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The olive fruit fly is worldwide considered a major harmful pest of the olive agroecosystem. In Italy, the fruit fly infestation is traditionally countered by spraying chemical insecticides (e.g., dimethoate), but due to the recent ban of dimethoate by the Reg EU2019/1090 and the increasing awareness of consumers of food sustainability, the interest in developing chemical-free alternatives to pesticides, such as the use of particle-films, is rising. A field experiment was conducted to assess the effect of different particle films (kaolin-base and zeolitite-base) on leaf gas exchanges and leaf optical properties. Results showed that with the dust accumulation on the leaves’ surface, photosynthesis, stomatal conductance, transpiration and water use efficiency were significantly lower in kaolin-treated olive trees compared to those treated with zeolitite and to the control, while olive trees treated with zeolitite showed physiological parameters similar to the untreated plants. Microstructural differences of different particle film on the leaf and olive surfaces emerged by ESEM observations also influenced leaf optical properties. Oils produced by zeolitite-treated plants show higher intensities of gustatory and olfactory secondary flavors compared to kaolin and test oils.

Olive fruit fly (Bactrocera oleae) is the most dangerous pest of olive fruits and strongly impairs both quality and quantity of the resulting olive oil. Organic farms have few tools against this pest and are constantly looking for effective and sustainable products; furthermore, for conventional farms the recent ban on dimethoate use in EU, made the defence from B. oleae very difficult. In this context the use of zeolitites, applied as particle films, began to take hold.Since particle film covers the leaves, the organs responsible for gas exchange, a study on the plant responses to zeolite foliar coating was carried out by measuring photosynthetic rates from July to October (harvest) in two orchards located at San Lazzaro di Savena and Montiano in the Emilia Romagna region (Italy), respectively under organic and conventional farming.Plant response to foliar treatment was also evaluated by measuring oil quantity in olives fruits. The layer of particle film covering leaves and fruits reduces the attractiveness of visual cues and prevents insects from recognizing and finding the plant parts on which they lay eggs: volatile organic compounds (VOC) emitted from both leaves and olives could act as oviposition promoters and were determined as well. Finally, chemical and sensory analyses on the resulting olive oils were performed. In the San Lazzaro orchard the tested treatments were: natural zeolitite (NZ), natural zeolitite enriched with ammonium (EZ) and Spyntor Fly® (SF), a protein bait based on spinosad for the control of B. oleae. In the Montiano orchard the treatments tested were: Dimethoate (DM), an organophosphate insecticide, natural zeolite with a reduced dose of dimethoate (ZN-DM) and negative control (Test).Photosynthetic activity of plants treated with EZ was higher than the other two treatments in all dates, while no differences in photosynthetic rate were found between SF and NZ. In the Montiano orchard a slight reduction in photosynthetic rate was found only on the last two dates. The analyses of the VOC emitted by leaves and fruits allowed to identify respectively 35 and 31 different chemical compounds, belonging mainly to the chemical classes aldehydes, alkanes and alcohol, ketones, esters, ethers and terpenes. Chemical and sensory characteristics of oils were influenced by the incidence of olive fruit fly rather than foliar treatment with zeolite. In the Montiano orchard, subjected to a severe B. oleae attack, the effectiveness of the zeolite against the pest was observed, and the oil from untreated plants showed higher chemical parameters associated with secondary oxidation phenomena. In the San Lazzaro orchard, where a weak B. oleae attack occurred, sensory differences were recorded between treated (NZ and EZ) and untreated plants. According to the results of this study, the use of zeolite film cover on olive tree canopy do not negatively influence the plant physiology and represents a useful tool against olive fruit fly.

Understanding urban tree responses to drought, salt stress, and co-occurring stresses, as well as the capability to recover afterward, is important to prevent the cited stresses&rsquo, negative effects on tree performance and ecological functionality. We investigated the impact of drought and salinity, alone and in combination, on leaf water potential, gas exchange, chlorophyll a fluorescence, xanthophyll cycle pigments, and isoprene emission of the urban tree species Liquidambar styraciflua L. Generally, drought had a rapid negative impact, while the effect of salt stress was more long lasting. Both stressors significantly decreased photosynthesis, transpiration, and stomatal conductance, as well as the maximum quantum efficiency of photosystem II (Fv/Fm) and the photochemical efficiency of PSII (&Phi, PSII), but increased nonphotochemical quenching (NPQ). Under stress conditions, a strong negative correlation between the PSII efficiency and the xanthophyll cycle pigment composition indicated a nocturnal retention of zeaxanthin and antheraxanthin in a state primed for energy dissipation. Drought and salt stress inhibited isoprene emission from leaves, although its emission was less responsive to stresses than stomatal conductance and photosynthesis. Full recovery of photosynthetic parameters took place after rewatering and washing off of excess salt, indicating that no permanent damage occurred, and suggesting downregulation rather than permanent impairment of the photosynthetic apparatus. Sweetgum trees were capable of withstanding and surviving moderate drought and salt events by activating defense mechanisms conferring tolerance to environmental stresses, without increasing the emission in the atmosphere of the highly reactive isoprene.

Urban greening helps to improve environment quality and human health thanks to the ability of plants to absorb greenhouse gases and remove significant amounts of air pollutants. Green roofs, providing vegetated surfaces in dense cities, can help to mitigate the negative effects of urban pollution. The present study aimed to evaluate the potential ability of fifteen green roof species (Lonicera pileata, Satureja repandens, Hypericum moserianum, Erigeron karvinskianus, Solidago praecox, Rudbeckia sullivantii ‘Goldsturm’, Filipendula purpurea, Filipendula vulgaris ‘Kahome’, Gaura lindheimeri, Campanula persicifolia, Veronica longifolia, Sedum spectabile, Origanum vulgare, Salvia nemorosa, and Achillea millefolium) to mitigate carbon dioxide (CO2) and urban pollutant concentration analysing the leaf physiological traits (gas exchange) and morphological structures (stomata, trichomes, epicuticular waxes and cuticular ornamentation) involved in pollutant removal. Furthermore, considering the important role of biogenic volatile organic compounds (BVOC) on the photochemical reactivity of the atmosphere, their species-specific emission was also assessed together with the derived ozone forming potential (OFP). Our results suggested that the potential mitigation capacity based on the investigated traits of the shrubs and herbaceous species was species-specific. The very low potential of all the tested species to form ozone indicated their suitability for urban planning programs.

The ecosystem services provided by urban forests contribute to ameliorate air quality and human well-being in cities. An integrated approach based on direct measurements of leaf functional multi-traits and on estimation of the plant mitigation potential was used for predicting the species-specific impact on air quality of 29 species, including trees and shrubs, commonly present in the urban context. In addition, volatile organic compound (VOC) emissions and ozone forming potential (OFP) of each species were evaluated. At plant levels, pollution deposition equations and the i-Tree Eco model were applied for estimating particulate (PM10) and ozone (O-3) removal potential and for calculating carbon dioxide (CO2) storage and sequestration by the studied species. The results highlight the plant species-specific ability to capture atmospheric pollutants based on their physiological (CO2 assimilation and stomatal conductance) and morphological (stomata, trichomes, waxes and cuticular ornamentation) leaf traits. Trees with abundant trichomes, waxes and wrinkled leaf surfaces are considered more suitable for capturing pollutants. Most of the studied species are suitable for urban planning programs as they result for the majority low VOC emitters and consequently are characterized by low or moderate OFP. Annual O-3 and PM10, removal of the investigated trees species ranged from about 58-140 g plant(-1) yr(-1) and from about 17-139 g plant(-1) yr(-1), respectively. Total tree CO2 storage ranged from about 164-215 kg plant(-1) and gross annual CO2 sequestration from 11 to 20 kg plant(-1) year(-1). Liriodendron tulipifera, Celtis australis, Acer campestre and Acer platanoides, were efficient species in capturing PM10 and absorbing O-3. Prunus cerasifera, Quercus cerris, together with Celtis australis, Acer campestre and Acer platanoides, were efficient for carbon sequestration and storage. As aspected, lower potential of pollutant removal and CO2 storage and sequestration were estimated for shrubs, due to their smaller leaf area and structure.

The composition in Volatile Organic Compounds (VOC) of the biogas produced by seven landfills of Giugliano (Naples, Campania, Italy) was determined and VOC emission rates assessed to verify if these compounds represent a potential threat to the population living nearby. VOC composition in the biogas could not be predicted, as heterogeneous waste was dumped from the late 1980s to the early 2000s and then underwent biological degradation. No data are available on the amount and composition of VOC in the biogas before the landfills closure as no operational biogas collection system was present. In this study, VOC composition was determined by gas chromatography–mass spectrometry (GC–MS), after collecting samples from collection pipes and from soil fractures in cover soil or capping. Individual VOC were quantified and data compared with those collected at two landfills in Latium, when they were still in operation. Relevant differences were observed, mainly due to waste aging, but no specific VOC revealing toxic waste dumping was found, although the concurrent presence of certain compounds suggested that dumping of industrial wastes might have occurred. The average VOC emission was assessed and a dispersion model was run to find out if the emitted plume could affect the health of population. The results suggested that fugitive emissions did not represent a serious danger, since the concentrations simulated at the neighboring cities were below the threshold limits for acute and chronic diseases. However, VOC plume could cause annoyance at night when the steady state conditions of the atmosphere enhance pollutants accumulation in the lower layers. In addition, some of the emitted VOC, such as alkylbenzenes and monoterpenes, can contribute to tropospheric ozone formation.

Switchgrass (Panicum virgatum L.) is a perennial lignocellulosic crop that has recently gained large interest as a feedstock for advanced biofuels. Using an eddy-covariance system, we monitored the net ecosystem gas exchange in a five-ha rainfed switchgrass crop located in the Po River Valley for four consecutive years. Switchgrass absorbed 58.2 Mg CO2 ha-1 y-1 (GPP - gross primary production), of which, 24.5 (42%) were fixed by the ecosystem (NEE - net ecosystem exchange). NEE resulted negative (C sink) even in the first year when biomass and canopy photosynthesis are considerably lower compared to the following years. Taking into account the last three years only (productive years), which are more representative of a long-term switchgrass stand, mean NEE was -26.9 Mg CO2 ha-1 y-1. Water use efficiency (WUE), i.e. the ratio of GPP or NEE to the water used by the crop as the flux of transpiration (ET), was also remarkable: over the four years, it corresponded to 1.6 mg C per gram of H2O, meaning that, on average, 170 m3 of water were needed to fix one Mg of CO2. Again, considering only the productive years, WUE was 1.7 mg C g-1 of H2O. It resulted that about the half (50% to 59%) of annual precipitation was used by the crop every year. We conclude that switchgrass can be a valuable crop to capture significant amount of atmospheric CO2 while preserving water reserves, and estimated that its potential large scale deployment in the Mediterranean could lead to a greenhouse gas reduction of 0.63% of EU's emission every year.

In recent years, optical sensing techniques have been widely spread since they allow the non-invasive evaluation of water deficit stress in a timely fashion. In this study, innovative services and support systems to farmers for optimising irrigation, scheduling and practices were tested in two vineyards located in Usini and Arzachena (Sardinia, Italy). Four different irrigation treatments were applied to three grapevine cultivars and physiological observations were integrated and combined with remote sensing measurements carried out with a modified Mikrokopter UAV equipped with a multispectral camera to obtain vegetation indices (e.g., NDVI) and thermal cameras to measure water deficit stress indices. In addition, an automated digital imaging system collected high-resolution vegetation images at daily intervals and the changes in plant colour coordinates (RGB) due to changes in vine phenological stage and water status were detected. The indices obtained from remote sensing observations were then related with stem water potential, photosynthesis and chlorophyll fluorescence measurements. In general, calculated CWSI increased in stressed treatments (dry and T2), while the wet treatment yielded the lowest CWSI and SWP, as expected. Preliminary results indicated that net photosynthesis declined under high stress conditions (T2 and dry) and when CWSI values increased. ExG values showed high differences between the two irrigation treatments of up to 60% in 'Vermentino, while this behaviour was less stable for 'Cagnulari'. The tested techniques were able to detect the physiological status of plants, indicating the usefulness of remote and proximal sensing techniques to monitor vine water deficit stress.

At present, research activities on the role of orchard systems in sequestering atmospheric CO2 remain scarce. This paper aimed to contribute to assessing the carbon balance of a Mediterranean olive (Olea europea) orchard. The net ecosystem exchange, the ecosystem respiration and the gross primary production were computed for two consecutive years through eddy covariance, and the different biomass accumulation terms were also inferred in the same period through an inventorial method. The net carbon exchange ranged from 13. 45 t(C) ha-1 year-1 to 11. 60 t(C) ha-1 year-1. Very similar values [12. 2 and 11. 5 t(C) ha-1 year-1] were found with the direct carbon accumulation inventory. The intensive farming management (irrigation included) and the young age of the plants (12-16 years old), still in an active growing phase, led the olive plantation to be a higher carbon sink with respect to other evergreen orchards reported in the literature. © 2012 Springer Science+Business Media Dordrecht.

Il comprensorio Acerrano si inserisce in una realtà territoriale ed ambientale complessa, per la presenza di fattori di pressione ambientale diversificati e per le problematiche comuni alla cosiddetta 'terra dei fuochi'. Nel dominio oggetto di studio sono presenti: ? l'impianto di incenerimento e valorizzazione di rifiuti solidi urbani; ? sorgenti di inquinanti di tipo industriale e di trattamento dei rifiuti; ? intenso traffico veicolare (autostrade, strade principali e centri urbani); ? sorgenti emissive legate al riscaldamento degli edifici ad uso residenziale/terziario. In questo contesto, l'attività del progetto SAmbA ha realizzato un apparato d'indagine ambientale integrato, basato su misure da piattaforme mobili terrestri ed aeroportate, rilievi di dettaglio dei parametri biofisici ed ambientali e simulazioni modellistiche dell'evoluzione della qualità dell'aria che hanno permesso di quantificare l'apporto delle diverse sorgenti alla qualità dell'aria nel comprensorio acerrano. Sul territorio oggetto di studio sono stati dislocati apparati sperimentali per il monitoraggio della qualità dell'aria e condotte campagne di misura con strumentazione installata su mezzi mobili stradali e su aerei, per approfondire le informazioni sulla qualità ambientale del territorio e far fronte alle carenze informative ed al contempo fornire elementi quantitativi di verifica per le simulazioni modellistiche. Il precedente Studio modellistico di ricaduta delle emissioni del termovalorizzatore di Acerra contestualizzato all'interno della realtà territoriale (©CNR Edizioni, ISBN 978 88 8080 229 7, Aprile 2016), ha fornito dati quantitativi per la determinazione dell'impatto ambientale dell'impianto di termovalorizzazione dei rifiuti, mediante un approccio integrato che ha quantificato l'apporto delle diverse sorgenti inquinanti nel comprensorio di Acerra - attraverso l'uso combinato un modello dispersivo di tipo lagrangiano a particelle e di un modello fotochimico. Il presente volume riporta i risultati di dettaglio delle ampie e diversificate misure e analisi ambientali svolte, che consentono di ricomporre un quadro complesso a partire dall'analisi di numerosi parametri ambientali a diverse scale di indagine.

MONTES (>Woodlands>) was a multidisciplinary international field campaign aimed at measuring energy, water and especially gas exchange between vegetation and atmosphere in a gradient from short semi-desertic shrublands to tall wet temperate forests in NE Spain in the North Western Mediterranean Basin (WMB). The measurements were performed at a semidesertic area (Monegros), at a coastal Mediterranean shrubland area (Garraf), at a typical Mediterranean holm oak forest area (Prades) and at a wet temperate beech forest (Montseny) during spring (April 2010) under optimal plant physiological conditions in driest-warmest sites and during summer (July 2010) with drought and heat stresses in the driest-warmest sites and optimal conditions in the wettest-coolest site. The objective of this campaign was to study the differences in gas, water and energy exchange occurring at different vegetation coverages and biomasses. Particular attention was devoted to quantitatively understand the exchange of biogenic volatile organic compounds (BVOCs) because of their biological and environmental effects in the WMB. A wide range of instruments (GC-MS, PTR-MS, meteorological sensors, O3 monitors,. .) and vertical platforms such as masts, tethered balloons and aircraft were used to characterize the gas, water and energy exchange at increasing footprint areas by measuring vertical profiles. In this paper we provide an overview of the MONTES campaign: the objectives, the characterization of the biomass and gas, water and energy exchange in the 4 sites-areas using satellite data, the estimation of isoprene and monoterpene emissions using MEGAN model, the measurements performed and the first results. The isoprene and monoterpene emission rates estimated with MEGAN and emission factors measured at the foliar level for the dominant species ranged from about 0 to 0.2mgm-2h-1 in April. The warmer temperature in July resulted in higher model estimates from about 0 to ca. 1.6mgm-2h-1 for isoprene and ca. 4.5mgm-2h-1 for monoterpenes, depending on the site vegetation and footprint area considered. There were clear daily and seasonal patterns with higher emission rates and mixing ratios at midday and summer relative to early morning and early spring. There was a significant trend in CO2 fixation (from 1 to 10mgCm-2d-1), transpiration (from1-5kgCm-2d-1), and sensible and latent heat from the warmest-driest to the coolest-wettest site. The results showed the strong land-cover-specific influence on emissions of BVOCs, gas, energy and water exchange, and therefore demonstrate the potential for feed-back to atmospheric chemistry and climate. •We present a multidisciplinary biosphere-atmosphere field campaign.•We measured a gradient from semi-desertic shrublands to wet temperate forests.•A wide range of instruments and vertical platforms were used.•Land cover strongly influenced emissions of BVOCs and gas, energy and water exchange.•Vegetation has strong potential for feed-back to atmospheric chemistry and climate. © 2013 Elsevier Ltd., We are indebted to the Spanish government projects CONSOLIDER INGENIO MONTES (CSD2008-00040), and CGL2010-17172 and the Catalan government project SGR2009-458. NCAR is sponsored by the U.S. National Science Foundation. The research was also partially funded by the Italian Ministry for Research and University under the project CarboItaly (FISR funds). RS was partially supported by a postdoctoral grant from Fundación Ramón Areces.

In recent years, optical sensing techniques have been widely spread since they allow the non-invasive evaluation of water stress in a timely fashion. The experimentation, carried out in two vineyards located in Usini and Arzachena (Sardinia, Italy), consisted of four treatments: i) two irrigation treatments applied according to specific leaf water potential thresholds (HIGH and LOW); ii) two reference irrigation treatments (DRY, no irrigation, and WET, irrigation at field capacity). An experimental campaign using the Mikrokopter Okto drone took place on August 2015. The drone was equipped with multispectral and thermal cameras. Since the canopy temperature is an indicator of water stress, crop water stress index (CWSI) values were calculated as the temperature differences between the canopies of the LOW and HIGH treatments and the canopies of the reference treatments. In addition, an automated digital imaging system collected high-resolution vegetation images at daily intervals and the changes in plant colour coordinates (RGB) due to changes in vine phenological stage and water status were detected. The indices obtained from optical sensing observations were then compared with stem water potential, photosynthesis, and fluorescence measurements.

Lo studio è finalizzato alla determinazione dell'impatto ambientale dell'impianto di termovalorizzazione dei rifiuti di Acerra mediante un approccio integrato che, a partire della verifica delle principali sorgenti emissive, prevede rilievi di qualità dell'aria dei comprensori limitrofi e simulazioni modellistiche. Nell'ambito di questo progetto si è realizzato un apparato d'indagine ambientale integrato, basato su misure da piattaforme mobili terrestri ed aeroportate, rilievi di dettaglio dei parametri biofisici ed ambientali e simulazioni modellistiche dell'evoluzione della qualità dell'aria che hanno permesso di ottenere un "source apportionment" a scala locale in grado di quantificare l'apporto delle diverse sorgenti alla qualità dell'aria nel comprensorio di Acerra.

The book addresses in a comprehensive way the full greenhouse gases budget of the Italian landscape, focusing on land use and terrestrial ecosystems. In recent years there has been a growing interest in the role of terrestrial ecosystems with regard to the carbon cycle and only recently a regional approach has been considered for its specificity in terms of new methodologies for observations and models and its relevance for national policies on mitigation and adaptation to climate changes. In terms of methods this book describes the role of flux networks and data-driven models, airborne regional measurements of fluxes and specific sectoral approaches related to important components of the human and natural landscapes. There is also a growing need on the part of institutions, agencies and policy stakeholders for new data and analyses enabling them to improve their national inventories of greenhouse gases and their compliance with the UNFCCC process. In this respect the data presented is a basis for a full carbon accounting and available to relevant stakeholders for improvements and/or verification of national inventories. The wealth of research information is the result of a national project, CARBOITALY, which involved 15 Italian institutions and several researchers to provide new data and analyses in the framework of climate policies

La futura richiesta di biomassa vegetale per soddisfare lo sviluppo della green-economy stimolerà la coltivazione a larga scala di alcune colture dedicate, come ad esempio del panico (Panicum virgatum L.), considerata tra le più promettenti. Capire come questa coltura utilizza l'acqua è fondamentale per comprendere gli effetti a livello di bacino idrico di una coltivazione diffusa, soprattutto in condizioni di clima mediterraneo, dove la disponibilità di acqua in alcuni periodi può essere molto limitata. Lo scopo di questo lavoro è stato quello di monitorare i flussi di H2O, al fine di avere indicazioni sull'efficienza del suo utilizzo per immagazzinare sostanza organica.

Late frost are dangerous climatic hazards that can be responsible of fruit trees yield losses. Late frost potential hazard is, in particular, increased by the enhancement of low-temperature episodes in spring and to the concomitant early-blooming consequent to higher winter temperatures induced by the earth global warming. This paper reports observations on the micrometeorological features associated to frost occurrence in a representative area of the Po valley in order to characterize the atmospheric physics during frost formation episodes, to understand the frequency and the type of risk and to develop the most suitable protection practices. Energy balance and soil radiation balance are reported together with the main atmospheric features (air turbulence included), and the data-set collected are verified against the similarity equations. The computation of the surface roughness and the friction velocity, fundamental to the definition of the distinctive features of the site, has been also done by applying the similarity theory.

A GIS-based model was developed so to predict Biogenic Volatile Organic Compounds (BVOCs) emissions from the Italian forest ecosystems in order to estimate the fraction of the Net Primary Production lost as reduced carbon and to assess the impact of BVOCs in the formation of ozone and secondary organic aerosols. The performance of the model was verified by comparing the predictions with BVOC fluxes measured in a CarboItaly site using the gradient method with tethered balloon profiles, but also with BVOC fluxes measured in previous years. The agreement between observations and predictions indicated a rather accurate estimation of the model and confirmed the importance in the Italian peninsula of monoterpene emissions, expecially of the fast reacting sabinene in areas dominated by Fagus sylvatica L. and Castanea sativa L.

This work was carried out by a consortium of agencies and research institutes, in order to obtain indications on water demand and adaptation of irrigation management of important Italian crops in the coming decades, in the light of climatic scenarios provided by the Agroscenari project. The main results obtained regard integration and improvement of the Criteria crop water balance model and its use to evaluate future irrigation needs of crops like permanent meadows, maize, wheat, tomato, kiwifruit and citrus crops in diverse northern and southern Italy environments. We also developed and implemented an example of "climate service" for early crop classification and seasonal summer irrigation need forecasting in Emilia-Romagna.

SummaryA preliminary analysis was performed to evaluate the structural differences in the different parts of a representative peach tree trained to palmette. The shoot inclination angles showed a spherical and planophile distribution at the top and at the bottom, respectively. The measured canopy transmittance was found to depend on the LAI and solar elevation angle. An empirical model, using an extinction coefficient as a function of the solar elevation angle, was tested to determine the light transmittance in a peach orchard. A good agreement was found between the daily means measured and predicted by the model at three heights in the canopy. The model proved to be useful for estimating diurnal and seasonal variation in the total sunlit leaf area.

This study is the first investigation carried out in EU in a switchgrass field large enough to enable the use of high frequency continuous monitoring. The objective of this study is to describe the net ecosystem exchange of CO2 and the water use efficiency of the agro-ecosystem during the establishment phase.

SummaryThe leaf area index (LAI) of trees at any given time is an important parameter in light interception, photosynthetic productivity and ecophysiological studies. An indirect method based on photosynthetic irradiance measurements is here used to infer the LAI of a peach tree trained to flat palmette. Between the possible probability distributions, the negative binomial distribution appears the more suitable to represent the light penetration inside the canopy throughout the whole growing period, and the specific clumping coefficient of 16.2 is found.

Morphogenic and growth processes were studied in relation to photosynthetically active radiation (PAR), and red, far red and blue spectral bands monitored at three different heights of a peach canopy during the vegetative season. The PAR intercepted by the bottom of the tree was significantly lower than that at the top, and blue fluence rate changed with height and season in a manner similar to PAR. Phytochrome photoequilibria indicated spatial and temporal differences in the three layers of the canopy: significantly lower values were detected at the bottom in correspondence with the maximum leaf area index. In this layer, a stimulation of internode elongation and a decrease of flower density were detected. Higher shoot growth rates and about double number of lateral shoots were found at the top of the canopy, where a greater number of sun leaves was present. Possible explanations in terms of different growth strategies induced by shade, depletion of blue, and low phytochrome levels at the bottom of the canopy are given.

The morphogenic effect of different light wavelengths on in vitro rooting of Prunus insititia GF655-2 in relation to the presence of napthaleneacetic acid (NAA) in the culture medium was investigated. Results of experiments in which plantlets were rooted in NAA enriched medium showed that the presence of auxin induced rooting even in the dark after an initial lag period. Illumination of the cultures with Red light was as effective in promoting rooting as treatment with 0.5 μM NAA; Red was more active in stimulating rooting in the short term than was NAA. The pattern of root formation resulting from the addition of NAA appeared to dominate development under White, Blue and Far Red treatments. Although it was possible to correlate the rooting response to the phytochrome photoequilibrium induced by the light treatments used, there arises a possible interference of specific Blue absorbing photoreceptors.

Un'’interessante scoperta fatta nella foresta amazzonica ha dato il via alle ricerche sull'’impiego del carbone di legna in agricoltura .Dopo le prime prove realizzate sulla lattuga i risultati sono promettenti.

Endogenous and exogenous volatile substances were analyzed during 30 days' incubation of four cultivars of thePrunus avium species grown in vitro on a proliferation medium. Cultivars Bigarreau Moreau and Bigarreau Burlat show photosynthetic capability at 35 ?mol·m-2·s-1; oxygen concentration slightly increased (22 to 24%), carbon dioxide was lowered to less than 300 ?·liter-1, and low ethylene (0.8 to 1.2·liter-1) accumulation was recorded. Quite different headspace evolution was observed during growth of cultivars Victoria and Casavecchia: a large oxygen concentration decrease was accompanied by a sharp carbon dioxide increase (19%) and ethylene boost (4 to 5 ?l·liter-1). The evolution of these gaseous metabolites has been correlated to photosynthetic incapability and respiratory stress responsible for leaf yellowing and tissue softening observed when acetaldehyde and ethanol started to form in cultivars Victoria and Casavecchia. Dry and fresh weight were measured, and no substantial difference was recorded among cultures with low and high photosynthetic capability. Evidence is reported that different genotypes within the same species may follow different metabolic pathways.

International audience; The drought of 2003 was exceptionally severe in many regions of Europe, both in duration and in intensity. In some areas, especially in Germany and France, it was the strongest drought for the last 50 years, lasting for more than 6 months. We used continuous carbon and water flux measurements at 12 European monitoring sites covering various forest ecosystem types and a large climatic range in order to characterise the consequences of this drought on ecosystems functioning. As soil water content in the root zone was only monitored in a few sites, a daily water balance model was implemented at each stand to estimate the water balance terms: trees and understorey transpiration, rainfall interception, throughfall, drainage in the different soil layers and soil water content. This model calculated the onset date, duration and intensity of the soil water shortage (called water stress) using measured climate and site properties: leaf area index and phenology that both determine tree transpiration and rainfall interception, soil characteristics and root distribution, both influencing water absorption and drainage. At sites where soil water content was measured, we observed a good agreement between measured and modelled soil water content. Our analysis showed a wide spatial distribution of drought stress over Europe, with a maximum intensity within a large band extending from Portugal to NE Germany. Vapour fluxes in all the investigated sites were reduced by drought, due to stomatal closure, when the relative extractable water in soil (REW) dropped below ca. 0.4. Rainfall events during the drought, however, typically induced rapid restoration of vapour fluxes. Similar to the water vapour fluxes, the net ecosystem production decreased with increasing water stress at all the sites. Both gross primary production (GPP) and total ecosystem respiration (TER) also decreased when REW dropped below 0.4 and 0.2, for GPP and TER, respectively. A higher sensitivity to drought was found in the beech, and surprisingly, in the broadleaved Mediterranean forests; the coniferous stands (spruce and pine) appeared to be less drought-sensitive. The effect of drought on tree growth was also large at the three sites where the annual tree growth was measured. Especially in beech, this growth reduction was more pronounced in the year following the drought (2004). Such lag effects on tree growth should be considered an important feature in forest ecosystems, which may enhance vulnerability to more frequent climate extremes. (c) 2007 Elsevier B.V. All rights reserved.

Microclimate modification induced by intermittent water sprinkling at ground level has proven to be suitable to enhance protection against spring hoarfrosts in orchards. This research investigates about the efficiency of different sprinkler types and water volumes in enhancing air temperature in the canopy layer and to optimise the amount and the cycling of the water applied. Tests have been done over three consecutive years in purpose-built boxes delimited by polyethylene film where different sprinklers and sprayers tested were positioned along two pipes. Microsprinklers and microsprayers with different characteristics and outflow capacity were compared to evaluate whether the size of the drops can induce modification of energy balance at the surface. The impact of below-tree water sprinkling on the temperature profile appeared to be evident independently on the irrigation device and of the outflow tested. While no substantial differences between sprinklers and sprayers did not arise when the temperatures kept above 3 C, when temperatures fell below 3 C (even down to 7/)8 C), a better performance of the microsprinklers with respect to microsprayers was observed. Differences tend to fade out with height. In the same temperature conditions, a better performance of the microsprinklers with higher outflow (65 l/h) with respect to the same model characterised by a lower outflow (45 l/h) clearly emerged.

Light partition has been examined and evaluated on five woody species (Olea europaea, Ficus carica, Pittosporum tobira, Hedera helix maculata, Persica vulgaris) in relation to their leaf morpho-histological characteristics, water and chlorophyll contents. Leaf parameters and optical properties (reflectance, transmittance, absorbance) in PAR, FR and NIR wavebands (400–1100 nm) were preliminarily submitted to a canonical correlation analysis where lamina thickness and water content showed a leading role in determining all the optical properties, while chlorophyll, influential in the PAR region, was remarkably effective only in an extreme pigment situation when green and albino patches of ivy leaves were compared. Transmittance appeared inversely related to lamina thickness in accordance with the Lambert Beer law. Significant correlations were found also between mesophyll water content and both transmittance (positive) and reflectance (negative). Olive leaves showed peculiar optical patterns because of the dense and continuous trichome layer on their abaxial surface.

Light absorbance and reflectance were measured on representative shrubs of two dominant shrub species (Pistacia lentiscus and Juniperus phoenicea) of coastal Mediterranean macchia ecosystems in Sardinia (Italy). An array of 64 calibrated photodiodes was adopted for both calculations of leaf area index (LAI) and canopy transmittance of photosynthetic active radiation (PAR). PAR and NIR reflectance of canopies having similar LAI allowed us to establish the particular optical properties of each species. Lentisk reflected twice as much as juniper in the 700–1,100 spectral region. Water indexes of the two species were also different in relation to leaf water content and red edge amplitude appeared to be related to chlorophyll content. Epidermis and mesophyll structures of both species are shown.