Effects Of Thinning In a Water-Limited Holm Oak Forest

ABSTRACT

A natural holm oak forest was selectively thinned to test thinning as a tool to reduce tree mortality, increase productivity, and reverse the recent regression of the dominant species (Quercus ilex) induced by climate change. Thinning increased aboveground productivity and reduced stem mortality in this Mediterranean forest during four years just after thinning, contributing to the maintenance of forest functioning under changing climatic conditions. Q. ilex was the only species positively affected by the thinning: stem growth increased for all stem sizes, and mortality was significantly lower in thinned plots. On the contrary, mortality rates of Phillyrea latifolia and Arbutus unedo were not significantly lower. Stem growth increased for P. latifolia only in the smallest stem-size class. Our results highlight the suitability of selective thinning for improving the forest productivity and ensuring the conservation of Mediterranean coppices. Other benefits of selective thinning, such as a decrease in the risk of fire dispersion and an increase in the water supply for human populations, are also discussed.     

Incorporation of Whole Lupin,Lupinus albus,Seed Meal in Commercial Extruded Diets for Rainbow Trout,Oncorhynchus mykiss: Effect on Growth Performance,Nutrient Digestibility,and Muscle Fatty Acid Composition

Whole lupin seed meal was evaluated as partial replacement for fishmeal in extruded diets for rainbow trout, with particular emphasis on the effect on growth performance and apparent digestibility coefficient (ADC) of protein, lipids, carbohydrates, and energy. Effect on muscle fatty acid composition was also evaluated. All diets were formulated to be isonitrogenous and isoenergetic and to contain approximately 45% crude protein and 5.5 kcal energy g/diet. Diets were formulated to include whole lupin seed meal at 0, 10, 15, and 20%. Triplicate groups of fish weighing 65.9 ± 15.1 g on average were fed twice a day until apparent satiation during 12 wk. Growth, feed intake, hepatosomatic index, hepatic histology, proximate composition of whole body, and muscular fatty acid profile were determined. Growth and feed utilization were similar in all treatments and whole‐body composition did not vary among treatments. Polyunsaturated fatty acids of the n‐6 and n‐3 series remained constant in muscle as the amount of lupin in diets increased. Furthermore, the ADCs were similar among all diets. These results suggest that inclusion of whole lupin seed meal up to 20% in extruded diets for rainbow trout do not have any negative effect on growth, feed performance, or flesh quality.     

Utilization of genetic resources for the introduction and adaptation of exotic vegetable crops: The case of pepino (Solanum muricatum)

Summary Pepino (Solanum muricatum), a vegetatively propagated plant from the Andean region used for its edible fruits, has been identified as a potential crop for greenhouse cultivation in Mediterranean regions. However, attempts for introducing it have been unsuccessful, either because of the low yield, poor fruit quality, or both. Screening of germplasm under Mediterranean conditions showed that sources of variation for high yield existed in the cultivated genepool and that wild species S. caripense and S. tabanoense could contribute to a considerable improvement of soluble solids content (SSC) of pepino. Progenies obtained after crossing genetically distant (AFLP-based) parental clones were heterotic for yield, and allowed the selection of clones with an improved combination of yield and SSC. As a result of this intraspecific programme, two new improved cultivars (‘Turia’ and ‘Valencia’), which outperform the rest of cultivars available, have been selected for cultivation in Mediterranean conditions. The interspecific programme involved the selection of clones with high yield and SSC in backcross generations. The results show that introgression of genes from the wild species can contribute to improve the SSC of pepino. The backcross programme is in an advanced stage and new cultivars derived from the interspecific crosses are expected to be released in a near future. New prospects for the future in pepino breeding include the genetic transformation, the establishment of a genetic map, and the use of the genomic information from related Solanaceae important crops. All the information obtained is illustrative for the breeding for adaptation of vegetatively propagated crops.     

Multivariate analysis of invasive plant species distributions in southern US forests

Landscape Ecology - Invasive plants cause significant impacts in forested areas throughout the world. However, little is known about the relative importance of environmental drivers on the...     

Nutrient solution monitoring in greenhouse cultivation employing a potentiometric electronic tongue

This work investigates the use of electronic tongues for monitoring nutrient solution compositions in closed soilless systems. This is a horticultural technique in which the nutrient solution is continuously recirculated and an automatic recomposition system maintains the concentration of the different ions in the optimum range for the plants. Electronic tongues used in this study comprised an array of potentiometric sensors and complex data processing by artificial neural networks. A first experiment was able to carry out the simultaneous inline monitoring of ammonium, potassium, sodium, chloride, and nitrate ions during the winter. In the second and third applications, done during summer, some changes were introduced in the sensor array to improve its response toward chloride ions and to incorporate phosphate in the model. This electronic tongue was validated with real greenhouse samples and was also able to detect the variations in the ion concentrations caused by an incorrect configuration of the recomposition system.     

A rapid confirmatory method for analyzing tetracycline antibiotics in bovine, swine, and poultry muscle tissues: matrix solid-phase dispersion with heated water as extractant followed by liquid chromatography-tandem mass spectrometry

A rapid, specific, and sensitive procedure for determining four widely used tetracycline antibiotics and three related epimers in bovine, swine, and poultry muscle tissues is presented. The method is based on the matrix solid-phase dispersion technique with heated water as the extractant followed by liquid chromatography (LC)-tandem mass spectrometry (MS) equipped with an electrospray ion source. Target compounds were extracted from tissues with 5 mL of water heated at 70 degrees C. After acidification and filtration, 100 microL of the aqueous extract was injected in the LC column. MS data acquisition was performed in the multireaction monitoring mode, selecting two precursor ion to product ion transitions for each target compound. Heated water appeared to be an excellent extractant, since the absolute recovery data ranged between 70 and 78%. The accuracy of the method was determined at three spike levels, using minocycline as a surrogate analyte, in any different kind of muscle tissues considered and varied between 88 and 109% with relative standard deviations ranging between 3 and 11%. Limits of quantification were estimated to range between 1 (chlortetracycline) and 9 ng/g (4-epioxytetracycline), based on a signal-to-noise ratio of 10, and are well below the tolerance levels set by the European Union. The effects of the extraction temperature, volume of the extractant, and washing of the material supporting the biological matrix with ethylenediamine tetraacetic disodium salt on the analyte recovery were studied.     

Tepoxalin reduces pruritus and modified CADESI-01 scores in dogs with atopic dermatitis: a prospective, randomized, double-blinded, placebo-controlled, cross-over study

Thirty dogs with atopic dermatitis were given tepoxalin (Zubrin®, Intervet/Schering-Plough Animal Health, Boxmeer, the Netherlands) or placebo once daily for 4 weeks, followed by a wash-out period of 1 week before reversing the treatments. Pruritus was scored by the owners using the Edinburgh Pruritus Scale and one investigator employed a modification of the Canine Atopic Dermatitis Extent and Severity Index-01 (mCADESI-01) to score the physical lesions. After administration of tepoxalin there was a ≥ 50% reduction in pruritus and mCADESI-01 scores in 36% and 25% of the dogs, respectively, whereas following administration of the placebo there was a ≥ 50% reduction in pruritus and mCADESI-01 scores in only 25% and 16% of the dogs, respectively. Analysis of pooled data indicated that tepoxalin resulted in a significant reduction in pruritus ( P  = 0.012) and mCADESI-01 ( P  = 0.002) scores but there was no significant change after placebo. The median pruritus scores before and after tepoxalin were 2 (range 1–5) and 1 (range 0–5), respectively, and before and after placebo were 2 (range 0–4) and 2 (range 0–4), respectively. The median mCADESI scores before and after tepoxalin were 23 (range 0–68) and 16 (range 0–72), respectively, and before and after placebo were 18 (range 3–79) and 24 (range 0–65), respectively. At the dose used in this study (10.0–19.1 mg kg⁻¹), tepoxalin was well-tolerated and no adverse effects were noted.     

Supplementation of Citric Acid and Amino Acid Chelated Trace Elements in Low‐Fish Meal Diet for Rainbow Trout Affect Growth and Phosphorus Utilization

This study was conducted to evaluate the effect of citric acid (CA) and amino acid chelated trace elements (AA) on the growth, phosphorus (P) utilization efficiency and loading in rainbow trout fed a diet formulated with a low‐fish meal (FM) concentration. A low‐FM basal diet with or without monocalcium phosphate supplementation served as positive and negative control correspondingly. Dietary treatments consisted of the basal diet supplemented either with 1% CA, AA (equivalent to 40 Zn, 20 Mn, and 4 Cu mg/Kg of diet instead of inorganic trace element mix) or a combination of both. Duplicate groups of 35 fish (13.2 g) were fed until apparent satiation during 12 wk. Group of fish fed diets supplemented with 1% CA or AA had a final growth and feed utilization similar to that observed in fish fed the positive control diet (P > 0.05). P absorption was increased with the addition of CA or AA. P retention efficiency rates for these diets were higher in comparison with the rest of the treatments consequently showing the lowest P loading values (P < 0.05). The results indicate that addition of 1% CA or AA, to a low‐FM diet without inorganic P supplementation enhanced fish growth, P retention, and decreased P load to the environment.     

Implications of landscape configuration on understory forage productivity: a remote sensing assessment of native forests openings

Agroforestry Systems - Sound management of native forests used for cattle grazing requires understanding the dynamics of forage productivity in the openings. Despite their importance, forage...