## 1 Introduction  
The Mediterranean basin, a biodiversity hotspot [1] known for its rich cultural heritage and unique landscapes, has witnessed a long-standing symbiotic relationship between humans and nature [2, 3]. Over centuries, this long-standing interaction has resulted in the development of diverse agroecosystems that have dual roles as sources of agricultural stentance and reservoirs of biodiversity [4; 5; 6]. Within the spectrum of these agroecosystems, it is discernible that traditional olive groves are a distinctive and emblematic agroecological system [7] that evolved and adapted to changing agricultural practices over time, reflecting their ability to navigate shifts in societal and environmental dynamics [8; 9; 10]. Despite the impact of modernization [9; 11; 12] marked by a gradual shift from traditional and low-density systems to intensive and highly-intensive cultivation practices [13; 14], as well as land abandonment deriving from socioeconomic processes [15; 16; 17; 18; 19; 20; 21], traditional olive groves have consistently displayed remarkable resilience [2; 22], demonstrating their ability to adapt to changing environmental conditions and sustain olive production over centuries. Situated at the core of these groves, centennial traditional olive trees play a pivotal role as integral components of the ecosystem [23]. They leverage their physiological attributes and life history to make a substantial contribution to a broader ecological context, one that identifies them as High Nature Value ancient olive orchards [24]. These systems involve the implementation of low-intensity cropping methods [25], diverse land cover, and semi-natural vegetation, often accompanied by various ecological infrastructures such as terraces and dry-stone walls [26; 27]. These practices aim to achieve multiple objectives, including the maintenance and enhancement of soil quality [28], erosion mitigation [29], water resource conservation [30], and the facilitation of carbon sequestration [31; 32]. Furthermore, they hold immense economic significance in the Mediterranean region and beyond as the primary source of olive oil production, vital for the economies of many Mediterranean countries through its agricultural and export sectors, while also playing an integral role in the cultural heritage of these regions [7; 8]. Additionally, they play a crucial role in supporting and sustaining high levels of biodiversity [33; 34]. Coupled with their ecological significance, delving into the intricate physiology of centennial olive trees reveals a complex interplay between their unique adaptations and their pivotal role in these biodiverse ecosystems. Regarding their physiology, olive trees, distinguished by their longevity and slow growth [35], undergo significant changes and adaptations throughout their extended lifespans which are intrinsically linked to the tree's unique growth and defense mechanisms, which have evolved over centuries to ensure their survival, longevity, and resilience. Essentially, like the majority of tree species, olive trees activate a wide range of defense strategies, which encompass the synthesis of chemical compounds deterring wood-decaying fungi and bacteria to protect against threats such as injuries, infections, and decay as they age [36]. While these defenses effectively safeguard the structural integrity of the tree, they may concurrently culminate in the eventual formation of deep grooves and cavities within their trunks, as the tree resists decay-inducing agents [37]. Specifically, when olive trees encounter injuries or infections, they exhibit an extraordinary ability to compartmentalize and sequester these affected areas [37; 38]. This process entails the creation of both physical and chemical barriers, preventing the proliferation of pathogens and decay agents throughout the tree [39]. Over time, these sequestered zones can evolve into profound grooves and cavities as the tree continues its growth around them.