Scientific Journals of INIA (Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria)
Not a member yet
3042 research outputs found
Sort by
Guanaco’s diet and forage preferences in Nothofagus forest environments of Tierra del Fuego, Argentina
Get PDFAim of study: Guanaco (Lama guanicoe Müller), is a South American native ungulate widely distributed in Patagonia, which in the island of Tierra del Fuego (TF), extends its habitat into Nothofagus spp. forests. Within these forests, guanacos consume lenga (Nothofagus pumilio) leaves and twigs, and other understory species. The aim of this work was to determine: 1) the spring and summer diet of free ranging guanacos, and 2) which plants, grown in the forest understory, guanacos do prefer, or avoid, in these seasons of great forage abundance.Area of study: Tierra del Fuego (Argentina), on three representative areas which combined Nothofagus forests and adjacent meadows (vegas).Material and Methods: Guanacos’ diet was determined by comparing epidermal and non-epidermal plant fragments with micro-histological analyses of feces. The analysis was made from composite samples of fresh feces, collected at the seasons of maximum forage productivity (spring and summer).Main results: During spring, 48% of guanacos’ diet was composed of lenga leaves, 30% of grass-like species, 15% of grasses, and less than 7% of herbs, shrubs, and lichens. In summer, 40% of the diet was composed of grasses, 30% of lenga leaves, 25% of grass-like species and the rest corresponded to herbs, shrubs, and lichens. Within the forest understory, guanaco selected lenga leaves and twigs, grass species were consumed according to their availability (or sometimes rejected), while other herbs were not consumed at all.Research highlights: Guanacos’ consumption preference for lenga, even considering the high availability of other forages, could adversely affect forest regeneration
Self-thinning dynamics in cork oak woodlands: providing a baseline for managing density
Get PDFAim of study: The study aims to evaluate the maximum potential stocking level in cork oak (Quercus suber L.) woodlands, using the ecologically-based size-density relationship of the self-thinning law.Area of study: The study area refers to cork oak forests in mainland Portugal, distributed along its 18 districts from north to south.Material and Methods: A dataset with a total of 2181 observations regarding pure cork oak stands was collected from the Portuguese Forest Inventory (NFI) databases and from research plots. The dataset was subjected to two filtering procedures, one more restrictive than the other, to select the stands presenting the higher stocking values. The two resulting subsets, with 116 and 36 observations, from 16 and 10 districts of mainland Portugal, respectively, were then used to assess and describe the allometric relationship between tree number and their mean diameter.Main results: The allometric relationship was analysed and modelled using the log transformed variables. A slightly curvilinear trend was identified. Thus, a straight line and a curve were both fitted for comparison purposes. Goodness-of-fit statistics point out for a good performance when the data is set to the uppermost observed stocking values. A self-thinning line for cork oak was projected from the estimated relationship.Research highlights: The self-thinning model can be used as an ecological approach to develop density guidelines for oak woodlands in a scenario of increasing cork demands. The results indicate that the recommendations being applied in Portugal are far below the maximal potential stocking values for the species. It is therefore of the utmost importance to review the traditional silvicultural guidelines and endorse new ones
A new approach to defining rotation ages on the basis of productive and technological aspects. Application to natural Pinus sylvestris L. stands in Central Spain
Get PDFAim of study: To propose a new approach to defining rotation ages on the basis of productive and technological aspects and to present an example of application of the methodology to natural Pinus sylvestris stands in relation to silvicultural treatment (light or heavy thinning) and site index.Area of study: Central Spain.Material and methods: We assumed that the price per m3 of logwood suitable for veneer is four times higher than logwood not apt for veneer. Considering the yield distribution for different technological and commercial classes, a model of diameter distributions and yield tables, the variation in an average price index for different age classes, site indexes and silvicultural treatments was calculated. The age at which the price index rises by less than 3%, the proportion of trees with d.b.h. higher than 40 cm, and other aspects such as the possible presence of fungal decay in old-growth stands were also taken into account to establish three criteria for defining rotation ages.Main results: The proposed methodology generates a wide range of rotation ages between 100 and 140 years for lightly thinned stands, and between 90 and 140 years for heavily thinned stands, depending on the site index.Research highlights: The proposed approach is based on technological and productive criteria, with the limitations imposed by sanitary risks. The methodology can be applied to generate rotation ages in relation to different site indexes and silvicultural treatments, provided that the timber market prices and the yield distribution for different technological and commercial classes are known, and that a model of diameter distributions and yield tables are available
CliPick – Climate change web picker. A tool bridging daily climate needs in process based modelling in forestry and agriculture
Get PDFAim of study: Climate data is a need for different types of modeling assessments, especially those involving process based modeling focusing on climate change impacts. However, there is a scarcity of tools delivering easy access to climate datasets to use in biological related modeling. This study aimed at the development of a tool that could provide an user-friendly interface to facilitate access to climate datasets, that are used to supply climate scenarios for the International Panel on Climate Change.Area of study: The tool provides daily datasets across Europe, and also parts of northern AfricaMaterial and Methods: The tool uses climatic datasets generated from third party sources (IPCC related) while a web based interface was developed in JavaScript to ease the access to the datasetsMain Results: The interface delivers daily (or monthly) climate data from a user-defined location in Europe for 7 climate variables: minimum and maximum temperature, precipitation, radiation, minimum and maximum relative humidity and wind speed). The time frame ranges from 1951 to 2100, providing the basis to use the data for climate change impact assessments. The tool is free and publicly available at http://www.isa.ulisboa.pt/proj/clipick/.Research Highlights: A new and easy-to-use tool is suggested that will promote the use of climate change scenarios across Europe, especially when daily time steps are needed. CliPick eases the communication between climatic and modelling communities such as agriculture and forestry
Resource communication. ORGEST: Regional guidelines and silvicultural models for sustainable forest management
Get PDFAim of the study: To develop regional guidelines for sustainable forest management.Area of the study: Forests of Catalonia (NE Spain).Material and methods: The process of developing the forest management guidelines (FMG) started by establishing a thorough classification of forest types at stand level. This classification hinges on two attributes: tree species composition and site quality based on ecological variables, which together determine potential productivity. From there, the management guidelines establish certain objectives and silvicultural models for each forest type. The forest type classifications, like the silvicultural models, were produced using both existing and newly-built growth models based on data from the National Forest Inventory (NFI) and expert knowledge. The effort involved over 20 expert working groups in order to better integrate the expertise and vision of different sectorial agents.Main results: The FMG consist in quantitative silvicultural models that include typical silvicultural variables, technical descriptions of treatments and codes of good practice. Guidelines now cover almost all forest types in Catalonia (spanning up to 90% of the Catalan forest area). Different silvicultural models have been developed for pure and mixed stands, different site quality classes (2–3 classes per species), and even- and multi-aged stands.Research highlights: FMG: i) orient the management of private and public forests, (ii) provide a technical scaffold for efficient allocation/investment of public subsidies in forest management, and (iii) bridge forest planning instruments at regional (strategic-tactical) and stand (operational) level
Evaluating two irrigation controllers under subsurface drip irrigated tomato crop
Get PDFSmart systems could be used to improve irrigation scheduling and save water under Saudi Arabia’s present water crisis scenario. This study investigated two types of evapotranspiration-based smart irrigation controllers, SmartLine and Hunter Pro-C2, as promising tools for scheduling irrigation and quantifying plants’ water requirements to achieve water savings. The effectiveness of these technologies in reducing the amount of irrigation water was compared with the conventional irrigation scheduling method as a control treatment. The two smart irrigation sensors were used for subsurface irrigation of a tomato crop (cv. Nema) in an arid region. The results showed that the smart controllers significantly reduced the amount of applied water and increased the crop yield. In general, the Hunter Pro-C2 system saved the highest amount of water and produced the highest crop yield, resulting in the highest water irrigation efficiency compared with the SmartLine controller and the traditional irrigation schedule. It can be concluded that the application of advanced scheduling irrigation techniques such as the Hunter controller under arid conditions can realise economic benefits by saving large amounts of irrigation water
Genetic diversity of the Northern Morocco goat population assessed with microsatellite markers
Get PDFThe main goal of this work was to study the genetic diversity of the Northern Morocco goat population through the analysis of 19 microsatellites in 144 animals from 61 herds. To detect a possible population structure, three distinct geographic subpopulations were characterized as a function of climate and environmental influences. Most of the markers were highly polymorphic, and the results revealed considerable genetic variation across the studied loci. A total of 204 alleles were detected, with an average number of 10.7 per locus. The PIC average was 0.728, and four microsatellites showed a significant deviation (p< 0.05) from Hardy-Weinberg Equilibrium. Analysis of molecular variance (AMOVA) indicated that only 0.5% of the variation corresponded to differences among subpopulations, and 99.5% corresponded to differences among individuals. Factorial correspondence analysis showed intense admixtures across the putative subpopulations, and the subdivision related to geographical or environmental adaptation was undetectable. The Northern Morocco goat population presented high genetic diversity and a lack of population structure. The main reason for these findings is the absence of the breed concept (reproductively closed population), resulting in uncontrolled crossbreeding with exotic breeds and other local goats
Is Mercosur promoting trade? Insights from Argentinean wine exports
Get PDFAs a consequence of the rapid and significative decrease in domestic demand, to avoid structural surplus traditional wine producing countries have been forced to export a growing share of their wine production. This article empirically investigates Argentinean trade policy on the wine sector over the last years, in order to understand its effect on export flows. An expanded gravity model was estimated through a Poisson pseudo-maximum likelihood estimator, in order to account for heteroskedasticity. The data used refer to Argentinean exports of bottled wine to all main world importers during the period 1997-2010, and account for more than 90% of total trade flows. Our results show that Mercosur membership has promoted Argentinean wine exports to other Latin American countries, but may as a whole have been counter-productive. A more open trade policy could increase Argentinean bottled wine exports by more than 5.8%. In addition, given the rise in wine importation and consumption in countries with high tariff barriers, such as China, the small number of free trade agreements could penalize Argentinean exports even more in the future
Evaluating the environmental sustainability of energy crops: A life cycle assessment of Spanish rapeseed and Argentinean soybean cultivation
Get PDFRapeseed oil is expected to be increasingly used in Spain as raw material to produce biodiesel to the detriment of extra-EU imports of biodiesel mainly based on soybean oil from Argentina. Therefore, the environmental impacts produced throughout the life cycle of energy crops used to produce biodiesel which is consumed in Spain could be radically affected. In this context, the environmental impacts of rapeseed cultivation in Spain and soybean cultivation in Argentina, were compared under certain growing conditions using Life Cycle Assessment (LCA). Two methods of calculation for Life Cycle Impact Assessment (LCIA) and two functional units (FUs) were used to test potential biases. The results showed that the cultivation of soybean in Argentina had, in general, fewer environmental impacts than rapeseed cultivation in Spain when the FU was the area of cultivation, but these findings are inverted when the analysis is conducted according to the energy content of the biodiesel obtained from these crops. Soybean in fact has very low oil content, meaning that larger areas of land are required to obtain the same amount of biodiesel and that consequently it has a higher environmental impact by energy content. Fertilization was, in general, the process that generated the greatest environmental burdens, and is an area in which improvement is necessary in order to increase sustainability, particularly with regard to Spanish rapeseed
Addition of arginine and leucine to low or normal protein diets: performance, carcass characteristics and intramuscular fat of finishing pigs
Get PDFThe effect of dietary crude protein (CP) reduction, supplementation with arginine or leucine on intramuscular fat (IMF) content was evaluated in (Landrace × Duroc) × Pietrain pigs. One-hundred and eight barrows (67 ± 4 kg) were assigned to six diets (n=6 pens of 3 pigs each): four normal CP diets containing 16% CP from 60 to 90 kg and 13% CP from 90 to 115 kg live weight (normal protein; normal protein high Arg, normal protein high Leu or normal protein high Arg and Leu) and two low CP diets containing 14% CP from 60 to 90 kg and 11.8% CP from 90 to 115 kg live weight (with or without supplementation of both amino acids). The high Leu and Arg diets were supplemented to obtain ratios of standard ileal digestible Leu/Lys and Arg/Lys of 4 and 2, respectively. While feed to gain ratio tended to increase (p<0.05), final weight (p<0.01), average daily feed intake (ADFI) (p<0.05) and average daily gain (ADG) (p<0.01) were reduced in animals fed low-protein diets supplemented with Arg and Leu compared to the ones fed low-protein diet unsupplemented. Marbling and IMF content in loin were reduced when Arg was supplemented (p<0.05) in normal protein diets. Supplementing these diets with Arg also reduced belly weight (p<0.01) and increased lean meat percentage (p<0.05). Contrary to the initial hypothesis, reduction of CP or dietary supplementation with Leu had no effect on IMF content and supplementation with Arg reduced it