Search results for "VEGETATION"

Mixing processes in vegetated rivers: experimental investigation in a laboratory flume

2018

The presence of vegetation in rivers exerts an important ecological function and is very important to maintain suitable habitat. Especially in recent years, some researchers (among others Perrucca et al., 2007) have focused their attention on the role of vegetation in channel’s morphodynamics. Alteration of hydrological conditions in fluvial systems inevitably leads to changes in river morphology, riparian or riverbed vegetation and ecosystems. Riparian vegetation distribution could also change in time and in space depending on the combination of factors affecting the settling and growth of vegetated elements. In the present paper attention is focused on the turbulent and mixing processes i…

Is it possible to understand a book missing a quarter of the letters? Unveiling the belowground species richness of grasslands

2022

Abstract Knowledge of species richness patterns in plant communities is biased toward its hidden belowground part and is derived only from the part visible aboveground. Studies on the relationship of the above- to belowground parts of plant communities suffer from the lack of a consistent and uniform approach to assess their taxonomic composition, particularly in species-rich ecosystems. This study described the proportion between above- and belowground parts of vegetation in three grassland types along with the environmental factors that affect them, using eDNA metabarcoding and an observer survey. The internal transcribed spacer 2 (ITS2) region was used to analyze the total plant richness…

Experimental investigation on the role of vegetation on sediment transport mechanism: review of recent results

2012

Germination Pattern of Chamaerops humilis Seed after Short-Time Storage

2015

Dwarf fan palm (Chamaerops humilis) plays an important ecological role in the thermo Mediterranean vegetation stage, both in woodlands, xerophitic shrub communities and degraded ecosystems. Dwarf fan palm is typically propagated from seeds. Whereas other palm species show reduced germination after few months of seed storage, no information is available on the effects of storage time on seed germinability . We examined the germination pattern of dwarf palm seeds aged after a storage of four, six or eight months in comparison to fresh seed (control). A covariance analysis was performed to test the effect of time within seed-storage treatment. The germination patterns were significantly fitted…

Verità e menzogna dei simboli

2008

Cosa sono e come funzionano i simboli? Quali sono i meccanismi di trasmissione dell’immaginario, i suoi spazi e la sua rilevanza sociale? Quali il ruolo e il perimetro del sacro, del mito, del rito, della magia e della religione in certi ambiti, erroneamente percepiti come marginali, della società contemporanea? Quali le strategie di trasmissione della memoria culturale e i processi di produzione e riproduzione dell’identità comunitaria? I saggi riuniti in questo volume cercano di fornire alcune risposte a questi interrogativi confrontandosi con la pervasiva, sebbene non di rado occulta, dialettica culturale tra immanenza e trascendenza e indagando sulle dinamiche psicologiche e sociali del…

Vegetation series as a marker of interactions between rural settlements and landscape: new insights from the archaeological record in Western Sicily

2020

[EN] Plant communities are complex and dynamic elements of the landscape, intertwined with both natural factors and human activities. Vegetation series reflect the environmental characteristics of the landscape, but also the anthropic impact, one of the exogenous forces that most profoundly affects the landscape formation process. This paper aims to investigate the interactions between long-term human settlement catchment areas and vegetation series. The case study area of the Sicani Mountains (Central-Western Sicily) proved to be an ideal place to perform GIS-based spatial analysis in order to compare a data set of rural archaeological sites and land units created through the mapping of ve…

The ecology of the cork-oark (Quercus suber L.) stands in NW Sicily

2017

The uneven presence of the cork oak (Quercus suber L.) within its distribution range seems to be affected not only by its climatic requirements but also by rather specific edaphic needs. In fact, most of the known populations throughout the Mediterranean area thrive on acidic soils deriving from metamorphic or volcanic rock outcrops. However, some Italian populations of this species behave as if they were independent on the chemical and physical characteristics of the substrate, e.g. growing on calcareous soils, which are considered less suitable. This is the case of some populations in central Italy (Latium) and NW Sicily (Trapani Mts. and Palermo Mts.). A multidisciplinary investigation c…

Database Species-Area Relationships in Palaearctic Grasslands

2012

The Database Species-Area Relationships in Palaearctic Grasslands (GIVD ID EU-00-003) is an initiative of the European Dry Grassland Group (EDGG) and primarily functions as repository for all data sampled during the EDGG Research Expeditions. During these expeditions two types of highly standardised sampling of dry grassland vegetation in the Palaearctic realm are carried out: (i) nested-plot sampling on squares of 0.0001, 0.001, 0.01, 0.1, 1, 10, and 100 m2; (ii) additional normal releves of 10-m2 plots. For all plot sizes, the terricolous vascular plants, bryophytes, and lichens are recorded that are superficially present (shoot presence). Additionally, for all 10-m2 plots species cover i…

Relaciones suelo-vegetación en una toposecuencia del Escudo Guayanés, Venezuela

2014

El Escudo Guayanés es uno de los territorios más antiguos del planeta; tiene millones de años sometido a procesos de lixiviación y erosión que dejan suelos oligotróficos. El objetivo de este trabajo fue hacer la caracterización de los parámetros físicos y químicos de los suelos, en diferentes comunidades boscosas de la Reserva Forestal Imataca, e identificar ciertas relaciones entre los componentes edáficos y las especies que allí se presentan. Se realizó un inventario de todos los individuos mayores a 10cm dap (diámetro a la altura del pecho) en 15 parcelas (1ha); en cada una de esas parcelas se evaluaron cuatro sub-parcelas de sotobosque (100m²) para contabilizar todas las espermatofitas;…

Mapping soil water content under sparse vegetation and changeable sky conditions: comparison of two thermal inertia approaches

2013

A critical analysis of a thermal inertia approach to map surface soil water content on bare and sparsely vegetated soils by means of remotely sensed data is reported. The study area is an experimental field located in Barrax, Spain. In situ data were acquired within the Barrax 2011 research project. An advanced hyperspectral scanner airborne imager provides images in the visible/near-infrared and thermal infrared bands. Images were acquired both in day and night times by the Instituto Nacional de Técnica Aeroespacial between 12th and 13th of June 2011. The scene covers a corn irrigation pivot surrounded by bare soil, where a set of in situ data have been collected both previously and simult…