1,720,971 research outputs found
L'influenza di Pasquale Saraceno nella formulazione della programmazione economica in Italia:cenni essenziali
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Analysis of the functional composition of the hilly forest landscape in the Monti Sibillini National park
No full textWe define the pattern of functional composition of the herb layer in a hilly forest landscape in relationship with environmental constraints
The effects of environmental features and overstory composition on the understory species assemblage in sub-Mediterranean coppiced woods: implications for a sustainable forest management
No full textUnderstanding the relationship among environmental factors, overstory and understory is a key step for the improvement of sustainable forest management. Our aim was to understand how environmental features (topographic factors) and overstory (tree species) composition affect understory (shrub and herb species) assemblage in sub-Mediterranean coppiced woods. The study area lies in the Monti Sibillini National Park (central Italy). In 205 plots (20 x 20 m) we collected topographic features and species cover values; moreover, we defined the Social Behaviour Type (SBT - i.e. species ecological and dynamic features) of each understory species. Data were analysed using Redundancy Analysis and Generalized Linear Modeling. We found that topographic factors shaped percentage cover of different tree species and hence determined forest community type. Topography-related factors were further mediated by the tree layer composition, in filtering understory assemblage, on the basis of species SBT. We found no effect of over story species diversity on understory species diversity. However, the presence of tree species different from the dominant ones increased understory species richness. This effect was particularly notable in evergreen woods, dominated by Quercus ilex. We conclude that, to improve the management sustainability, coppicing management should be focused on the achievement of the greater tree species diversity
Functional response of an invasive tall grass (Brachypodium genuense) to environmental variability in sub-Mediterranean climate
Full text linkWe found that in more productive conditions (deeper soil, medium/high pH values, northfacing
slopes, and “conservative” land forms) populations of B. genuense showed higher
SLA, plant height and cover values. This underlies a fast-growing strategy based on high
resource acquisition/use rate, as well as higher competitive ability for above-ground
resources (e.g. light). The opposite trend emerged for unproductive/dry conditions (southfacing
slopes, shallow soils, lower pH values). Under these constraints, SLA, plant height
and cover value decreased underlying a slow-growing strategy with high conservation and
low acquisition rate of resource. In addition, we found that very high nitrogen amount might
have a detrimental effect on B. genuense individuals decreasing the SLA values, thus
requiring the plant to change the growth strategy
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Context-dependent variation of SLA and plant height of a dominant, invasive tall grass (Brachypodium genuense) in sub-Mediterranean grasslands
No full textThe cessation of semi-extensive farming and the abandonment of settlements are threatening European pastoral landscapes and their biodiversity, affecting species assemblage and ecosystem functioning. This process typically involves invasion by coarse tall grasses, mostly with competitive stress-tolerant strategies, and rapid development of mono-dominance stands. A key species in this respect is Brachypodium genuense (DC.) Roem. et Schult., an endemic, rhizomatous, tall-grass that grows in the semi-natural grasslands of the Italian peninsula over 1200-1400 m a.s.l.
We hypothesized that B. genuense was able to spread and dominate the grassland communities subjected to a wide range of environmental conditions through its broad spectrum of performances. In fact, it has considerable morphological variability, mirrored by high variations of traits, namely Specific Leaf Area (SLA), individual height, and tussock cover values. The study area encompassed the Monti Sibillini National Park (central Italy). We found that in more productive conditions (deeper soil, medium/high pH values, north-facing slopes, and "conservative" landforms) populations of B. genuense had higher SLA, plant height and cover values than in low productive conditions (south-facing slopes, shallow soils, lower pH values). This indicates a fast-growing strategy based on a high rate of resource acquisition and use, as well as high competitive ability for aboveground resources such as light under productive conditions. Under unproductive and/or dry conditions decreased SLA, plant height and cover value indicate a slow growing strategy with high conservation and low rate of resource acquisition. In addition, we found that a very high amount of nitrogen in the soil might have a detrimental effect on B. genuense individuals, decreasing the SLA values, thus requiring the plant to change its growth strategy. Finally, we inferred that the observed variability in SLA might have a paramount role in the invasive/dominant behavior of Brachypodium genuense
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