The expansion of olive groves is reducing habitat suitability for the Great Bustard Otis tarda and the Little Bustard Tetrax tetrax in Southern Spain: could Important Bird Areas (IBAs) reduce this expansion?

Abstract

Olive groves in the Mediterranean basin have undergone a tremendous increase during the last two decades, with most of the new olive groves being planted on arable land. This conversion may affect habitat suitability for steppe birds, which are associated with arable land and other open-land habitats, such as natural pastures. In this work, we evaluate the presence of new olive groves in the distribution of the Great Bustard Otis tarda and the Little Bustard Tetrax tetrax in Southern Spain (the largest olive oil production zone in the world), and we compare the percentage of different land uses in 2000 and 2018 using data provided by the Corine Land Cover. From 2000 to 2018, new olive groves occupied 2.14 and 2.61% of the distribution areas of the Great Bustard and the Little Bustard, respectively. The decrease in arable land and the increase in permanent crops were the main drivers of the landscape composition changes during the study period. The fragmentation index of arable land was higher in 2018 than 2000. These changes in the landscape suggest a decrease in habitat availability and suitability for steppe birds that could affect the distribution and abundance of their populations. Moreover, there were no differences in the proportion of new olive groves planted inside and outside the limits of Important Bird Areas (IBAs) from 2000 to 2018, which were created to protect these steppe birds, thus suggesting that the management policy of the IBAs should be reviewed to prevent harmful land-use changes.

Alarming decline of the Little Bustard Tetrax tetrax in one of its two population strongholds in Sardinia, Italy

“…The declines reported here (annual rate of approximately 2%) are somewhat lower in magnitude than those reported for the stronghold areas of the species in the Iberian Peninsula (approximately 6%) (Morales and Bretagnolle 2022). The slower rate of decline in Sardinia may be due to the rather traditional pastoral and extensive land use in inland Sardinia that has not notably changed over the past decades, as opposed to the rapid transformations occurring in the cereal steppe of the Iberian Peninsula (Guerrero-Casado et al 2022, Morales and Bretagnolle 2022). Therefore, while alarming, these declines may still leave time and scope for evidence-based conservation management interventions to be implemented.…”

Anomalous Gold Concentrations in Hypersaline Wetland Sediments (Laguna Honda, South Spain) Caused by Nanoparticles Used in Agricultural Practices: Environmental Transformation

“…The interest in metal nanoparticles in this sector as a sustainable alternative has grown due to their ability to slowly release nutrients and pesticides in a controlled manner [ 14 , 15 , 16 ]. Spain is the biggest olive oil manufacturer worldwide [ 17 ], and around 1.6 million ha of land in Andalusia (South of Spain) is dedicated to olive culture, especially in the Guadalquivir River Basin of the Jaén and Cordoba provinces [ 18 ]. This area is characterized by the presence of frequently eutrophicated wetlands completely surrounded by olive groves, which are usually considered hotspots for controlling the biogeochemical transformations of nutrients (P and N coming from agricultural practices) [ 19 ] and can be sensitive systems for the concentration and modification of pesticides that may contain nanoparticles used in olive culture.…”