1,721,080 research outputs found
The importance of local scale for assessing, monitoring and predicting of air quality in urban areas
No full textThe importance of the spatial scale for counteracting urban air pollution is highlighted in this work. In particular, the concept of Environmental Areas is used here in a wider sense than the current one. The Environmental Area is an area where the traffic conditions are more favourable for walkability and cycling compared to those of private motor vehicles. This work extends this concept to integrate several approaches coming from dimensional analysis, ecology, urban planning and transport engineering, to define a suitable spatial scale for an estimation of the PM10 removal through the street trees. Results highlight that, within the monitored area (the Monteverde neighbourhood, Rome Italy), the street trees are able to remove 0.142 t ha(-1) year(-1) of PM10 (about the 57% of the total particulate emission) with a re-suspension from plant canopies of 4%. Results have also demonstrated how is important an effective management of trees and the choice of appropriate trees made in according to the leaves' characteristics but also related to urban context in which trees are placed. We highlight that integrated planning among different elements of the public urban space is of great importance for ameliorating the urban liveability. Moreover, we remark that this Environmental Areas-based approach contributes to promote in citizens a greater knowledge of the territory and awareness of the dynamics that affect it and consequently a wider participation to public decisions concerning the choice, implementation and management of the street trees, reduction of car-based mobility and increase of pedestrian and cyclist mobility
Risposte ecofisiologiche alle condizioni ambientali estive di due specie legnose sempreverdi.
No full textDallo studio emerge l'importanza dei parametri micro-ambientali nell'influenzare l'andamento dell'attività fisiologica fogliare delle due specie analizzate. L'umidità relativa risulta essere un parametro importante nel controllo dell'attività stomatica, anche se in tal caso devono essere considerati anche i fattori endogeni. le due specie risultano essere particolarmente avvantaggiate, rispetto ad altre specie mediterranee, riguardo al mantenimento funzionale degli scambi gassosi, anche in condizioni ambientali limitanti
Cambiamenti climatici in area mediterranea: simulazione della risposta funzionale di una faggeta del centro Italia in condizioni di limitazione idrica.
No full textSono esposti i risultati di una simulazione di uso dell'acqua da parte di una faggeta dell'Italia centrale in condizioni climatiche attuali e future. L'eccessiva richiesta di acqua da parte della faggeta nelle condizioni di cambiamento climatico futuro non consente il mantenimento nel tempo e nello spazio della faggeta stessa
Monitoring tropospheric ozone impact on plants in natural and urban areas with a Mediterranean climate
No full textTo investigate the real linkage and effectiveness of using the AOT40 index and ozone stomatal flux (FO3) in the assessment of physiological alteration/leaf injury on clover clones sensitive to ozone and Quercus ilex plants, two statistical techniques Partial Least Squares (PLS) and Neural Net Analysis (NNA)-were applied. Different results were obtained in relation to the statistical method chosen. Linear methodologies applied to clover highlighted the role of temperature (TEMP) and O-3 concentration (O(3)Mean) in affecting photosynthesis (PHOTO), leaf injury, and stomatal conductance (COND). In Quercus plants, COND was linearly correlated to two environmental variables, TEMP and Vapour Pressure Deficit (VPD), and to two physiological variables, PHOTO and Leaf Transpiration (TRASP), whereas PHOTO was correlated with TEMP, sO(3), COND and sub-stomatal CO2/external CO2 ratio (Ci/Ca). These linear relationships were, in part, modified by NNA. In fact, non-linear relationships between environmental variables, and morphological and physiological variables were evident, suggesting caution when risk assessments are made on ozone concentration-based critical levels. Both plant types showed a relationship with FO3 that negatively affected leaf injury and PHOTO in clover and Quercus plants, respectively, suggesting that ozone flux-based critical levels were more effective in linking with leaf injuries or reduction in carbon metabolism
Stima della produttività di Vitis vinifera L., tramite un modello big-leaf
No full textIn order to assess primary productivity and transpiration of plant communities
several approaches are used. Here a modification of the model
developed by Vitale et al., based on the ‘big leaf’ approach, has
been used to model functional behaviour of Vitis vinifera L. Model
inputs are: latitude; mean temperature on monthly basis; maximum
photosynthesis rate; Quantum Yield as a temperature function; leaf
angle; reference temperature for respiration. Field gas-exchange measurements
were carried out at leaf level and it was necessary to make
some assumptions on canopy structure in order to avoid overestimation
of biomass production. These assumptions are required since canopies
structure in known to influence productivity and to determine
canopy conductance. The model estimates a crop net production of
186 g dry weight/m2, in accordance with field data. The model also
highlights the relationship between biomass production and canopy
structure in accordance with those productivity models based on
allometric relationship
Studio ecofisiologico condotto su Citrus sinensis (L.) Osbeck nell’ambito del progetto internazionale B.E.M.A.
No full textLo studio condotto ha permesso di rilevare che: 1) i valori di fotosintesi delle foglie con età maggiore di 1 anno sono inferiori rispetto a quelle di 1 anno o meno; 2) le condizioni micro-climatiche influenzano notevolemente la risposta funzionale delle foglie; 3) i due cloni di Citrus sinensis esaminati (Iniasel 72-12 e 2-7) presentano differenti pattern fotosintetici. Tali risultati contribuiscono alla fattibilità di un modello di simulazione su altra scala per la stima delle emissioni biogeniche e del loro trasporto nell'atmosfera
Risposta funzionale di Quercus cerris L. e Ostrya carpinifolia Scop. a differenti condizioni ambientali.
No full textL'obiettivo della ricerca è stato quello di approfondire la conoscenza della risposta del cerro e del carpino nero a diverse condizioni ambientali di luce e di CO2 ma in condizioni di umidità costante. I risultati evidenziano la maggiore capacità fotosintetica del cerro e un maggiore adattamento funzionale del carpino nero nei riguardi dell'efficienza quantica e dell'uso dell'acqua. Le differenti risposte funzionali consentono di bene interpretare il ruolo descritto negli ambiti successionanli propri di queste due importanti specie vegetali
Report on the 2nd BEMA measuring campaign Monpellier - France, June 1995. Ecophysiological studies of Mediterranean plant species in the frame of interdisciplinary research programme B.E.M.A. 1995.
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