Leaf mineral concentrations of Erica arborea, Juniperus communis and Myrtus communis growing in the proximity of a natural CO2 spring

Leaf mineral concentrations of co-occurring Erica arborea, Juniperus communis and Myrtus communis were measured at bimonthly intervals throughout a year in a natural CO2 spring and in a nearby control site with similar soil chemistry in a Mediterranean environment. There were different responses to the elevated [CO2] (c. 700 μL L−1) of the spring site plants depending on the element and the species. In the CO2 spring site K, Ca, Mg, Mn, Al, Fe, and Ti leaf concentrations and the ratio C/N showed significant greater values in at least one or two of the three species. Leaf S concentration were greater in all three species. Leaf concentrations of N, Sr, Co, and B were lower in at least one or two species, and those of C and Ba were lower in all the three studied species near the CO2 spring. P, Na, Zn, Si, Cu, Ni, Cr, Pb, Mo, V and Cd leaf concentrations and the specific leaf area (SLA, measured in Myrtus communis) did not show any consistent or significant pattern in response to the elevated [CO2] of the spring site. There was a slight trend towards maximum concentrations of most of these elements during autumn-winter and minimum values during the spring season, especially in Myrtus communis. Multivariate principal component analyses based on the leaf elemental concentrations clearly differentiated the two sites and the three species. Lower concentrations at the spring site were not the result of a dilution effect by increased structural or nonstructural carbon. In contrast to most experimental studies of CO2 enrichment, mainly conducted for short periods, several of these elements had greater concentrations in the CO2 spring site. Nutrient acclimation and possible causes including decreased nutrient export, increased nutrient uptake capacity, photosynthetic down-regulation, Mediterranean water stress, and higher H2S concentration in the spring site are discusse

Forest stand structure and coarse woody debris determine the biodiversity of beetle communities in Mediterranean mountain beech forests

Abstract The relationships between structural complexity, deadwood abundance, microhabitat type and species-diversity indicators are excellent tools to monitor biodiversity in forest ecosystems. In spite of their importance, correlations between structural traits and Coleoptera communities in Mediterranean mountain forests have only rarely been investigated. Consequently, the magnitude and direction of the relationships between forest traits and biodiversity indicators remain poorly understood. In this study, we analyzed whether biodiversity indices of saproxylic and non-saproxylic beetle communities could be influenced by stand structure, microhabitat type, and deadwood abundance in two protected beech forests located in the central and southern Apennines (namely Gran Sasso e Monti della Laga National Park, GSML, and Cilento, Vallo di Diano e Alburni National Park, CVDA). Standard measurements of forest structural traits and quantitative assessment of tree microhabitats and deadwood were carried out. Adult beetles were collected using window flight traps and emergence traps on decaying deadwood. The two beech forests were different in terms of both beetle communities and structural traits. A two-block partial least squares analysis 2B-PLS highlighted differences in biodiversity indices and structural traits between the two forest ecosystems. In GSML, we observed that biodiversity indices were positively correlated with the volume of coarse woody debris and the presence fungal infections, clefts into the sapwood, and woodpecker cavities, while more dominant beetle communities were found under denser canopy cover. In CVDA, Coleoptera abundance was positively correlated with the basal area and crown broken microhabitats. Our results point toward the relevance of ecological attributes in tracking changes in beetle biodiversity in specific forest contexts. In these protected Mediterranean mountain beech stands, in which the main forest management strategies have the primary objective of biodiversity conservation, we suggest to progressively increase the structural diversity and canopy dynamics, as well as the volume of coarse woody debris

Influenza dei cambiamenti d'uso del suolo e delle strategie di gestione del bosco sull'allocazione del carbonio nel suolo negli ecosistemi forestali

L'allocazione del C verso le strutture ipogee delle piante e uno dei principali flussi di C negli ecosistemi terrestri, sebbene ancora non ben quantificato. RAICH e NADELHOFFER (1989), dopo il riesame della letteratura su numerosi ecosistemi forestali, hanno suggerito che l'allocazione ipogea totale di C puo essere stimata dalla differenza fra tassi annuali di respirazione del suolo e caduta di lettiera epigea. DAVIDSON et al. (2002) hanno esteso le analisi dei dati pubblicati confermando le conclusioni di RAICH e NADELHOFFER per foreste mature, sebbene, come osservato da GOWER et al. (1996), l'uso di modelli per la stima del C totale allocato alle radici e per la costruzione di bilanci del C di un soprassuolo non era considerato un metodo valido per la misura dei flussi di C del suolo. Nel presente lavoro di revisione della letteratura abbiamo analizzato nuove misure di respirazione del suolo e di caduta di lettiera, includendo nell'analisi a scala globale sia foreste mature sia formazioni giovani. I risultati ottenuti concordano, in genere, con i lavori precedenti, affermando che la produzione epigea ed ipogea e controllata dagli stessi fattori. Attraverso un gradiente di C da lettiera oscillante fra 52 a 530 g m-2 anno-1, l'allocazione totale ipogea di C aumenta da circa 90 a 1800 g m-2 anno-1. Il rapporto fra allocazione totale ipogea di C e caduta di lettiera diminuisce approssimativamente da 12 a 2.5, con incrementi di C da lettiera da 50 a 200 g m-2 anno-1, ma varia poco quando il C da lettiera aumenta 200 a 500 g m-2 anno-1. Un'analisi di regressione applicata ai dati derivanti da foreste di tutto il mondo ha prodotto la seguente relazione: respirazione annuale del suolo = 140 + 3.09 × caduta annuale di lettiera. La pendenza della regressione indica che, in media, la respirazione del suolo e grossolanamente il triplo del C di lettiera epigea, implicando che l'allocazione ipogea totale di C rappresenta circa il doppio del C di lettiera epigea caduta annualmente. La regressione per i dati provenienti dalle formazioni giovani e piu ripida, rispetto a quanto osservato per le foreste mature, indicando un'eventuale proporzionalmente maggiore allocazione ipogea totale di C, ma l'assunzione dello stato stazionario e piu problematica per le foreste giovani. In effetti, queste deduzioni sono basate su ipotesi incerte sulla stabilita della scorta di C nel suolo. Tuttavia, le variazioni del C del suolo dovrebbero essere molto ampie per modificare la conclusione the l'allocazione ipogea totale di C e generalmente molto maggiore della caduta di lettiera. Queste relazioni permettono la realizzazione di semplici bilanci del C che possono essere usati per porre dei limiti sulla stima della produzione di radici fini in ecosistemi forestali. La determinazione dei tassi di respirazione radicale (radici vive) in ecosistemi forestali puo ulteriormente restringere il raggio di possibili tassi di produzione delle radici, e controllare le ipotesi che l'allocazione totale di C alle radici aumenta con la produzione primaria netta del soprassuolo e che il rapporto fra allocazione totale di C alle radici e produzione primaria netta del soprassuolo diminuisce lungo gradienti globali di disponibilita di risorse. La relazione statistica universale, derivata usando bilanci forestali del C, dovrebbe essere valutata a scala minore, per identificare come variano i modelli d'allocazione del C nelle foreste in funzione dell'eta del bosco, della composizione specifica, e delle pratiche di gestione

White rot fungal impact on the evolution of simple phenols during decay of silver fir wood by UHPLC‐HQOMS

6openInternationalItalian coauthor/editorIntroduction Silver fir (Abies alba Mill.) is one of the most valuable conifer wood species in Europe. Among the main opportunistic pathogens that cause root and butt rot on silver fir are Armillaria ostoyae and Heterobasidion abietinum. Due to the different enzymatic pools of these wood-decay fungi, different strategies in metabolizing the phenols were available. Objective This work explores the changes in phenolic compounds during silver fir wood degradation. Methodology Phenols were analyzed before and after fungus inoculation in silver fir macerated wood after 2, 4 and 6 months. All samples were analyzed using high-performance liquid chromatography coupled to a hybrid quadrupole-orbitrap mass spectrometer. Results Thirteen compounds, including simple phenols, alkylphenyl alcohols, hydroxybenzoketones, hydroxycinnamaldehydes, hydroxybenzaldehydes, hydroxyphenylacetic acids, hydroxycinnamic acids, hydroxybenzoic acids and hydroxycoumarins, were detected. Pyrocatechol, coniferyl alcohol, acetovanillone, vanillin, benzoic acid, 4-hydroxybenzoic acid and vanillic acid contents decreased during the degradation process. Methyl vanillate, ferulic acid and p-coumaric were initially produced and then degraded. Scopoletin was accumulated. Pyrocatechol, acetovanillone and methyl vanillate were found for the first time in both degrading and non-degrading wood of silver fir. Conclusions Despite differences in the enzymatic pool, both fungi caused a significant decrease in the amounts of phenolic compounds with the accumulation of the only scopoletin. Principal component analysis revealed an initial differentiation between the degradation activity of the two fungal species during degradation, but similar phenolic contents at the end of wood degradation.openDi Lella, Stefania; La Porta, Nicola; Tognetti, Roberto; Lombardi, Fabio; Nardin, Tiziana; Larcher, RobertoDi Lella, S.; La Porta, N.; Tognetti, R.; Lombardi, F.; Nardin, T.; Larcher, R

A Multimodal Perception Framework for Users Emotional State Assessment in Social Robotics

In this work, we present an unobtrusive and non-invasive perception framework based on the synergy between two main acquisition systems: the Touch-Me Pad, consisting of two electronic patches for physiological signal extraction and processing; and the Scene Analyzer, a visual-auditory perception system specifically designed for the detection of social and emotional cues. It will be explained how the information extracted by this specific kind of framework is particularly suitable for social robotics applications and how the system has been conceived in order to be used in human-robot interaction scenarios

Tree-Ring Stable Isotopes Reveal Twentieth-Century Increases in Water-Use Efficiency of Fagus sylvatica and Nothofagus spp. in Italian and Chilean Mountains

Abstract Changes in intrinsic water use efficiency (iWUE) were investigated in Fagus sylvatica and Nothofagus spp. over the last century. We combined dendrochronological methods with dual-isotope analysis to investigate whether atmospheric changes enhanced iWUE of Fagus and Nothofagus and tree growth (basal area increment, BAI) along latitudinal gradients in Italy and Chile. Post-maturation phases of the trees presented different patterns in 18 O, Ci (internal CO 2 concentration), iWUE, and BAI. A continuous enhancement in isotope-derived iWUE was observed throughout the twentieth century, which was common to all sites and related to changes in Ca (ambient CO 2 concentration) and secondarily to increases in temperature. In contrast to other studies, we observed a general increasing trend of BAI, with the exception of F. sylvatica in Aspromonte. Both iWUE and BAI were uncoupled with the estimated drought index, which is in agreement with the absence of enduring decline in tree growth. In general, d 13 C and d 18 O showed a weak relationship, suggesting the major influence of photosynthetic rate on Ci and d 13 C, and the minor contribution of the regulation of stomatal conductance to iWUE. The substantial warming observed during the twentieth century did not result in a clear pattern of increased drought stress along these latitudinal transects, because of the variability in temporal trends of precipitation and in specific responses of populations