Search results for "forest"

Winter feeding leads to a shifted phenology in the browntail moth Euproctis chrysorrhoea on the evergreen strawberry tree Arbutus unedo

2010

1 The browntail moth Euproctis chrysorrhoea is a highly polyphagous univoltine forest pest. Although its young larvae usually overwinter in diapause from early autumn to the beginning of spring, winter larval feeding has been reported when this species feeds on the evergreen woody shrub strawberry tree Arbutus unedo. 2 The present study investigated life-history traits of four populations of E. chrysorrhoea feeding on A. unedo, including phenology of the different life stages, larval feeding activity and diapause incidence. By modelling the relationship between larval size and host plant leaf persistence, elevation and mean annual temperature, we also studied larval development in ten popul…

Soil biodiversity monitoring in Europe : ongoing activities and challenges

2009

International audience; The increasing interest in soil biodiversity and its protection includes both the biodiversity conservation issues and the mostly unknown economic and ecological values of services provided by soil biodiversity. Inventory and monitoring are necessary tools for the achievement of an adequate level of knowledge regarding soil biodiversity status and for the detection of biodiversity hot spots as well as areas where current levels of biodiversity are under threat of decline. In this paper the main tools and methodological approaches for soil biodiversity measurement are presented. Technical aspects related to the inventory and monitoring activities at a large spatial sc…

Modelling bulk surface resistance by MODIS data and assessment of MOD16A2 evapotranspiration product in an irrigation district of Southern Italy

2016

Abstract In this study, accurate estimates of daily actual evapotranspiration, ET a , were obtained based on the direct Penman–Monteith application, in which the bulk surface resistance term was computed by considering, as main input, daily remotely sensed Land Surface Temperature (LST). In particular, Eddy Covariance measurements of ET a , associated to LST obtained by MODIS time series (MOD11A2) characterized by 8-day resolution, allowed to calibrate a simple bulk surface resistance model, based on two-years of data observations collected in a quite homogeneous irrigation district of Sicily, where olive grove is the main crop. The model was then validated by an independent database collec…

Mapping evapotranspiration on vineyards: A comparison between Penman-Monteith and energy balance approaches for operational purposes

2012

Estimation of evapotranspiration (ET) in Sicilian vineyard is an emerging issue since these agricultural systems are more and more converted from rainfed to irrigated conditions, with significant impacts on the management of the scarce water resources of the region. The choice of the most appropriate methodology for assessing water use in these systems is still an issue of debating, due to the complexity of canopy and root systems and for their high spatial fragmentation. In vineyards, quality and quantity of the final product are dependent on the controlled stress conditions to be set trough irrigation. This paper reports an application of the well-known Penman-Monteith approach, applied i…

A NEW VERSION OF THE USLE-MM FOR PREDICTING BARE PLOT SOIL LOSS AT THE SPARACIA (SOUTH ITALY) EXPERIMENTAL SITE

2015

Improving empirical prediction of plot soil erosion at the event temporal scale has both scientific and practical importance. In this investigation, 492 runoff and soil loss data from plots of different length,  (11 <  < 44 m), and steepness, s (14.9 < s < 26.0%), established at the Sparacia experimental station, in Sicily, south Italy, were used to derive a new version of USLE-MM model, by only assuming a value of one for the topographic length, L, and steepness, S, factors for  = 22 m and s = 9%, respectively. An erosivity index equal to (QREI30)b1, QR and EI30 being the runoff coefficient and the event rainfall erosivity index, respectively, with b1 > 1 was found to be …

Sulfur-free pulping of hot-water-extracted spruce sawdust

2016

Softwood (Picea abies) sawdust was hot-water-extracted with two multi-phase processes (160-180°C, 100-280 min, and liquor-to-wood ratio 5 l/kg) corresponding to P-factors of ~780 (yield 80.0%) and ~4580 (yield 72.4%). The pre-treated materials were then pulped with the soda-AQ cooking (170°C, NaOH charge 20%, AQ charge 0.1%, 30-150 min, and liquor-to-wood ratio 5 l/kg), resulting in a yield range of 36.1-61.4% (for reference cooks without pre-extraction 47.9-60.0%). It was observed that the pre-extraction under moderate conditions enhanced the dissolution especially of large-molar-mass lignin during cooking, and the total amount of the dissolved lignin was also higher than that removed from…

ASSESSING FAO-56 MODEL TO ESTIMATE TABLE OLIVE WATER CONSUME UNDER SOIL WATER DEFICIT CONDITIONS

2012

Agro-hydrological models can be considered an economic and simple tool to quantify crop water requirements. In the last two decades, agro-hydrological physically based models have been developed to simulate mass and energy exchange processes in the soil-plant-atmosphere system. Although very reliable, due to the high number of required variables, simplified models have been proposed as simple tools to quantify crop water consumes. The main aim of the paper is to assess, for a Sicilian orchard of table olive, the suitability of FAO-56 agro-hydrological model to estimate the crop transpiration under soil water deficit conditions. The model validation is carried out by means of measurements of…

Adapting FAO-56 Spreadsheet Program to estimate olive orchard transpiration fluxes under soil water stress condition

2012

Sviluppi recenti e nuove tecnologie per la stima dei fabbisogni irrigui in ambiente mediterraneo

2008

Estimating crop coefficients and actual evapotranspiration in citrus orchards with sporadic cover weeds based on ground and remote sensing data

2022

AbstractAccurate estimations of actual crop evapotranspiration are of utmost importance to evaluate crop water requirements and to optimize water use efficiency. At this aim, coupling simple agro-hydrological models, such as the well-known FAO-56 model, with remote observations of the land surface could represent an easy-to-use tool to identify biophysical parameters of vegetation, such as the crop coefficient Kc under the actual field conditions and to estimate actual crop evapotranspiration. This paper intends, therefore, to propose an operational procedure to evaluate the spatio-temporal variability of Kc in a citrus orchard characterized by the sporadic presence of ground weeds, based o…