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processes (Díaz-Delgado 2010). The protocols associated with this approach are
mainly applied using a combination of remote sensing images, sensu lato, and
ground truth data from permanent field plots (Barrett 2013; Richards 2013). One
advantage of this approach is the possibility to look back in time and use the first
available aerial photos as a temporal reference. The current availability of long time
series of images for many places in the world enables us to identify trends and shifts
in different ecological processes and features (Gardiner and Díaz-Delgado 2007).
The landscape scale monitoring focuses on three different subject areas: the
Doñana wetland ecosystems, including marshes and ponds, geophysical processes,
and terrestrial plant communities.
Ground-Truthing
The landscape-scale approach uses plots, transects and in situ sampling points as
ground-truth for validation purposes, which includes percentage cover for most
plant communities present in Doñana.
The multi-scale approach uses involves sampling from the individual plots
(microscale) through to the landscape level including mesoscale plots. When dealing with woodlands, the spatial location and associated information on individual
trees (size and species) is recorded to allow scaling up using airborne (including
drone) and spaceborne data.
Since 1999, we have reported trends and changes in the surface cover of dominant plant communities in Doñana. For example, there has been a general increase
in the density and area occupied by Stone Pine (Pinus pinea) woodlands and a
decrease of Erica scoparia healthlands replaced by more xeric species, including
woodlands dominated by Juniper (Juniperus phoenicea spp. turbinata). These plots
also provide information on habitat structure, species density, population dynamics,
species abundance and diversity.
Monitoring of Doñana Wetlands
Monitoring the annual flooding and drying out processes of the Doñana natural
marshes has allowed to test the ‘largely assumed’ hypothesis of an increase in the
hydroperiod in recent decades (Díaz-Delgado et al. 2016a; Díaz-Delgado et al.
2010; Díaz-Delgado et al. 2006). Figure 1 shows the median trend estimated from
the 1974–2014 time series of flooding masks retrieved from Landsat MSS, TM and
ETM+ images. This approach allows us to spatially locate the temporal trends
(increases or reductions) in the duration of the flooding: this is a critical variable for
the biological communities of Doñana marshes. The temporal analysis reveals two
significant trends: on the one hand, the hydroperiod has increased in the
Long-Term Ecological Monitoring at the Landscape Scale for Nature Conservation…
processes (Díaz-Delgado 2010). The protocols associated with this approach are
mainly applied using a combination of remote sensing images, sensu lato, and
ground truth data from permanent field plots (Barrett 2013; Richards 2013). One
advantage of this approach is the possibility to look back in time and use the first
available aerial photos as a temporal reference. The current availability of long time
series of images for many places in the world enables us to identify trends and shifts
in different ecological processes and features (Gardiner and Díaz-Delgado 2007).
The landscape scale monitoring focuses on three different subject areas: the
Doñana wetland ecosystems, including marshes and ponds, geophysical processes,
and terrestrial plant communities.
Ground-Truthing
The landscape-scale approach uses plots, transects and in situ sampling points as
ground-truth for validation purposes, which includes percentage cover for most
plant communities present in Doñana.
The multi-scale approach uses involves sampling from the individual plots
(microscale) through to the landscape level including mesoscale plots. When dealing with woodlands, the spatial location and associated information on individual
trees (size and species) is recorded to allow scaling up using airborne (including
drone) and spaceborne data.
Since 1999, we have reported trends and changes in the surface cover of dominant plant communities in Doñana. For example, there has been a general increase
in the density and area occupied by Stone Pine (Pinus pinea) woodlands and a
decrease of Erica scoparia healthlands replaced by more xeric species, including
woodlands dominated by Juniper (Juniperus phoenicea spp. turbinata). These plots
also provide information on habitat structure, species density, population dynamics,
species abundance and diversity.
Monitoring of Doñana Wetlands
Monitoring the annual flooding and drying out processes of the Doñana natural
marshes has allowed to test the ‘largely assumed’ hypothesis of an increase in the
hydroperiod in recent decades (Díaz-Delgado et al. 2016a; Díaz-Delgado et al.
2010; Díaz-Delgado et al. 2006). Figure 1 shows the median trend estimated from
the 1974–2014 time series of flooding masks retrieved from Landsat MSS, TM and
ETM+ images. This approach allows us to spatially locate the temporal trends
(increases or reductions) in the duration of the flooding: this is a critical variable for
the biological communities of Doñana marshes. The temporal analysis reveals two
significant trends: on the one hand, the hydroperiod has increased in the
Long-Term Ecological Monitoring at the Landscape Scale for Nature Conservation…