Landscape ecology for conservation : investigating the potential for restoration and connectivity of selected sites and species

Abstract

The United Nations Decade on Ecosystem Restoration (2021-2030) aims to halt and reverse ecosystem degradation resulting in improved ecosystem services and recovered biodiversity. Ecosystem restoration has gained traction amongst the scientific community, encompassing a wide range of practices that aim to recover native ecosystems and slowdown biodiversity loss. However, this has not been fully integrated into conservation programmes and management practices in the Maltese Islands. The present study aimed to investigate the potential for ecological restoration and connectivity in selected sites and species through the landscape approach. Three case studies were chosen to evaluate how ecological restoration strategies can be applied to different local scenarios through site-specific and species-specific methodologies. The case study of Comino aimed to restore and introduce maquis vegetation in suitable areas of the island; this study thus evaluated existing habitat patches of Annex I maquis habitats of the Habitats Directive and proposed ways for their natural, albeit aided, expansion. Pressures and threats affecting each area of study were taken note of, together with various abiotic conditions to assess the level of degradation present and propose specific restoration actions respectively. It was evident from the Comino case study that afforestation on the islet needed to deviate from a quantity-oriented approach and focus more on appropriate post-planting maintenance, whilst investing in re-introduction of threatened local species. The second case study aimed to evaluate the vulnerability of Heteracris adspersa (Orthoptera) and examine the extent of its habitat at Is-Salini and Il-Magħluq at Marsaxlokk, as also propose ways to enhance its conservation status. Population estimation at Is-Salini was estimated to be slightly <600 individuals (sex ratio with a slight bias towards the females), whilst at Il-Magħluq, it was not possible to carry out an accurate estimate as a result of somewhat wetter terrain to that of Is-Salini. Nonetheless, an incalculable number of saltating individuals gave the impression taht the population at Il-Magħluq was significantly more abundant, although more restricted spatially. In terms of restoration, it is crucial that habitats of this highly localised stenotopic acridid are afforded adequate space for further expansion whilst conservation action plans are compiled specific to the species’ requirements, given its local distribution is significantly restricted. The third case study aimed to assess the creation of woodland corridors for connectivity of Gonepteryx cleopatra (Lepidoptera). Mapping of Rhamnus alaternus, the main larval host-plant, was undertaken, with the highest number being located at Il-Bosk and Ta’ Rapa areas, followed by the pinetum at Ix-Xuxa and near Chateau Buskett. Sightings of Mediterranean Brimstone butterflies during the course of research only comprised males, encountered flying at these aforementioned localities within the Buskett area. The study found that Olea and Ceratonia forests (Annex I habitat 9320) appeared to be the most fragmented and, therefore, planting of Rhamnus sp. would need to be implemented with a view to act as corridors between patches and also to link nearby valley systems, where the butterfly species under investigation was also recorded.