Conservation of Mediterranean oak woodlands: understorey dynamics under different shrub management

The effect of experimental disturbances on the dynamics of a shrub community was studied on a ‘Montado’ ecosystem, in southern Portugal. The evolution of the community physiognomy, composition and diversity were monitored after shrub clearing followed by biomass removal, deposition on soil surface and incorporation with the soil, over a 9-year period. Maximum shrub density was recorded in the first year after the disturbances, excepting in mulched plots which showed the greatest number of individuals 1 year later. The increment of shrub leaf biomass was very fast in the first 3 years, whereas wood production was slower but occurred along the whole study period. At the end of the study, leaf and wood biomass was still significantly lower than in the predisturbance situation. The variation pattern of leaf area index was similar to that of leaf biomass. The evolution of total plant cover and diversity was similar across treatments. The highest species richness and diversity were recorded 2 years after cutting, decreasing afterwards with the increasing dominance of shrubs. Thus it seems likely that, although a 9 year period is too short for these communities to reach steady equilibrium, they are very resistant and resilient to disturbances, as regeneration was fast and vegetation dynamics was not influenced by differences among treatments. We can conclude that shrub clearing promotes biodiversity and the time of permanence of shrub patches depends on the particular goal we want to achieve

Conservation of Mediterranean oak woodlands: understorey dynamics under different shrub management

The effect of experimental disturbances on the dynamics of a shrub community was studied on a ‘Montado’ ecosystem, in southern Portugal. The evolution of the community physiognomy, composition and diversity were monitored after shrub clearing followed by biomass removal, deposition on soil surface and incorporation with the soil, over a 9-year period. Maximum shrub density was recorded in the first year after the disturbances, excepting in mulched plots which showed the greatest number of individuals 1 year later. The increment of shrub leaf biomass was very fast in the first 3 years, whereas wood production was slower but occurred along the whole study period. At the end of the study, leaf and wood biomass was still significantly lower than in the predisturbance situation. The variation pattern of leaf area index was similar to that of leaf biomass. The evolution of total plant cover and diversity was similar across treatments. The highest species richness and diversity were recorded 2 years after cutting, decreasing afterwards with the increasing dominance of shrubs. Thus it seems likely that, although a 9 year period is too short for these communities to reach steady equilibrium, they are very resistant and resilient to disturbances, as regeneration was fast and vegetation dynamics was not influenced by differences among treatments. We can conclude that shrub clearing promotes biodiversity and the time of permanence of shrub patches depends on the particular goal we want to achieve

Socio-Ecological Perceptions of Wildfire Management and Effects in Greece

Adapting to the growing frequency of catastrophic wildfires in Greece and mitigating their effects is a complex socio-ecological problem. We used an online survey to query more than 100 engaged stakeholders who can potentially influence possible legislation and fire management organizational reform, emphasizing civil protection agencies and research entities. We focused the questionnaire on the importance of different wildfire effects to understand which were considered negative or unacceptable, indifferent, or positive. For fire prevention, we examined the range of acceptance and views on fuel management and fire use activities that are limited in extent or not allowed in Greece. We also examined the beliefs regarding ignition causes and responsibility, in addition to how different policies might reduce wildfire-related problems. The results revealed an emphasis on reforming wildfire management policies to deal with the way society and agencies function and interact, and mitigate the influence of climate change in wildfire frequency and behavior. In addition, respondents had a negative stance towards allowing wildfires to burn for resource objectives and a strong belief that arsonists are behind most ignitions. They also believe the lack of a national cadaster system is a major source of wildfire-related problems. The results indicate little support for fuel treatments, but increased acceptance for the legalization of fire use during firefighting (backfires). This study summarizes current wildfire perceptions in Greece and identifies opportunities and barriers to changes in wildfire governance to improve risk management programs and guide post-fire management and mitigation

Abiotic and biotic patterns across Mediterranean coastal wetland systems, North East Aegean, Greece

1 - Coastal wetlands are regarded as transitional ecosystems regulating fluxes of materials and energy between the land and the sea and are protected habitats under the NATURA 2000 European network of protected areas. Description of spatial heterogeneity in abiotic and biotic constituents of coastal wetland systems is a prerequisite for the establishment of long-term monitoring programs and a first step in elucidating their functional role in the landscape; both of particular significance to management. Spatial variability of water and substratum physicochemical variables and of substratum macroinvertebrate fauna composition and abundance across five sea-coastal wetland-land systems, Kalloni bay, Lesvos Island, Greece, were quantified during the growing season of 2005. 2 - The studied coastal wetlands develop on an alluvial flat plain of mineral soils as indicated by low values of percent organic matter, circumneutral pH, and high values of bulk density. Trends in physicochemical variables of substratum varied among the five coastal wetland systems studied even when the same variable was examined. Canonical discriminant analysis indicated that the most important substratum physicochemical variable in differentiating among the sea-wetland-land units of the studied gradients was electrical conductivity (salt influence) in four out of the five coastal wetland systems. Total nitrogen concentration of substratum was the only variable among the ones studied which was related positively either with total phosphorus concentration or/and percent organic matter of substratum in all wetland systems studied; the highest values occurred where vegetation was present. 3 - Distribution and abundance of substratum macroinvertebrate taxa across the sea-wetland-land gradients studied reflected the interaction between the marine and terrestrial environment. Gasteropoda, bivalvia and schaphopoda were found in higher abundances at sea and sea-influenced stations, which gradually decreased towards the land. On the other hand, insecta appeared at stations further away from the shore and their abundance progressively increased towards land. Gasteropoda and insecta were the taxa responsible for the identification of at least three clusters of stations across all five coastal systems studied. Two clusters contained clearly "terrestrially-influenced" or "sea-influenced" stations while intermediate clusters contained stations with varying degree of salt influence. 4 - Distribution and abundance of gasteropoda and insecta, however, were found to be directly related to nutrient status and not to electrical conductivity of substratum

Hypotheses, mechanisms and trade-offs of tolerance and adaptation to serpentine soils: from species to ecosystem level

International audienc

Induction of Seed Germination in Cistus heterophyllus (Cistaceae): A Rock Rose Critically Endangered in Spain

Seed germination from the only European population of the Iberian-North African endemism Cistus heterophyllus Desf. was studied by using germination inducing pretreatments. A seeding-cultivation method with flowerpots in a greenhouse was also tested and compared with the usual germination method using Petri dishes in a growth chamber. Seeds were collected in three different years. Germination percentages ca. 43% were obtained without pretreatment. This can be considered a high percentage in the genus Cistus and abnormally large for an isolated population composed by only nine individuals. A large variability in seed germination was found among the samples from the same population collected in different years. The dry-heat pretreatment (87 ±3 °C for 12 min and soaking in water at 20 °C for 48 h) significantly increased the germination percentage, reaching 81.5%. Germination in greenhouse was as effective as in growth chamber. The seeds maintained their viability until at least 6 years after collection and storage in a dry atmosphere at laboratory temperature. These results mean the first contribution to the germination ecophysiology of this species and they are fundamental to the recovery plan of the last remnant population of C. heterophyllus in Spain.Peer reviewe