Pino Angelo Ruiu

Mediterranean cork oak forests provide essential ecosystem services but face increasing threats from climate change, ecosystem simplification, and oak decline. Ensuring their long-term sustainability requires governance approaches that integrate regional planning frameworks with international certification standards. This study presents a pioneering case of public cork oak forest management in Alà dei Sardi, Sardinia (Italy), where municipal forest planning was aligned with national and regional regulations and further enhanced through Forest Stewardship Council^® (FSC^®) certification. The FSC system offers internationally recognized standards and the Ecosystem Services Procedure (FSC-PRO-30-006 v2-1) to verify responsible forest management and quantify key ecosystem benefits. The Alà dei Sardi forest is the first publicly owned municipal cork oak forest to achieve FSC Forest Management certification, with demonstrated positive impacts of its management activities on biodiversity conservation, carbon sequestration and storage, water protection, soil conservation, and recreational services. The certification process integrated management planning, stakeholder engagement, monitoring, and adaptive interventions, showing that public institutions can combine legal frameworks with voluntary standards to enhance ecological performance, accountability, and socio-economic value. This case illustrates a potentially scalable and replicable model for sustainable forest governance, linking territorial planning with market-based mechanisms, and provides a practical example of governance for resilient and multifunctional forest systems.

The efficacy of two formulations (Foray^® 76B AVIO and Rapax^® AS AIR) containing different Bacillus thuringiensis kurstaki (Btk) strains (ABTS-351 and EG-2348, respectively) was evaluated against Lymantria dispar larval populations in cork oak forests in Sardinia (Italy), in 2018 and 2019. The experimental design involved the following treatments: (I) untreated control; (II) Foray^® 76B at the dose of 2.0 L/ha; (III) Foray^® 76B at the dose of 2.5 L/ha; (IV) Rapax^® AS AIR at the dose of 2.0 L/ha. Aerial applications were carried out using a helicopter equipped with four electronic rotary atomizers adjusted to sprinkle 160 micron-sized drops. Btk efficacy was evaluated by assessing the larval density reduction 7, 14, and 21 days after the application in each experimental plot in comparison with an untreated check. In addition to field surveys, the mortality of second and third instar larval samples, randomly collected from each plot after treatment and fed with foliage from the same plot, was determined in the laboratory. All Btk treatments were similarly effective, and no differences in larval density reduction among Btk strains and doses were found in either year. Twenty-one days after application, the average larval density reduction in the field was approximately 70% in all treated plots in 2018, whereas in 2019 it reached 80% only in areas treated with Foray 76B at 2.5 L/ha. Laboratory observations showed that all Btk-based products were effective against gypsy moth larvae, with significant differences in mortality between untreated control and the different Btk treatments. Our results shed light on the possibility of alternating different Btk strains for resistance management purposes and of applying lower doses than labeled, in order to achieve cost savings for product shipment and distribution and to reduce the environmental impact.

Cork oak forests are of immense importance in terms of economic, cultural, and ecological value in the Mediterranean regions. Since the beginning of the 20th century, these forests ecosystems have been threatened by several factors, including human intervention, climate change, wildfires, pathogens, and pests. Several studies have demonstrated the primary role of the oomycete Phytophthora cinnamomi Ronds in the widespread decline of cork oaks in Portugal, Spain, southern France, and Italy, although other congeneric species have also been occasionally associated. Between 2015 and 2019, independent surveys were undertaken to determine the diversity of Phytophthora species in declining cork oak stands in Sardinia (Italy). Rhizosphere soil samples were collected from 39 declining cork oak stands and baited in the laboratory with oak leaflets. In addition, the occurrence of Phytophthora was assayed using an in-situ baiting technique in rivers and streams located throughout ten of the surveyed oak stands. Isolates were identified by means of both morphological characters and sequence analysis of internal transcribed spacer (ITS) regions of ribosomal DNA. In total, 14 different Phytophthora species were detected. Phytophthora cinnamomi was the most frequently isolated species from rhizosphere soil, followed by P. quercina, P. pseudocryptogea, and P. tyrrhenica. In contrast, P. gonapodyides turned out to be the most dominant species in stream water, followed by P. bilorbang, P. pseudocryptogea, P. lacustris, and P. plurivora. Pathogenicity of the most common Phytophthora species detected was tested using both soil infestation and log inoculation methods. This study showed the high diversity of Phytophthora species inhabiting soil and watercourses, including several previously unrecorded species potentially involved in the decline of cork oak forests.