SummaryThe Ecuadorian coast has two main types of forests, which are differentiated by their phenology: dry forests are deciduous and more humid forests are evergreen. Less of the dry forests on the Ecuadorian coast is protected (13% of its area) than the evergreen forests (28%), and the area devoted to the protection of dry forests (1069 km2) is substantially less than the area devoted to the protection of evergreen forests (2800 km2). Yet the conservation status of dry forests is more critical, with 83% of their area classified as having very low connectivity, 70% as being highly fragile and 86% as being highly threatened. In addition, the dry forests have fewer protected areas than the evergreen forests. It is therefore necessary to increase the protection of deciduous ecosystems as part of a comprehensive national strategy because they support high levels of biodiversity and many endemic species.
Background Fragmentation and deforestation are one of the greatest threats to forests, and these processes are of even more concern in the tropics, where the seasonal dry forest is possibly one of the most threatened ecosystems with the least remaining surface area. Methods The deforestation and fragmentation patterns that had occurred in Ecuadorian seasonal dry forests between 1990 and 2018 were verified, while geographic information systems and land cover shapes provided by the Ecuadorian Ministry of the Environment were employed to classify and evaluate three types of seasonal dry forests: deciduous, semi-deciduous, and transition. The study area was tessellated into 10 km2 hexagons, in which six fragmentation parameters were measured: number of patches, mean patch size, median patch size, total edge, edge density and reticular fragmentation index (RFI). The RFI was also measured both outside and inside protected natural areas (unprotected, national protected areas and protected forest). Moreover, the areas with the best and worst conservation status, connectivity and risk of disappearance values were identified by means of a Getis-Ord Gi* statistical analysis. Results The deforestation of seasonal dry forests affected 27.04% of the original surface area still remaining in 1990, with an annual deforestation rate of − 1.12% between 1990 and 2018. The RFI has increased by 11.61% as a result of the fact that small fragments of forest have tended to disappear, while the large fragments have been fragmented into smaller ones. The semi-deciduous forest had the highest levels of fragmentation in 2018. The three categories of protection had significantly different levels of fragmentation, with lower RFI values in national protected areas and greater values in protected forests. Conclusions The seasonal dry forest is fragmenting, deforesting and disappearing in some areas. An increased protection and conservation of the Ecuadorian seasonal dry forest is, therefore, necessary owing to the fact that not all protection measures have been effective.
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.
There are many local fragmentation metrics, but most can be grouped into four types (composition/area, isolation, edge, and shape), and none of them alone determines the degree of fragmentation of a patch. Here, we grouped together the main fragmentation metrics (area, edge, shape, and isolation) in order to propose a new metric/index, the Patch Fragmentation Index (PFI), with which to determine fragmentation at patch scale. The index was subsequently verified with the Ecuadorian seasonal dry forest by employing geographic information layers and temporal land uses changes in 1990, 2000, 2008, and 2018. The PFI was applied to calculate the fragmentation per patch, spatial and temporal changes of fragmentation based on PFI were assessed, and the spatial patterns (Getis-Ord Gi * analysis) were calculated. The Ecuadorian seasonal dry forest obtained a mean PFI value of 0.88 (median = 0.99) in 2018. This value has increased by 8.6% since 1990, and 3451 patches of forest disappeared between 1990 and 2018. The Getis-Ord Gi * analysis was effective with regard to describing the spatial patterns, and 62% of the patches that were classified as hot patches in 1990 had disappeared by 2018. The PFI has proven to be a useful tool with which to describe fragmentation patterns at patch scale (regardless of its size) and can be extrapolated to other landscapes. The PFI will provide a new vision and can help in the decision-making related to the conservation and management of fragmented ecosystems.
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