Search results for "Conservation"
showing 10 items of 2328 documents
Plant hunting: exploring the behaviour of amateur botanists in the field
2021
We asked what are the behavioural and logistic preferences of professional and amateur botanists when exploring flora in the field. We extracted temporal and spatial data on vas- cular plant species occurrences from three datasets of Sicilian flora: a subset of iNaturalist, a dataset collected by a Facebook group focused on the flora of Sicily and a subset of the professional database European Vegetation Archive. We used the time span of individual contributor’s activity as a proxy of their commitment to collecting information about the flora of Sicily. Climate and landscape data were used to better characterize the spatial and temporal activity of data contributors. Finally, we assessed wh…
Genetic diversity in Cytisus aeolicus Guss. (Leguminosae), a rare endemite of the Italian flora
1998
ABSTRACT Cytisus aeolicus Guss, is an endemic plant restricted to the isles of Vulcano, Stromboli and Alicudi in the Aeolian archipelago. All known populations were assayed for genetic variability using enzyme polymorphism. Allozyme variation at 16 loci coding for 10 enzyme systems was examined. The great majority of loci turned out to be monomorphic or fixed heterozygous. The observed genetic depauperation is indicative of historical factors, such as the bottleneck effect associated with migration, and the founder effect in population re-establishment. The low genetic diversity is largely partitioned within rather than among populations, indicating that extant populations have not been est…
A report on the conservation status of segetal weeds in Tajikistan
2014
Summary Intensification of agriculture has significantly diminished the populations of segetal weeds worldwide in recent decades. Remarkable changes to the entire flora and vegetation of man-made habitats are being observed in agroecosystems. The present study analyses, for the first time, the threat status of segetal weeds in Tajikistan. A group of 871 weed species were evaluated against IUCN criteria. The assessment of threat status revealed that 214 weed taxa have to be regarded as threatened in Tajikistan, including 18 endemic and four subendemic plants. Five species have been classified as extinct, 27 as critically endangered, 27 as endangered, 39 as vulnerable, 34 as near threatened a…
First record of Ribes uva-crispa L. (Grossulariaceae) from the Madonie Mts., a new species of the Sicilian flora.
2011
Abstract In this study, a first record of Ribes uva-crispa L. (Grossulariaceae) – a new species of the Sicilian flora – from the Madonie Mts. is reported. The autochthonous and relict new population of Ribes uva-crispa L. (Grossulariaceae) is found on Mount Carbonara (Madonie Mts., North-Central Sicily), which is several hundred kilometers away from the Central Apenninic and the South Mediterranean locations of its distribution range. R. uva-crispa shows a distribution similar to other taxa extending from the Euro-Asiatic area to the mountains of North Africa with disjunct populations on the main Sicilian reliefs (Madonie and Nebrodi Mts.), testifying ancient phytogeographical connections. …
Using the ARP-03 for high-resolution mapping of calcic horizons
2013
A b s t r a c t. The aim of this work is to present a fast and cheap method for high-resolution mapping of calcic horizons in vineyards based on geoelectrical proximal sensing. The study area, 45 ha located in southern Sicily (Italy), was characterized by an old, partially dismantled marine terrace and soils with a calcic horizon at different depths. The geoelectrical investigation consisted of a survey of the soil electrical resistivity recorded with the Automatic Resistivity Profiling-03 sensor. The electrical resistivity values at three pseudo-depths, 0-50, 0-100 and 0-170 cm, were spatialized by means of ordinary kriging. A principal component analysis of the three electrical resistivit…
A simple procedure to improve the pressure evaluation in hydrodynamic context using the SPH
2009
In literature, it is well know that the Smoothed Particle Hydrodynamics method can be affected by numerical noise on the pressure field when dealing with liquids. This can be highly dangerous when an SPH code is dynamically coupled with a structural solver. In this work a simple procedure is proposed to improve the computation of the pressure distribution in the dynamics of liquids. Such a procedure is based on the use of a density diffusion term in the equation for the mass conservation. This diffusion is a pure numerical effect, similar to the well known artificial viscosity originally proposed in SPH method to smooth out the shock discontinuities. As the artificial viscosity, the density…
Sensitivity of soil processes in northern forest soils: are management practices a threat?
2000
Abstract There is evidence that forest management practices influence soil-decomposer communities. It is also established that changes in the trophic structure and composition of these communities can induce changes in soil-nutrient dynamics, thereby affecting plant growth. Whether forest productivity is affected by management-induced changes in, e.g. soil faunal structure, is, however, yet to be shown. The aim of this study was (1) to determine the resolution of the ecological hierarchy (e.g. species, functional groups, trophic levels) at which a change in soil fauna would alter biotically-controlled processes in soils, and (2) to examine the sensitivity of soil fauna of the boreal forest …
Short-term responses of soil decomposer and vegetation communities to stump harvesting in boreal forests
2011
Recently, in addition to logging residues, stumps have become an important component in energy production since there is growing global interest in the use of renewable energy sources in order to decrease anthropogenic carbon emissions. Harvesting of stumps influences the forest floor by changing vegetation and soil organic layers and exposing mineral soil across large areas. We studied whether stump harvesting after clear felling poses further short-term changes in boreal forest soil decomposer community (microbes and mesofauna) and vegetation when compared to the traditional site preparation practice (mounding). In general, stump harvesting caused decline in enchytraeid abundance but did …
Spot mounding and granulated wood ash increase inorganic N availability and alter key components of the soil food web in clear-cut Norway spruce fore…
2012
Abstract The interactive effects of site preparation (spot mounding) and fertilization (granulated wood ash) on soil properties, soil micro- and mesofauna and ground vegetation were studied in two Norway spruce plantations established in clear-cut forests in Central Finland. Half of the seedlings were planted on mounds created by the planting machine, and the rest on intact forest floor. Half of the seedlings on mounded and intact forest floor were fertilized by adding granulated wood ash to circular plots surrounding the seedlings. Initial samples were taken from mounded and intact soil immediately after planting in June. Samples were taken from all treated plots in the autumn in the first…
The implications of stand composition, age and spatial patterns of forest regions with different ownership type for management optimisation in northe…
2015
Abstract Forests with different ownership type often form complex mosaics of stands, thus adding new challenges to the spatial planning of sustainable management in forested landscapes. This study attempted to analyse the spatial patterns and age structures of forest regions with different ownership type and to formulate suggestions for the optimisation of tactical planning of forest management planning by addressing ecological functionality at the landscape level. We hypothesised that structure of forests of various ownership groups differs significantly. National forest inventory data from 2011 was used in this study to compare spatial patterns of forest stands and clearcuts, as well as f…