Clearing in pine woods

On sloping ground in a forest clearing are several well-established mastic bushes and between and around them small plants and young trees that have benefited from increased sunlight and less competition.

Whatever caused this opening up, the clearing is now in a state of succession. If the young pine trees dominate it will be subsumed in the surrounding dense pine woods, but if affected by fire, disease, or predation, conditions may favour hard-leaved plants such as kermes and holm oaks.

The small, leathery evergreen leaves of mastic reduce water loss. It is early summer and after heavy downpours in spring, there will be little rain for months. The previous week temperatures reached the mid thirties. These conditions suit mastic which is resilient in many locations but prefers to be oriented towards the sun (the slope faces south west) and on well-drained soil.

The plants will not fruit till late summer and only on female plants that have reached maturity (after seven years). The fruit (drupes) will be attractive to birds later in the year when resources are limited. In return, their seeds are widely dispersed as part of a mutualistic relationship.

Between the mastic bushes are common centaury (Centaurium erythraea), a biennial. Those in flower are in their second year. At the base of their stems many of the rosettes that developed in their first year have withered and died.

Both mastic and common centaury tolerate a range of environments and a variety of soils from alkaline to mildly acidic. Their ability to adapt to altered conditions is a trait of pioneer species in areas undergoing secondary succession. Mastic plants are slow growing and deep rooted but they must have been sufficiently well placed to spread out in the absence of trees blocking access to light. The common centaury, by contrast, is able to colonise new territory rapidly.

Another pioneer species is Arabian pea (Bituminaria bituminosa) which is numerous in the clearing though widely spread out. A single bee stopped at each plant, causing its flower head to bend momentarily under its weight. As a legume, Arabian pea can fix nitrogen, a biological process where root nodules form in response to symbiotic bacteria. Both pollination and nitrogen fixation are symbiotic relationships.

The rocky, shallow soil is limestone in the main with the odd piece of quartz or chert. Poor soil and hot summers favour deep rooted perennials and fast growing annuals that flower and seed in spring or early summer. One such plant found in the clearing is French lavender (Lavandula stoechas), most of which have already finished flowering. Lavender thrives in nutrient-poor, mineral-rich soils where other species may struggle.

Beneath the pine trees at the edge of the clearing needle litter lowers the soil's pH. Strawberry trees (Arbutus unedo), species in the genus Cistus, and acid-loving ferns, thrive in acidic conditions but none are present. The plants in the clearing all tolerate soils that are alkaline to mildly acidic.

The needle litter also contains allelopathic compounds further reducing understory diversity. The spiky nature of this mulch layer also acts as a partial barrier against predation from wild boar whose presence in the wider area is revealed by prints, scat and the numerous fine but clearly visible - and accessible - paths that cross the hillside.