Impact of grazing on the species richness of plant communities in Mediterranean temporary pools (western Morocco)

Status of Ecosystem Services in Abandoned Mining Areas in the Iberian Peninsula: Management Proposal

An abandoned sphalerite mining area in the southwest (SW) of the Iberian Peninsula was studied to evaluate the impact that the presence of metal(loid)s has on soil and ecosystem health. Five zones were delimited: sludge, dump, scrubland, riparian zone, and dehesa. Critical total levels of lead (Pb), zinc (Zn), thallium (Tl), and chromium (Cr), well above the limit indicative of toxicity problems, were found in the areas close to the sources of contamination. Pb-Zn concentrations were very high in the riparian zone, reaching values of 5875 mg/kg Pb and 4570 mg/kg Zn. The whole area is classifiable as extremely contaminated with Tl, with concentrations above 370 mg/kg in the scrubland. Cr accumulation mainly occurred in areas away from the dump, with levels up to 240 mg/kg in the dehesa. In the study area, several plants were found growing luxuriantly despite the contamination. The measured metal(loid)s content is the cause of a significant decrease in ecosystem services, resulting in unsafe soils for food and water production, so the implementation of a decontamination program is advisable. The plant species Retama sphaerocarpa, present in the sludge, scrubland, riparian zone, and dehesa, is postulated as suitable for use in phytoremediation.

The degradation of forest areas in Morocco: Case of Benslimane province

This article aims to shed light on the process of known degradation of the forest area of Benslimane province during the period 1990–2020 and to specify the most important human causes which contributed to it (quarries, extension of the built-up area, the impact of agricultural activities, grazing and collection of firewood), by using remote sensing techniques (spatial images for the years 1990–2000–2010–2020) to produce Land Cover maps. The following satellite images were used, Landsat 5 TM, Landsat 7 ETM+ and Landsat 8 OLI, with a spatial precision of 30 m, the Semi-Automatic Classification Plugin (SCP) in QGIS was used for atmospheric correction, and the Spectral Angle Mapping algorithm for the images’ classification. The rating evaluation of the Kappa coefficient shows the following ratios for the years 1990–2000–2010–2020 respectively ; 0.89–0.90–0.90–0.93. The results showed that the forest area of Benslimane province has declined by 11.4% or about 6,027.7 ha between 1990–2020 at the rate of 200 ha/year, which has been turned into matorral land or bare land. This forest also lost 35.2% of its vegetative density and has become much sparser, while the original grazing areas surrounding it have been reduced by 50.4%. Moreover, the area of quarries increased by 1,097.4%, the percentage of built-up area increased by 328.2%, and the agricultural area expanded by 32.7%. These results can be used as preliminary data for future studies and can help policymakers focus on the real drivers of forest degradation, in order to develop interventions to ensure the sustainability of natural resources.

Decades of Recovery From Sheep Grazing Reveal No Effects on Plant Diversity Patterns Within Icelandic Tundra Landscapes

Tundra plant communities are often shaped by topography. Contrasting wind exposure, slopes of different inclination and landforms of different curvature affect habitat conditions and shape plant diversity patterns. The majority of tundra is also grazed by ungulates, which may alter topographically induced plant diversity patterns, but such effects may depend on the spatial scales of assessments. Here we ask whether topographically induced patterns of within (alpha) and between (beta) plant community diversity are different in contrasting grazing regimes. We studied plant communities within tundra landscapes that were located in the North and Northwest of Iceland. Half of the studied landscapes were grazed by sheep, whereas the other half was currently un-grazed and recovering for several decades (up to 60 years). Alpha and beta diversity were assessed on explicitly defined, nested spatial scales, which were determined by topographical units. Although we contrasted currently grazed vegetation to vegetation that witnessed several decades of grazing recovery, we found no statistically significant differences in plant diversity patterns. We relate these findings to the low resilience of our study system toward grazing disturbances, which has important implications for management practices in the tundra. Effects of topography on species richness were only found for specific spatial scales of analyses. Species rich topographical units were associated with relatively large biomass of plant growth forms that promote nutrient availability and potential plant productivity in the tundra, such as forbs. This suggests that biomass of such plant growth forms within habitats can be a useful proxy of potential plant productivity and may predict spatial patterns of plant species richness in tundra.