Papers by G. Scarascia-mugnozza
Ecological Studies, 2000
... In: Borghetti M (ed) Proc 1st Congr of the Italian Sylviculture and Forest Ecology Society 1,... more ... In: Borghetti M (ed) Proc 1st Congr of the Italian Sylviculture and Forest Ecology Society 1, Padova, Italy, pp 225-232 Nihlgard B, Lindgreen L (1977) Plant biomass, primary production and bioelements of three mature beech forests in South Sweden. ...
Plant Science, 2001
During an open-top chamber experiment performed in evergreen 'macchia' ecosystem, which was repre... more During an open-top chamber experiment performed in evergreen 'macchia' ecosystem, which was represented by the clumps of natural vegetation dominated by Quercus ilex trees, the trees were exposed to one of two CO 2 concentrations (ambient CO 2 , AC-variant and elevated CO 2 , i.e. ambient plus 350 mmol CO 2 mol − 1 , EC-variant) continuously over 5 years. Clumps of natural vegetation were enclosed in open top chambers (OTCs). Within the crowns of investigated Quercus ilex trees in OTCs, two crown layers i.e. sunny (E-leaves) and shaded (S-leaves), were identified as differing in solar radiation environment. To evaluate the effect of elevated CO 2 , as well as the functional differentiation in assimilation activity of E-versus S-leaves, gas exchange and chlorophyll a6 fluorescence techniques were used. The stimulatory effect of the long-term elevated CO 2 on the A N-PPFD relation was evident in E-and S-leaves of investigated Quercus trees. The A Nmax sensitivity of AC-variant leaves to the sudden application of elevated CO 2 was higher for S-leaves (42%) than for E-leaves (24%). The PPFD saturated rate of regulated thermal energy dissipation (ERD) confirmed the foliage differentiation caused by the long-term influence of elevated CO 2. The ERD of E-and S-leaves in the AC-variant were 1.11 times of that in the EC-variant. However, the estimated rates of photochemistry (ERP) of E-and S-leaves in the EC-variant were 1.35 and 1.22 times of E-and S-leaves in the AC-variant. The achievement of the critical value of q P =0.4 in E-and S-leaves from the EC-variant under lower values of PPFD compared to the AC-variant indicates a higher degree of PSII over-reduction. Thus, elevated CO 2 can be responsible for an increased susceptibility of photosynthetic apparatus to high irradiance. The obtained results support the hypothesis on the foliage vertical distribution effect on the whole canopy response to elevated CO 2. The S-layers of the canopy can play an important role in providing storage space for photosynthesis under elevated CO 2 .
Scientific Tools and …
... of Forests to Global Change: Measurements and Modelling Simulations in a Mountain Forest of t... more ... of Forests to Global Change: Measurements and Modelling Simulations in a Mountain Forest of the Mediterranean Region1 Giorgio Matteucci1, Alberto ... PH, Berbigier, P., Bernhofer, Ch., Clement, R., Elbers, J., Granire, A., Grünwald, T., Morgenstern, K., Pilegaard, K., Rebmann ...
Plant, Cell and Environment, 1996
ABSTRACT
New Phytologist, 2001
• A new design of free-air CO 2 enrichment (FACE) is presented that has been used to expose a pop... 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. • This system releases pure CO 2 at high velocity, through a large number of small gas jets, causing rapid mixing between CO 2 and air. The theoretical and practical aspects of this design are described, with emphasis on the fluid mechanics of air-CO 2 mixing in sonic jets. Field performance data, including spectral analysis of shortterm fluctuations in CO 2 concentrations as well as temporal and spatial CO 2 control, are reported for the European project POPFACE facility. • Temporal and spatial performances of the operational POPFACE systems were adequate with average long-term CO 2 mole fractions on target. Averages over 1 min measured in the centre of the rings were within ± 20% and ± 10% of the target concentration for > 91% and > 75% of the time, respectively. • The data presented provide convincing evidence that a pure-CO 2 FACE system can achieve reliable control, in terms of the quality of the CO 2 control, with significant simplification of construction and reduced capital cost.
Global Biogeochemical Cycles, 2004
In order to establish suitability of forest ecosystems for long-term storage of C, it is necessar... more In order to establish suitability of forest ecosystems for long-term storage of C, it is necessary to characterize the effects of predicted increased atmospheric CO 2 levels on the pools and fluxes of C within these systems. Since most C held in terrestrial ecosystems is in the soil, we assessed the influence of Free Air Carbon Enrichment (FACE) treatment on the total soil C content (C total) and incorporation of litter derived C (C new) into soil organic matter (SOM) in a fast growing poplar plantation. C new was estimated by the C3/C4 stable isotope method. C total contents increased under control and FACE respectively by 12 and 3%, i.e., 484 and 107 gC/m 2 , while 704 and 926 gC/m 2 of new carbon was sequestered under control and FACE during the experiment. We conclude that FACE suppressed the increase of C total and simultaneously increased C new. We hypothesize that these opposite effects may be caused by a priming effect of the newly incorporated litter, where priming effect is defined as the stimulation of SOM decomposition caused by the addition of labile substrates.
Nature Geoscience, 2019
Large herbivores, such as elephants, can have important effects on ecosystems and biogeochemical ... more Large herbivores, such as elephants, can have important effects on ecosystems and biogeochemical cycles. Yet, the influence of elephants on the structure, productivity and carbon stocks in Africa's rainforests remain largely unknown. Here, we quantify those effects by incorporating elephant disturbance in the Ecosystem Demography model, and verify the modelled effects by comparing them with forest inventory data from two lowland primary forests in Africa. We find that the reduction of forest stem density due to the presence of elephants leads to changes in the competition for light, water and space among trees. These changes favour the emergence of fewer and larger trees with higher wood density. Such a shift in African's rainforest structure and species composition increases the long-term equilibrium of aboveground biomass. The shift also reduces the forest net primary productivity, given the trade-off between productivity and wood density. At a typical density of 0.5 to 1 animals per km 2 , elephant disturbances increase aboveground biomass by 26-60 t ha −1. Conversely, the extinction of forest elephants would result in a 7% decrease in the aboveground biomass in central African rainforests. These modelled results are confirmed by field inventory data. We speculate that the presence of forest elephants may have shaped the structure of Africa's rainforests, which probably plays an important role in differentiating them from Amazonian rainforests.
Plant Biosystems - An International Journal Dealing with all Aspects of Plant Biology, 2011
In this study, the genes of the Aux/IAA family were used as functional markers to characterise bu... more In this study, the genes of the Aux/IAA family were used as functional markers to characterise bud break stages in a white poplar clone. In the first experiment, under greenhouse conditions, the sprouting of repressed sylleptic buds was obtained by pruning the shoot tip during growing season. Buds were collected at 0, 6, 24 and 48 h after pruning for molecular analyses. A decrease in transcript level of IAA4 and IAA8 genes was observed in the first and second bud below the cut after 6 and 24 h, respectively. In the second experiment, bud break of post-dormant proleptic buds was induced by forcing in climatic chamber. The first 6 and the following 6 buds below the apical one were sampled every 48 h during forcing. Anatomical studies were also carried out on buds and plants were equipped with stem and bud radial growth sensors to check their swelling. In both experiments, gene expression patterns showed a decrease and a successive increase in expression of IAA4 and IAA8 genes during bud break. The transient down-regulation of these genes was observed only in buds that formed new branches. Thus, similar molecular mechanisms are involved in bud break of both sylleptic and proleptic buds.
Forest@ - Rivista di Selvicoltura ed Ecologia Forestale, 2011
Forest@ - Rivista di Selvicoltura ed Ecologia Forestale, 2005
Biologia plantarum, 2011
Rooted cuttings of Populus nigra L. clone Poli and Salix alba L. clone SS5 were treated for three... more Rooted cuttings of Populus nigra L. clone Poli and Salix alba L. clone SS5 were treated for three weeks with 50 μM CdSO 4 in nutrient solution. The willow showed a far higher Cd tolerance, expressed as tolerance index (Ti), than the poplar in both roots and leaves. The root Cd content was higher in poplar than in willow, whereas in leaves the opposite was found. As a consequence, the translocation factor (Tf) revealed a greater ability of Cd transport in willow than in poplar. Cd treatment enhanced cysteine, γ-glutamylcysteine and reduced glutathione contents in roots of both species, whereas in leaves they were only enhanced in poplar. Furthermore, only poplar leaves showed an enhanced content of phytochelatins, whereas malic and citric acids rose in response to Cd only in the willow leaves. Cd treatment increased putrescine, spermidine and spermine contents in both roots and leaves of the willow, whereas in poplar only the putrescine content was enhanced in roots.
On the 5 th and 6 th of July 2004, the Heads of National Forest Research Institutes (NFRIs) of MC... more On the 5 th and 6 th of July 2004, the Heads of National Forest Research Institutes (NFRIs) of MCPFE-countries convened in Vienna for their first meeting 1. One of the decisions taken at that meeting was that the NFRIs together, with the European Forest Institute as coordinator, will undertake steps aiming at a better integration of forest research in the upcoming EU's 7 th Framework Programme for R&D, inviting also other institutions and organisations to participate in this effort. A small Task Force was established for this task, consisting of François Houllier, INRA,
It becomes apparent that some of the relations that were established along the CANIF transect nee... more It becomes apparent that some of the relations that were established along the CANIF transect need to be confirmed for a broader range of habitats The selected sites for CANT were mainly old stands that were in equilibrium with site conditions. It remains unclear how forest management interferes with these processes.
Forest@ - Rivista di Selvicoltura ed Ecologia Forestale, 2007
Forest@ - Rivista di Selvicoltura ed Ecologia Forestale, 2009
Soil carbon accumulation in a Populus spp. plantation supplied with high atmospheric CO 2 and nit... more Soil carbon accumulation in a Populus spp. plantation supplied with high atmospheric CO 2 and nitrogen fertilization. This work was carried out in the experimental area POPFACE (Tuscania, Viterbo, Italy), where a poplar short rotation forest (SRF) was treated with 550 ppm of atmospheric CO 2 for six years. The experimental plots (Control and FACE) were divided in two halves, one of which was treated with nitrogen fertilization. The general aim of this research was to quantify the impact of the two rotation cycles, the CO 2 enrichment and the nitrogen fertilization on: i) soil organic matter fractions more relevant for microbial metabolism; ii) microbial C mineralization activity; and iii) the ecosystem capacity to store C in the soil. On soil samples collected from 2000 to 2004, the soil Organic C (TOC), the total extractable C (TEC) and several labile C fractions (MBC, WSC, ExC) were analysed. The microbial mineralization activity was also analysed. In comparison with the previous culture crop, the plantation increased the organic C storage in soil by about 23% in the second rotation cycle. Under elevated CO 2 , the increase of above-and belowground productivity supported a greater accumulation of labile C in soil, favouring a microbial C immobilization process. Fertilization treatment induced short-term changes in the soil C content, without overall modifications in the second rotation cycle.
Environmental pollution (Barking, Essex : 1987), 2014
Ozone flux estimates from the i-Tree model were compared with ozone flux measurements using the E... more Ozone flux estimates from the i-Tree model were compared with ozone flux measurements using the Eddy Covariance technique in a periurban Mediterranean forest near Rome (Castelporziano). For the first time i-Tree model outputs were compared with field measurements in relation to dry deposition estimates. Results showed generally a good agreement between predicted and measured ozone fluxes (least sum square=5.6 e(-4)) especially when cumulative values over the whole measurement campaign are considered. However at daily and hourly time-step some overestimations were observed in estimated values especially in hot dry periods. The use of different m values in the Ball-Berry formula in the different periods, produced the best fit between predicted and measured ozone fluxes. This suggests that a variable value for the coefficient m accounting for water availability may be appropriate to improve model estimates for Mediterranean and drought prone regions.
iForest - Biogeosciences and Forestry, 2015
Nitrogen removal and its determinants in hybrid Populus clones for bioenergy plantations after tw... more Nitrogen removal and its determinants in hybrid Populus clones for bioenergy plantations after two biennial rotations in two temperate sites in northern Italy.
Forest@ - Rivista di Selvicoltura ed Ecologia Forestale, 2007
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Papers by G. Scarascia-mugnozza