1,720,982 research outputs found
Quantifying tree and volume mortality in Italian forests
No full textTree mortality plays a key role in forest development and function, reducing net annual increments (NAI) even in the absence of major disturbances, although its extent in semi-natural forests is often overlooked. While losses are most commonly quantified as a fraction of stand density, in many cases this could prove misleading due to the non-random nature of competition and mortality, and a quantification of volume mortality rates would provide additional insight. Of great interest is also the quantification of losses relative to gross annual increments (GAI), both from an ecological perspective and in order to better assess net increments and the sustainability margins of forest management. All three perspectives were compared in the present study, based on available data from permanent sample plots across Italy covering a wide range of species, ages and management types. The frequency distribution of all three measures of mortality was highly skewed, with a high number of stands showing little losses; this was apparently not the result of an insufficient monitoring area or time span. Mortality resulted in an average loss of 2.25 m3 ha−1 yr−1, which corresponds to 20.7% of GAI. Mortality rates by number and by volume amounted on average to 1.35% and 0.51%, respectively, demonstrating the need to distinguish between the two perspectives. Two rather distinct clusters were apparent in the relationship between the two mortality rates, with a 1:1 relationship in thinned or disturbed stands but much lower volume mortality rates when self-thinning prevailed, resulting in the loss of many small, suppressed trees. When considering volume mortality rates, however, the relative contribution from dominant or co-dominant trees to total stand mortality was much more important, as a result of their larger volume. If extrapolated to national level, these results could help refine current estimates of net annual increments in Italian forests, and of the margin of sustainability of current harvest levels, which would amount to 45% of NAI
Monitoring managed forest structure at the compartment-level under different silvicultural heritages: an exploratory data analysis in Italy
No full textThe more and more diffused multifunctional role addressed nowadays to public forests, calls for targeted analysis aimed at highlighting the overall outcome of different practices implemented on the same forest compartment, according to the locally prevailing function. This study was carried out in four Italian beech forests across a latitudinal gradient representative of multiple management history, stand structure, and dominant stand age. We analyze forest structure at the compartment scale before and after silvicultural practices. We aim to explore relationships and similarities between 10 stand attributes (mensurational and structural variables) to identify relevant indicators for the monitoring and management of forest ecosystems. Results indicate changing patterns of correlation and similarity among mensurational variables following practice implementation. A sensitivity gradient to silvicultural practice was finally identified within the four sites investigated as a result of the diverging stand structure. Our approach suggests a way and provides an insight for the design of adaptive forestry management practices required to meet environmental targets, in addition to the already acknowledged supply of primary goods and service
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
Biodiversity - Its assessment and importance in the Italian programme for the intensive monitoring of forest ecosystems CONECOFOR
No full textBiodiversity – its assessment and importance in the Italian intensive forest monitoring programme CONECOFOR.
No full textFactors influencing vascular species richness in the CONECOFOR permanent monitoring plots
No full textExploring nonlinear intra-annual growth dynamics in Fagus sylvatica L. trees at the Italian ICP-forests level II network
Full text linkThe European beech (Fagus sylvatica L.) is a widely distributed tree species across Europe, highly sensitive to climate change and global warming. This study illustrates results of a 5-year monitoring time period from eight sites of the ICP-Forests Level II (intensive monitoring network) along the Italian latitudinal gradient. The tree-level relationship between tree growth dynamics and environmental factors, including seasonal climate fluctuations were investigated by means of tree-level Generalized Additive Mixed Models (GAMMs). Model results revealed that climate was responsible for just a portion of the variability in beech growth dynamics. Even if climatic predictors were highly significant in almost all sites, the model explained nearly 30% of the total variance (with just a maximum value of 71.6%), leaving the remaining variance unexplained and likely connected with forest management trajectories applied to each site (e.g., aged coppice and fully grown high forest). Climate change scenarios were then applied to predict site-specific future responses. By applying climate change scenarios, it was predicted that central and northern Italy would face similar climatic conditions to those currently detected at southern latitudes. A special case study was represented by VEN1 plot (Veneto, Northern Italy) whose current and future climate regimes were grouped in a unique and separated cluster
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
Early impact of alternative thinning approaches on structure diversity and complexity at stand level in two beech forests in Italy
No full textStand structure, tree density as well as tree spatial pattern define natural dynamics and competition process. They are therefore parameters used to define any silvicultural management type. This work aims to report first data resulting from a silvicultural experiment in beech forests. The objective of the trial is testing the structure manipulation in terms of diversity and the reduction of inter-tree competition of different thinning approaches. Alternative thinning methods have been applied in two independent experimental sites located in the pre-Alps and Southern Apennines, in Italy. Specific goals were to: (i) verify the impact early after thinning implementation on forest structure through a set of diversity and competition metrics resulting from a literature review; (ii) the sensitivity of tested indexes to effectively detect thinning manipulation. Main result show the low sensitivity of stand structure indexes and the ability of competition metrics to detect thinning outcome
- …
