Stefano Mazzoleni | Università degli Studi di Napoli "Federico II" (original) (raw)

Papers by Stefano Mazzoleni

Microbial Cell, Dec 3, 2023

Extracellular DNA (exDNA) can be actively released by living cells and different putative functio... more Extracellular DNA (exDNA) can be actively released by living cells and different putative functions have been attributed to it. Further, homologous exDNA has been reported to exert species-specific inhibitory effects on several organisms. Here, we demonstrate by different experimental evidence, including 1 H-NMR metabolomic fingerprint, that the growth rate decline in Saccharomyces cerevisiae fed-batch cultures is determined by the accumulation of exDNA in the medium. Sequencing of such secreted exDNA represents a portion of the entire genome, showing a great similarity with extrachromosomal circular DNA (eccDNA) already reported inside yeast cells. The recovered DNA molecules were mostly single strands and specifically associated to the yeast metabolism displayed during cell growth. Flow cytometric analysis showed that the observed growth inhibition by exDNA corresponded to an arrest in the S phase of the cell cycle. These unprecedented findings open a new scenario on the functional role of exDNA produced by living cells.

Forest Ecology and Management, Jul 1, 2023

Community Ecology, Aug 1, 2019

Plant litter decomposition is a crucial process of nutrient cycling within ecosystems. However, m... more Plant litter decomposition is a crucial process of nutrient cycling within ecosystems. However, many studies have shown that, apart from its several beneficial effects, organic matter decomposition can be disadvantageous to seed germination, seedling growth, and physiological activity of plants. Litter decomposition was reported to affect both plants and their associated soil microbial communities. The aim of this work was to test the relationships between seed-associated endophytic fungi on the either positive or negative plant's response to different litter types. Leaf material of four species was collected and used in a decomposition experiment inside a growth chamber for 120 days. The plant growth experiment was set in a greenhouse using Trifolium repens and Triticum durum with and without their associated endophytic fungi in the presence of the different litter species at two decay levels (fresh litter and after 120 days of decomposition). Results demonstrated that fresh litter exerted a strong inhibition effect on the plant total biomass when compared to decomposed litter. Moreover, seed-associated endophytic fungi enhanced the inhibitory effect of litter in the observed experimental conditions. The removal of seed-associated endophytic fungi improved the capacity of tested plants to resist to litter inhibitory effect.

Community Ecology, Dec 1, 2017

Unlike vagile organisms, plants perform a wide range of phenotypic responses to cope with environ... more Unlike vagile organisms, plants perform a wide range of phenotypic responses to cope with environmental stresses. A special case of interaction with external factors is the ability of plants to recognize genetic relatedness of neighbour plants, a�t�all� �ell k���� a� ki� �e����iti��. T�e ��e�e�t ���k ai�e� t� ���vi�e a val�able ���t�ib�ti�� t� t�e �el� �� ki� �e����ition in plants through a common garden experiment. To avoid bias involved in pot experiments, we perform an experiment in unconstrained root growth conditions comparing the development of coupled kin, non-kin and solitary plants of Xanthium italicum. Biometrics of plants with different genetic relatedness were measured, then architecture and competitive interaction were assessed using the relative interaction index (RII) for above and belowground portions of plants. X. italicum showed different allocation depending on the neighbourhood. Root biomass was declined in plants growing with kin compared to non-kin coupled plants, while plants coupled with kin allocated more shoot than roots compared to solitary plants. RII explains phenotypic response of decreased competition in roots rather than in shoots. Despite high values of RII for the aboveground portion, the architectural analysis of shoot, number, angle and length of branches and roots reveals dramatic but indistinctive change in the �t���t��e �� �la�t� ����i�� �ea� ki� �� ��� ki� ����a�e� t� a ��lita�� �la�t. T�e�e �e��lt� ������ ��e��t��i� �e�����e� �� ki� recognition in unconstrained environment.

Community Ecology, Dec 1, 2015

The consequences of decline in biodiversity for ecosystem functioning is a major concern in soil ... more The consequences of decline in biodiversity for ecosystem functioning is a major concern in soil ecology. Recent research efforts have been mostly focused on terrestrial plants, while, despite their importance in ecosystems, little is known about soil microbial communities. This work aims at investigating the effects of fungal and bacterial species richness on the dynamics of leaf litter decomposition. Synthetic microbial communities with species richness ranging from 1 to 64 were assembled in laboratory microcosms and used in three factorial experiments of decomposition. Thereafter, the functionality of the different microcosms was determined by measuring their capability to decompose materials with different chemical properties, including two species of litter (Quercus ilex L. and Hedera helix L.), cellulose strips and woody sticks. Incubation was done in microcosms at two temperatures (12°C and 24°C) for 120 days. The number of microbial species inoculated in the microcosms positively affected decomposition rates of Q. ilex and H. helix litters, while relationships found for cellulose and wood were not statistically significant. Diversity effect was greater at higher incubation temperature. We found lower variability of decay rates in microcosms with higher inoculated species richness of microbial communities. Our study pointed out that the relationships between inoculum microbial diversity and litter decomposition is dependent on temperature and litter quality. Therefore, the loss of microbial species may adversely affects ecosystem functionality under specific environmental conditions.

Mycorrhiza, 2020

Interactions between plants and soil affect plant-plant interactions and community composition by... more Interactions between plants and soil affect plant-plant interactions and community composition by modifying soils conditions in plant-soil feedback, where associated microbes have the most crucial role. Both arbuscular mycorrhizal fungi (AMF) and microbial seed endophytes have been demonstrated to influence, directly or indirectly, biotic or abiotic soil properties, thus affecting subsequent plant growth, and community structure. However, little is known about how plant endophyte communities, individually or in interaction with AMF, affect plant-soil feedback processes. Here, we investigated, through a manipulative experiment, the behavior of endophyte-free and endophyte-associated Trifolium repens plants grown in soils previously conditioned by conspecific endophyte-free and endophyte-associated plants, inoculated or not by Rhizophagus intraradices. Furthermore, we identified microbial endophytes directly from the inner tissues of seeds by high-throughput sequencing, to compare seed fungal and bacterial endophyte composition. Results demonstrated that the outcome of simultaneous occurrence of seed endophytes and AMF on plant behavior depended on matching the endophytic status, i.e., either the presence or absence of seed microbial endophytes, of the conditioning and response phase. Seed fungal endophytes generated strong conspecific negative feedback, while seed bacterial endophytes proved to shift the feedback from negative to positive. Moreover, the simultaneous occurrence of both seed endophytes with AMF could either generate or expand negative plant-soil feedback effects. Our results show that seed and root symbionts can play a significant role on setting conspecific plant-soil feedback.

The yeast Saccharomyces cerevisiae is a reference model system and one of the widely used microor... more The yeast Saccharomyces cerevisiae is a reference model system and one of the widely used microorganisms in many biotechnological processes. In industrial yeast applications, combined strategies aim to maximize biomass/product yield, with the fed-batch culture being one of the most frequently used. Flow cytometry (FCM) is widely applied in biotechnological processes and represents a key methodology to monitor cell population dynamics. We propose here an application of FCM in the analysis of yeast cell cycle along the time course of a typical S. cerevisiae fed-batch culture. We used two different dyes, SYTOX Green and SYBR Green, with the aim to better define each stage of cell cycle during S. cerevisiae fed-batch culture. The results provide novel insights in the use of FCM cell cycle analysis for the real-time monitoring of S. cerevisiae bioprocesses.

Oikos, 2019

This article has been accepted for publication and undergone full peer review but has not been th... more This article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to differences between this version and the Version of Record. Please cite this article as

Plant and Soil, 2018

Background and aim Litter decomposition is of great concern as it plays a key role in regulating ... more Background and aim Litter decomposition is of great concern as it plays a key role in regulating global carbon cycle and nutrient budgets, especially in tropical forests where it is very fast. Therefore, we studied the decomposition and subsequent changes in element concentrations and amounts of 11 tropical leaf litter. Methods Fresh litters were characterized in terms of elemental, proximate features, as well as organic carbon compositions by 13 C-NMR spectroscopy. Controlled litterbag decomposition was carried out for 180 days in the laboratory, bags were retrieved at three dates and analyzed for mass loss and concentration of nitrogen (N), potassium (K), sodium (Na), carbon (C), magnesium (Mg), manganese (Mn), iron (Fe), phosphorus (P), zinc (Zn), and percentage of ash, extractives, cellulose and lignin. Results Terminalia arjuna showed highest mass loss, while the lowest was observed in Shorea robusta showing significant positive correlation with litter initial K, Mg, Fe and di-O-alkyl C, O-alkyl C, while significant negative correlation with Mn, lignin and Methoxyl C, Alkyl C. Trajectories shows that Fe, Mg, K, Mn, Zn and Na concentrations increased in most of the litter types, except Terminalia arjuna and Toona ciliata, where Fe, Mg, K concentrations decreased during decomposition. Surprisingly, in most of the species with the exception of Terminalia arjuna, N concentrations decreased at a faster rate than C concentrations, resulting in an increase in C/N ratios. Expectedly, lignin progressively increased, while cellulose decreased. Conclusions Observed differences in decomposition rate and dynamics of chemical changes among litters were strongly affected by the litter type, decomposition time and their interactions.

Scientific Reports, Nov 13, 2023

Many mushroom-forming fungi can develop circular colonies affecting the vegetation in a phenomeno... more Many mushroom-forming fungi can develop circular colonies affecting the vegetation in a phenomenon named fairy rings. Since the nineteenth century, several hypotheses have been proposed to explain how fairy ring fungi form ring-like shapes instead of disks and why they produce negative or positive effects on the surrounding vegetation. In this context, we present a novel process-based mathematical model aimed at reproducing the mycelial spatial configuration of fairy rings and test different literature-supported hypotheses explaining the suppressive and stimulating effects of fungi on plants. Simulations successfully reproduced the shape of fairy rings through the accumulation of fungal self-inhibitory compounds. Moreover, regarding the negative effects of fungi on vegetation, results suggest that fungal-induced soil hydrophobicity is sufficient to reproduce all observed types of fairy rings, while the potential production of phytotoxins is not. In relation to the positive effects of fungi on plants, results show that the release of phytostimulants is needed to reproduce the vegetation patterns associated to some fairy ring types. Model outputs can guide future experiments and field work to corroborate the considered hypotheses and provide more information for further model improvements. Fairy Rings (FRs) are biological formations caused by fungi. They can be detected by the regular arrangement of sporophores and/or circular bands of changing vegetation that are caused by dense mycelial fronts radially expanding in the soil 1-3. FRs are formed by a vast number of fungal species, mainly basidiomycetes 4 , both saprotrophic and mycorrhizal 2. These formations can be found in both natural and anthropized ecosystems such as grasslands, forests, pastures, dunes, managed lawns, gardens and, rarely, in cultivated fields 1,5-9. FRs size can vary from less than a meter to hundreds of meters in diameter 2. Previous studies, relating the yearly advancement to the overall diameter of the colony, estimated that fungi can live for hundreds of years in the form of advancing fronts 10-13. The study of FR fungi is one of the oldest topics in soil ecology, with the first studies dating back to1807 14. During centuries of investigations, the research effort moved in two directions: (1) understanding the mycelium growth dynamics and spatial configurations in the soil, and (2) studying the change in soil chemical and physical characteristics operated by the fungal mycelium and its effect on the vegetation. Regarding the reconstruction of mycelial dynamics resulting in FRs spatial patterns, mathematical models were developed to reproduce the centrifugal growth of the mycelium in a homogeneous soil environment assuming the expansion of a ring shape originating from a central starting point 10,15,16 or, when considering a discontinuous soil environment, reproduced fragmented patterns in which some portions of FRs fronts collapses assuming other shapes such as arcs 17 and rotors 16. To the best of our knowledge, the mathematical models explaining FR mycelial dynamics pay little attention to the mechanisms determining why the fungal mycelium disappears inside the colonies resulting in a ring-like shape instead of a disk-like one. Bayliss in 1911, for the first time addressed the question of why those masses of mycelium developed in rings instead of disks. The author proposed that mycelium degeneration in the inner part of the colony could be associated with the accumulation

Zenodo (CERN European Organization for Nuclear Research), Dec 31, 2012

The functional description of natural systems requires the representation of different classes of... more The functional description of natural systems requires the representation of different classes of processes including chemical, biochemical, and physical functions, with or without their spatial representation. On the other hand, there are several cases where a realistic representation of the process dynamics needs a spatially explicit implementation of the model (eg. hydrological flows, fire propagation, pollution diffusion, etc.). In more general terms, and for different scientific fields, scaling problems and the issue of linking dynamic and spatial processes require an integrated logic and appropriate software solutions. Different tools aimed at implementing spatial modelling capability (PCRaster, SME, SimARC) have not yet achieved a full integration of spatial and dynamic processes, especially for users with limited programming ability. In pursuit of this capability, a new raster-based spatial modelling system named "5D environment" has been implemented and it is presented here.

Frontiers research topics, 2017

Journal of Soil Science and Plant Nutrition, Mar 15, 2022

Frontiers in Environmental Science, Aug 29, 2016

Phytocoenologia, Apr 19, 1993

A study of bryophyte population characters in relation to vascular vegetation patterns was done i... more A study of bryophyte population characters in relation to vascular vegetation patterns was done in the island of Capri, southern Italy. 118 phytosociological samples were analyzed by multivariate methods of classification and ordination. 15 interpretable clusters of releves were found, clearly defined by differential bryophyte species, growth forms and ecological characters, whose trends were related to vegetation disturbance patterns

Phytochemistry Reviews, Nov 9, 2021

Microbial Cell, Dec 3, 2023

Extracellular DNA (exDNA) can be actively released by living cells and different putative functio... more Extracellular DNA (exDNA) can be actively released by living cells and different putative functions have been attributed to it. Further, homologous exDNA has been reported to exert species-specific inhibitory effects on several organisms. Here, we demonstrate by different experimental evidence, including 1 H-NMR metabolomic fingerprint, that the growth rate decline in Saccharomyces cerevisiae fed-batch cultures is determined by the accumulation of exDNA in the medium. Sequencing of such secreted exDNA represents a portion of the entire genome, showing a great similarity with extrachromosomal circular DNA (eccDNA) already reported inside yeast cells. The recovered DNA molecules were mostly single strands and specifically associated to the yeast metabolism displayed during cell growth. Flow cytometric analysis showed that the observed growth inhibition by exDNA corresponded to an arrest in the S phase of the cell cycle. These unprecedented findings open a new scenario on the functional role of exDNA produced by living cells.

Forest Ecology and Management, Jul 1, 2023

Community Ecology, Aug 1, 2019

Plant litter decomposition is a crucial process of nutrient cycling within ecosystems. However, m... more Plant litter decomposition is a crucial process of nutrient cycling within ecosystems. However, many studies have shown that, apart from its several beneficial effects, organic matter decomposition can be disadvantageous to seed germination, seedling growth, and physiological activity of plants. Litter decomposition was reported to affect both plants and their associated soil microbial communities. The aim of this work was to test the relationships between seed-associated endophytic fungi on the either positive or negative plant's response to different litter types. Leaf material of four species was collected and used in a decomposition experiment inside a growth chamber for 120 days. The plant growth experiment was set in a greenhouse using Trifolium repens and Triticum durum with and without their associated endophytic fungi in the presence of the different litter species at two decay levels (fresh litter and after 120 days of decomposition). Results demonstrated that fresh litter exerted a strong inhibition effect on the plant total biomass when compared to decomposed litter. Moreover, seed-associated endophytic fungi enhanced the inhibitory effect of litter in the observed experimental conditions. The removal of seed-associated endophytic fungi improved the capacity of tested plants to resist to litter inhibitory effect.

Community Ecology, Dec 1, 2017

Unlike vagile organisms, plants perform a wide range of phenotypic responses to cope with environ... more Unlike vagile organisms, plants perform a wide range of phenotypic responses to cope with environmental stresses. A special case of interaction with external factors is the ability of plants to recognize genetic relatedness of neighbour plants, a�t�all� �ell k���� a� ki� �e����iti��. T�e ��e�e�t ���k ai�e� t� ���vi�e a val�able ���t�ib�ti�� t� t�e �el� �� ki� �e����ition in plants through a common garden experiment. To avoid bias involved in pot experiments, we perform an experiment in unconstrained root growth conditions comparing the development of coupled kin, non-kin and solitary plants of Xanthium italicum. Biometrics of plants with different genetic relatedness were measured, then architecture and competitive interaction were assessed using the relative interaction index (RII) for above and belowground portions of plants. X. italicum showed different allocation depending on the neighbourhood. Root biomass was declined in plants growing with kin compared to non-kin coupled plants, while plants coupled with kin allocated more shoot than roots compared to solitary plants. RII explains phenotypic response of decreased competition in roots rather than in shoots. Despite high values of RII for the aboveground portion, the architectural analysis of shoot, number, angle and length of branches and roots reveals dramatic but indistinctive change in the �t���t��e �� �la�t� ����i�� �ea� ki� �� ��� ki� ����a�e� t� a ��lita�� �la�t. T�e�e �e��lt� ������ ��e��t��i� �e�����e� �� ki� recognition in unconstrained environment.

Community Ecology, Dec 1, 2015

The consequences of decline in biodiversity for ecosystem functioning is a major concern in soil ... more The consequences of decline in biodiversity for ecosystem functioning is a major concern in soil ecology. Recent research efforts have been mostly focused on terrestrial plants, while, despite their importance in ecosystems, little is known about soil microbial communities. This work aims at investigating the effects of fungal and bacterial species richness on the dynamics of leaf litter decomposition. Synthetic microbial communities with species richness ranging from 1 to 64 were assembled in laboratory microcosms and used in three factorial experiments of decomposition. Thereafter, the functionality of the different microcosms was determined by measuring their capability to decompose materials with different chemical properties, including two species of litter (Quercus ilex L. and Hedera helix L.), cellulose strips and woody sticks. Incubation was done in microcosms at two temperatures (12°C and 24°C) for 120 days. The number of microbial species inoculated in the microcosms positively affected decomposition rates of Q. ilex and H. helix litters, while relationships found for cellulose and wood were not statistically significant. Diversity effect was greater at higher incubation temperature. We found lower variability of decay rates in microcosms with higher inoculated species richness of microbial communities. Our study pointed out that the relationships between inoculum microbial diversity and litter decomposition is dependent on temperature and litter quality. Therefore, the loss of microbial species may adversely affects ecosystem functionality under specific environmental conditions.

Mycorrhiza, 2020

Interactions between plants and soil affect plant-plant interactions and community composition by... more Interactions between plants and soil affect plant-plant interactions and community composition by modifying soils conditions in plant-soil feedback, where associated microbes have the most crucial role. Both arbuscular mycorrhizal fungi (AMF) and microbial seed endophytes have been demonstrated to influence, directly or indirectly, biotic or abiotic soil properties, thus affecting subsequent plant growth, and community structure. However, little is known about how plant endophyte communities, individually or in interaction with AMF, affect plant-soil feedback processes. Here, we investigated, through a manipulative experiment, the behavior of endophyte-free and endophyte-associated Trifolium repens plants grown in soils previously conditioned by conspecific endophyte-free and endophyte-associated plants, inoculated or not by Rhizophagus intraradices. Furthermore, we identified microbial endophytes directly from the inner tissues of seeds by high-throughput sequencing, to compare seed fungal and bacterial endophyte composition. Results demonstrated that the outcome of simultaneous occurrence of seed endophytes and AMF on plant behavior depended on matching the endophytic status, i.e., either the presence or absence of seed microbial endophytes, of the conditioning and response phase. Seed fungal endophytes generated strong conspecific negative feedback, while seed bacterial endophytes proved to shift the feedback from negative to positive. Moreover, the simultaneous occurrence of both seed endophytes with AMF could either generate or expand negative plant-soil feedback effects. Our results show that seed and root symbionts can play a significant role on setting conspecific plant-soil feedback.

The yeast Saccharomyces cerevisiae is a reference model system and one of the widely used microor... more The yeast Saccharomyces cerevisiae is a reference model system and one of the widely used microorganisms in many biotechnological processes. In industrial yeast applications, combined strategies aim to maximize biomass/product yield, with the fed-batch culture being one of the most frequently used. Flow cytometry (FCM) is widely applied in biotechnological processes and represents a key methodology to monitor cell population dynamics. We propose here an application of FCM in the analysis of yeast cell cycle along the time course of a typical S. cerevisiae fed-batch culture. We used two different dyes, SYTOX Green and SYBR Green, with the aim to better define each stage of cell cycle during S. cerevisiae fed-batch culture. The results provide novel insights in the use of FCM cell cycle analysis for the real-time monitoring of S. cerevisiae bioprocesses.

Oikos, 2019

This article has been accepted for publication and undergone full peer review but has not been th... more This article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to differences between this version and the Version of Record. Please cite this article as

Plant and Soil, 2018

Background and aim Litter decomposition is of great concern as it plays a key role in regulating ... more Background and aim Litter decomposition is of great concern as it plays a key role in regulating global carbon cycle and nutrient budgets, especially in tropical forests where it is very fast. Therefore, we studied the decomposition and subsequent changes in element concentrations and amounts of 11 tropical leaf litter. Methods Fresh litters were characterized in terms of elemental, proximate features, as well as organic carbon compositions by 13 C-NMR spectroscopy. Controlled litterbag decomposition was carried out for 180 days in the laboratory, bags were retrieved at three dates and analyzed for mass loss and concentration of nitrogen (N), potassium (K), sodium (Na), carbon (C), magnesium (Mg), manganese (Mn), iron (Fe), phosphorus (P), zinc (Zn), and percentage of ash, extractives, cellulose and lignin. Results Terminalia arjuna showed highest mass loss, while the lowest was observed in Shorea robusta showing significant positive correlation with litter initial K, Mg, Fe and di-O-alkyl C, O-alkyl C, while significant negative correlation with Mn, lignin and Methoxyl C, Alkyl C. Trajectories shows that Fe, Mg, K, Mn, Zn and Na concentrations increased in most of the litter types, except Terminalia arjuna and Toona ciliata, where Fe, Mg, K concentrations decreased during decomposition. Surprisingly, in most of the species with the exception of Terminalia arjuna, N concentrations decreased at a faster rate than C concentrations, resulting in an increase in C/N ratios. Expectedly, lignin progressively increased, while cellulose decreased. Conclusions Observed differences in decomposition rate and dynamics of chemical changes among litters were strongly affected by the litter type, decomposition time and their interactions.

Scientific Reports, Nov 13, 2023

Many mushroom-forming fungi can develop circular colonies affecting the vegetation in a phenomeno... more Many mushroom-forming fungi can develop circular colonies affecting the vegetation in a phenomenon named fairy rings. Since the nineteenth century, several hypotheses have been proposed to explain how fairy ring fungi form ring-like shapes instead of disks and why they produce negative or positive effects on the surrounding vegetation. In this context, we present a novel process-based mathematical model aimed at reproducing the mycelial spatial configuration of fairy rings and test different literature-supported hypotheses explaining the suppressive and stimulating effects of fungi on plants. Simulations successfully reproduced the shape of fairy rings through the accumulation of fungal self-inhibitory compounds. Moreover, regarding the negative effects of fungi on vegetation, results suggest that fungal-induced soil hydrophobicity is sufficient to reproduce all observed types of fairy rings, while the potential production of phytotoxins is not. In relation to the positive effects of fungi on plants, results show that the release of phytostimulants is needed to reproduce the vegetation patterns associated to some fairy ring types. Model outputs can guide future experiments and field work to corroborate the considered hypotheses and provide more information for further model improvements. Fairy Rings (FRs) are biological formations caused by fungi. They can be detected by the regular arrangement of sporophores and/or circular bands of changing vegetation that are caused by dense mycelial fronts radially expanding in the soil 1-3. FRs are formed by a vast number of fungal species, mainly basidiomycetes 4 , both saprotrophic and mycorrhizal 2. These formations can be found in both natural and anthropized ecosystems such as grasslands, forests, pastures, dunes, managed lawns, gardens and, rarely, in cultivated fields 1,5-9. FRs size can vary from less than a meter to hundreds of meters in diameter 2. Previous studies, relating the yearly advancement to the overall diameter of the colony, estimated that fungi can live for hundreds of years in the form of advancing fronts 10-13. The study of FR fungi is one of the oldest topics in soil ecology, with the first studies dating back to1807 14. During centuries of investigations, the research effort moved in two directions: (1) understanding the mycelium growth dynamics and spatial configurations in the soil, and (2) studying the change in soil chemical and physical characteristics operated by the fungal mycelium and its effect on the vegetation. Regarding the reconstruction of mycelial dynamics resulting in FRs spatial patterns, mathematical models were developed to reproduce the centrifugal growth of the mycelium in a homogeneous soil environment assuming the expansion of a ring shape originating from a central starting point 10,15,16 or, when considering a discontinuous soil environment, reproduced fragmented patterns in which some portions of FRs fronts collapses assuming other shapes such as arcs 17 and rotors 16. To the best of our knowledge, the mathematical models explaining FR mycelial dynamics pay little attention to the mechanisms determining why the fungal mycelium disappears inside the colonies resulting in a ring-like shape instead of a disk-like one. Bayliss in 1911, for the first time addressed the question of why those masses of mycelium developed in rings instead of disks. The author proposed that mycelium degeneration in the inner part of the colony could be associated with the accumulation

Zenodo (CERN European Organization for Nuclear Research), Dec 31, 2012

The functional description of natural systems requires the representation of different classes of... more The functional description of natural systems requires the representation of different classes of processes including chemical, biochemical, and physical functions, with or without their spatial representation. On the other hand, there are several cases where a realistic representation of the process dynamics needs a spatially explicit implementation of the model (eg. hydrological flows, fire propagation, pollution diffusion, etc.). In more general terms, and for different scientific fields, scaling problems and the issue of linking dynamic and spatial processes require an integrated logic and appropriate software solutions. Different tools aimed at implementing spatial modelling capability (PCRaster, SME, SimARC) have not yet achieved a full integration of spatial and dynamic processes, especially for users with limited programming ability. In pursuit of this capability, a new raster-based spatial modelling system named "5D environment" has been implemented and it is presented here.

Frontiers research topics, 2017

Journal of Soil Science and Plant Nutrition, Mar 15, 2022

Frontiers in Environmental Science, Aug 29, 2016

Phytocoenologia, Apr 19, 1993

A study of bryophyte population characters in relation to vascular vegetation patterns was done i... more A study of bryophyte population characters in relation to vascular vegetation patterns was done in the island of Capri, southern Italy. 118 phytosociological samples were analyzed by multivariate methods of classification and ordination. 15 interpretable clusters of releves were found, clearly defined by differential bryophyte species, growth forms and ecological characters, whose trends were related to vegetation disturbance patterns

Phytochemistry Reviews, Nov 9, 2021

PiroPinus was developed in Portugal as a decision support-tool to prescribed burning use in Pinus... more PiroPinus was developed in Portugal as a decision support-tool to prescribed burning use in Pinus pinaster. Although tailored for site-specific conditions, it is empirically-based and so its performance outside the environmental range of development is uncertain. The objective of the present study is to test PiroPinus 2.2 utilities to define prescriptions, implement and evaluate prescribed burning for fire hazard reduction in Pinus halepensis plantations. The study site was located in the Cilento and Vallo di Diano National Park, one of the most fire-prone areas of Southern Italy. The experimental design consisted of 3 burn plots (BU), 0.2 ha in size, and 2 controls (CO). In all plots the plantation presented high fire risk. Pre-burn surface fuels (5.2±1.3 t ha-1 of litter, and flammable Ampelodesmos mauritanicus) and elevated fuels (dominated by Erica arborea) presented horizontal and vertical continuity. Objectives for the burn were: (1) reduce surface fuels; (2) create vertical discontinuity. PiroPinus was used as a reference guide to define burning windows. All plots were burned in May 2009. Most of burning parameters fell within the PiroPinus prescriptions. Fire behaviour was assessed with a microplot scale approach. Observed average surface litter moisture was 17%; rate of spread 0.22 ± 0.06 m min-1; flame length range 0.2-1.0 m; fireline intensity 52 ± 10 kW m-1. PiroPinus provided an accurate estimate of observed values: 17%, 0.25 m min-1, 0.5 m and 48 kW m-1 respectively. Prescribed burning objectives were achieved to some extent. According to the PiroPinus fire interpretation table the burn was conducted at the upper limit of moisture conditions. In fact, in summer 2009 surface fuels in BU were reduced only in part. Major changes were observed in elevated fuels whose cover decreased from 58% to 3%; the vertical continuity was remarkably reduced. Finally, PiroPinus was used to model post-treatment fire behaviour under different weather conditions. It predicted a remarkable mitigation of fire behaviour in BU vs. CO for all weather scenarios. Under the 97.5th scenario, simulated rate of spread, flame length and intensity in BU were respectively 75%, 31% and 12% of the CO values. PiroPinus resulted a useful tool to support prescribed burning in Pinus halepensis plantations of the Cilento Park. Despite constraints (research issues to address are outlined), this study showed that experimental data can be used to improve the performance of PiroPinus, extending its use as a reference guide for Mediterranean pine forests other than Pinus pinaster.