26 results on '"Virzo De Santo, Amalia"'
Search Results
2. Indirect effects of trophic interactions govern carbon circulation in two beech forest soil ecosystems.
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Lozano Fondón, Carlos, Scotti, Marco, Innangi, Michele, Bondavalli, Cristina, De Marco, Anna, Virzo De Santo, Amalia, Fioretto, Antonietta, Menta, Cristina, and Bodini, Antonio
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FOOD chains ,BEECH ,PREDATION ,CARBON ,ECOSYSTEMS - Abstract
Forest soils harbour a vast array of organisms that govern the processing of organic matter. Through their trophic interactions, they give rise to carbon flows that sustain soil ecosystem functioning. Understanding how soil food webs shape carbon flows may enhance our knowledge about the role of biodiversity on soil processes.In this work, we assembled trophic networks representing soil food webs of two beech forests during spring and autumn, and compiled mass‐balanced models quantifying carbon flows between their components. These models were investigated using network analysis to identify the role of the components on carbon flow, cycling and functional trophic relationships. Moreover, we explored how the structure of carbon exchanges promote efficiency and stability.Results indicate the importance of indirect interactions. Most trophic groups exhibit a diffuse dependency on all the compartments for their carbon requirement although certain groups such as Collembola play the role of hubs in distributing carbon. Indirect interactions often reverse the impacts of direct trophic relationships being antagonistic to the direction of change predicted based on predator–prey interactions. The high incidence of generalist feeding habits increases the redundancy of energy channels thereby making such food webs more resilient against perturbations but at the expense of carbon transfer efficiency.Although differences can be observed across sites and periods, food web structure rather than environmental variability seems to be the main factor responsible for patterns of carbon flows in the two beech forests. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]
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- 2023
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3. Impact of the invasive tree black locust on soil properties of Mediterranean stone pine-holm oak forests
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De Marco, Anna, Arena, Carmen, Giordano, Maria, and Virzo De Santo, Amalia
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- 2013
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4. NMR (1H) analysis of crude extracts detects light stress in Beta vulgaris and Spinacia oleracea leaves
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Guadagno, Carmela Rosaria, Della Greca, Marina, Virzo De Santo, Amalia, and D’Ambrosio, Nicola
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- 2013
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5. Non-additive effects of litter mixtures on decomposition of leaf litters in a Mediterranean maquis
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De Marco, Anna, Meola, Angela, Maisto, Giulia, Giordano, Maria, and Virzo De Santo, Amalia
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- 2011
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6. Factors regulating litter mass loss and lignin degradation in late decomposition stages
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Virzo De Santo, Amalia, De Marco, Anna, Fierro, Angelo, Berg, Björn, and Rutigliano, Flora A.
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- 2009
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7. Growth and gas exchange response to water shortage of a maize crop on different soil types
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Vitale, Luca, Di Tommasi, Paul, Arena, Carmen, Riondino, Michele, Forte, Annachiara, Verlotta, Angelo, Fierro, Angelo, Virzo De Santo, Amalia, Fuggi, Amodio, and Magliulo, Vincenzo
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- 2009
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8. Effects of water stress on gas exchange of field grown Zea mays L. in Southern Italy: an analysis at canopy and leaf level
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Vitale, Luca, Di Tommasi, Paul, Arena, Carmen, Fierro, Angelo, Virzo De Santo, Amalia, and Magliulo, Vincenzo
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- 2007
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9. Trace metals in the soil and in Quercus ilex L. leaves at anthropic and remote sites of the Campania Region of Italy
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Maisto, Giulia, Alfani, Anna, Baldantoni, Daniela, De Marco, Anna, and Virzo De Santo, Amalia
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- 2004
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10. Suitability of soil microbial parameters as indicators of heavy metal pollution
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Virzo de Santo Amalia, Castaldi Simona, Rutigliano Flora Angela, Castaldi, Simona, Rutigliano, Flora Angela, and VIRZO DE SANTO, A.
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Pollution ,Environmental Engineering ,biology ,Chemistry ,Ecological Modeling ,media_common.quotation_subject ,Biomass ,heavy metal ,Soil contamination ,microbial activity ,soil ,Respirometry ,microbial bioma ,Biochemistry ,Microbial population biology ,Environmental chemistry ,Soil water ,Biomonitoring ,biology.protein ,Environmental Chemistry ,biomarker ,pollution ,Arylsulfatase ,Water Science and Technology ,media_common - Abstract
Several microbial parameters (microbial biomass, respiration, dehydrogenase, phosphatase, sulphatase, glucosidase, protease and urease activities) were measured in soils from five sites located in urban green areas close to roads differing in traffic density. Our aims were to evaluate the suitability of such parameters as field biomarkers of stress induced by heavy metal pollution, and to compare results obtained by single microbial parameters with results given by an index expressing the average microbial (AME) response of the microbial community. Data showed that all parameters were significantly reduced in the sites characterized by the highest load of metals in soil. Dehydrogenase, sulphatase, glucosidase activities and respiration, declined exponentially with increasing metal concentration, whereas phosphatase activity and AME decreased following a sigmoidal type relationship. In contrast, protease, urease and microbial biomass were not significantly correlated with soil metal concentration. Microbial parameters differed both in sensitivity to critical metal concentrations and in the rate of decline at increasing metal loads in soil. Due to the complex interplay of chemical, physical and biological factors which influence microbial activities and biomass, the proposed index (AME) appeared more suitable than single microbial parameters for a biomonitoring study of this type.
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- 2004
11. Decomposition rates in late stages of Scots pine and Norway spruce needle litter: Influence of nutrients and substrate properties over a climate gradient.
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Berg, Björn, Lönn, Mikael, Ni, Xiangyin, Sun, Tao, Dong, Lili, Gaitnieks, Talis, Virzo De Santo, Amalia, and Johansson, Maj-Britt
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SCOTS pine ,NORWAY spruce ,RED pine ,PLANT litter decomposition ,SILVER fir - Abstract
• Annual mass loss for Scots pine and Norway spruce needle litter in a long-term experiment differed along a climate gradient. • For the late decomposition stage there was no climate effect on decomposition rate. • We found different substrate-based rate-regulating factors for the two litter species. • Limit values for decomposition were determined by different factors for the two litter species. • We may distinguish two different pathways leading to stabilized residues as identified by the limit values. The aim of this paper is to show different patterns for decomposition of the main mass of needle litter from two boreal and temperate coniferous tree species, both leading to a stabilized fraction of litter. To this purpose we have reviewed information on decomposition patterns in the lignin-dominated (late) stages of two local foliar litter types, namely those of Scots pine (Pinus silvestris) and Norway spruce (Picea abies) from two climatic gradients of equal extension. We have also reviewed factors determining the limit values for both species. Long-term decomposition studies were used to calculate annual mass loss in the lignin-dominated decomposition stage and relate these to mean annual temperature (MAT), mean annual precipitation (MAP) and concentrations of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), manganese (Mn) and acid unhydrolyzable residue (gravimetric lignin, AUR). There was no effect of MAT on decomposition of either needle litter type. MAP had a rate-dampening effect on decomposition of Norway spruce litter. There was a rate-stimulating effect of Mn for Norway spruce litter but not for that of Scots pine. In spite of the strong negative effect of AUR and N on decomposition of Scots pine litter there was none at all for that of Norway spruce. Limit values for decomposition were related to the litters' initial concentrations of N, Mn and AUR and differed between litter types for locally collected, natural litter and for that from experimental litter, the latter having higher N and lower Mn concentrations than the natural litter. We conclude that the two litter types have clear differences as regards rate- regulating factors for decomposition in the late lignin-dominated stage as well as for the stable fraction and suggest two different pathways for their decomposition. This is the first time that different pathways have been suggested for decomposing litter. [ABSTRACT FROM AUTHOR]
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- 2022
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12. Impact of the invasive tree black locust on soil properties of Mediterranean stone pine-holm oak forests.
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Marco, Anna, Arena, Carmen, Giordano, Maria, and Virzo De Santo, Amalia
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NITROGEN fixation ,BLACK locust ,ITALIAN stone pine ,HOLM oak ,SOIL profiles ,TREE growth - Abstract
Background and aims: Invasion by N-fixing species may alter biogeochemical processes. We hypothesized that the grade of invasion by the N-fixer black locust ( Robinia pseudoacacia L.) could be related to the distribution and pools of carbon (C) and nitrogen (N) along the profile of two Mediterranean mixed forests of stone pine ( Pinus pinea L.) and holm oak ( Quercus ilex L.). Methods: A low-invaded (LIN) and a high-invaded (HIN) mixed forest were studied. We assessed: N concentration in green and in senescent leaves; C and N pools along the soil profile; seasonal changes of soluble C and N fractions, and microbial activity. Results: Compared to coexisting holm oak and stone pine, black locust had higher N content in green and in senescent leaves. In the mineral soil: N stocks were similar in LIN and HIN; water soluble C and microbial activity, were lower in HIN compared to LIN; water soluble N showed seasonal changes consistent with tree growth activity in both HIN and LIN. In the organic layer of HIN, C and N stocks were about twofold larger than expected on the basis of stand density. Conclusion: Black locust increased C and N stocks in the upper organic layers that are more vulnerable to disturbance. However, it did not increase N stocks in the mineral soil. [ABSTRACT FROM AUTHOR]
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- 2013
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13. Ranges of nutrient concentrations in Quercus ilex leaves at natural and urban sites.
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Maisto, Giulia, Baldantoni, Daniela, De Marco, Anna, Alfani, Anna, and Virzo De Santo, Amalia
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HOLM oak ,FOLIAR diagnosis ,MICRONUTRIENTS ,HUMUS ,PLANT nutrients ,CITIES & towns - Abstract
The leaf nutrient concentrations and the N-to-nutrient ratios were analyzed to evaluate the nutritional status of holm oaks ( Quercus ilex L.) experiencing various anthropogenic pressures. Leaves (1 year old) of Q. ilex and surface soil (0-5 cm) surrounding the trees were collected at seven natural and seven urban sites in Campania Region (Southern Italy) and analyzed for the concentrations of macro (C, N, P, S) and micronutrients (Mn, K, Na, Cu, Mg, Ca, Fe, Zn). The available soil fraction of micronutrients was also evaluated. The nutrients showed different concentration ranges for the natural and the urban sites in the soil (total and available) and in the leaves, that we reported separately. Organic-matter content and macronutrient concentrations were higher in the natural soils, while the highest leaf N, S, and P concentrations were found at some urban sites. Concentrations of Cu, Na and Zn both in leaves and soil, and Mg and Fe in leaves from the urban sites appeared to be affected by air depositions. Manganese was the only micronutrient to show higher concentrations at the natural than at the urban sites, both in soil and leaves. For this nutrient, in addition, a relationship between leaf and available soil concentrations was found at the natural sites. The ratios between the concentrations of N and each studied nutrient in the leaves highlighted a different nutritional status between the plants from the natural and urban sites. [ABSTRACT FROM AUTHOR]
- Published
- 2013
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14. NMR (H) analysis of crude extracts detects light stress in Beta vulgaris and Spinacia oleracea leaves.
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Guadagno, Carmela, Della Greca, Marina, Virzo De Santo, Amalia, and D'Ambrosio, Nicola
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In highlight stress conditions, the mechanism of non-photochemical quenching (NPQ) of chlorophyll fluorescence is triggered at the chloroplast level. This process allows thermal quenching of the excessive excitation energy and it is strictly related to the efficiency of the xanthophyll cycle. Nowadays, the utilization of the nuclear magnetic resonance (NMR) spectroscopy provides a powerful complementary way for the identification and quantitative analysis of plant metabolites either in vivo or in tissue extracts. Seeing that the oxidative damage caused by light stress in plants and the consequent involvement of pigments are widely studied, NMR spectroscopy can be utilized to compare crude leaf extract at different levels of light stress, allowing an analysis of these compounds. In this paper, the identification of possible relationships between light stress and H NMR signal variations is discussed. The analysis of the H NMR (1D) spectra of two agronomic species ( Spinacia oleracea and Beta vulgaris) exposed to different light intensities is presented. In particular, change in carotenoids and xanthophylls signals are analyzed. [ABSTRACT FROM AUTHOR]
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- 2013
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15. Anatomy and photochemical behaviour of Mediterranean Cistus incanus winter leaves under natural outdoor and warmer indoor conditions.
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De Micco, Veronica, Arena, Carmen, Vitale, Luca, Aronne, Giovanna, and Virzo De Santo, Amalia
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PLANT anatomy ,CISTACEAE ,PHOTOCHEMISTRY ,EFFECT of temperature on plants ,WINTER ,LEAVES ,CLIMATE change ,CHLOROPLASTS - Abstract
Copyright of Botany is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
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- 2011
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16. Non-additive effects of litter mixtures on decomposition of leaf litters in a Mediterranean maquis.
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Marco, Anna, Meola, Angela, Maisto, Giulia, Giordano, Maria, and Virzo De Santo, Amalia
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MAQUIS plants ,BIOTIC communities ,ECOLOGICAL research ,MAQUIS ecology ,BIODEGRADATION ,OAK - Abstract
Many studies across a range of ecosystems have shown that decomposition in mixed litter is not predictable from single-species results due to synergistic or antagonistic interactions. Some studies also reveal that species composition and relative abundance may be more important than just richness in driving non-additive effects. Most studies on litter decomposition in Mediterranean maquis, an high-diversity shrubby ecosystem, have dealt exclusively with single species. In this study we investigated, at the individual-litter level, as well as at the litter-mixture level, the effect of litter mixing on decomposition of 3-species litter assemblages with different relative abundance of the component litters; we set up two types of litter assemblages that reflected the heterogeneity of bush cover in the inner maquis and at the edge maquis/gaps, as related to the leaf traits, i.e. sclerophylly vs mesophylly. We measured mass loss, decay of lignin, cellulose and ADSS (acid detergent soluble substances) and fungal mycelium ingrowth. The results show that over a 403-day incubation period, the decomposition of individual litters in mixtures deviated from that of monospecific litters and had different directions. In litter mixtures of the sclerophylls Phillyrea angustifolia and Pistacea lentiscus with the mesophyll Cistus, decomposition was lower than expected (antagonistic effect); in the mixtures of litters with similar physical structure ( Ph. angustifolia and P. lentiscus with Quercus ilex) decomposition was faster than expected (synergistic effect). When considering the different decomposition phases, both negative and positive effects occurred in Quercus mixtures depending on the phase of decomposition. In both types of 3-species litter assemblages the greatest effect occurred in uneven mixtures rather than in even mixtures. Our results show that species composition drives the direction whilst the decomposability and the relative abundance drive the magnitude of non-additive effects of litter mixing on decomposition. [ABSTRACT FROM AUTHOR]
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- 2011
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17. Fungal mycelium and decomposition of needle litter in three contrasting coniferous forests
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Virzo De Santo, Amalia, Rutigliano, Flora Angela, Berg, Björn, Fioretto, Antonietta, Puppi, Gigliola, and Alfani, Anna
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MYCELIUM , *PINE straw , *COELOMYCETES - Abstract
The fungal mycelium ingrowth and the rates of mass loss and respiration of needle litter of Pinus pinea, Pinus laricio, Pinus sylvestris, and Abies alba were investigated, in three coniferous forests, over a 3-year period by means of a composite set of incubations. In the early stages, the fungal flora of the decomposing needles was dominated by dematiaceous hyphomycetes and coelomycetes. Basidiomycetes reached a peak after 6 months on pine needles, but were absent from the N-rich needles of A. alba. Soil fungi (Penicillium, Trichoderma, Absidia, Mucor sp. pl.) became most frequent in later stages. At the end of the study period, the total mycelium amount showed the lowest values in all pine needles incubated in the P. laricio forest and the highest ones in P. pinea needles incubated in the P. pinea forest. In all data sets, as in data for boreal forests examined for comparison, the concentration of litter fungal mycelium versus litter mass loss followed a common exponential model. However, in later stages, the amount of litter fungal mycelium was very close to that of the humus at the incubation site, thus supporting the hypothesis of a logistic growth pattern. Respiration rates of decomposing litters varied with season and decreased with litter age to values close to those of the humus at the incubation site. Respiration of water-saturated litter was negatively correlated with the total mycelium concentration, and this was consistent with the observation that in far-decomposed litter only a minor fraction of the total mycelium is alive. [Copyright &y& Elsevier]
- Published
- 2002
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18. Litter Inhibitory Effects on Soil Microbial Biomass, Activity, and Catabolic Diversity in Two Paired Stands of Robinia pseudoacacia L. and Pinus nigra Arn.
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De Marco, Anna, Esposito, Fabrizio, Virzo De Santo, Amalia, Berg, Björn, and Zarrelli, Armando
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BIOMASS ,SOIL microbiology ,BLACK locust ,AUSTRIAN pine ,AFFORESTATION - Abstract
Research Highlights: Plant cover drives the activity of the microbial decomposer community and affects carbon (C) sequestration in the soil. Despite the relationship between microbial activity and C sequestration in the soil, potential inhibition of soil microbial activity by plant cover has received little attention to date. Background and Objectives: Differences in soil microbial activity between two paired stands on soil at a very early stage of formation and a common story until afforestation, can be traced back to the plant cover. We hypothesized that in a black locust (Robinia pseudoacacia L.) stand the high-quality leaf litter of the tree, and that of the blackberry (Rubus fruticosus L.) understory had an inhibitory effect on soil microbial community resulting in lower mineralization of soil organic matter compared to the paired black pine (Pinus nigra Arn.) stand. Materials and Methods: We estimated potential mineralization rates (MR), microbial (MB), and active fungal biomass (AFB) of newly-shed litter, forest floor, and mineral soil. We tested the effects of litters' water extracts on soil MR, MB, AFB and its catabolic response profile (CRP). Results: Newly-shed litter of black locust had higher MR than that of blackberry and black pine; MR, MB, and AFB were higher in forest floor and in mineral soil under black pine than under black locust. Water extracts of black locust and blackberry litter had a negative effect on the amount, activity of microorganisms, and CRP. Conclusions: The results demonstrate the potential for black locust and blackberry litter to have a marked inhibitory effect on decomposer microorganisms that, in turn, reduce organic matter mineralization with possible consequences at the ecosystem level, by increasing C sequestration in mineral soil. [ABSTRACT FROM AUTHOR]
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- 2018
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19. Discriminating between Seasonal and Chemical Variation in Extracellular Enzyme Activities within Two Italian Beech Forests by Means of Multilevel Models.
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Fioretto, Antonietta, Innangi, Michele, De Marco, Anna, Menta, Cristina, Papa, Stefania, Pellegrino, Antonella, and Virzo De Santo, Amalia
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EXTRACELLULAR enzymes ,ORGANIC compounds ,BEECH ,FORESTRY & climate ,TREES & climate ,FOREST litter - Abstract
Enzymes play a key-role in organic matter dynamics and strong scientific attention has been given to them lately, especially to their response to climate and substrate chemical composition. Accordingly, in this study, we investigated the effects of chemical composition and seasons on extracellular enzyme activities (laccase, peroxidase, cellulase, chitinase, acid phosphomonoesterase, and dehydrogenase) by means of multilevel models within two Italian mountain beech forests. We used chemical variables as the fixed part in the model, season as random variation and layers (decomposition continuum for leaf litter and 0–5, 5–15, 15–30, and 30–40 cm for soil) as nested factors within the two forests. Our results showed that seasonal changes explained a higher amount of variance in enzyme activities compared to substrate chemistry in leaf litter, whereas chemical variation had a stronger impact on soil. Moreover, the effect of seasonality and chemistry was in general larger than the differences between forest sites, soils, and litter layers. [ABSTRACT FROM AUTHOR]
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- 2018
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20. Effetti del pascolo di cinghiali sul suolo nel parco Nazionale del Cilento e del Vallo di Diano
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DE MARCO, ANNA, FULGIONE, DOMENICO, Maselli, V., Russo, G., Rippa, D., Virzo De Santo, A., De Marco Anna, Fulgione Domenico, Maselli Valeria, Russo Giuliana, Rippa Daniela, Virzo De Santo Amalia, DE MARCO, Anna, Fulgione, Domenico, Maselli, Valeria, Russo, Giuliana, Rippa, Daniela, Virzo De Santo, Amalia, Organizing committee, Maselli, V., Russo, G., Rippa, D., and Virzo De Santo, A.
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Grufolate, pascolo intenso, biomassa microbica e fungina, respirazione, nutrienti - Published
- 2010
21. Decomposition of black locust and black pine leaf litter in two coeval forest stands on Mount Vesuvius and dynamics of organic components assessed through proximate analysis and NMR spectroscopy
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De Marco, Anna, Spaccini, Riccardo, Vittozzi, Paola, Esposito, Fabrizio, Berg, Björn, and Virzo De Santo, Amalia
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BLACK locust , *AUSTRIAN pine , *FOREST litter , *NUCLEAR magnetic resonance spectroscopy , *HUMUS , *CELLULOSE - Abstract
Abstract: Litter quality is an important determinant of soil organic matter formation. Changes of organic components were investigated along decomposition of black locust (Robinia pseudoacacia L.) leaf litter and black pine (Pinus nigra Arn.) needle litter in the native adjacent coeval forest stands. To this purpose, data from proximate analyses were compared with those from CPMAS 13C NMR. Newly shed leaf litter of black locust had significantly higher concentrations of ADSS (acid detergent soluble substances) as well as lower concentrations of cellulose and AUR (acid unhydrolyzable residues that include lignin) and higher AUR-to-Cellulose ratio than that of black pine. The 13C CPMAS NMR spectra of newly shed leaf litter of black locust and black pine revealed that O-Alkyl-C components (including cellulose and hemicelluloses) accounted, respectively, for 53.8% and 61.4% of the total area of the spectra. All other C fractions were relatively more abundant in black locust than in black pine. Within individual sampling periods, relationships between residual litter mass and concentrations of ADSS, cellulose and AUR were examined, as were relationships between residual litter C and NMR fractions. Four periods were defined based on the slopes of the decomposition curve, with the length of period I defined by the start of a net decrease of AUR. Proximate analyses and NMR data showed changes in chemical composition over the decomposition process, as well as changes in decay rates of the residues, following different paths in the two litters. ADSS decayed faster in black locust litter; in contrast cellulose and AUR decayed faster in that of black pine. AUR concentration increased in both litters during decomposition; however, compared to black pine, the remaining litter of black locust was richer in AUR, despite the lower initial concentration, and had a higher AUR-to-Cellulose ratio. Phenol-C and Aryl-C decayed faster in black locust litter, while Alkyl-C decayed faster in that of black pine. In both litters, mass loss in periods was negatively correlated to concentration of AUR at the start of the periods. C loss in periods was negatively correlated to the concentration at the start of the periods of MC-to-PC (an index of lignin content) in black locust litter and positively correlated to Alkyl-C and O-Alkyl-C in that of black pine. Phenol-C, O-Alkyl-C and Aryl-C were the most decomposable C fractions in black locust. O-Alkyl-C and Alkyl-C were the most decomposable C fractions in black pine. Limit value was lower in black pine than in black locust. Consequently the different pattern of litter decomposition can affect the size of C sequestration in the forest floor and the quality of accumulated organic carbon. [Copyright &y& Elsevier]
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- 2012
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22. Nutrient dynamics in litter mixtures of four Mediterranean maquis species decomposing in situ
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Maisto, Giulia, De Marco, Anna, Meola, Angela, Sessa, Ludovica, and Virzo De Santo, Amalia
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MAQUIS plants , *PLANT nutrients , *MANGANESE , *LIGNINS , *BIODEGRADATION , *BIODIVERSITY , *LITTERS , *PHILLYREA - Abstract
Abstract: In natural conditions, litters shed from different species become mixed with each other, and decompose together. Most studies deal with decomposition of individual species; few studies investigate the influence of litter mixing on decomposition and nutrient dynamics; the results are contradictory as positive, negative, or no effect, of litter mixing have been observed. In this study we test the hypothesis: i) that litter mixing in the Mediterranean maquis, a nutrient poor, high diversity ecosystem, produces non-additive effects on nutrient dynamics; ii) that the effects vary with the composition in species of the mixture and with the relative amount of the species component the mixture. Two types of 3-species mixtures were set up; one contained three sclerophylls, Phillyrea angustifolia, Pistacia lentiscus and Quercus ilex; the other contained the first two species with the mesophyll Cistus. Litterbags, containing monospecific litters and even and uneven mixtures, were incubated under natural condition in situ; even mixtures had the 3 species in equal proportion, whereas uneven mixtures had one of the species as dominant (50%) and the other two species in equal proportion (25%:25%). Litterbags were retrieved after 92, 188 and 403 days; litters from the mixtures were separately analyzed for mass loss and content of nitrogen (N), potassium (K), sodium (Na), calcium (Ca), magnesium (Mg), manganese (Mn), iron (Fe), copper (Cu), and zinc (Zn). Results indicate that mixing influences the dynamics of N, Mn, Ca, Mg, Fe, Cu and Zn, but scarcely affects the dynamics of K and Na. The comparison of observed to expected values for changes of nutrients in litterbags indicates the occurrence of non-additive effects of litter mixing on movements of N, Fe, Cu, and Zn to or from the litterbags containing the mixtures. The effects depend on the composition in species of the mixture, whereas the relative amount of the species component the mixture is not relevant. [ABSTRACT FROM AUTHOR]
- Published
- 2011
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23. Changes in chemical composition of Pinus sylvestris needle litter during decomposition along a European coniferous forest climatic transect
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McTiernan, Kevin B., Coûteaux, Marie-Madeleine, Berg, Björn, Berg, Matty P., Calvo de Anta, Rosa, Gallardo, Antonio, Kratz, Werner, Piussi, Pietro, Remacle, Jean, and Virzo De Santo, Amalia
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SCOTS pine , *LIGNINS , *CELLULOSE - Abstract
The objective of this investigation was to assess the changes in chemical composition (lignin, cellulose, hemicelluloses, non-structural compounds, N, and ash) of decomposing litter. Standard Pinus sylvestris needle litter, originating from southern Sweden, was incubated in litterbags at 15 sites selected from the Netherlands to south Spain. The changes in chemical composition of this litter were determined using near infrared reflectance spectroscopy. The hypothesis was that standard (chemically uniform) litter decomposing under a range of climates would show different dynamics of accumulation and loss of C-fractions, N, and ash, relative to mass loss. It was shown that, for a given mass-loss value (10, 20, 30, 40, or 50%), the proportion of lignin, cellulose, hemicelluloses, non-structural compounds, N, and ash in the decomposing pine needles differed between sites. Lignin concentration in the litter residue at 50% mass loss ranged from approximately 26 to 43%, cellulose from 19 to 27%, hemicelluloses from 7 to 11%, non-structural compounds from 19 to 25%, N from 0.7 to 1.3%, and ash content from 1.4 to 10.1%. Lignin concentrations showed the highest range of variation. Lignin concentrations during decomposition were positively related to moisture factors as significant correlations were found with actual evapotranspiration and were improved in multiple regressions by the mean annual precipitation or the water surplus. Cellulose was degraded further at sites with high precipitation whereas hemicellulose degradation was related to temperature. This leads to the conclusion that the remaining organic matter produced by standard litter decomposition within the studied climatic range of variations tended to be more recalcitrant under wet and warm climatic conditions than under cold or dry climate. [Copyright &y& Elsevier]
- Published
- 2003
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24. Shifts in soil chemical and microbial properties across forest chronosequence on recent volcanic deposits.
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De Marco, Anna, Berg, Björn, Zarrelli, Armando, and Virzo De Santo, Amalia
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VOLCANIC soils , *AUSTRIAN pine , *OLD growth forests , *BLACK cotton soil , *CHEMICAL properties , *SOIL mineralogy - Abstract
Afforestation of new unconsolidated volcanic deposits is a practice used to stabilize barren areas and enhance the accumulation of organic matter in the developing soil. Changes in soil carbon (C) and nitrogen (N) pools, including the soluble and microbial fractions, within the first decades since afforestation have been poorly investigated. Therefore the objective of the present study was to investigate how key C and N pools vary in litter and soil of four forests planted on barren volcanic deposits from recent Mount Vesuvius eruptions. We examined three forest stands (40, 70 and 100 years old) afforested with Stone pine (Pinus pinea L.) and a 40-year old forest of Black pine (Pinus nigra Arn.). As a baseline of C and N pools prior to afforestation, data from treeless sites were included in the study. Both the inputs with litter fall and soil C and N stocks increased with forest age in the Stone pine stands. In the mineral soil, C concentration per gram soil dry weight and C:N ratio increased with age from treeless sites to the oldest forest. Microbial biomass C and fungal biomass as a fraction of organic carbon (OC) and respiration per unit OC (an index of organic matter mineralization potential) decreased significantly with stand age. The results suggest that a main driver of C accumulation in the mineral soil is the decline with increasing stand age of the microbial fraction of organic matter and its activity. The comparison between the two pine species revealed that litter production was more abundant in the Black pine than in the even-aged, 40-year-old, Stone pine stand; moreover Black pine litter was more acidic and had a higher stable residue than Stone pine litter. Therefore a different pattern of C sequestration occurs with a higher C stock in the organic layers and a lower C stock in the mineral soil of Black pine compared to Stone pine. • Soil C increased with stand age from treeless to forest sites. • Microbial carbon (MC), fungal biomass (FB) and respiration (R) per g soil were steady. • MC, FB and R per unit organic carbon decreased from treeless to forest sites. • The decline of MC, FB and R per unit organic carbon is a main driver of C accumulation. • Litter quality controls C allocation in organic and mineral soil layers of Black pine and Stone pine. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
25. Discriminating between Seasonal and Chemical Variation in Extracellular Enzyme Activities within Two Italian Beech Forests by Means of Multilevel Models
- Author
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Antonietta Fioretto, Anna De Marco, Amalia Virzo De Santo, Michele Innangi, A. Pellegrino, Stefania Papa, Cristina Menta, Fioretto, A., Innangi, M., De Marco, A., Menta, C., Papa, S., Pellegrino, A., Virzo De Santo, A., Fioretto, Antonietta, Innangi, Michele, De Marco, Anna, Menta, Cristina, Papa, Stefania, Pellegrino, Antonella, and Virzo De Santo, Amalia
- Subjects
0106 biological sciences ,seasonal trend ,multilevel models ,Multilevel model ,010603 evolutionary biology ,01 natural sciences ,seasonal trends ,medicine ,Organic matter ,beech forests ,soil enzymes ,organic matter ,soil enzyme ,Chemical composition ,Beech ,beech forest ,chemistry.chemical_classification ,biology ,Chemistry ,Substrate (chemistry) ,Forestry ,04 agricultural and veterinary sciences ,Seasonality ,Plant litter ,medicine.disease ,biology.organism_classification ,Agronomy ,Soil water ,040103 agronomy & agriculture ,Litter ,0401 agriculture, forestry, and fisheries - Abstract
Enzymes play a key-role in organic matter dynamics and strong scientific attention has been given to them lately, especially to their response to climate and substrate chemical composition. Accordingly, in this study, we investigated the effects of chemical composition and seasons on extracellular enzyme activities (laccase, peroxidase, cellulase, chitinase, acid phosphomonoesterase, and dehydrogenase) by means of multilevel models within two Italian mountain beech forests. We used chemical variables as the fixed part in the model, season as random variation and layers (decomposition continuum for leaf litter and 0–5, 5–15, 15–30, and 30–40 cm for soil) as nested factors within the two forests. Our results showed that seasonal changes explained a higher amount of variance in enzyme activities compared to substrate chemistry in leaf litter, whereas chemical variation had a stronger impact on soil. Moreover, the effect of seasonality and chemistry was in general larger than the differences between forest sites, soils, and litter layers.
- Published
- 2018
26. Biomonitoring of trace element air contamination at sites in Campania (Southern Italy).
- Author
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Maisto G, Baldantoni D, De Marco A, Alfani A, and Virzo De Santo A
- Subjects
- Cadmium analysis, Chromium analysis, Copper analysis, Dose-Response Relationship, Drug, Iron analysis, Italy, Lead analysis, Manganese analysis, Nickel analysis, Plant Leaves metabolism, Quercus metabolism, Soil Pollutants analysis, Vanadium analysis, Zinc analysis, Air Pollutants, Environmental Monitoring methods, Trace Elements
- Abstract
Surface soils and one-year-old Quercus ilex L. leaves were investigated for element concentrations to evaluate the air quality of some sites in Campania (Southern Italy). Sampling was carried out at 7 natural and 7 urban sites from September 1998 to February 1999. The investigated elements were Cd, Cr, Cu, Fe, Mn, Ni, Pb, V and Zn. At the urban sites, Cr, Cu, Fe, Ni and Pb Leaf concentrations were on average two fold higher than at the natural sites. Cu, Pb and Zn soil concentrations were also higher at the urban sites. On the contrary, Cd, Cr and Mn soil concentrations were significantly lower than at the natural sites. Leaf and soil element concentrations were positively correlated for Cu and Pb, and negatively correlated for Cr. Both leaves and soil element accumulations showed a conspicuous deposition of Cu, Pb and Zn at the urban sites of Campania.
- Published
- 2003
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