Search results for "MORPHOLOGY"
showing 10 items of 1425 documents
What do leaf anatomy and micromorphology tell us about the psammophilous Pancratium maritimum (Amaryllidaceae) in response to sand dune conditions?
2015
Abstract The present study aimed at verifying the morphological variation in leaf traits among different populations of Pancratium maritimum (sea daffodil) and the correlation between leaf diversity and climate conditions at different sites. Eleven populations of P. maritimum from Mediterranean coastal sand dunes were investigated with respect to leaf surface micro-morphology, leaf anatomy, and vascular pattern. Morphometric analysis was based on 29 quantitative foliar parameters. One-way analysis of variance (ANOVA), principal component analysis (PCA), discriminant function analysis (DFA), and clustering by Ward’s method were used for the statistical evaluation. Results revealed a rather u…
Environmental conditions for gravelly and pebbly dunes and sorted bedforms on a moderate-energy inner shelf (Marettimo Island, Italy, western Mediter…
2008
12 pages, 11 figures, 1 table
Morphological observations on the co-occurring geophytes Isoetes duriei Bory (Lycophyta, Isoetaceae) and Romulea columnae Sebast. et Mauri (Anthophyt…
2003
Some preliminary observations on the morphoplogy and leaf anatomy of two geophytes, Isoetes duriei and Romulea columnae, co-occurring in a Mediterranean temporary pond, have been reported. The species examined possess characters favourable to the survival of both flooded and arid conditions. The adaptive traits to flooding appear plastic in R. columnae, while I. duriei is “structurally” an aquatic plant. Evolutionary and ecological aspects are briefly discussed.
Environmental Constraints on Pathways of Organic Detritus in a Semi-enclosed Marine System (W-Mediterranean)
2001
In order to assess seasonal and spatial changes in water-sediment interaction processes in a semi-enclosed marine system of Western Sicily (Marsala lagoon; W-Mediterranean), the biochemical composition of suspended and sediment organic matter was studied, during a one-year sampling period. The observed dynamic balance of resuspension vs. sedimentation processes and the macroalgal and vascular plant coverage appear major factors in affecting both amounts and biochemical composition of suspended and sedimentary organic matter and allowed us to identify two different sub-systems. The northern area, characterised by frequent wind-induced sediment resuspension events and by a scant vegetation, d…
HalocnemumM. Bieb. vegetation in the Mediterranean Basin
2013
The aim of the article is the syntaxonomic interpretation of hyperhalophilous woody or semi-woody vegetation with Halocnemum M. Bieb. along the coasts of the Mediterranean Basin. For this area, the two species of Halocnemum, H. strobilaceum (Pall.) M. Bieb. and H. cruciatum (Forssk.) Tod. are identified; their morphological characteristics, synonymy and distribution are here described. The study carried out of particular aspects of the plant morphology and the micromorphological characteristics of the seeds collected from different places in the Mediterranean allows to better differentiate the two species. Vegetation studies already done in many communities of the Mediterranean by several a…
Lluvias torrenciales y cambios geomórficos en una pequeña cuenca de montaña : el barranco de la Cuesta de la Vega (Valencia)
2013
In this paper the effects of great magnitude -450 mm.- as well as high continued intensity -> 90 mm. for 3h.- storm-rains have been studied for a small mediterranean drainage basin (Ayora, Valencia). Such rains caused anormal flows -between 11.2 y 38.2 m3/sec/km2- and the reactivation of erosiona! and aggradational processes, especially at flat bottomed valleys with terrace culture, where new channels were formed. Severa! types of deposits and erosiona! phenomena are established; among them valley amplitude, local slopes, culture abandonment (in a positive sense ), and valley floor terracing are pointed out.
Using topographical attributes to evaluate gully erosion proneness (susceptibility) in two mediterranean basins: advantages and limitations
2015
Empirical multivariate predictive models represent an important tool to estimate gully erosion susceptibility. Topography, lithology, climate, land use and vegetation cover are commonly used as input for these approaches. In this paper, two multivariate predictive models were generated for two gully erosion processes in San Giorgio basin (Italy) and Mula River basin (Spain) using only topographical attributes as independent variables. Initially, nine models (five for San Giorgio and four for Mula) with pixel sizes ranging from 2 to 50 m were generated, and validation statistics were calculated to estimate the optimal pixel size. The best models were selected based on model performance using…
Geomorphology of the Capo San Vito Peninsula (NW Sicily): An Example of Tectonically and Climatically Controlled Landscape
2017
The Capo San Vito peninsula is located along the north-westernmost sector of the Sicilian coastline. It is characterized by a complex geomorphological setting, where a large variety of coastal, gravity-induced and karst landforms allow the visitor to easily detect the interactions between Quaternary tectonics and climate changes as well as morphodynamic processes responsible for shaping the landscape. Thanks to natural reserves, the peninsula preserves a typical Mediterranean natural environment, marked by spectacular and suggestive landforms.
Relationships between a new slope morphometric index and calanchi erosion in northern Sicily, Italy
2012
The Italian badlands, or “calanchi”, are common landforms in Mediterranean areas including central and southern Italy. Calanchi landforms may be compared to small hydrographic basins. These landforms are characterised by dense, hierarchical and rapidly evolving drainage systems carved into steep clayey slopes and by a sharply alternating pattern of furrows and narrow, generally sharp crests. This work presents a study of morphometric characteristics and a statistical analysis for two sites in northern Sicily (Italy), on outcrops of silty-clay deposits affected by active erosion processes, which give this area a typical calanchi landscape. In particular, factors closely linked to the charact…
Study And Monitoring Of Salt Water Intrusion In The Coastal Area Between Mazara Del Vallo And Marsala (South-Western Sicily)
2007
In this chapter the study of a coastal aquifer located in South-Western Sicily (between the towns of Marsala and Mazara del Vallo) is presented, carried out using geochemical, hydro-geological and geophysical techniques. The aquifer has been over-exploited to the point of being subject to intense and worrisome salt-water intrusion. A preliminary chemical and physical characterization of the waters was carried out; this included measuring their conductivity and their chloride content. This allowed to detect the marine intrusion wedge in the coastal aquifer. A series of electromagnetic soundings, suitably calibrated by well logs, were effected in the whole area and allowed to create a 3D inte…