Papers by Franco Miglietta
New Phytologist, 2001
A new design of free-air CO 2 enrichment (FACE) is presented that has been used to expose a popla... more A new design of free-air CO 2 enrichment (FACE) is presented that has been used to expose a poplar plantation to elevated atmospheric CO 2 concentrations in otherwise unaltered conditions, in the open.
Global Biogeochemical Cycles, 2003
index. Thus, for a monthly timescale, we developed a simple T&P&LAI model that includes leaf area... more index. Thus, for a monthly timescale, we developed a simple T&P&LAI model that includes leaf area index as an additional predictor of soil respiration. This extended but still simple model performed nearly as well as the more detailed time step model and explained 50% of the overall and 65% of the site-to-site variability. Consequently, better estimates of globally distributed soil respiration should be obtained with the new model driven by satellite estimates of leaf area index. Before application at the continental or global scale, this approach should be further tested in boreal, cold-temperate, and tropical biomes as well as for non-woody vegetation. INDEX TERMS: 1615 Global Change: Biogeochemical processes (4805); 3210 Mathematical Geophysics: Modeling; KEYWORDS: carbon balance, drought, leaf area index Citation: Reichstein, M., et al., Modeling temporal and large-scale spatial variability of soil respiration from soil water availability, temperature and vegetation productivity indices, Global Biogeochem.
Global Change Biology, 2005
This paper discusses the advantages and disadvantages of the different methods that separate net ... more This paper discusses the advantages and disadvantages of the different methods that separate net ecosystem exchange (NEE) into its major components, gross ecosystem carbon uptake (GEP) and ecosystem respiration (Reco). In particular, we analyse the effect of the extrapolation of night-time values of ecosystem respiration into the daytime; this is usually done with a temperature response function that is derived from long-term data sets. For this analysis, we used 16 one-year-long data sets of carbon dioxide exchange measurements from European and US-American eddy covariance networks. These sites span from the boreal to Mediterranean climates, and include deciduous and evergreen forest, scrubland and crop ecosystems.We show that the temperature sensitivity of Reco, derived from long-term (annual) data sets, does not reflect the short-term temperature sensitivity that is effective when extrapolating from night- to daytime. Specifically, in summer active ecosystems the long-term temperature sensitivity exceeds the short-term sensitivity. Thus, in those ecosystems, the application of a long-term temperature sensitivity to the extrapolation of respiration from night to day leads to a systematic overestimation of ecosystem respiration from half-hourly to annual time-scales, which can reach >25% for an annual budget and which consequently affects estimates of GEP. Conversely, in summer passive (Mediterranean) ecosystems, the long-term temperature sensitivity is lower than the short-term temperature sensitivity resulting in underestimation of annual sums of respiration.We introduce a new generic algorithm that derives a short-term temperature sensitivity of Reco from eddy covariance data that applies this to the extrapolation from night- to daytime, and that further performs a filling of data gaps that exploits both, the covariance between fluxes and meteorological drivers and the temporal structure of the fluxes. While this algorithm should give less biased estimates of GEP and Reco, we discuss the remaining biases and recommend that eddy covariance measurements are still backed by ancillary flux measurements that can reduce the uncertainties inherent in the eddy covariance data.
Global Change Biology, 1997
Global Change Biology, 2002
Eddy covariance and sapflow data from three Mediterranean ecosystems were analysed via top-down a... more Eddy covariance and sapflow data from three Mediterranean ecosystems were analysed via top-down approaches in conjunction with a mechanistic ecosystem gas-exchange model to test current assumptions about drought effects on ecosystem respiration and canopy CO 2 /H 2 O exchange. The three sites include two nearly monospecific Quercus ilex L. forests ± one on karstic limestone (Pue Âchabon), the other on fluvial sand with access to ground water (Castelporziano) ± and a typical mixed macchia on limestone (Arca di Noe Á). Estimates of ecosystem respiration were derived from light response curves of net ecosystem CO 2 exchange. Subsequently, values of ecosystem gross carbon uptake were computed from eddy covariance CO 2 fluxes and estimates of ecosystem respiration as a function of soil temperature and moisture. Bulk canopy conductance was calculated by inversion of the Penman-Monteith equation. In a top-down analysis, it was shown that all three sites exhibit similar behaviour in terms of their overall response to drought. In contrast to common assumptions, at all sites ecosystem respiration revealed a decreasing temperature sensitivity (Q 10 ) in response to drought. Soil temperature and soil water content explained 70±80% of the seasonal variability of ecosystem respiration. During the drought, light-saturated ecosystem gross carbon uptake and day-time averaged canopy conductance declined by up to 90%. These changes were closely related to soil water content. Ecosystem water-use efficiency of gross carbon uptake decreased during the drought, regardless whether evapotranspiration from eddy covariance or transpiration from sapflow had been used for the calculation. We evidence that this clearly contrasts current models of canopy function which predict increasing ecosystem water-use efficiency (WUE) during the drought. Four potential explanations to those results were identified (patchy stomatal closure, changes in physiological capacities of photosynthesis, decreases in mesophyll conductance for CO 2 , and photoinhibition), which will be tested in a forthcoming paper. It is suggested to incorporate the new findings into current biogeochemical models after further testing as this will improve estimates of climate change effects on (semi)arid ecosystems' carbon balances.
The effect of training system and cultivar on the rate of leaf appearance of the grapvine (Vitis vinifera L.)
Go to AGRIS search. Try it! Journal International des Sciences de la Vigne et du Vin (Avr-Jun 1995).
Applicazioni della modellistica in agrometeorologia
Foliar antioxidant status of plants from naturally high‐CO2 sites
2. Abstract We compared the foliar antioxidant status of native Agrostis stolonifera L. communiti... more 2. Abstract We compared the foliar antioxidant status of native Agrostis stolonifera L. communities growing at two distinct CO 2-enriched sites of geothermal origin (E) and at a control field location with normal CO 2. Compared to the control, plants from both E-sites showed an increased size of the GSH pool, essentially due to enhanced GSSG levels, and a consequent decrease in the ratio between reduced and oxidised glutathione forms.
Plant response to elevated carbon dioxide
Stomatal numbers in holm oak (Quercus ilex L.) leaves grown in naturally and artificially CO2-enriched environments.
Abstract The objects of the present study were:(1) to investigate the stomatal morphology of leav... more Abstract The objects of the present study were:(1) to investigate the stomatal morphology of leaves of holm oak trees grown in a naturally CO 2-enriched environment;(2) to compare it with the stomatal density of leaves of holm oak seedlings grown in an artificially CO 2-enriched environment. Among the stomatal morphology parameters we analysed, the only significant alteration we observed in trees which had grown by the CO 2 spring was a reduction in stomatal density.
Free air carbon dioxide enrichment of a poplar plantation: description and performance of the POPFACE system
Validating an integrated strategy to model net land carbon exchange against aircraft flux measurements
Aircraft eddy covariance technique is a modern and powerful means to directly measure net ecosyst... more Aircraft eddy covariance technique is a modern and powerful means to directly measure net ecosystem exchange (NEE) over relatively large land areas. The NEE measurements taken by a specifically developed aircraft platform (Sky Arrow ERA) over a transect in Central Italy during an 18-month period are used to validate a recently proposed modeling strategy.
Ecosystem response to CO2: The MAPLE project results
Experiments on the effects of increased temperature and/or elevated concentrations of carbon dioxide on crops. Mini Free Air Carbon dioxide Enrichment (FACE) experimenst on grapevine
The impact of elevated CO2 on the growth of Agrostis canina and Plantago major adapted to contrasting CO2 concentrations.
Abstract Plant species native to CO 2 springs have evolved along gradients of naturally elevated ... more Abstract Plant species native to CO 2 springs have evolved along gradients of naturally elevated atmospheric CO 2 concentrations that differ as much as predicted for anthropogenic increases in CO 2 over the next 100-200 years. This study characterized differences in growth and dry matter partitioning under controlled conditions in two species, Agrostis canina L. spp. montelucci (Selvi, 1994) and Plantago major L., adapted to contrasting atmospheric CO 2 concentrations.
Keita integrated project: an appropriate model for sustainable development
Free air CO2 enrichment of potato: leaf consumption and larval growth of Colorado potato beetle (Leptinotarsa decemlineata Say).
Abstract There is evidence that elevated atmospheric CO 2 concentrations alter the chemical compo... more Abstract There is evidence that elevated atmospheric CO 2 concentrations alter the chemical composition of the leaves of plants. This effect was examined on larval growth of Colorado potato beetle (Leptinotarsa decemlineata Say) in a study in Italy. Leaves grown at different CO 2 concentrations in a potato FACE (free air CO 2 enrichment) experiment, were used to feed larvae of Colorado potato beetle. Measurements of larval growth were made daily for one week.
EC Fifth Framework Project QLK5-1999-01554: Risks associated with Tilletia indica, the newly-listed EU quarantine pathogen, the cause of Karnal bunt of wheat
Sansford, C.; Baker, R.; Brennan, J.; Ewert, F.; Gioli, B.; Inman, A.; Kelly, P.; Kinsella, A.; L... more Sansford, C.; Baker, R.; Brennan, J.; Ewert, F.; Gioli, B.; Inman, A.; Kelly, P.; Kinsella, A.; Leth, V.; Magnus, H.; Miglietta, F.; Murray, G.; Peterson, G.; Porta-Puglia, A.; Porter, JR; Rafoss, T.; Riccioni, L.; Thorne, F.; Valvassori, M.
Plant-CO2 responses in the long term: plants from CO2 springs in Florida and tombs in Egypt.
Abstract Seeds were collected from populations of Boehmeria cylindrica growing in naturally enric... more Abstract Seeds were collected from populations of Boehmeria cylindrica growing in naturally enriched concentrations of CO 2. In the controlled environment plants grown from populations which are normally exposed to enriched atmospheres of CO 2 (400 to 575 ppmv) show a greater CO 2-sensitivity of growth than plants from ambient (370 ppmv) sites.
Mini Free Air Carbon Dioxide Enrichment (FACE) Experiments on Grapevine
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Papers by Franco Miglietta