CREA Journals (Consiglio per la ricerca in agricoltura e l’analisi dell’economia agraria)
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Le pinete demaniali costiere di Ravenna e Ferrara: analisi dei tipi forestali e strutturali per la scelta del trattamento selvicolturale nel processo di pianificazione
Get PDFThe state-owned pine forests on the coast of Ravenna and Ferrara: analysis of forest and structure types for choice of silvicultural system in the planning process. Results of the analysis on typology and structure of state forests dominated by maritime pine (Pinus pinaster Ait.) are reported. These formations grow on a narrow coastal belt between Cervia (Ravenna) and Volano (Ferrara), in the Emilia-Romagna region (Italy). The aim of the study is to support the proper silvicultural system in order to satisfy multiple use of pine forests using the analysis of forest types and model types of structure. Main ecological and structural features of principal pine forest types and experimental criteria on silvicultural systems are explained
Rimboschimenti della Presila di Cosenza: tre conifere a confronto
Get PDFReforestation of Presila di Cosenza: three conifers compared. A comparison was made between forestations of Atlas cedar, Douglas fir and Calabrian pine realized in the mid-70s of the last century with identical modalities and in the same station conditions, in the Presila of Cosenza. The results achieved by the plantations must be considered, according to their main aim that was concerned with the fulfilments of essentially protective tasks, definitely positive. The data relating the rates of take and mortality through the years confirm the great ability to colonise and to form thick and pure crops on behalf of the calabrian pine, while the incremental ones emphasise the Douglas fir as a species with a quicker growth. The densities does not allow, in the test areas, the regeneration to assert itself. Surveyings on the phytosanitary state of the forest stands do not evidence, in the test areas, symptoms of suffering, while the margin plants in the warm slopes of the pine-wood strongly turn out exposed to the processionary attacks. The more important requirement, for the investigated crops, is represented by the carrying-out of silvicultural cuttings, which aim at: regulating their thickness and structure, increasing their biological stability, creating favourable conditions for their renaturalization
Rinnovazione agamica e produttività degli eucalitteti di E. occidentalis e di E. x trabutii della fascia ionica crotonese nei primi quattro cicli colturali
Get PDFAgamic regeneration and wood productivity in the E. occidentalis and E. x trabutii plantation of the ionian area of Crotone at the first four cultivation cycles. Here are explained the results of clear cutting without the release of standards trials conducted in stands of E. occidentalis and E. x trabutii of the ionian area of Crotone (Calabria) at the end of the first four cultivation cycles: gamic (April 1974) and agamic (April 1984, 1993, 2001). The plantations, even if partially expressing their productive potentialities for the environment, objectively difficult where there have been plantings, have guaranteed, in the first three agamic cycles, a low mortality of the stumps, a discrete ability of regeneration, a good shooting faculty. The mortality in the E. x trabutii is higher than the one in the E. occidentalis, both in the gamic phase and in the group of the agamic cycles. The ability of agamic regeneration and the shooting faculty in the E. occidentalis are higher than in the E. x trabutii . As regards the bearing of the coppice shoots, the first class (vertical) stems are a prerogative of the E. x trabutii. The average diameter and height in the E. x trabutii coppice shoots are higher than in the E. occidentalis ones. The ipsodiametrical ratio of the coppice shoots is high both in the E. x trabutii and in the E. occidentalis, so the agamic stems, in comparison with seed plants, are at greater risk of weather damage. In the last two agamic cycles the regeneration of the radical coppice shoots with an invasive feature and short and worn out crowns, appeared in some areas of both species. The cormometrical volume per hectare produced by the two species in the agamic cycles is sensibly higher than the one found in the gamic phase and, in the last cycle, still slightly growing. In the coppices the eight-year-old wood stands vary from 42-49 m3ha-1 for the E. occidentalis, to 59-83 m3ha-1 for the E. x trabutii. The plantations of eucalypts of Crotone, for the availability of remarkable quantities of biomass for industrial use and in order to be still extended on about 4500 hectares, constitute stands of great economic interest
Prove di diradamento in acero-frassineti di neoformazione nella Comunità Montana Agno-Chiampo (VI). Risultati dopo il secondo intervento
Get PDFThinning trials in secondary growth ash-maple stands carried out in the Agno-Chiampo district (VI): results after second thinning. The second thinning results undertaken in four ash-maple stands of different age are described. In three stands a target tree management system (free thinning around few target trees) was applied. In the oldest stand one mixed thinning has been implemented. In the youngest stand 400 target trees have been preselected and numerically half reduced after a second free thinning (aged 18 yr). The basal area of this stand decreased globally with 34%. In the middle aged stand (aged 28 and 31 yr), all the target trees, previously selected, were favoured. Among them, only those seriously damaged (by logging and frost) were cut down. The overall uptake in this stand has been the 30% of basal area. In the oldest stand the second traditional thinning (aged 37 yr) was more intensive, than the previous: the 34% of basal area has been felled. The analysis of target trees diameter growth has revealed that free thinning has been efficient for the youngest stand (a constant diameter increment of 8,6 mm yr-1). Conversely, a progressive reduction of diameter increment (5,5 mm yr-1) has been found in the control plot. The reaction to thinning in the middle aged stand was inferior in terms of homogeneity and diameter increment through years (6 mm yr-1 average), this underline a less reaction of crowns. In the oldest stand, late thinnings had little incremental effect, however the general stability and specific diversity improved . The experimental results confirm the necessity to carry out the first thinning in young stands (aged 15-20 yr) with a frequency of 4-6 yr in a restricted number of target trees (100-200 per hectare). In the oldest stands the chance to improve the production of good quality timber is reduced, but timber with fairly good technological characteristics can be however obtained
Messa a punto di un metodo per l'individuazione di β-1,3- glucanasi e chitinasi attraverso Native PAGE su estratti di piante di Prunus avium L. inoculate con Phytophthora spp.
Get PDFTecnique to detect on ß-1,3- glucanase and chitinasi by native PAGE, in Prunus avium (L.)clones inoculated with Phytophthora spp. ß-1,3-glucanase and chitinase activities have been detected by native PAGE (poliacrylamide gel electrophoresis) on leaf extracts of wild cherry (P. avium) inoculated with different species of Phytophthora spp.. These pathogens are aggressive in wild cherry and they can cause wiltings and death of the plant. These two PR (pathogen-related) proteins are normally produced by plants as first resistance strategy towards pathogens. The PR activities are involved in ifal cell wall degradation and growth. Usually, the techniques to detect them are based on colorimetric assay performed with the total protein extracts or in the poliacrylamide gels, through expensive procedures. In this work a direct colorimetric detection on a Carboximetil (cm)-Curdlan RBB (Remazol Brilliant Blu) and Glycol Chitosan substrate, is used to reveal ß-1,3-glucanase and chitinasi respectively. This protocol resulted to be very sensible in detecting the two proteins, very simply, reliable and cheap
Risultati di prove di diradamento in rimboschimenti di pino laricio
Get PDFResults of thinning trials for artificial stands of calabrian pine. The results of thinning trials carried out in plantations (aged 45) of Pinus nigra laricio Calabrica, at an intermediate stand development between the adolescent and the high forest, are here reported 10 years later the second thinning and after the third one. Within system of selective thinnings related to the differed number (800, 600 and 400) and to social position of selected trees in the main crops, the following theses are being compared: light thinning, intermediate thinning, heavy thinning and control. The second thinning effected positively the standing crop as compared with control plot: reducing mortality; increasing the annual diameter increments; differentiating the trees distribution for higher diameter classes; favouring the physical stability, the increments of basal area and stem volume, the renaturalization with autochthonous heavy seed broadleaves (chestnut, beech, turkey oak). Following the third thinning trees, the selected trees belong to the large-sized and high commercial value categories
Does the phenotypic selection affect the genetic structure and diversity? A study case on Walnut in eastern central Italy (the region of Marche)
Get PDFThe Persian walnut (Juglans regia L.) is widely planted in western Europe, either for fruit either for high quality timber production. This tree is generally considered non authoctonous, probably introduced from East some 7000 years ago and spread by several ancient civilisations. The possible artificial origin seems confirmed by the low intra-specific variation and the higher individual variability recorded by several Authors as well as by the lack of natural populations. Indeed, only wider fruit cultivation areas or small groups, lines or isolated walnut trees can be recorded in Italy. The occurrence of walnuts in forest, escaped from cultivation areas, is very rare. Due to the increased interest of planters, walnut plantations have been extended several ten thousands hectares throughout all western Europe. As a consequence of that it was evident the necessity of selected suitable basic populations in order to supply high quality reproductive materials. The conventional method based on the organisation of a wide and exhaustive seed procurement from the native range to establish provenance tests is at the present impossible. Thus it is necessary to study methods of selection which consider basic materials growing within the western European range. This study is aimed to test the efficiency of the multi-trait Selection Index method, in preserving levels of genetic diversity and structures compatible with the standards observed within a reference system of extended Italian populations. As a consequence of the relatively recent introduction, the genetic structure of the species shows individual variation higher than inter-population diversity. Those genetic structure characteristics were revealed also during a survey of walnut resources in the region of Marche, central Italy. The survey was the starting point for selecting and preserving basic materials for high quality woody production, possibly interesting for forest nurseries in the region. The genetic variation of Marche’s population, compared to a reference system of 7 other Italian provenances, was used as a base to establish a possible improvement strategy together with basic guidelines to manage those genetic resources. Indeed, the very important individual component of the genetic variation suggested to select directly superior phenotypes in view of establishing a comparative multisite progeny test network. No substantial differences were detected concerning the genetic structure of the Italian population, neither within the Marche population, neither in the phenotypically selected material. Homozygosity was always high, probably due to genetic erosion, isolation and adaptation to extreme conditions. Given this general situation in the Marche area, a special care should be payed in the management of walnut reproductive materials, in order to maintain sufficient levels of variation in plantations
Delimitazione di Regioni di Provenienza per la gestione dei Materiali Forestali di Base in Campania
Get PDFDelimitation of Provenance Regions for the management of Forest Reproductive Materials in Campania.The 1999/105/CE Directive has set Provenance Regions as the standard European management approach of forest propagation materials (mainly for “Source Identified” and “Selected Materials”) . The Authors report about a method for establishing Provenance Regions for forest species in Mediterranean environments (partitive-ecologic approach). The method consists of an iterative two steps procedure: a scheme of Provenance Regions is first worked out on the grounds of environmental factors and technical qualifications, and then validated by statistical analysis (Discriminant Analysis) performed on bio-climatic and geo-lithologic data. The method, applied to region Campania, led to the definition of six Provenance Regions. The initially considered regions of the interior and higher elevation areas under more “oceanic” conditions, R5 and R6 appeared really homogeneous and were merged to form two sub-regions. The same method was applied to merge regions R1 and R2 in sub-regions. Anyway, because of the supposed higher differentiation among fractionated ranges of many southern species, these Provenance Regions should be kept distinct in order local Forest Genetic Resources will be preserved
Confronto tra metodi di diradamento in un impianto puro d farnia (Quercus robur L.)
Get PDFComparison between different thinning systems in a pure common oak plantation.- First results of thinning trials, in a 19 years old pure common oak plantation, carried out during winter 2001/2 are reported. A previous thinning had been applied in 1993. Two different thinning methods were tested: systematic-selective method (50% tree felling) and selective thinning method (felling around 80 target tree per hectare). In spite of different thinning intensity (43% and 28% of basal area) in order to keep constant the diameter increments of target trees, the effects of both methods were similar. During the first five years after thinning, the target trees in both thinned plots showed constant diameter increments around 1,1 cm , while in the control plot the diameter increment decreased progressively to 0,7 cm. After thinning and pruning, epicormic branches developed on target trees. In the specific, about 68% of target trees in the thinned plots are characterized by epicormic branches, although only the 17% are vigorous. In the control plot, 62% of target trees developed epicormic branches, none of them vigorous
La gestione dei rimboschimenti di pino nero appenninici. I diradamenti nella strategia di rinaturalizzazione
Get PDFManagement of black pine stands in the Appennines. Thinning for renaturalisation - The first stages of management and renaturalisation of black pine plantations are founded on thinnings, which are primarily aimed at increasing physical stability and creating favourable ecological conditions for the natural regeneration of autochthones species. The research aims at experimenting two different intensities in the first thinning of a black pine young stand of good fertility in the area of Pratomagno (Arezzo). The effects of the thinning on the main dendrometric parameters have been evaluated by means of three different inventories: i) 1998 before and after thinning, ii) 2002, iii) 2006. In particular the dynamics of horizontal structure (permanent transects) and the trend of stability indicators (height – diameter ratio, crown depth, crown area, crown diameter – stem diameter ratio) have been investigated. Thinning intensity is strictly related to increasing of the pine forest functionality. In a thirty years old stand in good fertility conditions a “strong thinning” (reduction of about half the number of trees and 35% of basal area) is proved to be effective in increasing stability and stimulating crown growth