Flora e Vegetazione Dell'Isola Di Pianosa (Isole Tremiti)

Abstract

Flora and vegetation of the Isle of Pianosa (Isles Tremiti). – The flora and vegetation of the Isle of Pianosa are here described. The flora is composed of common mediterranean species with some adriatic endemics. The vegetation has a halophilous-nitrophilous character. The plant formations identified on this isle are shown in the map (fig. 1).     

Proposte Per La Tutela Di Alcune Aree,Di Particolare Interesse Geobotanico,Nel Parco Nazionale Del Circeo

Abstract

Proposals for the protection of some areas, of particular geobotanical interest, in the Circeo National Park. — The Circeo National Park is located south of Rome in the province of Latina. Its area is about 7.445 hectares. It is characterised by three neatly differentiated environments: the calcareous massive of Mt. Circeo, the State Forest of Sabaudia and the littoral dune. The Park's vegetation is threatened by numerous dangers. These are caused by the progressive building expansion in act on Mt. Circeo as well as on the littoral dune; by the introduction of various alien species, particularly in parks and gardens, which contaminate the local flora; by the afflux of picnickers who converge mainly on the dune; by pasture allowed in the State Forest; by the building of a road which cuts in half the southern slope of Mt. Circeo; by the exploitation of a stone-mine on Mt. Circeo. In order to preserve, at least partially, the vegetation from such threats, the Author proposes that five areas should be fenced and declared « Integral protected area ». Three areas are included in the State Forest, one on Mt. Circeo and the other on the dune. The total area is about 583 hectares. These areas comprise the most interesting aspects of the natural vegetation of the Park and groups of introduced arboreal plants (Pinus and Eucalyptus) of particular technical interest. The establishment of these reserves will have a scientific as well as an experimental aim. In such reserves all human activities should be prohibited with the exception of some cultural interventions on the introduced species. The areas of the State Forest include a nucleus of forest of Quercus cerris; a mesohygrophilous cenosis in which Quercus pedunculata predominate, with Alnus glutinosa and Fraxinus oxycarpa; a scrubby heath with Erica arborea, Erica scoparia and Myrtus communis, with specimen of Quercus pseudo-suber; a small prairie abundant with annual species; a plot of Eucaliptus grandis. The area of Mt. Circeo include large patches of maquis and wood-maquis (macchia and macchia-foresta), alophilous cenosis, rocky plant communities, and other facies of Mediterranean vegetation with specimen of Chamaerops humilis. The area of the dune is variegated with patches of maquis on sandy soil, swamp cenosis, fragments of mesohygrophilous vegetation, and small nuclei of introduced species. The Author suggests some executive norms in order to provide full protection of the proposed areas as well as the environment of the Park. He favours a solution by which the State should acquire both areas of the dune and of the Mt. Circeo, and also suggests particular bonds for the defense of the natural vegetation of the State Forest. In the forest, in fact, no plants of Quercus pedunculata, Quercus suber, Quercus ilex, Quercus pseudo-suber, Cytisus laburnum, Acer campestre and Tilia europaea should be utilised. Finally the Author advises against the introduction in the forest of species alien to the local flora and the destruction, except in particular cases, of the underwood.     

The urban vascular flora of Palermo (Sicily,Italy)

Abstract

This article presents a comprehensive inventory of the urban vascular flora of the town of Palermo. The data were gathered from extensive field collections, from specimens kept in different herbaria, and publications of the last 30?years. The floristic catalogue includes all the vascular plants that occur spontaneously within the urban area. Thirteen taxa are endemic to Sicily and one of these, Clinopodium raimondoi, is exclusive to Palermo’s area. The inventory comprises 1052 taxa belonging to 119 families and 225 genera, and contains 170 taxa non-native to the Italian flora.     

Pugillo Di Licheni Dell'Abissinia E Dell'Eritrea

Abstract

The long pollen sequences from four volcanic lakes of the Lazio région are presented in order to outline the history of flora and vegetation on the Tyrrhenian side of Central Italy during the last hundred thousand years. The four long pollen records correlate satisfactorily with each other and reflect climatic changes at least at regional scale. Particular attention is paid to the development of arboreal vegetation during the last glacial. The local name “Lazio Complex” is given to the seven main fluctuations of trees of the Pleniglacial (from about 60,000 to about 30,000 years B.P.). The history of Zelkova, Abies, Picea, Fagus, Corylus, Ulmus, Carpinus betulus, Tilia in central Italy is outlined.     

Changes in the plant community of a Brazilian grassland savannah after 22 years of invasion by Pinus elliottii Engelm

Abstract

Background: The invasion by Pinus elliottii is one of the most serious threats to the remaining native cerrado vegetation in São Paulo State, Brazil, causing biodiversity losses yet to be evaluated. We conducted a study in an area where P. elliottii began establishing in 1988.

Aims: To estimate diversity losses in the plant community and to understand the floristic and structural changes resulting from pine tree invasion of grassland savannah.

Methods: All plants taller than 50 cm were sampled in 35 plots (64 m² each) within an area densely invaded by P. elliottii and in 10 plots in non-invaded grassland savannah. Density, species richness, diversity, ground cover and spatial distribution were compared by Wilcoxon tests, non-metric multidimensional scaling and Payandeh indices.

Results: Twenty-two years after the arrival of the first invasive trees (founders), the grassland savannah has become a dense pine forest with 12,455 individuals ha^?1, a basal area of 26.44 m² ha^?1, a sparse native woody understory comprised of 16 species (H'?=?0.44), density of 1210 individuals ha^?1 and the herbaceous layer totally absent.

Conclusions: Invasion by Pinus elliottii has completely changed the structure of the grassland savannah and caused severe plant diversity losses. Native species surviving the invasion in the understory do not typically represent the previous composition and functional traits of the native vegetation.     

La Vegetazione e L'ecologia Di Pratofiorito (Appennino Settentrionale)

Abstract

Ecology and vegetazion of mount Pratofiorito. — The author examines position, climatic conditions, geological nature and vegetation of Mount « Pratofiorito » in the Tuscan Appennine.

Mount Pratofiorito is a residue of secondary rocks and derived soil surrounded by tertiary and quaternary rocks and soil.

Its vegetations is actually constituted by grass-land and so it differs-from that of the neihbouring mountains which comprises the flora has been made. This list was then comparend with spades found in the adjacent beech and helm-oak zones.

From these comparisons one can deduce thath the meadow of « Graminaceae » and « Cyperaceae » growing on Mount Pratofiorito may bed considered as a grass-land resulting from the degradation of an arboreal zone, problably from a beech-wood.     

Notes on the Scottish flora

Background: Abernethy Forest, an area of native Caledonian Scots pine forest, includes areas of open or sparsely forested peatland, largely ombrotrophic, but locally influenced by water from mineral ground.

Aims: To relate vegetation species-composition to the limit of ombrotrophy inferred from water chemistry.

Methods: Species composition was listed in 300 sample quadrats; chemical analyses of water samples were available from 200 of these. The vegetation data were classified using TWINSPAN. Relationships between vegetation and chemical results were analysed statistically using contingency tables.

Results: Eleven ‘vegetation types’ were recognised, five (189 samples) judged as primarily ombrotrophic-bog vegetation. The others showed evidence of flushing, or transition to forest. A previous analysis of major cations in the 200 water samples indicated that a limiting Ca/Mg ratio of 1.0 divided 61 samples showing telluric influence from 139 essentially ombrotrophic samples. Neither division was sharp. Contingency tables showed that the division based on vegetation types was strongly associated with the division of the water samples based on cation ratios.

Conclusions: Large areas of bog south and east of Loch Garten are unequivocally ombrotrophic; the main telluric-influenced sites occupy openings in the forest west of the loch. The limited ‘fen’ flora probably reflects the small size and isolation of the calcium-rich sites and the dominating influence of the ombrotrophic peats.     

The endemic vascular flora of Peloritani Mountains (NE Sicily): Plant functional traits and phytogeographical relationships in the most isolated and fragmentary micro-plate of the Alpine orogeny

This study is aimed at (1) producing a complete and updated inventory of the endemic vascular flora of Peloritani Mountains, (2) defining the geographical limits of Peloritani, regarded here as a biogeographical district and (3) highlighting possible paleogeographic connections with other Mediterranean lands. The heterogeneity analysis of the endemic flora was performed by means of contingency tables, through the χ² test. The endemic flora of this area consists of 129 specific and infraspecific taxa, of which 15 are restricted to the Peloritani Mountains. The analysis of habitats revealed that endemic taxa are most abundant on cliffs, rangelands, woods and garrigues. A large number of surveyed taxa are endemic to central-southern Italy and Sicily, while the number of endemic taxa in common with Calabria, Etna and Aeolian Islands turned out to be rather low, in spite of the geographical proximity. The endemic flora of Peloritani allows to emphasize palaeogeographical relationships not only with the neighbouring Mediterranean territories, but also with currently remote ones, such as southern Spain, Sardinia and Corsica. The phytogeographical framework substantiates the hypothesis that the Peloritani floristic district coincides with the limit given to Peloritani Mountains by structural geologists.     

Flora Delle Acque Circostanti L'Isola Di Pianosa (Is. Tremiti)

Abstract

The marine flora of the Isle of Pianosa (Isles Tremiti). – The little Isle Pianosa (Middle Adriatic) presents an algal flora typical for clear, deep seas. Its main components are here described. Endolithic flora on calcareous rocks has been particularly well examined.     

Report of the Alpine Section

Background: Under climate-change scenarios, rock outcrops, by providing microclimatically diverse habitats, different from those of surrounding zonal vegetation matrix, may serve as climatic refugia and thereby facilitate the persistence of specialist species.

Aim: We tested whether rock outcrops of southern temperate latitudes could act as local refugia for a cold-adapted flora in the face of global warming.

Methods: We related species composition of 50 outcrops and that of their surrounding vegetation to climatic data at local and regional scales to establish whether species distributions reflected differences that could indicate the existence of climatic refugia.

Results: While at a regional scale, species composition of the outcrops across the study area was related to mean annual precipitation and mean annual maximum temperature, locally, southern faces of outcrops had different species and lower maximum temperatures than insolated north faces and surrounding vegetation plots.

Conclusions: South faces of outcrops by providing cool microhabitats, and currently harbouring species not found in the surrounding zonal vegetation matrix, could serve as local refugia for heat-intolerant plants and other microthermic organism. The degree of ‘stability’ of these refugia will depend on the degree of future change in climate. Therefore, it is important to plan protected area networks that maximise local environmental heterogeneity, including the protection of rock outcrops both as refugia for cold-adapted species and as potential stepping stones that would allow dispersal of these species between supportive environments through unfavourable ones.     

Human influence on the vascular flora of the Veggiano territory (Padova - Italy)

Abstract

This paper is the result of 10 years of floristic research carried out in the Veggiano area (Padova). A floristic list of 612 taxa was drawn from bibliography (BEGUINOT, 1909–1914). According to our data (1990) 386 taxa are still present, with a loss of approximately 40%. The main cause of this loss is the disappearance of certain habitats (i.e. wood) and the alteration of others due to human influence.     

Appunti Sulla Flora Stradale E Ruderale Dei Dintor Ni Di Molfetta (Bari)

Summary

The author has studied the flora of a few country lanes in the surroundings of Molfetta (Apulia). The various stations are described and the plants collected are listed.     

Aspetti della Faggeta Depressa Del Monte Fogliano (Lago Di Vico)

Summary

It is pointed out the widness of the imposing beechtree-grove, which in assembly of vulcanic Cimini mountains of Latium, covers the area of M. Fogliano (963 metres) to a level slightly above lake of Vico (507 m.). It means largely underneath the normal inferior altimetric limit of the beechtree in the Apennines.

It represents a climatic derelict of pluvial oceanic times, still in equilibrium with the local actual ambient characterized by frequent and heavy rains (one of the most rainy areas in Latium) and permanent humidity, due also becouse of the lower lake, and by relatively low medium temperatures. The above mentioned depression of the beechtree occurs in different areas of Latium.

Other plants included in the beechtree-grove are wisley the same of those of Central (or Southern) Europe, testifying thearefore the derelict of ancient forest once larger, joined to the Medium Apennines, untill the “subatlantic” stage of the past glacial era. But it is remarcable the vegetative prevalence of Western oceanic components (as Narcissus pöeticus, etc.) and endemic plants (as Allium pendulinum, etc.) which perhaps mark a Tyrrenian facies of the Apenninian forest of beechtree. The beechtree-grove of M. Fogliano is lapped, but slightly interfered by usual “Mediterranean” vegetation only.     

Enquêtes sur l'archipel de la Maddalena (Sardaigne NE): la flore et le paysage végétal de l'[icaron]le des Bisce

Abstract

Presented herevin are the results of research on the flora and vegetable landscape of the isola delle Bisce (NE Sardinia). The flora was found to be composed of 230 entities (1 Gymnospermae, 229 Angiospermae) belonging to 47 families and included in 156 genera. Failure to find numerous species is underscored and an overview of the vegetation landscape based on aerial photography is presented, with the identification of the vegetation formations and sites on the islands most sensitive to anthropic impact.     

I. Introduction

Background: Past research and ecological theory supports the hypothesis that alpine plants should be predominantly clonal, long-lived and reproduce by seed infrequently.

Aims: To challenge the entrenched view that alpine seedling establishment is uncommon and perhaps unsuccessful in maintaining alpine plant populations.

Methods: We looked for patterns in seedling establishment across a stress gradient of alpine sites and tested the notion that natural seedling recruitment would be reduced at higher altitudes due to a combination of stressful environmental conditions such as frosts, wind and extended snow cover.

Results: Seedlings were common at all study sites and there was a partial trend in mean seedling density with altitude. Seedling emergence was best predicted by a combination of altitude, plant litter and soil wilting point. Many seedlings survived to become established plants (37–61%) but there was no significant relationship between establishment and altitude. There was low similarity between the seedling flora and the standing vegetation, suggesting that patterns in seedling establishment are unlikely to be driving the patterns in the standing vegetation assemblage.

Conclusions: Although Australian alpine species predominantly reproduce vegetatively, this study shows that many plants depend on recruitment from seed in order to become established.     

Sul Metabolismo Dell'Alcool Etilico in Tessuti Di Fusto Di « Pisum »

Abstract

On the metabolism of ethanol in the Pea stem tissues. — The average concentration of ethanol in the growing part of the etiolated pea internodes is of the order of 10^-3M. Previous work showed that auxin at growth promoting concentration markedly lowers this level in the excised internodes. This finding prompted a series of investigations on C¹⁴ labeled ethanol utilization in this material.

The capacity of the segments to metabolize ethanol is remarkable: with an external ethanol concentration 5X10^-3M the C¹⁴ labeled CO₂ originated from 1-C¹⁴ ethanol accounted for about 10% of total CO₂ produced during the first hour of treatment. Moreover, an amount of ethanol about 10 fold higher that that dissimilated to CO₂ was metabolized to various yet unidentified compounds. The ratio between the contribution of ethanol to CO₂ and that to other metabolites appeared maximal in the first period after feeding the labeled compound. This ratio was significantly higher then that found for 6-C¹⁴ glucose.

These preliminary results suggest the possibility that ethanol produced in glycolysis could represent an interesting metabolite in an anabolic pathway different from the one leading from pyruvate to the Krebs cycle acids.     

Transactions of the Botanical Society of Edinburgh

Background: Due to the dry continental climate, the mountains of eastern Ladakh are unglaciated up to 6200–6400 m, with relatively large areas of developed soils between 5600 and 6000 m covered by sparse subnival vegetation. However, there are no studies on the composition of plant assemblages from such extreme elevations, their microclimates, vertical distributions and adaptive strategies.

Aims: The subnival vegetation was described and the relationship between microclimate, species distribution and species functional traits was analysed.

Methods: In total, 481 vegetation samples from 91 permanent plots, a floristic database of Ladakh and extensive microclimate measurements were used. Measurements of 15 functional traits were made and their relationship with species distribution between 4600 and 6150 m was tested.

Results: The subnival zone was characterised by extreme diurnal temperature fluctuations, a short growing season (between 88 and 153 days) and low soil temperature during the growing season (between 2.9 °C and 5.9 °C). It hosted 67 species, mainly hemicryptophytes, and ranged from ca. 5600 m to the highest known occurrence of vascular plants in the region (6150 m). The most common plant families were Brassicaceae, Asteraceae, Poaceae, Fabaceae and Cyperaceae. Subnival specialists with narrow elevational ranges represented 42% of the flora; these species were shorter, had relatively higher water content and water-use efficiency and contained more nutrients and soluble carbohydrates than species with a wider elevational range.

Conclusions: The subnival vegetation of eastern Ladakh is dominated by generalist species with wide vertical ranges and not by high-elevation specialists. These findings, in view of the vast unglaciated areas available for range extension, suggest a relatively high resilience of the subnival flora to climate change in this region.     

Scots pine growing on forested mires in Abernethy Forest,Strathspey, Scotland

Summary

A substantial proportion of the Abernethy Forest Reserve has Scots pine (Pinus sylvestris) growing on the surfaces of a variety of mires. The hydrology of the mires has been affected by drainage and peat cutting but this area is unusual in having had a long period of protection from grazing by domestic stock. There are three main types of pine populations found on these mires. Woodland bog comprises predominantly bog vegetation with abundant pine seedlings due to the heavy seed rain from the surrounding woodland. Only a few very small trees survive, which are stunted, heavily diseased and have very low seed production. Wooded bog also comprises predominately bog vegetation but there are scattered mature trees of a moderate height with an open canopy. The trees are fertile and can form uneven aged stands with regeneration. Bog woodland is a predominantly woodland vegetation with tall, dense tree cover on deep peat. The trees are well grown with a dense canopy. A few remnants of bog vegetation remain in the ground flora although most have been replaced by woodland bryophytes and shrubs. Each of these three types is described and their development is discussed.     

Effetto Del Dinitrofenolo Sulla Conversione Del Glicerolo A Glucidi in Fettine Di Carote E in Internodi Di Pisello

Abstract

On the effect of dinitrophenol on carbohydrate activation in higher plant tissues. — Previous investigations on the effects of 2,4 dinitrophenol (DNP) on carbohydrate metabolism in isolated pea internodes and in yeast showed that the increased rate of glycolysis induced by the uncoupler corresponds to an increased rate of the conversion of free hexoses and polysaccarides to hexose phosphates. In yeast about 30% of the radioactivity supplied and taken up as ¹⁴C labelled glucose, and 20% of that supplied and taken up as glycerol is recovered as soluble sugar and glycogen; this phenomenon is almost completely suppressed by 10^-4M DNP.

This suggested that a mechanism involving kinase enzymes, on one hand, and phosphatases, on the other, is mediating the interconversion of phosphorylathed and free sugars, and that the apparent increase of hexose phosphorylation observed in the presence of DNP might depend on a decreased rate of phosphatase mediate reactions, consequent to the decrease of phosphorylated sugars level in the cell.

The experiments here reported were planned to test the validity of this hypothesis in the case of higher plant tissues.

Material used in these experiments were segments from the growing part of the third internode isolated from 7 day old, etiolated pea seedlings, and carrot root diks (0,7 mm thick, 7 mm diameter) preincubated for 24 hours in aerated distilled water. Both of these materials show an active, steady respiration and some growth activity, so that they may be taken as representing a condition close enough to that of the generally physiologically active higher plant tissues.

The reversibility of the hexose phosphate-free sugar interconversion process was tested by feeding 10^-3M 1-C¹⁴ labeled glycerol, and measuring after 150 minutes the amount of radioactivity incorporated into CO₂, soluble sugars, organic acids and proteins. The results of these experiments are summarized in table I and II.

Glycerol metabolism as well as its response to DNP appears very similar in the two material used. In both cases, glycerol uptake and incorporation into organic acids and amino acids is almost insensitive to DNP. In contrast large differences are observed for the free sugar fraction. In the absence of the uncoupler, a consistent amount of the radioactivity fed as glycerol is found in this fraction. It appears reasonable to assume that the glycerol-sugar interconversion comprehends, as intermediate steps, glycerol-P, fructose di-P (or sedoeptulose di-P) and hexose-6-P. If this is true, the observed data implicate that a continuous interconversion occurs, in the cell, between sugar phosphates and free sugars and vice-versa, one reaction direction involving the activity of phosphatases, and the other one that of kinases. The true rate of this interconversion process is probably much larger than indicated by the radioactivity found in free sugars: as a considerable part of the triose-P transormed into sugars must immediately re-enter the descending flux of glycolysis.

This view finds some support in the fact that DNP almost completely inhibits the incorporation of radioactivity in the free sugar fraction. It has been previously observed that DNP very markedly decreases the level of hexose mono- and di-phosphates and of triose-phosphates in the pea stem tissues. If phosphatases acting on fructose di-phosphate and on hexose-6-P are not saturated by their substrates, a decrease of the rate of free hexose synthesis from sugar phosphates should be expected.

The present results are thus consistent with the hypothesis that hexose phosphates and free sugars in the cell are continuously interconverted by the simultaneous action of phosphatases and kinases; and that the effect of DNP, and thus of any physiological conditions decreasing the ATP/ADP ratio in accelerating free hexose utilizations is at least in part due to a decreased rate of the reactions catalized by fructose diphosphate and hexose-6-P phosphatases. The reversibility of the kinase-phosphatase system would thus represent a crucial link in the mechanism by which the rate of carbohydrate activation and breackdown is controlled by the rate of utilization of high-energy phosphate bonds.     

Naturalizzazione E Riproduzione Spontanea Di Piante Ornamentali Nella Liguria Occidentale

Abstract

Effects of the growth-retarding compounds «CCC» and «AMAB» on the growth and alkaloidal content of Datura Stramonium L. — Datura Stramonium L. was administered two fortnightly-doses of 200 cc 10 ^-2 M solutions of (2-cloroethyl)-trimethylammonium chloride (CCC) or (allyl)-trimethylammonium bromide (AMAB), poured on the soil of every pot. In the treated plants were noted shorter and thicher stems and petioles and leaves larger in size and darker green than in the controls. Yields of leaves in CCC and AMAB-treated plants were not significantly changed while root fresh and dry weights were decreased. The per-cent concentration of total alkaloids in the leaves and roots of both CCC and AMAB-treated plants was not significantly different in comparison with that of normal plants. Therefore the A. assumes that the growth-retarding chemicals must not interfere with alkaloidal synthesis.