We assess if the structural and floristic diversity of
forests from Pico Island (Azores) corresponds to a mosaic of different phases of a forest cycle, by identifying the phases of that cycle and the dynamic relations between them. Eight 100 m
plots were placed randomly in areas with structural and floristic differences but having in common the presence of live and/or dead individuals of the dominant tree species (
). In each plot the number of seedlings, saplings, and adults as well as canopy height and width and maximum height of live
adults were recorded. The floristic composition was determined in a 25 m
plot, placed inside each 100 m
forests show a cyclic patch dynamic triggered by the senescence and death of even-aged individuals of
. In this forest cycle, five phases were identified, such as gap, building, mature, initial degenerative and final degenerative. The first two phases are dominated by
however in the degenerative phases
is the dominant tree species. The cycle may be divided into an upgrade series (comprising the first two phases) and a downgrade series (between the mature and final degenerative phases). In these forests there was no climax micro-succession detected since changes in the dominant tree species occur in the degenerative phases. This paper brings the first evidence for the existence of a forest cycle in Macaronesian forests.
Vitreousness is an important quality characteristic that affects the yield of semolina during milling of durum wheat. It has been observed that kernel vitreousness seems to be lower when durum is exposed to damp conditions just before harvest. The main objective of this research was to determine the effect of high relative humidity (RH) on kernel vitreousness of ten durum wheat cultivars. Spikes were exposed to 88% RH at room temperature for 1 and 3 days. This resulted in increased spike moisture, kernel moisture and kernel size. Vitreous kernel content (vitreousness) decreased 23.6% after spikes were exposed to high relative humidity for 3 days. Exposure to 88% RH caused the greatest decline in vitreousness with the cultivar ‘Ben’.
This article reports the experimental results of a conductometric study on the time evolution, over a 541-day period, of 450 samples of Extremely Diluted Solutions (EDS) of fullerene and carbon nanotube and 450 samples of twice-distilled water, stored in alternate rows of EDS and water spaced 0.5 cm apart. The purpose was to establish whether these two aqueous systems are able to transmit, via electromagnetic fields, their variations in the supramolecular structure of the solvent water which has not undergone any previous perturbation. The chemical-physical method employed was conductometry, which proved to be the simplest and most efficient means for quickly and accurately monitoring the structural variations. In addition, since it has been demonstrated that there is a clear linear correlation between specific conductivity and heat of mixing with alkaline solutions, the conductometric result can also be extended to the calorimetric result. These findings, though doubtless unexpected and intriguing, are highly significant. The alterations over time of the pure water samples follow those of the EDS surprisingly closely.
Conductometric and calorimetric titrations of Extremely Diluted Solutions (EDS) were performed by adding HCl or NaOH solutions. The aim of this study is to obtain further confirmation of the hypothesized presence, in the EDS, of molecular aggregates of water molecules. The measurements on the EDS evidenced some relevant differences compared to those on solutions with just water as solvent. The conductivity and the pH caused by adding the titrant, namely NaOH or HCl, were markedly different to those of the control solutions. We suppose that the preparation procedure of the EDS could produce non-equilibrium changes in the supramolecular structure of water. The experimental results were interpreted by considering the interactions that can take place between the OH− or H3O+ and the hypothesized molecular aggregates of water molecules i.e. dissipative structures. A comparison was made about the nature of the driving force that leads to the formation of the complexes between the two ions deriving from probes and the molecular aggregates of water molecules (dissipative structures). In this study, we have determined the thermodynamic parameters of association between molecular aggregates of water molecules (dissipative structures) in the EDS and OH− or H3O+ probe ions. The experimental results were interpreted by considering a favorable interaction between the H3O+ and OH− ions and the dissipative structures, due, probably, to steric hindrance and chemical affinity with the aggregates.
An extensive study has been carried out on extremely diluted aqueous solutions (EDS). These solutions revealed a really intriguing
physico-chemical behaviour, characterized by multiple independent variables. Because of their behaviour, EDS can be described
as far-from-equilibrium systems, capable of self-organization as a consequence of little perturbations.
In this paper we investigate the stability of the calorimetric behaviour of EDS with a high ionic force, due to the presence
of the sodium chloride electrolyte. We measured the excess heats of mixing of EDS with basic solutions, both with and without
a high concentration of NaCl, and compared the results. In particular, we explored these concentrations: 0.5 and 1Mmol kg−1). The analysis of the experimental results shows that the calorimetric response of the EDS is stable when they are in a concentrated
solution of NaCl. That is of great relevance for the eventual pharmacological action of these solutions, since it involves
the interaction with fluids of complex chemical composition and high concentration.
Disturbance related vegetation dynamics differs with Azorean mountain forest communities, where each tree species has its own regeneration strategy. Knowledge of the spatial distribution of tree species may help us to generate hypotheses on the relation between disturbance, regeneration and spatial organization and on the possible underlying ecological mechanisms. In view of this, we asked the following questions regarding the spatial pattern of tree species: What is the spatial distribution of saplings and adults? Are there any spatial associations or exclusions between saplings and adults of the same and different species? To what extent do the disturbance regimes and regeneration strategies of each species explain its spatial pattern? Six 225 m2 (15 × 15 m) plots were placed in each of three different forest types in three Islands (Pico, Terceira and Flores). Patterns of tree individuals were analysed through Morisita’s index of dispersion (Iδ) and Iwao ω index. With the exception of Laurus azorica and Frangula azorica, saplings are in most cases aggregated. Erica azorica is the only species whose adults are aggregated at short distances. Spatial distribution is mostly random for the other species. At short distances, few strong associations or exclusions were detected. Pioneer species such as Juniperus brevifolia tend to be more aggregated due to their dependence on gaps to germinate and recruit new individuals. In fact, increasing disturbance and gap size enhances the regeneration of J. brevifolia. Primary species tend to be randomly distributed in part due to their strategy of forming seedling-sapling banks. Spatial pattern of tree species is largely explained by disturbance regimes and regeneration strategies of each species. However, factors such as habitat related patchiness, competition and dispersion limitation may also explain many of the observed patterns.
Authors:V. Elia, L. Elia, N. Marchettini, E. Napoli, M. Niccoli, and E. Tiezzi
An extensive study has been carried out on aqueous ‘extremely diluted solutions’ (EDS). The employed experimental methodologies
were well established physico-chemical techniques: flux calorimetry, conductometry, pH-metry, e.m.f. of suitable galvanic
cell. The obtained results show that the preparation procedure significantly alters the physico-chemical behaviour of such
solutions. Moreover, the analysis of the experimental data vs. the ‘arrow of time’ turned out to be astonishingly important.
In fact some measured physico-chemical parameters evolve with time. Some experimentally measurable physico-chemical properties
of the solvent water were largely affected by both time and the ‘life path’ of the samples. In particular, we evidenced two
new experimental phenomena characterizing the EDS: the presence of a series of maximums in the measured electrical conductivity
vs. the sample age; the dependence of said maximums on the volume of the EDS during its ageing.
All of these new experimental results clearly suggest the presence of an extended and ‘ordered’ dynamics involving the whole
of the water molecules in the liquid. A temporal evolution, featuring three maximums in the course of four years of ageing
and the dependence on the ageing volumes do not fit the framework of classical thermodynamics. It therefore seems appropriate
to interpret these phenomena on the basis of the thermodynamics of dissipative structures, which are far from equilibrium
Authors:C. Elias, E. Fernandes, E. França, M. Bacchi, and F. Tagliaferro
Epiphytic bromeliads have been used as biomonitors of air pollution since they have specialized structures in leaves for absorbing
humidity and nutrients available in the atmosphere. Leaves of five bromeliad species were collected in the conservation unit
Parque Estadual Ilha do Cardoso, São Paulo State, Brazil, and analyzed by INAA. Vriesea carinata was the species showing most accumulation, with the highest mass fractions of K, Na, Rb and Zn. Similar results were previously
found for the same species collected in the dense ombrophilous forest. Chemical composition of bromeliads provided an indication
of the atmosphere status in the conservation unit.
Authors:C. Elias, E. Fernandes, E. França, M. Bacchi, and F. Tagliaferro
Resuspended soil and other airborne particles adhered to the leaf surface affect the chemical composition of the plant. A
well-defined cleaning procedure is necessary to avoid this problem, providing a correct assessment of the inherent chemical
composition of bromeliads. To evaluate the influence of a washing procedure, INAA was applied for determining chemical elements
in the leaves of bromeliads from Vriesea carinata species, both non-washed and washed with Alconox, EDTA and bi-distilled water. Br, Ce, Hg, La, Sc, Se, Sm and Th showed higher
mass fractions in non-washed leaves. The washing procedure removed the exogenous material without leaching chemical elements
from inside the tissues.
Authors:C. Elias, E. Fernandes, E. França, and M. Bacchi
Studies concerning the accumulating capacity of native epiphytic bromeliads are of utmost relevance, due to the continuous
incorporation of chemical elements provided by these organisms in the ecosystems. Bromeliad species from diverse São Paulo
State conservation units, Brazil, were sampled for young, mature and old leaves using a sustainable sampling method. By applying
INAA, the accumulation of ten chemical elements, i.e. Br, Ca, Co, Fe, K, Na, Rb, Sc, Sr and Zn, was investigated in different
leaf vegetative stages. The bromeliads showed divergent chemical element distribution patterns, demonstrating a real complexity
in the accumulation and translocation mechanisms utilized by these plants.