70
2012). Shoreline regression and progradation (beach creation) are mapped along the
25 km of coastline (Díaz-Delgado 2008).
We also monitor the sedimentation processes in Doñana marshes: these data
enabled us to assess the effects of the restoration actions of the Doñana 2005 project. For instance, we mapped the progressive reduction of the dejection cone caused
by the Arroyo del Partido, one of the main tributaries to the marshes. We also located
the emergence of new streams from the artificial lagoons created to retain the
sediments.
Monitoring of Terrestrial Plant Communities
The application of a landscape scale monitoring approach to the Juniper woodlands
has revealed the dramatic effects of the mortality events in the autumn of 2005.
Mortality and damage in these plant communities affected juvenilies (canopy height
lower than 1 m) more than adults (higher than 1 m). Greater damage and mortality
was observed in areas with high plant density (Díaz-Delgado et al. 2014). The
effects of these types of events persist during the following years despite the vigorous sprouting observed from damaged individuals (Fig. 3). In addition, a retrospective spatial analysis starting from 1956 revealed both an expansion of Juniper
woodlands and a increase in plant density (García et al. 2014).
This monitoring program also benefited from using airborne hyperspectral
images to map the abundances of the dominant woody species in the shrublands, by
using spectral unmixing techniques (Jiménez 2011; Jiménez et al. 2005, 2011 )
based on spectroradiometric ground measurements (Jiménez and Díaz-Delgado
2015). The periodic detailed mapping provides evidence of the dramatic effects of
drought on the monte negro hygrophytic plant communities and the defoliation processes in monte blanco xeric shrublands.
The setting-up of permanent ground-truth monitoring plots has provided a better
understanding of the resilience of Doñana shrubland communities. By quantifying
the functional diversity of the different plant species combined with the ground
survey information on the percentage cover, structure and density of plants, we have
established the great stability of shrubland communities in Doñana after extreme
events (Lloret et al. 2016; Pérez-Ramos et al. 2017; de la Riva et al. 2017).
In the case of the permanent plots in the floodplain forest of Arroyo de la Rocina
(tributary to Doñana marshes), we have evidenced the need for an integrated monitoring approach using field plots and remote sensing (Rodríguez-González et al.
2017). We found a consistent and decreasing trend of the area occupied by Willows
(Salix atrocinerea) and an increase in the stem density of Narrow-leaved Ash trees
(Fraxinus angustifolia) (Fig. 4). We found a higher percent of fallen Willow trunks
in the plots. The results highlight the recent hydrological changes in one of the most
important tributary rivers entering the Doñana marshes.
R. Díaz-Delgado
2012). Shoreline regression and progradation (beach creation) are mapped along the
25 km of coastline (Díaz-Delgado 2008).
We also monitor the sedimentation processes in Doñana marshes: these data
enabled us to assess the effects of the restoration actions of the Doñana 2005 project. For instance, we mapped the progressive reduction of the dejection cone caused
by the Arroyo del Partido, one of the main tributaries to the marshes. We also located
the emergence of new streams from the artificial lagoons created to retain the
sediments.
Monitoring of Terrestrial Plant Communities
The application of a landscape scale monitoring approach to the Juniper woodlands
has revealed the dramatic effects of the mortality events in the autumn of 2005.
Mortality and damage in these plant communities affected juvenilies (canopy height
lower than 1 m) more than adults (higher than 1 m). Greater damage and mortality
was observed in areas with high plant density (Díaz-Delgado et al. 2014). The
effects of these types of events persist during the following years despite the vigorous sprouting observed from damaged individuals (Fig. 3). In addition, a retrospective spatial analysis starting from 1956 revealed both an expansion of Juniper
woodlands and a increase in plant density (García et al. 2014).
This monitoring program also benefited from using airborne hyperspectral
images to map the abundances of the dominant woody species in the shrublands, by
using spectral unmixing techniques (Jiménez 2011; Jiménez et al. 2005, 2011 )
based on spectroradiometric ground measurements (Jiménez and Díaz-Delgado
2015). The periodic detailed mapping provides evidence of the dramatic effects of
drought on the monte negro hygrophytic plant communities and the defoliation processes in monte blanco xeric shrublands.
The setting-up of permanent ground-truth monitoring plots has provided a better
understanding of the resilience of Doñana shrubland communities. By quantifying
the functional diversity of the different plant species combined with the ground
survey information on the percentage cover, structure and density of plants, we have
established the great stability of shrubland communities in Doñana after extreme
events (Lloret et al. 2016; Pérez-Ramos et al. 2017; de la Riva et al. 2017).
In the case of the permanent plots in the floodplain forest of Arroyo de la Rocina
(tributary to Doñana marshes), we have evidenced the need for an integrated monitoring approach using field plots and remote sensing (Rodríguez-González et al.
2017). We found a consistent and decreasing trend of the area occupied by Willows
(Salix atrocinerea) and an increase in the stem density of Narrow-leaved Ash trees
(Fraxinus angustifolia) (Fig. 4). We found a higher percent of fallen Willow trunks
in the plots. The results highlight the recent hydrological changes in one of the most
important tributary rivers entering the Doñana marshes.
R. Díaz-Delgado