Climatic signals of tree-ring in Quercus gussonei (Borz\uec) Brullo in the Mediterranean region

Change in growth is among the primary response of trees to environmental variation. Tree-rings contain a wealth of information related to the climatic conditions. A dendroclimatic study on Quercus gussonei (Borz\uec) Brullo was carried out in the Nature Reserve of \u201cBosco della Ficuzza, Rocca Busambra, Bosco Del Cappelliere, Gorgo Del Drago\u201d (southern Italy). Q. gussonei is an endemic deciduous oak and thermophilous form of Quercus cerris L. that is found only in Sicily, although with clear sign of decline. The knowledge of ecology of this species should help to establish criteria for forest conservation in the Mediterranean region. For definining the ecological character and understanding the potential causes of the oak decline, we collected cores from ten trees with an increment borer. Precipitation and temperature data were obtained from a meteorological station located nearby from the stand. Annual ring widths, earlywood and latewood analyses were used in order to investigate and better understand the climatic dynamics influencing the oaks\u2019 growth. We determined the stable isotope discrimination of carbon (D13C) in the wood in order to investigate wateruse efficiency variations and the expression of possible plant adaptive traits. Climate-growth relationship, for the chronology 1951-2008, were analyzed using response, correlation and moving correlation functions. Our finding mostly highlight relationships between tree-rings width and climate data. Furthermore, D13C in treerings was used to identify long-term adjustments in water-use efficiency

Climate-growth relationships of Quercus gussonei (Borz\uec) Brullo in the Mediterranean region: adaptive traits and water use efficiency.

Due to their marginal distribution, peripheral tree populations are highly vulnerable and are more likely to be influenced by extreme climate conditions. This occurrence is known to cause dieback in many species at their Mediterranean margins. Quercus gussonei (Borz\uec) Brullo is a deciduous oak endemic of Sicily. It is a thermophilous, peripheral form of Quercus cerris L. which is showing an incipient but ongoing decline. A deeper ecophysiological knowledge is urgently needed on this species in order to plan proper conservation actions and reduce the risk of its extinction. In the aim to understand at what extent changes in environmental conditions could be responsible for Q. gussonei decline, we carried out dendrochronological and water-use efficiency investigations. Annual ring widths, earlywood and latewood analyses were accomplished in order to assess the climatic factors influencing the growth of Q. gussonei. In addition, we determined the carbon isotope discrimination (\u394 13C) in tree rings, allowing to evaluate WUE variations and the expression of possible plant adaptive traits. Climate-growth relationship were analyzed using response functions. Our findings highlight significant relationships between tree-rings width and climate data. The dendrochronological analysis of Q. gussonei showed a rather good adaptation of this species to the typical Mediterranean climate and oak trees seem to retain a certain resilience to efficiently face 14 less favorable environmental conditions. Furthermore \u394 13C indicates a long-term adjustment in water-use efficiency and the increase of WUE could be interpreted as a fair adaptation of this species to drought-prone environments

Seasonality and microhabitat selection in a forest-dwelling salamander

Many small terrestrial vertebrates exhibit limited spatial movement and are considerably exposed to changes in local environmental variables. Among such vertebrates, amphibians at present experience a dramatic decline due to their limited resilience to environmental change. Since the local survival and abundance of amphibians is intrinsically related to the availability of shelters, conservation plans need to take microhabitat requirements into account. In order to gain insight into the terrestrial ecology of the spectacled salamander Salamandrina perspicillata and to identify appropriate forest management strategies, we investigated the salamander\u2019s seasonal variability in habitat use of trees as shelters in relation to tree features (size, buttresses, basal holes) and environmental variables in a beech forest in Italy.We used the occupancy approach to assess tree suitability on a nonconventional spatial scale. Our approach provides finegrained parameters of microhabitat suitability and elucidates many aspects of the salamander\u2019s terrestrial ecology. Occupancy changed with the annual life cycle and was higher in autumn than in spring, when females were found closer to the stream in the study area. Salamanders showed a seasonal pattern regarding the trees they occupied and a clear preference for trees with a larger diameter and more burrows. With respect to forest management, we suggest maintaining a suitable number of trees with a trunk diameter exceeding 30 cm. A practice of selective logging along the banks of streams could help maintain an adequate quantity of the appropriate microhabitat. Furthermore, in areas with a presence of salamanders, a good forest management plan requires leaving an adequate buffer zone around streams, which should be wider in autumn than in spring

A new approach for an adaptive forest management planning to improve resilience of beech forests in relation to climate change: the LIFE AForClimate project

Vita.Flash conversion remains a necessary choice for high-speed Analog-to-Digital (A/D) conversion, despite its many disadvantages. Such conversion, by nature, involves 2^N sampling elements for an N bit converter. The differences in the signal delays to each of these sampling elements results in sampling the wrong value of the input, and gives rise to a systematic voltage error in a sequence of sampled voltages. The mechanisms that give rise to such delay differences, normally referred to as dynamic errors, are analyzed. Converter's dynamic performance in the presence of these errors is simulated using high level simulations. Simulating the converter's dynamic behavior, expressed as its Signal-to-Noise plus Distortion ratio (SNDR), using accurate timing simulators such as SPICE, is known to be computationally intensive. Furthermore, such simulations do not necessarily incorporate all of the dynamic errors in the converter. A methodology is presented herein, where the converter's dynamic performance is simulated without excessive CPU time. All of the dynamic errors in the converter are lumped into a single effective timing error of the sampling clock. The timing error is a function of the input signal dynamics as well as the physical layout of the converter. An 8-bit Flash converter, with practical layout and circuits, is taken as an example, and its dynamic performance is simulated using this methodology. Computer usage time on the order of a few hours has been achieved with this methodology to obtain the SNDR of the converter. The accuracy of the simulation is expected to be comparable to that of SPICE. Testing the dynamic performance of high-speed converters requires function generators with a linearity better than that of the converter under test. A novel compensation algorithm is presented which allows one to test the converter using function generators with nonlinearities comparable to or larger than those in the converter. The algorithm uses two sets of measurements: one set taken with the function generator and the A /D converter, and another taken with an all-pass filter inserted between the function generator and the A/D converter. Simulation results indicate that A/D converters with a SNDR of 60-70dB can be measured with an absolute accuracy of better than 0.2dB using a function generator that has ~40dB distortion components

IDPlanT: the Italian database of plant translocation

IDPlanT is the Italian Database of Plant Translocation, an initiative of the Nature Conservation Working Group of the Italian Botanical Society. IDPlanT currently includes 185 plant translocations.The establishment of a national database on plant translocation is a key step forward in data sharing and techniques improvement in this field of plant conservatio