Search results for "plant community"
showing 10 items of 117 documents
Reliability and effectiveness of Ellenberg’s indices in checking flora and vegetation changes induced by climatic variations
2001
Two methods are proposed to assess the significance of time-spanned local variations of Ellenberg’s indicator values in floristic and phytosociological data sets respectively. Both methods are based on frequencies and averages of the indicator values within and among data sets. Main goal of proposed methods is to determine the threshold above which the observed variations are to be considered significant. In order to relate the observed floristic variations to recent climatic changes, attention was focused on the Ellenberg’s indices dealing with the main climatic variables: heliophany, temperature and precipitation. Study-cases from Zannone Island (Pontine Archipelago, Mediterranean region)…
Multi-Temporal Soil Salinity Assessment at a Detailed Scale for Discriminating Halophytes Distribution
2016
A multi-temporal survey of soil salinity in a salt lake, recolonized by halophytes, was performed using electromagnetic induction (EMI) providing volume integrated values of soil apparent electrical conductivity (ECa). Inventories of plant communities were recorded according to the Braun-Blanquet method. In each of six areas monospecific with Suaeda vermiculata, Suaeda vera, Sarcocornia fruticosa, or Arthrocnemun macrostachyum, ECa was measured intensively in two seasons. Mean and range of ECa differ for each plant community. Soil was sampled in the six areas and analyzed for ion composition of the soil saturated paste extract. The electrical conductivity of the saturated paste extract (ECe…
Ecological aspects of plants inhabiting Mediterranean cliffs. Challenges and prospects of life in vertical environments
2021
[ES] Esta tesis investiga las oportunidades, desafíos y limitaciones para la investigación en el campo de la ecología vegetal, en el contexto de los acantilados mediterráneos. En concreto, las especies casmofiticas, cuyos hábitats naturales se caracterizan por su acusada pendiente. Las laderas de las montañas de piedra caliza en la proximidad del mar, en la parte central y occidental del área mediterránea se consideran objetos de estudio. Los estudios se llevaron a cabo en los cinturones costeros de montaña de las costas del noroeste de Sicilia y la costa diánica en la Comunidad Valenciana. El primer capítulo, titulado "The complexity of environmental factors: cliff microclimate", investiga…
Trying to link vegetation units with biomass data: the case study of Italian shrublands
2014
Although their carbon stock is relevant in assessing the baseline for the negotiation of future agreements with respect to carbon balance, there still are few available studies concerning the biomass and the net ecosystem exchange capacity of Mediterranean shrublands. In this chapter a preliminary overview on the biomass values concerning Italian shrubland communities and/or their dominant/ characteristic woody species is provided. Many useful data on above- and belowground biomass issued from investigations carried out in other Mediterranean countries and concerning plant communities, which share the same ecological, floristic and structural traits of Italian shrublands. A preliminary find…
Reviving extinct Mediterranean forest communities may improve ecosystem potential in a warmer future
2015
The Mediterranean Basin is the region of Europe most vulnerable to negative climate-change impacts, including forest decline, increased wildfire, and biodiversity loss. Because humans have affected Mediterranean ecosystems for millennia, it is unclear whether the region's native ecosystems were more resilient to climate change than current ecosystems, and whether they would provide sustainable management options if restored. We simulated vegetation with the LandClim model, using present-day climate as well as future climate-change scenarios, in three representative areas that encompass a broad range of Mediterranean conditions and vegetation types. Sedimentary pollen records that document n…
Tertiary relict laurophyll vegetation in the Madonie mountains (Sicily)
2014
Laurel woodlands in the Madonie mountains (Sicily) are characterized by the presence of Laurus nobilis, Rhamnus lojaconoi and Vitis vinifera subsp. sylvestris. The results of a phytosociological study are presented, and a new endemic association, Rhamno lojaconoi–Lauretum nobilis, is described. Present Mediterranean laurel communities are the result of an adaptive response by Tertiary laurel forest to the peculiar microclimatic conditions that characterize the refugia where they persist. These refugia have been recently considered as a priority habitat under the Directive 92/43/EEC, and their plant communities are very vulnerable. Protection measures of the studied laurel populations are ne…
Opportunistic Germination Behaviour of Gypsophila (Caryophyllaceae) in Two Priority Habitats from Semi-arid Mediterranean Steppes
2011
Gypsophila tomentosa and G. struthium are closely related species, characteristic of two European priority habitats, salt and gypsum inland steppes, respectively. Germination strategies of the two taxa were investigated in plants from two nearby populations, growing under the same climatic conditions but on different types of soil, and belonging to different plant communities. Their germination patterns were studied at five constant temperatures in darkness: 5oC, 10oC, 15oC, 20oC and 25oC, and the base temperature and the thermal time requirement were calculated. As the distribution area of both species is subjected to a Mediterranean continental climate with significant differences between…
Weevils (Coleoptera: Curculionoidea) of the Stobrawski Landscape Park
2011
Weevils (Coleoptera: Curculionoidea) of the Stobrawski Landscape ParkThe work presents the results of faunistic and ecological studies on the weevils (Coleoptera: Curculionoidea without Scolytinae) of the Stobrawski Landscape Park. Between 2006-2008 more than 4 000 specimens representing 285 species of weevils were collected from nine types of plant communities.Mesotrichapion punctirostre, Nanophyes brevis, Otiorhynchus lepidopterus, Phytobius leucogaster, Rhaphitropis marchicuswere collected for the first time in Lower or Upper Silesia. The geographical, habitat and food preferences of particular species are presented. The relationships between weevil species and the different habitats are…
Bacterial and Archaeal Communities Change With Intensity of Vegetation Coverage in Arenized Soils From the Pampa Biome
2019
Arenization occurs in regions that present sandy soils with normal rainfall levels. Predatory use of environmental sources, the dissolution of arenitic rocks and reworking of non-consolidated surface sands intensify this degradation scenario. Thus, this work aimed to evaluate the impact of the arenization process in the Brazilian Pampa Biome and how this phenomenon affects the soil microbial and plant communities. For this purpose, three arenized areas in Southern Brazil (Pampa Biome) were selected and, in each one, three sampling points were studied: arenized (ARA), arenized to grassland transition (AGT), and grassland (GRA) areas. In the three sampling points, soils presented low levels o…
Vegetation of rock crevices of the montane and colline zones in the Pamir-Alai and Tian Shan Mts in Tajikistan (Middle Asia)
2014
The paper presents the results of phytosociological research conducted on the vegetation of rock habitats in the montane and colline zones of the Pamir-Alai Mountains (Tajikistan). During field surveys done in 2010–2013, 122 phytosociological releves were sampled. Plant species were recorded according to the Braun-Blanquet cover-abundance scale. The vegetation studies were carried out generally in the western Pamir-Alai and south-western Tian Shan Mts, especially in the Zeravshan, Hissar, Hazratishoh, Darvaz, Rushan, Turkestan, Kuramin and Vanch ranges. A synopsis of the rock communities of the montane and colline zones in Tajikistan is proposed. The collected material presents most of the …