Long-term monitoring of woody plants of Doñana shrublands 2008-2023

Study Extent

The study area is located in southwest Spain in the Guadalquivir Basin and covers Doñana Protected Area (542.51 km2). Climate is Mediterranean sub-humid with Atlantic coast influence deriving in wet mild winters and dry warm summers. The rainy season occurs between October and April, with a peak in December–January (average rainfall is about 550 mm). Four main ecosystems are monitored in the area: freshwater marshes, mobile sand dunes, Mediterranean shrublands and woodlands and Doñana shoreline of 30 km. This monitoring is carried out in 21 permanent plots on Mediterranean shrublands in the Doñana Biological Reserve and sampled once per year, between March and May.

Sampling

The long-term monitoring of Doñana shrublands started in 2008 by setting 21 permanent plots across the Doñana Biological Reserve. Each plot is sampled during the one sampling campaign per year in the flowering season (between March and May) in 21 permanent square plots (15x15 m). Cover is measured using the line intercept method in 3 transects of 15 m length oriented from East to West and located at fixed points of 2.5, 7.5 and 12.5 metres at both sides of the plot. Using the line-intercept method, the coverage of each species is measured with a measuring tape, including the class age (adult or seedling) and the canopy status (green or dead). This method enables to calculate the percent cover for each species across the transect and for the whole plot, including data on class age and percent of dry and green canopy, additionally to the percent of bare soil, plant density, species richness and vascular plant diversity for every plot.

Quality Control

Taxonomic identification is assessed by different observers at the time in the field using flower and fruits to complement correct identification. Plots are located with permanent stakes and coordinates collected with a D-GPS. Although more than 10 observers have participated in the sampling, 80% of the sampling was led by the same observer. Data is digitally collected using mobile devices by means of a specifically designed Cybertracker (https://cybertracker.org/) sequence. This procedure guides the observer through a sequence of screens in a step-by-step way, some of them mandatory to prevent the lost of data. A map and a list of the plots as well as a plant species list and observer names are also available in the sequence for the observer. Unidentified plants in the field are later taxonomically identified. Contiguous individuals from the same species are recorded separately to improve plant density calculation. Data is transferred to a central database used for basic quality assessment where the most frequent error (95%) corresponds to wrong tape measurements which are corrected according to the previous record. Interannual plot percent cover comparisons are also used to assess consistency on plant species occurrences and relative abundance, although the plant cover dynamics of these plant communities show highly variable.

Method steps

1. Along each plot there was three different transects of 15 metres, on which a measuring tape was extended. The three transects are distributed at fixed distances from the Eastern side of the plot, the first one at 2.5 metres from the NE corner, the second one at 7.5 and the last one at 12.5 metres. All the individuals intercepted by measuring tape are identified and tape distance of the initial and the final contact point recorded, in order to calculate the total cover in the transect per species. Ancillary data on age class (adult or seedling: plant height under 25 cm) and the canopy status as a living or dead specimen. Average plant height is recorded for every transect. Percent cover of each species is calculated per transect and per plot. Data is collected in the field using a CyberTracker programmed sequence and download as Excel or CSV files.

N/A

1. Ericaceae
   rank: family
2. Malvales
   rank: order
3. Liliopsida
   rank: class
4. Santalales
   rank: order
5. Santalaceae
   rank: family
6. Lamiaceae
   rank: family
7. Cistaceae
   rank: family
8. Fabaceae
   rank: family
9. Lamiales
   rank: order
10. Myrtaceae
    rank: family
11. Caryophyllales
    rank: order
12. Thymelaeaceae
    rank: family
13. Tracheophyta
    rank: phylum
14. Pinopsida
    rank: class
15. Asterales
    rank: order
16. Asphodelaceae
    rank: family
17. Plantae
    rank: kingdom
18. Ericales
    rank: order
19. Cyperaceae
    rank: family
20. Fabales
    rank: order
21. Oleaceae
    rank: family
22. Magnoliopsida
    rank: class
23. Cupressaceae
    rank: family
24. Asparagaceae
    rank: family
25. Pinales
    rank: order
26. Caryophyllaceae
    rank: family
27. Pinaceae
    rank: family
28. Poales
    rank: order
29. Asteraceae
    rank: family
30. Asparagales
    rank: order
31. Myrtales
    rank: order
32. Plumbaginaceae
    rank: family

Doñana LTSER Platform. Doñana Protected Area. Doñana National Park. Doñana Biological Reserve (RBD).