágenes procedentes de Satélites de Observación de la Tierra está en continuo crecimiento, siendo además su obtención cada vez más sencilla y barata en los últimos años. El Banco de Imágenes del Laboratorio de SIG y Teledetección de la Estación Biológica de Doñana (LAST-EBD) dispone para una misma zona, entre otras, de 400...

Azolla filiculoides es un helecho acuático invasor, que fue detectado por primera vez en la marisma Doñana en el año 2000. Aparece como cubierta dominante o por debajo de helófitos. En las zonas invadidas termina cubriendo totalmente la lámina de agua, modificando las características reflectivas de la superficie. La biología de esta especie (escaso...

The water fern Azolla filiculoides is a floating plant native from central America. It was detected for the first time in the year 2000 in the Guadalquivir river marshes, within Doñana National Park. These are seasonal fresh-water marshes that flood in winter and dry­up in summer. The water fern, although original from tropical permanent fresh­wate...

El sensor hiperespectral AHS (Airborne Hyperspectral Scanner), operativo desde Septiembre de 2003, representa una importante apuesta tecnológica de gran versatilidad por parte del Instituto Nacional de Técnica Aeroespacial (INTA). El Parque Nacional de Doñana fue sobrevolado con dicho sensor en Abril de 2008. El objetivo de este estudio ha consisti...

We have used Landsat-5 TM and Landsat-7 ETM+ images together with simultaneous ground-truth data at sample points in the Doñana marshes to predict water turbidity and depth from band reflectance using Generalized Additive Models. We have point samples for 12 different dates simultaneous with 7 Landsat-5 and 5 Landsat-7 overpasses. The best model fo...

There is a major concern on current restoration and management programmes being applied over Doñana Ramsar Site. Historical inundation regime has been largely changed according to human transformations. On site measurements along short and recent periods have provided scant local information on inundation variability. Historical inundation patterns...

Remote sensing is a very useful tool that provides accurate flood extent and helps to monitor wetland changes, but has not been fully confirmed when aimed for to identify different flood levels. The goal of this study is to determine the potential of Landsat imagery to characterize and map flooding levels of Doñana marshes, a very heterogeneous mos...

Abstract— We analyze the potential of Landsat TM and ETM images to discriminate inundation, depth and turbidity patterns in the very heterogeneous shallow marshes of Doñana National Park. According to the results we will reconstruct historical changes in such variables with a long time series of Landsat images (MSS, TM and ETM+). For this purpose w...

En este trabajo se analiza el potencial de las imágenes del sensor TM de Landsat para determinar la presencia de inundación, y los valores de profundidad y turbidez en zonas de inundación somera espacialmente heterogéneas. El objetivo final es valorar la información radiométrica de los sensores de la serie Landsat (MSS, TM y ETM+) para reconstruir...

Resumen En este trabajo se presenta la metodología utilizada en el proyecto de "Análisis de la dinámica de inundación histórica de las marisma de Doñana" a partir de una serie temporal larga de 247 imágenes Landsat (MSS, TM y ETM+) de los últimos 30 años (1975-2004). Para determinar el mejor criterio de discriminación de zonas inundadas se tomaron...

In this work, we check the ability of Landsat TM images to discriminate flooded areas and to quantify depth and turbidity in very spatially heterogeneous shallow wetlands. We aim at evaluating whether radiometric values of Landsat sensors (MSS, TM y ETM+) aid to reconstruct historical and seasonal changes on physico-chemical characteristics of the...

Resumen En este trabajo se presenta una metodología para la cartografía automática de la superficie inundada con la que se está realizando el proyecto actual de análisis de la dinámica de inundación histórica de las marismas de Doñana a partir de una serie temporal larga de 249 imágenes Landsat (MSS, TM y ETM+) de los últimos 30 años (1975-2004). P...