Challenges to Mediterranean Fagaceae Ecosystems Affected by Phytophthora cinnamomi and Climate Change

Academic Background

The Mediterranean Fagaceae ecosystems, including oak trees (Quercus ilex and Quercus suber) and chestnut trees (Castanea sativa), are vital ecological and economic resources in southern Europe. However, in recent years, these ecosystems have faced severe decline, primarily due to the spread of an invasive pathogen—Phytophthora cinnamomi (Phytophthora). This pathogen infects tree roots, leading to gradual weakening and even death of the trees. Additionally, climate change has exacerbated the issue, particularly the warming and aridification trends in the Mediterranean region, which provide more favorable conditions for the spread and reproduction of Phytophthora.

To address this challenge, research institutions from Italy, Spain, and Portugal collaborated to publish a review paper, aiming to comprehensively analyze the biological characteristics, ecological impacts, and current diagnostic and management measures of Phytophthora in Mediterranean Fagaceae ecosystems. The study also explores how Integrated Pest Management (IPM) strategies can mitigate the impact of Phytophthora and calls for increased public and stakeholder involvement to protect these critical forest ecosystems.

Source of the Paper

This paper was co-authored by Carmen Morales-Rodríguez, Andrea Vannini, Bruno Scanu, and others, affiliated with institutions such as the University of Tuscia in Italy, the University of Córdoba in Spain, and the University of Trás-os-Montes e Alto Douro in Portugal. Published in 2025 in the journal Current Forestry Reports, the paper is titled Challenges to Mediterranean Fagaceae Ecosystems Affected by Phytophthora cinnamomi and Climate Change: Integrated Pest Management Perspectives.

Main Content of the Paper

1. Biological and Ecological Characteristics of Phytophthora

Phytophthora cinnamomi is a soil-borne pathogen that primarily infects fine roots through motile zoospores. The pathogen can form thick-walled dormant structures (such as chlamydospores and oospores) under harsh environmental conditions, enabling it to survive drought and high temperatures. Research shows that the spread of Phytophthora is closely linked to human activities, such as the movement of contaminated nursery stock, machinery, and the footwear of tourists and hikers. Additionally, climate change (e.g., warm winters and frequent rainfall) provides favorable conditions for the reproduction of Phytophthora.

2. Impact of Phytophthora on Fagaceae Ecosystems

The impact of Phytophthora on Mediterranean Fagaceae ecosystems is mainly reflected in two diseases: ink disease in chestnut trees and decline disease in evergreen oaks. Symptoms of chestnut ink disease include reduced leaf size, chlorosis, and root necrosis, which can lead to tree death in severe cases. Decline disease in evergreen oaks manifests as crown thinning, leaf yellowing, and branch dieback. Studies indicate that the role of Phytophthora in these diseases varies by region and climate conditions. For example, in the Iberian Peninsula, Phytophthora is the primary pathogen causing chestnut ink disease, while in Greece and Italy, Phytophthora × cambivora (another Phytophthora species) is more prevalent.

3. Integrated Pest Management (IPM) Strategies

To address the threat of Phytophthora, the paper proposes a series of IPM strategies, including: - Chemical Control: Using phosphonate compounds (e.g., potassium phosphonate) and fungicides (e.g., fosetyl-aluminium) for trunk injections to reduce Phytophthora infection. - Biological Control: Utilizing antagonistic microorganisms (e.g., Trichoderma fungi) and plant extracts (e.g., isothiocyanates from mustard plants) to inhibit Phytophthora growth. - Sanitation Measures: Establishing disinfection stations in infected areas to prevent the spread of Phytophthora via footwear and vehicle tires. - Monitoring Technologies: Employing drones and multispectral cameras for forest health monitoring, combined with Geographic Information Systems (GIS) and remote sensing technologies, to assess the spread of Phytophthora and tree health in real time.

4. Public and Stakeholder Engagement

The paper emphasizes that public and stakeholder engagement is crucial for the success of IPM. By raising awareness of the Phytophthora threat and encouraging participation in monitoring and sanitation measures, the spread of Phytophthora can be effectively reduced. For example, the Life FAGESOS project implemented large-scale IPM strategies in the Mediterranean region and enhanced local community awareness of forest conservation through awareness campaigns and training workshops.

Significance and Value of the Paper

This paper not only comprehensively summarizes the threat of Phytophthora to Mediterranean Fagaceae ecosystems but also proposes practical management strategies, providing important references for future research and practice. By combining chemical, biological, and sanitation measures, the paper demonstrates a comprehensive management approach that can effectively mitigate the impact of Phytophthora. Additionally, the paper highlights the importance of public participation and interdisciplinary collaboration, offering valuable insights for other regions globally affected by Phytophthora.

Highlights

• Comprehensiveness: The paper covers the biological characteristics, ecological impacts, diagnostic methods, and management strategies of Phytophthora, providing a holistic perspective.
• Innovation: It proposes monitoring methods based on drones and remote sensing technologies, combined with chemical and biological control measures, showcasing the potential of IPM.
• Practicality: Through the case study of the Life FAGESOS project, the paper demonstrates how to apply IPM strategies in practice and emphasizes the importance of public engagement.

This paper provides scientific foundations and practical guidance for the protection of Mediterranean Fagaceae ecosystems, holding significant ecological and economic value.