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Abstract: Natural grasslands play an important role in sheep production in Southern Portugal. The increase of browse species (e.g., Cistus spp. shrubs) supplies green material to grazing animals and can be the only source of nutrients during some periods of the year, particularly when there is a shortage of conventional feedstuffs. The aim of this study was to characterize leaves, flower buds and fruits from Cistus salvifolius shrubs, harvested at different maturity stages in the Alentejo region of Portugal, by phenological, gas production methods. C. salvifolius shrubs presented leaves during the entire year, with a continuous increase of leaves from November until March. Fruits were found from November to May and flower buds were observed from April to June. Stems constituted the highest dry weight (DW40°C; weight after drying at 40°C) proportion of the plant (545g/kg DW40°C), followed by the leaves (370g/kg DW40°C) and reproductive organs (85g/kg DW40°C). The neutral detergent fibre (NDF) and lignin (sa) contents of the leaves ranged from 267 to 350g/kg DM and 68 to 148g/kg DM, respectively. Leaf CP and total phenolics levels decreased linearly with time. Linear regressions resulted in R 2 of 0.961 (P=0.00002) and 0.825 (P=0.0128), respectively. Levels in leaves and flower bud fractions reached levels as high as 120 and 85g/kg DM, respectively. In the fitted models for gas production rates, the maximum rates for the November, December, January and June harvests were approximately one half of those in February, March, April and May. The highest fitted levels of total leaf gas production were in November (31.66ml/200mg DM) and the lowest in March (13.35ml/200mg DM). The highest fitted gas production levels were for fruits (40.29ml/200mg DM) and flower buds (30.74ml/200mg DM), which also had the lowest total phenolic contents (44.0g/kg DM – fruits and 65.0g/kg DM – flower buds). It is concluded that the use of C. salvifolius shrub (including the leaves) as a feed source for small ruminants in the farming system when there is a shortage of conventional feedstuffs, requires careful monitoring during the flower bud stage, when high TP levels are observed. The potential for metabolic disorders associated with high TP levels implies that diets based only on this shrub should be avoided. [Copyright &y& Elsevier]

Highlights • ERA-Iterim reanalysis weather variables were used for computing daily PM-ET o. • The accuracy of weather variables estimation was assessed and temperature was corrected for elevation. • Various bias correction approaches were tested for ET o REAN using cross-validation. • Bias correction used data aggregated quarterly to consider seasonality of climate. • Additive bias correction relative to the nearest grid point was selected because accurate and simple. Abstract This study aims at assessing the accuracy of estimating daily grass reference evapotranspiration (PM-ET o ) computed with ERA-Interim reanalysis products, as well as to assess the quality of reanalysis products as predictors of daily maximum and minimum temperature, net radiation, dew point temperature and wind speed, which are used to compute PM-ET o. With this propose, ET o computed from local observations of weather variables in 24 weather stations distributed across Continental Portugal were compared with reanalysis-based values of ET o (ET o REAN ). Three different versions of these reanalysis-based ET o were computed: (i) an (uncorrected) ET o based on the individual weather variables for the nearest grid point to the weather station; (ii) the previously calculated ET o corrected for bias with a simple bias-correction rule based only on the nearest grid point; and (iii) the ET o corrected for bias with a more complex rule involving all grid points in a 100 km radius of the weather station. Both bias correction approaches were tested aggregating data on a monthly, quarterly and a single overall basis. Cross-validation was used to allow evaluating the uncertainties that are modelled independently of any forcing; with this purpose, data sets were divided into two groups. Results show that ET o REAN without bias correction is strongly correlated with PM-ET o (R2>0.80) but tends to over-estimate PM-ET o , with the slope of the regression forced to the origin b 0 ≥ 1.05, a mean RMSE of 0.79 mm day−1, and with EF generally above 0.70. Cross-validation results showed that using both bias correction methods improved the accuracy of estimations, in particular when a monthly aggregation was used. In addition, results showed that using the multiple regression correction method outperforms the additive bias correction leading to lower RMSE, with mean RMSE of 0.57 and 0.64 mm day−1 respectively. The selection of the bias correction approach to be adopted should balance the ease of use, the quality of results and the ability to capture the intra-annual seasonality of ET o. Thus, for irrigation scheduling operational purposes, we propose the use of the additive bias correction with a quarterly aggregation. [ABSTRACT FROM AUTHOR]