The plants of the Park

The park is located on an abandoned olive grove that was affected by the September 2018 fire. Its current vegetation is the result of spontaneous recolonization and targeted interventions carried out by volunteers from the Agroecology Office of Calci.

Fires, mainly of anthropogenic origin, have been and continue to be among the main factors of ecological disturbance on Monte Pisano; it has been estimated that from the 1970s to the present day, only about 10% of the surface area of Monte Pisano has not been affected by fire. Fires have so strongly influenced the appearance of the mountain that many current vegetational formations have evolved under the selective pressure of fire, and they are dominated by PYROPHYTE species, which are capable of resisting or even benefiting from fire. Many of these species are also more or less acid-loving, meaning they prefer acidic soils that develop after a fire.

In the upper part of the park, there is a grove consisting of cork oak trees (Quercus suber L.) (in the photos). To increase the forested area, starting from the autumn of 2021, other cork oaks, holm oaks (Quercus ilex L.), downy oaks (Quercus pubescens Willd.), and strawberry trees (Arbutus unedo L.) have also been planted. These three oak species are characteristic of the sunniest terrains of Monte Pisano. In particular, the cork oak is a steno-Mediterranean evergreen species typical of the shrubland and a pyrophyte which, thanks to the thick insulating layer of cork, possesses the extraordinary ability of aerial regrowth in the event of a canopy fire.

After the fire, various hardy shrub species typical of the Mediterranean shrubland have spontaneously regrown, including tree heath (Erica arborea L.), myrtle (Myrtus communis L.), rockrose (Cistus salviifolius L.), phillyrea (Phyllirea latifolia L.), and wild asparagus (Asparagus acutifolius L.); and the laurel (Laurus nobilis L.) has spread significantly, most likely introduced by humans in the past on the property. Among these species are some important pyrophytes that have also contributed to the recolonization of other areas of Monte Pisano affected by fires: rockroses produce many seeds that greatly increase germinability when subjected to the heat of fire; tree heaths regenerate from underground parts, even if the external parts are completely burned, and asparagus quickly regrows new stems after a fire, thanks to the well-protected underground rhizomes.

All these species have invaded the abandoned olive grove, creating a highly varied environment. In the winter of 2023, additional hardy species typical of the shrubland environments of Monte Pisano were introduced to increase biodiversity and restore some areas damaged by the fire. These include wild lavender (Lavandula stoechas L.), wild roses (Rosa sempervirens L. and Rosa canina L.), red rockrose (Cistus creticus L. subsp. eriocephalus (Viv.) Greuter & Burdet), Mediterranean honeysuckle (Lonicera implexa Aiton), and three important nitrogen-fixing legumes (Fabaceae family): Spanish broom (Spartium junceum L.), Scotch broom (Cytisus scoparius (L.) Link), and hairy broom (Cytisus villosus Pourr.).

The impenetrable tangles of common blackberry (Rubus ulmifolius Schott) have been contained and limited to the border strips with the surrounding lands, along with rough bindweed (Smilax aspera L.), another climber typical of abandoned lands. It was not deemed necessary to eliminate them completely, also because these plants produce fruits that are appetizing to many animal species, and they create intricate environments that provide good shelter for various bird species and other small animals.

Dry-stone walls are the ideal environments to observe the succession of pioneer species. The first colonizers are always lichens, extraordinary examples of symbiosis between fungi and very small autotrophic organisms (algae or cyanobacteria), capable of attaching themselves to any type of substrate, including metals and bare rocks. They are followed by mosses (bryophytes), very simple and undemanding plants, then ferns (pteridophytes), and flowering plants (angiosperms). Both lichens and mosses are able to endure long periods of drought by losing much of their water, thanks to a survival strategy called anhydrobiosis. On the walls of the park, there are sweet ferns (genus Polypodium), other small ferns belonging to the genus Asplenium, and various flowering plants adapted to rocky environments, including common fumitory (Fumaria officinalis L.) and two true succulent plants* belonging to the Crassulaceae family: navelwort (Umbilicus rupestris (Salisb.) Dandy) and sedum (Sedum dasyphyllum L.).

*Succulent plants, or more correctly succulents, are plants with special tissues called water-storing parenchyma that allow them to store large amounts of water as a survival strategy in arid environments.

The olive tree (Olea europaea L.) is the quintessential Mediterranean plant! The Mediterranean area is defined based on where the olive tree grows. In Italy, the olive tree has been cultivated for its valuable oil since Etruscan times (7th-6th century BC) and is now widely spread in hilly areas, becoming a characteristic element of the landscape. On Monte Pisano, olive groves are terraced and cover a large part of the lower area, from the foothills up to about 300-350 meters above sea level. In the foothill area, the oldest olive groves are found, and indeed, larger trees can be seen here. As one goes higher, more recent plantations with smaller trees can be found. The plantations were not created by grafting but rather historically with local cuttings, and more recently with saplings, meaning that after each fire, the same qualities destroyed by fire regenerate from the stumps. The predominant cultivar is Frantoio, interspersed with sporadic Moraiolo and, in the oldest olive groves, Leccino trees for pollination. In the rare, more recent plain olive groves, more resistant Leccino trees have also been introduced, as they are better suited to humid conditions.
The high quality of the oil obtained from these olive trees is clear evidence of the sound agroecological choices made in the plantations on Monte Pisano! The olive trees in the park, after being affected by the fire in September 2018, are regrowing from the stumps while maintaining the same qualities as the ancient plantings, demonstrating the extraordinary resilience of these plants to repeated fire events. The olive trees in the park have been thinned, pruned, and spaced out to restore the characteristics of a productive olive grove. In the photos, an example of an olive tree before and after cleaning.

The park’s meadow is mowed only twice a year, in May and September, according to the principles of Agroecology, in order to protect both plant and animal biodiversity, especially that of pollinating insects which find the meadow environment to be an ideal place for shelter, feeding, and reproduction. Additionally, some lateral strips are left to grow completely naturally to ensure the flowering of all present herbaceous species. Like all meadows on Monte Pisano, the park’s meadow features numerous herbaceous species belonging mainly to the following families: Fabaceae (legumes), Poaceae (grasses), Asteraceae (composites), and Apiaceae (umbellifers), which, after the fire, rapidly recolonized the terrain. Some species typical of abandoned lands have particularly spread: sticky fleabane (Dittrichia viscosa (L.) Greuter), black nightshade (Solanum nigrum L.), great mullein (Verbascum thapsus L.), milk thistle (Galactites tomentosus Moench), common thistle (Cirsium vulgare (Savi) Ten.), field marigold (Glebionis segetum (L.) Fourr.), dyer’s chamomile (Cota tinctoria (L.) J. Gay), common fumitory (Fumaria officinalis L.), common poppy (Papaver rhoeas L.), prickly poppy (Papaver setigerum DC.), and Puglian tordylium (Tordylium apulum L.), an umbellifer. The resurgence of legumes has been very important, represented in the park by species such as spotted medick (Medicago arabica (L.) Huds.) and hop trefoil (Trifolium campestre Schreb), because, being nitrogen-fixing, they are able to colonize even poor soils and enrich them with nitrogen, making them suitable for colonization by other plant species.

One of the most striking aspects of the park is its changing colors throughout the year. Evergreen species such as laurel, olive, cork oak, tree heath, and rockrose guarantee shades of green throughout the year, complemented by the colors of various blooms that begin in late winter with the white and highly fragrant flowers of tree heath. In spring, the yellows of the field marigold, dyer’s chamomile, broom, and cytisus stand out; various shades of white from the female rockrose and roses, scarlet from the milk thistle, violet from wild lavender, red from the common poppy, and pink from the large prickly poppy and red rockrose. During the summer, many yellow flowers remain, along with the violet of the common thistle and the gold of dried-out grasses. At the end of summer, the yellow flowers of sticky fleabane start to bloom and continue until November, providing an important food source for bees during a period when flowers start to become scarce. In winter, the park comes to life with the red berries of rough bindweed and strawberry trees, as well as the false fruits (called hips) of roses.

Further Reading: la vegetazione del Monte Pisano.

S. Sorbi & P. Scaglia (2019) “I tesori del Monte Pisano II. Le piante e i funghi” Pacini Editore, Pisa.