Ecology and niche assembly of campanula tommasiniana, a narrow endemic of mt učka (Liburnian Karst, north-western Adriatic)

Abstract

-Campanula tommasiniana is a typical chasmophyte occupying calcareous rock crevices and cracks along a wide range of ecological gradients, demonstrating a high degree of ecological plasticity and stress tolerance with regards to abiotic factors. Generally, three ecologically and floristically distinct groups of stands were recognized and typified according to a sigmatistic approach: (a) Seslerio juncifoliae-Campanuletum tommasinianae ass. nov., with stands occupying higher elevated sites fully exposed to sun and strong winds; (b) Seslerio autumnalis-Campanuletum tommasinianae ass. nov., representing stands predominantly developed within thermophytic beech stands, semi-to fully--shaded by the tree canopy; (c) Cystopteri fragilis-Campanuletum tommasinianae, sciophytic, stands adapted to moisture and cold with high frequency and coverage of bryophytes. Results of DCA analyses using a unimodal model suggest that Campanula tommasiniana is primarily a plant of open and exposed sites of higher elevation despite being most frequently found in rock crevices within thermophytic and altimontane beech forests.

An innovative vegetation survey design in Mediterranean cliffs shows evidence of higher tolerance of specialized rock plants to rock climbing activity

“…Cliff ecosystems sustain plant species specialized for dwelling within rock balconies, including chamaephytes that colonize the most restrictive rocky microhabitats, as well as some generalist species that are not specifically adapted to cliffs but are able to establish in rupicolous habitats under certain circumstances (Davis, ; Escudero, ). However, the life histories of these species are remarkably different; while specialist rock plants have developed stress‐tolerant traits to survive adverse abiotic factors (De Micco & Aronne, ; Surina & Martinčič, ), less adapted plants are more sensitive to stressful environmental conditions and, hence, may be more vulnerable to external impacts. Mediterranean cliff microhabitats and their occupants contribute substantially to biodiversity in temperate regions, highlighting the conservation value of the cliff habitats.…”

Germination behavior of the extremely rare Hladnikia pastinacifolia Rchb. (Apiaceae) – a Pleistocene in situ survivor

“…Such habitats, when they exhibit high irradiation and simultaneous gaps in vegetation cover, are characterized by the ability to host species with weak competitive potential because of slow succession (Černý et al 2006). Similarly, the stenoendemic obligate chasmophyte Campanula tommasiniana (Surina 2013) is expected to have low biotic competitiveness, but this is in a way compensated with species' remarkable plasticity to tolerate various abiotic conditions (Surina and Martinčič 2014). The first indication that H. pastinacifolia has low competitive and low establishment potential in its habitats is the previously mentioned high germination rate of both seed types, which prevents seed accumulation in the soil seed bank to ensure persistence of the species over time.…”