Relitti Mediterranei all'imboccatura di Cavità Ipogee Carsiche

Abstract

Mediterranean relicts at the mouth of karstic caves. — Far away from the mediterranean maquis stretched along the coast of Trieste, we can still find some groups of rank evergreen-oaks with several other mediterranean species.

The survival of these thermophile species is probably due to warm ascensional drafts, coming just in winter from the underneath caves.     

Residui di vegetazione spontanea in Roma

Summary

The A. describes a large remainder of natural vegetation at the periphery of Rome on the «Monti Parioli». Mainly it is Quercus Ilex macchia — evergreen wood, which becomes on the septentrional declivities Quercus Ilex — Quercus lanuguinosa mixed wood; here among the shrubs some not typical mediterranean elements are contained.     

I piani di vegetazione in Italia

Abstract

Vertical zonation of vegetation in Italy. – A revision of the scientific terms used by Italian botanists for the vertical zonation of vegetation reveals some inconsistencies and allows to propose an alignement with the nomenclature used in English and proposed already during the International Botanical Congress of 1910: Belt (ital.: fascia) for the topographical zonation and zone (ital.: zona) for the geographical zonation. Italy belongs to two zones: the mediterranean and the medioeuropean one. A scheme of vegetation belts in both of the zones is proposed. The indications subalpine and montane are substituted by boreal and subatlantic.     

La vegetazione della Pineta dannunziana (Pescara)

Abstract

The vegetation of the Pescara pinewood. The littoral pinewood at Pescara, about 35 hectares wide, is entirely comprised within the urban environment of this city. It is a seminatural environment and its better preserved portion is a wood for which the phytosociological studies point out three main aspects: a) hygrophilous wood evolving towards Carici-Fraxinetum angustifoliae Pedrotti 1970 b) a mediterranean maquis type of vegetation; c) vegetation of Prunetalia spinosa type.

In the residual retrodunal sectors an impoverished garigue predominates. Pinus halepensis Miller is self-renovating in the open xerophilus areas, while it tends to disappear in the hygrophilous zones.     

Microfunghi del suolo di aree floristicamente omogenee di tre cenosi boschive delle Prealpi bellunesi

Abstract

Soil microfungi in homogeneous areas of three plant communities of North Italy.—The soil microfungi associated with three different community types in Prealpine region of North Italy were investigated. Frequency values for the taxonomic entities isolated were calculated, based on occurrence at sampling sites, in each community. Most of the entities were quantitatively rare. The microfungal communities associated with Acer pseudoplatanus and Fraxinus excelsior, with Ostrya carpinifolia and with Fagus sylvatica appeared to be a distinctive group, even if many of them contained a substantial number of species wich are common with other vegetation types.     

Flora Delle Argille e Dei Tufi di Civita di Bagnoregio (Alto Lazio)

Abstract

Flora of the clays and the tuffs of Civita di Bagnoregio (Upper Latium). — This work is the result of floristic research developed from 1968 to 1970 on tuffs and mainly on the clays of Civita di Bagnorcgio. After having summarily described the geo-ecological conditions, the author lists in all 489 entities. The biological spectrum of clays shows a high presence of Therophyta and a low percentage of Phanerophyta; on the contrary on the tuffs are present more Phanerophyta and less Therophyta; on the whole the flora is marked from the Emicryptophyta. Phytogeographical analysis indicates a prevalence of mediterranean elements. The author delineates moreover the most important floristic aspects, refering the frequentest entities and point out the intense anthropization wich has prevented the preservation of the woody formations, today completely away from clayey area.     

La vegetazione degli Stagni di Ossero (Cherso)

Summary

The Author has studied the vegetation of the Ossero pools (the large and the small one) analising especially the formation which are characteristic of them.

In the level partion of the large pool the following formations — starting from the beach — are to be noted: Salicornia herbacea L., Hordeum marinum Huds., Inula viscosa All. and Artemisia coerulescens L.

The Salicornia herbacea L. formation is sensibly homogencus in that portion of its area in which, owing to the high saline concentration of the soil, no other pecies is able to grow. In the remaining portion with a lower saline concentration, other species accompagny Salicornia herbacea.

The Hordeun marinum Huds. formation comprises that portion of the pool which, being but little above the sea level, is invaded by high tides during the winter time. The saline concentation of the soil is here lower than in the area of the Salicornia herbacea formation. On the sea side Hordeum marinum is mixed to Salicornia herbacea; on the opposite side it accompanies annual species with brief life cycle.

The Inula viscosa All. formation which is generally characteristic of the newly formed ground in the Ossero pound is only occasional and consequently unstable.

Last of all the Artemisia coerulescens formation is much more stable than that of Inula viscosa, although established in a ground of similar origin, but with a greater humus content.

Of special interest are two small lakes which are situated on the border of the large pool. Thir vegetation is composed by typically laky species.

The author compares the succession of formation described above with that of the other coast marsh in the mediterranean region, especially at Campora, Arbe (see Morton 1915).

Here is, however, the succession of formations not so regular as in the large pool of Ossero. Nevertheless, both Campora and Ossero are to be classified as « Formation des Meeresstrandes» (Morton).

Crypsis aculeata Ait., Hordeum marinum Huds., and Medicago litoralis Rohde found at Ossero were not known for the flora of Cherso.

The vegetation of the small pool at Ossero (which only rarely invaded by the sea water) does not show the regular succession of formations which is typical of the large pool it comprises two main groups of species, namely: 1) those living between the beach and the pool, and 2) those extending from the pool to the inland.

Some species present in the large pool (among them Crypsis aculeata, Hordeum marinum, Medicago litoralis) are not represented in the flora of the small pool and vice versa.     

Ricerche Sull'ultrastruttura dei Tubi Cribrosi di Piccioli di Foglie di Edera

Abstract

The ultrastructure of sieve tubes in leaf petioles of HEDERA HELIX. — The structural organization of the sieve elements in Hedera leaf petiole at the beginning of the second year of life has been studied. At this stage of life the sieve tubes are completely developed, but still in full activity.

Their plasmatic structures, though altered, show that they are still alive. The cytoplasm forms a parietal layer; mitochondria, endoplasmic reticulum and plastids are present although very peculiar in aspect. The cytoplasm is bounded externally by a plasmalemma; on the contrary no tonoplast is detectable.

The data reported in this paper are favourable to the idea of an active partecipation of the sieve tubes in the translocation of organic solutes, in agreement with the findings concerning the oat coleoptile.     

Fissazione di CO2 da Parte di Entomocecidi di Cuscuta Australis

Abstract

Fixation of carbon dioxide by galls of CUSCUTA AUSTRALIS. — The mechanism of the carbon dioxide fixation by Cuscuta is a controversial biochemical topic. Light induced reactions are involved in MacLeod's opinion while others as Ciferri and Poma believe that mainly a dark-fixation occurs.

In this study use is made of the galls, caused by the insect Smicronyx on Cuscuta australis, that appear more green coloured than the normal tissues.

Equal weights of excised galls were kept both in light and in darkness in contact with C¹⁴O₂for different incubation times, and the magnitude of the fixation was compared under these two conditions by measuring radioactivity of both soluble and acid hydrolysed fractions.

After short exposures to the tracer the fixation in light greatly exceeds that in dark (25–19/1) while with more prolonged exposures the ratio sharply decreases (to about 5/1): these figures can be interpreted with the assumption that a strong light-induced fixation superimposes itself to a low but definite dark-fixation activity.

The ratio does not change if radioactivity is measured in the hydrolysed fractions.

These results are of course referred to as being largerly preliminar and requiring further and more extensive studies.     

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).     

Studio preliminare sulla tipologia della vegetazione sommersa del Canale di Sicilia e isole vicine

Abstract

Preliminary studies on the marine phythobenthic communities in the Straits of Sicily and adjacent islands. — The results of algological researches carried out by the Gruppo di Algologia of the S.B.I. in the Straits of Sicily and adjacent islands are reported. 288 species have been collected, 275 of which have been identified: 160 were Rhodophyta, 62 Phaeophyta, 32 Chlorophyta, 16 Cyanophyta and 2 Angiospermae. The vegetational research leads to the following conclusions: 1 - the harbour areas (Pantelleria, Malta: loc. 1 and 11) show a nitrophile vegetation, particulary near La Valletta where an almost pure population of Pterocladia pinnata is found; 2 - there are important biogeographical differences between Pelagie islands (Lampedusa, Linosa) and Pantelleria. In fact the former ones have an algal flora composed mostly of eastern mediterranean species, whilst the latter shows strong affinities with the north-african basin, as is demonstrated by the rich well developed belt of Cystoseira sedoides; 3 - several species of atlantic origin, such as Callophyllis laciniata, Peyssonnelia coriacea, P. inamoena and Castagnea chordariaeformis, have been found on the banks (loc. 3, 6, 7).     

Vegetazione e ambiente delle Marche e relativi problemi di salvaguardia

Abstract

Vegetation and environment in the Marche and related problems of protection. – The « Marche » region is situated in central Italy and corresponds with the natural region east of the Appennine ridge and spreading as far as the coast which is washed by the Adriatic Sea.

As to the climate, we may distinguish a coastal strip with Mesomediterranean climate with dry season, corresponding to the distribution area of Quercus ilex; a hilly strip with Submediterranean climate, corresponding to the distribution area of Quercus pubescens; a mountain strip with temperate axeric climate with sub-dry period, corresponding to the distribution area of Fagus silvatica and finally a high mountain strip with cold axeric climate, corresponding to altitude pastures. The Marche vegetation is shown in the vegetation map of Fabriano sheet (scale 1:50,000) plotted according Ozenda's vegetational series.

The following vegetation series have been plotted: submediterranean series of Quercus ilex; series of thermophilic oak wood with priority of Quercus pubescens or Quercus cerris; series of Ostrya carpinifolia; series of Quercus petraea and series of Fagus silvatica.

As far as the problems to safegard environment are concerned, a plan is given providing for the institution of 4 complete nature reserves, 34 nature reserves, and 9 regional nature parks among which those of Monte Conero, of Monti Sibillini and Monti della Laga.     

Alcune Osservazioni Sul Contenuto del Cribro in Giovani Fusti di “Guizotia Abyssinica” Cass

Summary

The area of S. Rossore is part of an old marshy plane, placed on the right side of the mouth of the river Arno and reaching the mouth of the Serchio, which untill some centuries ago flowed indipendently into the Tirrenian and only later has been diversed into the Arno.

On the dunes and downs of S. Rossore a very interesting type of Flora survives; its present physionomy going up to the Quaternary period, could be preserved till today as S. Rossore has been since a long time a private farm and a park of princes, dukes and kings.

The most interesting Flora of S. Rossore is that of the downs, expecially of the oldest ones (pleistocenic) which separated untill historic times, the open sea from the lagoon of Fasana, which penetrated just inside the present walls of Pisa.

For this reason these downs have been studied with a particular care. The floristic research have been based not only in the study of the specimens collected by the author, but also on the material of which the author could dispose. That is: the specimens of the “Herbarium Centrale Italicum” of the Botanical Institute of Florence, the data of the “Prodromo alla Flora toscana” and of the “Supplemento” by Caruel and Baroni. Altogether the taxa listed up to the present date are more than 700.

The identification of the species has been critically made, adopting the rules of the “International Code of Botanical Nomenclature”. When those rules could not be follewed an explanation has been given.

The facies of the vegetation of S. Rossore are the following: The seashores, the dune tops, the wet downs, partially flooded during the winter, and the permanent marshes.

The facies of the meso-igrophilous woodlands, growing expecially in the most encient downs, has been particularly investigated. In these stations grows a mixed wood of Quercus pedunculata, with Fraxinus oxycarpa, Fraxinus Ornus, Alnus glutinosa, etc., with many boreal-montane plants and Sphagna colonies, particularly at the edge of the partially flooded areas. In these Sphagna colonies are located some of the most exigent atlantic species (Hypericum elodes, Hibiscus palustris, etc.).

These mesophilous-igrophilous woodlands represent a relict of the vegetation pushed planewards to sea level by the glacial climate, and to its ingression is due the scarse importance that presently has here the mesophilous macchia of Quercus Ilex, as is shown by the biological spectrum of the flora of S. Rossore, (P 11, Ch 3, H 33, Cr 20, Th 22) indicating a rather scarse mediterranean character, in comparison with that of M. Argentario.

The flora of S. Rossore has a rather low degree of community (70%) with that of the “Paludi Pontine” which are only a short tract southawrd (2°1/2) and which stood the same geological events. On the other side, the lower degree of community between the Floras of S. Rossore and the Pine Forest of Ravenna (60%) which are located at the same latitude, shows the importance of the Appennines placed as a barreer between the floras of Central Italy.

In this paper has been focussed the importance that the coastal marshes can have had for the preservation of an old tertiary flora during the quaternary period. This flora in fact could be able to move, during the Quaternary, from the marches to the impending hills and viceversa, according to the different glacial phases (a tipical example is Periploca graeca).

It has been particularly pointed out the importance of the woodlands of the plane and the coastal marshes in preserving the colonies of montane or boreal-meso-philous-igrophilous species during the interglacial periods, (for ex. Narcissus poëticus, Leucojum aestivum, Menyanthes trifoliata, etc.) This phenomenon is particularly important in the marshes, situated in the lower course of the river Arno, penetrating far into the Peninsula, where they are dominated by the peacks of the Appennines and of the Apuane Alps.

From this research it is possible to argue that some atlantic species (mediter-ranean-atlantic as Erodium maritimum and Anagallis tenella and eu-atlantic as Hypericum elodes) could have spread towards the mediterranean basin along the coastal platforms, which gradually emerged above sem level in consequance of the glacial eustatism.

This migration was possible during the ascending phases of the glaciacions, when the climate was markedly of an oceanic type.

This study has been made with the aim of emphasising the opportunity of the establishment of a “National Park” in S. Rossore, to preserve his relict formation so important to testify the history of the quaternary vegetation of the mediterranean coasts, and particularly the anteclimax of the higrophilous downs, represented by the coastal “Selve”.     

Habitat selection of Dartford Warbler Sylvia undata on Elba Island (Tuscan Archipelago,Italy)

Capsule Habitat selection of Dartford Warbler Sylvia undata on Elba Island (Tuscan Archipelago, Italy) was analysed, considering 1-ha square plots (104 occupied and 104 unoccupied). Dartford Warbler occurrence was positively associated with garrigues, maquis and meadows, whilst the urban areas have a negative effect. The most used vegetation types were the garrigues with Cistus and degraded tall maquis with Erica arborea, Arbutus unedo and Cistus monspeliensis.     

Ricerche Sulla Vegetazione dei Dintorni di Firenze

Summary

It is related on some phytocenoses of the southerly Florence hills, lying on the boundary of the two basal biochores of peninsular vegetation. Although the proximity and the chorographical analogy at the south-westerly ones and at Ceceri Mount, which are included yet in the » Quercetum Ilicis « ambit, these hills are whereas sensible displaced in the » Quercetum pubescentis «. They have microtherme elements of higher planes, but they have in yet the marks of littoral biochore, for instance Smilax aspera, abundantly penetrating in hedges and in a pine-grove but non in coppices of Quercus Cerris.     

Ricerche Comparate Sulla Morfologia e Sulla Fisiologia di Larix e di Picea

Abstract

Comparative researches on morphology and physiology of PICEA and LARIX. The chlorophyll content of seeds and seedlings during germinations in darkness. — Very different are the chlorophyll contents of the seeds and the seedlings of Picea excelsa and Larix decidua grown in darkness.

In Picea chlorophyll is abundantly synthetized in cotyledons in the passage from seed to seedling stages. In Larix however this synthesis is very poor. These differences are more evident after the outgrowth of cotyledons from the primary endosperm and its exhaustion.

If seedlings of both species are exposed to 3.000 lux of light intensity for 24 hours, after development in darkness, one can observe much stronger chlorophyll synthesis in Larix cotyledons than icea.

These figures quanti atively express the different light-dipendence of chlorophyll synthesis in these two plants and offer a more adherent interpretation of the different ecological behaviours that are caracteristic of these two plants.     

Analisi informazionale degli schemi di dinamica della vegetazione. Un esempio sul popolamento vegetale delle dune del litorale di Venezia

Abstract

A method to quantify the dynamic schemes of vegetation based on information functions.—The dynamic schemes of vegetation as proposed by Braun-Blanquet have been never quantified with the aim to give indirect measures of the probability of transition between the types. This work presents a method that quantifies the arrows between the types by means of a redundancy measure. This is calculated by comparing the phytosociological types two by two. Redundancy, as proposed here, measures the similarity between the tables not only based on species composition but also on the basis of species cooccurrence. The method relies on the assumption that in a succession the higher is the redundancy between the types, that are presumably in sequence, the higher is the probability and then the velocity of transition from one type to another one. An example is given with data from coastal dune grasslands of the Venice Lagoon.     

Fenomeni di Inattivazione e di Riattivazione Enzimatica in Endospermi di semi di Ricino

Abstract

Inactivation and riactivation of enzymes in endosperms of castor bean seeds. — On the basis of previous results, the possibility has been investigated of the reversible interconversion of active and inactive form of enzymes in castor bean seeds, during their development.

The results described here indicate that:

1. the activity of some glycolytic enzymes increases greatly (81% and 400% increase of, respectively, Gl-6-P-dehydrogenase and aldolase) upon incubation of dry seeds for few hours at 4 °C.

2. The decrease of enzyme activity upon dehydration of seeds and the increase during the subsequent imbibition can be shown reproducibly.

3. This same observation is made for oxygen uptake.

These results are interpreted to indicate the reversible inactivation of enzymes caused by dehydration of seeds.     

La vegetazione degli stagni della zona di Olbia (Sardegna nord-orientale)

Abstract

Vegetation of the ponds in the zone of Olbia (northeast Sardinia). – The present paper contains a study on the vegetation of the ponds and marshes in the neighbourhood of Olbia. The following well determined associations have been ascertained: Chaetomorpho-Ruppietum, Salicornietum fruticosae, Arthrocnemeto-Limoniastretum monopetali, Juncetum maritimi, Scirpetum maritimi, Caricetum divisae, Schoeneto-Plantaginetum crassifoliae. Furthermore, some other consociations have been observed (with: Pholiurus incurvas and Triglochin bulbosum; Juncus subulatus; Scirpus setaceus and Spergularia rubra; Agropyrum elongatum and Spartina juncea).

The authors have also taken into consideration the present distribution of the vegetation in relation to the modifications due to the fact that this area has been reclaimed.