Diversità funzionale in cloni di ciliegio da legno (Prunus avium L.) di provenienza Appennino toscano

Functionality in wild cherry (Prunus avium L.) clones of Tuscany Appenines provenances. Results of a research regarding the functionality of already selected wild cherry (Prunus avium L.) clones are reported. The main target was to select the genotypes with the best ecological efficiency and less sensible to environmental stress, in order to give concrete indications for arboriculture for wood productions. Starting from 2002, measurements were carried out in the experimental plot of Papiano (Stia, AR), where the following clones with provenance from the Tuscan Apennines were compared: Casina Alpe 1 (A), Casina Alpe 2 (D), Puzzòlo (C), Paradisino (E), Piantata Catenaia (F). Dendrometrical data were collected at the beginning and at the end of each season, in order to evaluate the growth and the individual current increment of the clones. To better characterize the canopies of each clone, measurements of photosynthetic active radiation (PAR) and of the leaf area index (LAI) where carried out with ceptometers and PCA LAI 2000. In order to evaluate differences between the clones regarding functionality and response to environmental stress, growth and productivity were related to the most important canopy characteristics. Ecological efficiency was calculated for the different clones using the net assimilation rate (NAR). The results show that the clone E has the most developed canopies and the best results in terms of growth. But at the same time it also presents densely branched round canopies and results more sensible to the effects of summer drought. These elements contribute to advise against the use of this clone in future genetic improvement programs and in high quality wood productions. On the contrary, the clones C and A have both good growth characteristics and a better general architecture and are therefore advised for high quality wood productions especially in the same geographic region

Effect of the silvicultural treatment on canopy properties, litter and seed production in beech coppices under conversion to high forest.

European beech (Fagus sylvatica L.) is widely distributed in Italy where it covers 1035103 ha, mainly concentrated in the mountainous areas at altitudes above 900 m. The major part is represented by high forest often issued from the conversion of coppice woods, which in the past was the silvicultural system most widely applied mainly to provide fire wood. The social changes occurred in the second half of the last century –fire wood market crisis and the increasing importance of environmental issues- enhanced the conversion into high forest of large areas previously managed as coppice by means of different silvicultural treatments and practices. Nevertheless, the environmental benefits of this choice were not adequately investigated. Results of annual measurements (1992-2009) made in a beech coppice stand aged 65 are here reported. The study area is located on the Alpe di Catenaia, a pre-Apennine outcrop close to Arezzo (Central Italy). Variables strictly related to stand productivity and dynamics such as annual litter and seed production, leaf area index (LAI) and transmittance (PAR) were measured in the research area of Buca Zamponi to estimate the effects of two theses, natural evolution (TEST) and conversion into high forest (DIR). Three thinnings were undertaken in the latter thesis in 1972, 1987 and 2002. Additional theses of natural evolution (CONTR) and advance seed cutting (TS) were added in 2002 in a nearby study area (Eremo della Casella). Results showed the high productivity of coppice stands, under conversion to high forest, with mean values of annual total litter, leaf litter and leaf area index of 5 Mg ha-1, 3 Mg ha-1 and 6 m2m-2, respectively. These findings confirm both the prompt response of beech to intensive thinning cycles and the reliability of undertaking coppice conversion into high forest. Furthermore, the positive trend observed in the ecological parameters and the high consistency of leaf fraction, highlight the still juvenile phase in progress in these stands. These results will be investigated further because of their significance in stands aged over 60. The applied silviculture produced positive outcomes in all the tested theses. Annual total litter, leaf area index and transmittance showed significant differences comparing DIR and TEST. The gap tends to vanish within 8-10 years after thinning occurrence. Seed cutting (TS) produced on the contrary heavy and lasting differences compared with all the theses. Leaf area index and transmittance were 1.97 m2m-2 and 24.8 % in TS vs. 4.22 m2m-2 and 7.89% in DIR. Seed cutting increased also the development of stand canopy and hastened seed production. The amount of seed production in TS was higher than in DIR representing 25% of total litter production. The DIR thesis resulted to be more appropriate for coppice conversion into high forest. Silvicultural practices hasten the conversion process and allow both ecological and economic returns throughout the conversion cycle by the repeated intermediate harvestings that amount to 250-300 m3ha-1 at the age of 60. A 15 yrs timeis recognized as the optimal interval between moderate to heavy thinnings. The complementary thesis of undertaking an advance seed cut (TS) relies more on management planning criteria than on ecologically-based issues

Early and long-term impacts of browsing by roe deer in oak coppiced woods along a gradient of population density

Over the last few decades, wild ungulate populations have exhibited relevant geographic and demographic expansion in most European countries; roe deer is amongst the most widespread ungulate species. The increasing roe deer densities have led to strong impact on forest regeneration; the problem has been recently recognized in coppice woods, a silvicultural system which is widespread in Italy, where it amounts to about 56% of the total national forested area.In this study we investigated the effect of roe deer browsing on the vegetative regeneration of Turkey oak few years after coppicing, along a gradient of roe deer density. A browsing index revealed that browsing impact was high at any given roe deer density but increased at higher density, with the browsing rate ranging from 65% to 79%. We also analyzed the long-term impact of browsing six and eleven years after coppicing under a medium roe deer density. Results indicated the early impact are not ephemeral but produced prolonged impacts through time, with an average reduction in volume of -57% and -41% six and eleven years after coppicing, respectively. Based on these results we proposed integrating browsing monitoring with roe deer density estimation to allow identifying ungulate densities which are compatible with silvicultural and forest management objectives. The proposed browsing index can be regarded as an effective management tool, on account of its simplicity and cost-effectiveness, being therefore highly suitable for routine, large scale monitoring of browsing impact

Tree canopy cover and natural regeneration into strictly-protected forest areas: the MaB reserve of Montedimezzo (Isernia,Italy).

The ecological analysis and the analysis of mechanisms underlying the natural regeneration process into strictly protected forest areas, is basic to the understanding of ecosystem functioning and to estimate the recovery ability as a function of time and environmental changes. Aim of the paper is to analyze the spatial-temporal dynamics of tree species regeneration into mixed Turkey oak-common beech stands growing undisturbed since more than one half- century. The ability of first establishment and following growth of natural regeneration related to the ecological parameters, the structural features of standing crop and its development stages, are analyzed in detail. The study was carried out into two permanent monitoring plots (A) and (B) where two different tree species play the main functional role. In (A) common beech is dominant (Fagus sylvatica L.-elevation 1040 m a.s.l.); in (B) Turkey oak is prevailing (Quercus cerris L.-elevation 940 m a.s.l.). In each plot, the analysis of vertical stand structure, of natural regeneration pattern and ecological surveys (LAI, trasmittance, soil moisture content, canopy interception of rainfall) were undertaken by monthly surveys from May to October into 57 sub-plots each 1m2 wide over the period 2005-2007. Results highlighted that (B), Turkey oak prevailing, shows a more complex structure, a higher tree canopy thickness and the lack of gaps. The area shows therefore a lower trasmittance and a higher LAI value; throughfall and soil moisture content are also reduced as compared to (A). As for the natural regeneration pattern, further to a first stage when seedlings mortality is high, their survival rate is being kept high and steady over time in (A). A further mortality peak has been detected vice versa over the following summer season in (B). The different main tree species composition and radiation regime seem to be the basic reasons of the dynamics observed as for mortality and survival rates. The way of seedlings establishment points out that optimal ecological conditions are present for the production and germination of seeds as well, but that the limiting factor is the reduced radiation amount that reaches the forest floor.

Roe deer browsing effects on growth development of Turkey oak and chestnut coppices.

Over the last three decades wild ungulates populations in Italy increased to values ranging from 300% to 600%. As a consequence, in Italy as well as in other European countries, situations with high ungulate density and, then, negative effects on the stability and dynamics of ecosystems, are increasing frequently. Starting from these evidences we investigated the effects of roe deer population on the vegetative regeneration of two different broadleaved tree species: Turkey oak (Quercus cerris L.) and chestnut (Castanea sativa Mill.) coppice stands. In Alpe di Catenaia (Apennines – Central Italy), after coppicing in 2002, we chose six experimental areas where fenced (P) and non-fenced (NP) plots were established. Measurements were performed at the beginning of the study period and in winter 2008 in both P and NP plots. Diameter and    height of all sprouts were measured. Results showed a different impact of roe deer on the two species. After seven years chestnut did not show any significant browsing-related damage, while in Turkey oak heavy differences between protected and non-protected areas are present: in NP plots roe deer browsing has produced a significant reduction in basal area (58%) and volume (57%) compared to P plots. The results agree with previous studies and confirm: (a) a selective browsing pressure on Turkey oak; (b) the lasting effect of the early impact after clear cutting, visible even seven years after. Based on the findings, we discussed the need for an integrated management of forest vegetation and forest fauna which should define the density of ungulates not only according to the theoretical carrying capacity    of ecosystems, but also considering (i) the preservation of the ecosystem overall functionality, (ii) the forest structure development and (iii) the forest management type

Structural and ecological changes in holm oak coppices 25 years after their conversion into high forest

Normal 0 14 false false false MicrosoftInternetExplorer4 Holm oak (Quercus ilex L.) is one of the most diffuse and economically important forest species in Sardinia, where it holds about 40% of holm oak cover in Italy. The forest type has also acquired a high ecological, recreational and landscape value over the last decades. Most of holm oak stands originated from overgrown coppice forests partly undergoing conversion into high forest. This study was set up in 1994 to analyse, as a function of site-index, the effects of conversion thinning on productivity, biodiversity, structural dynamics and canopy characteristics in an holm oak forest located in southern Sardinia. Two experimental permanent plots, differing in site index, stand structure and tree density, were established. The surveys were carried out in 1994-95 and 2010-11. The analysis included growth pattern, dynamics of stand structure and estimation of forest canopy attributes as leaf area index and canopy transmittance. Results pointed out the simplified stand structure, the poor biodiversity, the low LAI and high transmittance values 9 years after thinning implementation. These characteristics were more pronounced in the less productive area, characterised by substantial canopy gaps. 25 years after thinning implementation, both stands showed significant increase in the number of trees, strengthening of the clustered structure and high canopy recovery. Conversely, no significant changes in biodiversity and vertical structure were observed. Overall results contributed to a positive evaluation of the conversion practice based on periodical thinnings, even if the excessive reduction of tree density, mainly in the lower site-index area, did not allow yet the fully achievement of canopy recovery <object classid="clsid:38481807-CA0E-42D2-BF39-B33AF135CC4D" id=ieooui> st1\:*{behavior:url(#ieooui) } /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabella normale"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-ansi-language:#0400; mso-fareast-language:#0400; mso-bidi-language:#0400;} <![endif]--

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¹⁸F]Flortaucipir PET Across Various MAPT Mutations in Presymptomatic and Symptomatic Carriers

OBJECTIVE: To assess the [18F]flortaucipir binding distribution across MAPT mutations in presymptomatic and symptomatic carriers. METHODS: We compared regional [18F]flortaucipir binding potential (BPND) derived from a 130-minute dynamic [18F]flortaucipir PET scan in 9 (pre)symptomatic MAPT mutation carriers (4 with P301L [1 symptomatic], 2 with R406W [1 symptomatic], 1 presymptomatic L315R, 1 presymptomatic S320F, and 1 symptomatic G272V carrier) with 30 cognitively normal controls and 52 patients with Alzheimer disease. RESULTS: [18F]Flortaucipir BPND images showed overall highest binding in the symptomatic carriers. This was most pronounced in the symptomatic R406W carrier in whom tau binding exceeded the normal control range in the anterior cingulate cortex, insula, amygdala, temporal, parietal, and frontal lobe. Elevated medial temporal lobe BPND was observed in a presymptomatic R406W carrier. The single symptomatic carrier and 1 of the 3 presymptomatic P301L carriers showed elevated [18F]flortaucipir BPND in the insula, parietal, and frontal lobe co