Tissue Distribution and Biochemical Changes in Response to Copper Accumulation in Erica australis L.

Copper uptake, accumulation in different tissues and organs and biochemical and physiological parameters were studied in Erica australis treated with different Cu concentrations (1, 50, 100 and 200 µM) under hydroponic culture. Copper treatments led to a significant reduction in growth rate, biomass production and water content in shoots, while photosynthetic pigments did not change. Copper treatments led to an increase in catalase and peroxidase activities. Copper accumulation followed the pattern roots > stems ≥ leaves, being roots the prevalent Cu sink. Analysis by scanning electron microscopy coupled with elemental X-ray analysis (SEM–EDX) showed a uniform Cu distribution in root tissues. On the contrary, in leaf tissues, Cu showed preferential storage in abaxial trichomes, suggesting a mechanism of compartmentation to restrict accumulation in mesophyll cells. The results show that the studied species act as a Cu-excluder, and Cu toxicity was avoided to a certain extent by root immobilization, leaf tissue compartmentation and induction of antioxidant enzymes to prevent cell damage.

New Contributions to the Ericion umbellatae Alliance in the Central Iberian Peninsula

The study of heathlands dominated by Erica australis, E. umbellata and Cistus populifolius in the centre and west of the Iberian Peninsula allows us to separate the eight shrubland communities. The taxonomic analysis of E. australis distinguishes two subspecies: E. australis subsp. australis and E. australis subsp. aragonensis. The statistical treatment confirms the differences between the suballiances Ericenion aragonensis and Ericenion umbellatae. This ecological, bioclimatic, biogeographical and floristic study has allowed us to differentiate three new associations from the remaining five: TCp = Teucrio oxylepis-Cistetum populifolii nova. HEau = Halimio ocymoidis-Ericetum australis nova. DEu = Drosophyllo lusitanicae-Ericetum umbellatae nova. ECp = Erico australis-Cistetum populifolii Rivas Goday 1964. PCp = Polygalo microphyllae-Cistetum populifolii Rivas Goday 1964. HEa = Halimio ocymoidis-Ericetum aragonensis Rivas-Martínez 1979. HEu = Halimio ocymoidis-Ericetum umbellatae Rivas Goday 1964. UEu = Ulici eriocladi-Ericetum umbellatae.

Optimization of an Ultrasound-Assisted Extraction Method for the Analysis of Major Anthocyanin Content in Erica australis Flowers

Erica australis plants have been used in infusions and folk medicine for years for its diuretic and antiseptic properties and even for the treatment of infections. In addition, a recently published thorough study on this species has demonstrated its antioxidant, antibiotic, anti-inflammatory, anticarcinogenic and even antitumoral activities. These properties have been associated with the high content of anthocyanins in E. australis leaves and flowers. The aim of the present research is to optimize an ultrasound-assisted extraction methodology for the recovery of the anthocyanins present in E. australis flowers. For that purpose, a Box Behnken design with response surface methodology was employed, and the influence of four variables at different values was determined: namely, the composition of the extraction solvents (0–50% MeOH in water), the pH level of those solvents (3–7), the extraction temperature (10–70 °C), and the sample:solvent ratio (0.5 g:10 mL–0.5 g:20 mL). UHPLC-UV-vis has been employed to quantify the two major anthocyanins detected in the samples. The extraction optimum conditions for 0.5 g samples were: 20 mL of solvent (50% MeOH:H2O) at 5 pH, with a 15 min extraction time at 70 °C. A precision study was performed and the intra-day and inter-day relative standard deviations (RSDs) obtained were 3.31% and 3.52%, respectively. The developed methodology has been successfully applied to other Erica species to validate the suitability of the method for anthocyanin extraction.

Changes of Species Richness in Heathland Communities over 15 Years following Disturbances

The aim of this study was to define the species richness patterns over a period of 15 years during the vegetation recovery process after disturbances (burning, cutting and ploughing) in heathlands. Three communities were selected: two dominated byErica australisand one dominated byCalluna vulgaris. The alpha and gamma diversity patterns were site specific and influenced by the ecological traits of dominant shrub species. The shrubland dominated byErica australis, typical resprouters with a fast regeneration, showed the highest values of alpha and gamma diversity during the first 7 years of regeneration. The heathland dominated byCalluna vulgaris, an obligate seeder, had a contrasting pattern of alpha and gamma diversity, as the highest values appeared from year 7 until year 14. Thus, the speed of regeneration of the dominant shrub species could be the main factor affecting structural parameters in these communities. Species richness patterns did not vary in relation to the different types of perturbation. Cutting and burning would be the most suitable forestry management strategies to conserveErica australisheathlands, but burning is more appropriate inCalluna vulgarisones because cutting modified this community.