Reforestation in Kaisariani

The Impact of Water Scarcity and Extreme Heat

Reports of water scarcity, hot summers, and their related consequences and challenges reach us every year. The rise in global temperatures and the increasing frequency of extreme weather events, such as heatwaves and droughts driven by climate change, present ongoing issues that will increasingly pose significant challenges in the future. Droughts combined with extreme heat lead to a wide range of problems. Freshwater resources are becoming scarcer, which, in addition to directly affecting humans, also puts significant stress on vegetation.

Agricultural and Ecological Consequences of Drought

Agriculture and green spaces are particularly affected. This problem becomes especially severe when soils cannot retain large amounts of water, meaning water resources — whether from rainfall or targeted irrigation — cannot be fully utilized. This results in reduced crop yields; previously fertile soils become uncultivable, and ultimately, food security is threatened.

Wildfires and the Decline of Forest Ecosystems

In addition to agriculture, other types of vegetation are also affected by the consequences of climate change. Dry, hot summers have led to an increase in the frequency and intensity of wildfires. These fires result in the loss of natural habitats for many plants and animals and a decline in biodiversity. At the same time, the resilience of forests and ecosystems is weakened. The function of forests as vital carbon sinks to reduce CO2 in the atmosphere is also compromised.

Challenges of Reforestation Amidst Climate Change

Already, as of June 2024, numerous wildfires have been recorded in Greece, leaving behind devastated forest areas. In the worst cases, this is followed by soil erosion, making reforestation more difficult. Reforestation projects are also challenging because young plants in their early developmental stages are often not resilient enough to withstand high temperatures and dry conditions.

Collaborative Reforestation Effort in Kaisariani

The city of Kaisariani near Athens, following preparatory work by Prof. Alexopoulos, has partnered with FH Aachen for a reforestation project to test sustainable, biobased and biodegradable hydrogels in a field trial. This initiative involved a coalition of Greek and German partners, including political figures, volunteers and researchers.

Organizational and Financial Support

Greek organizations such as former citizens, deputy mayors, and the "Union for the Protection and Development of Hymettus (SPAY)" played key roles in organizing and coordinating the event. Donations from the "Association of German-Greek Societies" (VDGG) funded the seedlings, with special thanks to Dr. Skarpellis-Sperk and the VDGG members for their crucial contributions.

Expert Guidance and Local Involvement

Dr. Oliver Bens and Dr. Heiner Hoogen were available as external experts for planning. Ecology professor Margarita Arianoutsou from the University of Athens advised on tree species selection, while PhD students Nikolina Vidalis and Elias Katsas supported the project on-site. Local volunteers also contributed significantly, turning the reforestation into a community-focused event.

Academic and Financial Support from FH Aachen

Together with the Solar Institute Jülich (SIJ), the Institute of Applied Polymer Chemistry (IAP) represents the German side of the academic involvement at FH Aachen in the project. SIJ is involved in coordinating and planning with the Greek stakeholders and supports data evaluation. IAP conducts research on sustainable hydrogels and provided materials.  FH Aachen, which supported the project with financial resources from its fund for sustainable development. This covered material costs and made two necessary business trips for field trials in Kaisariani and participation in the reforestation action possible.

Interdisciplinarity as key for sustainable development

"Living collaboration and the strong synergies between the disciplines are what make an application-oriented university stand out," say the three professors. "A sustainable project is also characterized by involving many different parties, bringing them together, and examining a problem from as many perspectives as possible to develop a comprehensive solution strategy."

Final Preparations and Hydrogel Placement

On November 3, 2023, final preparations and coordination meetings were conducted at Kaisariani Town Hall with stakeholders from the city, SPAY and FH Aachen. The following day, scientists from IAP and SIJ placed approximately 2.2 kg of the sustainable hydrogel into holes prepared by SPAY for around 560 trees. The hydrogel application involved using 3.0 g or 5.0 g per tree for half of the trees, while a comparative study included 440 trees with a commercially available bio-based product, 100 trees with a fossil-based product and 500 trees without hydrogel.

Successful Reforestation Event

On November 5, 2023, the reforestation of 1600 trees on Arapis Hill in Kaisariani was completed in record time. The event aimed to enhance the regeneration and protection of Mount Hymettus, turning into a significant environmental action supported by meticulous planning and preparation.

Community Collaboration and Engagement

The reforestation effort saw active participation from SPAY, the Municipality of Kaisariani, VDGG and FH Aachen, along with local groups such as the Hymettus Hiking Group, the 2nd Scout Group of Kaisariani, local schools and volunteer fire brigades. The involvement of volunteers, families and local organizations made the event a vibrant community celebration.

Completion and Acknowledgements

The planting was completed in just about an hour, followed by initial watering by SPAY and volunteer fire brigades. VDGG was represented by Honorary President Dr. Sigrid Skarpelis-Sperk and Vice President Mrs. Stella Kirgiane-Efremidou. Dr. Skarpelis-Sperk, who initiated the project, and Mrs. Kirgiane-Efremidou actively participated in planting trees, marking the successful culmination of the project.

Post-Reforestation Observations

After the initial watering, no additional measurements or watering were conducted from November 2023 to March 2024. In March 2024, the first assessments began, focusing on plant height, number of leaves, appearance and mortality rate.

Early Results and Initial Findings

With the help of Elias Katsas, initial results showed differences between plants with and without hydrogel. Measurements in May 2024 confirmed that plants with hydrogel had more leaves and were taller. Due to ongoing heat and drought, SPAY has initiated further watering and tree measurements continue.

Potential of Sustainable Hydrogels

Studies and initial results indicate that hydrogels have significant potential as water-retaining soil additives. Sustainable hydrogels can conserve water and promote plant growth, making them a valuable tool in addressing climate change impacts.

Ongoing Research and Collaboration

The collaboration between Greek and German organizations highlights the importance of international and interdisciplinary research. Future plans include continued evaluation of the project and the development of a joint EU-level research initiative. The support from local politics and civil society has been crucial in advancing practical measures against climate change.