Scientific Journals of INIA (Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria)
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Carcass and meat quality traits of Iberian pig as affected by sex and crossbreeding with different Duroc genetic lines
Get PDFA total of 144 pigs were used to study the effects of sex (barrows or gilts) and terminal sire line (Iberian or three genetic lines of Duroc: Duroc 1, Duroc 2 and Duroc 3) on performance and carcass and meat quality traits. Gilts showed slightly lower average daily gain, shoulder weight and trimming losses, but slightly better primal cuts yields and higher loin weight, while there was no significant effect of sex on meat quality traits or on the fatty acid composition of lard and muscle. There were important differences in performance and in carcass and primal cuts quality traits between pure Iberian pigs and all Iberian × Duroc crossbreeds evaluated, partly due to the lower slaughter weights reached by the formers. The different sire lines showed differences in several traits; Duroc 1 group showed lower backfat thickness and ham and shoulder trimming losses, and higher primal cut yields than Duroc 2 and Duroc 3 groups. Intramuscular fat (IMF) content remained unaffected by crossbreeding, but meat color resulted more intense and redder in crosses from the Duroc 1 sire line. The accumulation of fatty acids in lard was not affected by Duroc sire line, while animals of the group Duroc 2 showed higher levels of monounsaturated fatty acid and lower of polyunsaturated ones in IMF. These results highlight the importance of considering not only performance, but also carcass and meat quality traits when deciding the Duroc sire line for crossbreeding in Iberian pig production
Experimental results and modelling of humidity control strategies for greenhouses in continental and coastal settings in the Mediterranean region. I: Experimental results and model development
Get PDFExperimental strategies for controlling humidity were compared in a greenhouse sited in Madrid, a continental sitein the Mediterranean region. Small roof window apertures significantly reduced the relative humidity with only alimited increase in associated energy consumption. A simplified climate model with four energy exchange terms(heating, insolation, losses through structure, and losses through windows) and three mass exchange terms(evapotranspiration, losses through structure, and losses through windows) was validated, allowing relative humidityto be predicted with an error of < 9%
Effects of arbuscular mycorrhizas on reproductive traits in sexually dimorphic plants: a review
Get PDFMost plant species grow in association with arbuscular mycorrhizal fungi in their roots forming arbuscular mycorrhizal (AM) symbiosis. The positive effects of this type of symbiosis on plant’s performance are well known and established. However, relatively little is known about how AM symbiosis affects plant reproduction, even though reproduction is probably the most important component of life history. This review begins with a summary of the existing data on plants with monomorphic breeding systems, as most of the research has been performed using hermaphroditic and monoecious plants. Later, the limited number of studies examining mycorrhizal effects on plants with dimorphic breeding systems is detailed. Finally, several key areas for future investigations are highlighted. These include examination of the incidence of sex-specific interactions in other plant species with dimorphic systems, the influence of AM symbiosis in seed germination and establishment in plants with different gender, or the study of the mechanisms behind the AM effects seen on plant reproduction. Evidence suggests that AM symbioses are beneficial for plants with monomorphic and dimorphic breeding systems, as AM symbioses improve both sexual and asexual reproduction. However, the effects observed strongly depend on both the plant and the AM fungus species involved. Plant interactions with AM fungi and the outcome of these interactions may further depend on the gender of the host: sex-specific patterns of root colonization and sex-specific benefits from AM symbioses have been reported in several plant species. However, the incidence and the importance of sex-specific relationships between AM fungi and plants are still largely unexplored
Site quality influence over understory plant diversity in old-growth and harvested Nothofagus pumilio forests
No full textAim of study: The effects and interactions of shelterwood forest harvesting and site qualities over understory plant species diversity and composition were compared among primary and harvested Nothofagus pumilio forests.Area of study: Tierra del Fuego (Argentina), on three pure conditions (one and six year-old harvested, and primary without previous harvesting forests) and three site qualities (high, medium and low).Material and Methods: Understory richness and cover (%) were registered in five replicates of 1 hectare each per treatment. Taxonomic species were classified in categories (groups, origin and life forms). Two-way ANOVAs and multivariate analyses were conducted.Main results: Shelterwood harvesting and site quality significantly influenced understory cover and richness, which allow the introduction of native and exotic species and increasing of dicot and monocot covers. In dicots, monocots, exotics and total groups, higher richness and covers were related to time. Meanwhile, cover reached similar high values in all site qualities on dicot, native and total groups. On the other hand, monocot and exotic richness and cover remain similar in primary and recently harvested forests, and greatly increased in old harvested forests. Mosses and ferns were among the most sensitive groups.Research highlights: Impacts of shelterwood cut depend on site quality of the stands and time since harvesting occurs. For this, different site quality stands should received differential attention in the development of conservation strategies, as well as variations in the shelterwood implementation (as irregularity and patchiness) should be considered to better promote understory plant species conservation inside managed areas.Key words: plant species conservation; years after harvesting; forest management; Tierra del Fuego
Variation of some wood macroscopic properties along the stem of Acacia melanoxylon R. Br. adult trees in Portugal
Get PDFAim of the study: The aim of the study is to assess the variation of pith eccentricity, heartwood proportion, latewood percentage and basic wood density along the stem of 45-year-old A. melanoxylon trees collected in four sites of Portugal, and investigate the eventual relationship between these variables.Area of study: Sites covering littoral north, mid interior north and centre interior of Portugal.Materials and methods: Four sites and five trees per site were selected in the Acacia melanoxylon Portuguese forest.One wood sample at each of six height levels per tree was collected in order to evaluate its basic density, pith eccentricity, heartwood and latewood proportions.Main results: The high variability of the wood macroscopic properties among trees from the same site regarding to the variation of the corresponding average properties along the stem is a key characteristic of the experimental data.As a consequence, a multiple linear regression model tested was not able to properly explain the wood basic density variation of the 120 wood samples analysed. In spite of this, the following trends could be recognized: (i) excluding the base level, wood basic density moderately increased with tree level; (ii) latewood proportion followed similar behaviour; (iii) pith eccentricity was low; (iv) heartwood proportion decreased markedly with tree height, from 70% at the base to 7% at the top.Research highlights: The high basic density, the relatively low variability along the stem and the low pith eccentricity enable us to anticipate good performance as raw material for the wood industry.Key words: Acacia melanoxylon; basic density; earlywood; latewood; heartwood; sapwood; pith eccentricity
Growth and structure of a young Aleppo pine planted forest after thinning for diversification and wildfire prevention
Get PDFAim of study: In the Mediterranean, low timber-production forests are frequently thinned to promote biodiversity and reduce wildfire risk, but few studies in the region have addressed such goals. The aim of this research was to compare six thinning regimes applied to create a fuelbreak in a young Aleppo pine (Pinus halepensis Mill.) planted forest.Area of study: A semiarid continental high plateau in south-eastern Spain.Material and Methods: Three thinning intensities (Light, Medium and Heavy) were combined with two thinning methods: i) Random (tree selection), and ii) Regular (tree spacing). Tree growth and stand structure measurements were made four years following treatments.Main results: Heavy Random thinning successfully transformed the regular tree plantation pattern into a close-to-random spatial tree distribution. Heavy Regular thinning (followed by the Medium Regular and Heavy Random regimes) significantly reduced growth in stand basal area and biomass. Individual tree growth, in contrast, was greater in Heavy and Medium thinnings than in Light ones, which were similar to the Control.Research highlights: Heavy Random thinning seemed the most appropriate in a youngAleppo pine planted forest to reduce fire risk and artificial tree distribution simultaneously. Light Regular thinning avoids understocking the stand and may be the most suitable treatment for creating a fuelbreak when the undergrowth poses a high fire risk.Keywords: Pinus halepensis; Mediterranean; Forest structure; Tree growth; Wildfire risk; Diversity
The effects of land use change on carbon content in the aerial biomass of an Abies religiosa (Kunth Schltdl. et Cham.) forest in central Veracruz, Mexico
Get PDFAim of study.) Were analyzed patterns and dynamics of forest cover change and land use for the period 1995-2005, and estimated carbon content in biomass in a forest of fir (Abies religiosa).Area of study. Ejido El Conejo in the Cofre de Perote National Park, Veracruz, Mexico.Material and Methods. Spatial data (maps, orthophotographs) were used: (UTM); GRS 80 spheroid; zone 14, datum ITRF92; units: metres. Maps for 1995 and 2005 were constructed and compared. Carbon content in the aboveground biomass of fir (Abies religiosa) was estimated using an equation specific to species.Main results. After one decade, the forested area had increased slightly (0.25%). The main type of land cover change was from shrubland to forest (probability of change 0.41); the change from forestland to shrubland with trees was 0.05%, and from forest to agriculture was 0.02%. Data from 2008 confirmed that the A. religiosa forest located in the ejido is distributed in largely unconnected fragments, of which some have a high density of young trees. Estimated carbon content in the aboveground biomass (163.51 Mg ha-1) was higher than that estimated for other forests of the same species in Mexico.Research highlights. It is recommended that ecological corridors be established throughout the reforested area, in order to connect these fragments (and increase carbon sequestration) and favour faunal and floral conservation. Finally, recognition should be given to the high vulnerability of A. religiosa forests to climate change, given their high degree of fragmentation and critical altitudinal limit.Key words: Aboveground biomass; carbon storage; ecological corridors; fir forest
Short Communication. Physiological effects of Rhizopogon Roseolus on Pinus halepensis seedlings
Get PDFAim of study: The inoculation of forest seedlings with ectomycorrhizal fungi can improve the morphological and physiological qualities of plants, especially those used for regeneration of arid areas. Rhizopogon roseolus is an ectomycorrhizal fungus (ECM) commonly used for reforestation. In this study, the specific objectives were to know some morphophysiological effects of Rhizopogon Roseolus on Pinus halepensis seedlings under standard nursery conditionsArea of study: ETSI Montes and EUIT Forestal, Madrid.Material and Methods: In nursery, under well watered conditions and peat growing substrates, Aleppo pine seedlings were inoculated with R. roseolus. Five months after the inoculations, we examined the growth, water parameters (osmotic potential at full turgor [Ψπfull], osmotic potential at zero turgor [Ψπ0], and the tissue modulus of elasticity near full turgor [Emax]), mycorrhizal colonization, and concentration and content of macronutrients in the seedlings. Subsequently, a trial was conducted to assess the root growth potential.Main results: The mycorrhization decreased the height and diameter of mycorrhizal seedlings but increased the root weight and root branching. R. roseolus did not cause any significant effect on the regeneration of new roots or on any of the tested hydric parameters, but it did improve N uptake of the seedlings.Research highlights: The mycorrhizal inoculation increased the N uptake. The mycorrhizal inoculation caused opposite effects on some growth parametersKeywords: Osmotic adjustment; elastic adjustment; mineral nutrition; root growth potential; nursery; Rhizopogon roseolus; Pinus halepensis.
Valuation of the recreational use of the Calares del Mundo and Sima Natural Park through the Travel Cost Method
Get PDFAim of study: The purpose of this study is to estimate the economic value of the recreational use of a protected natural area. The importance of the study lies in the justification of these valuations due to the use that society perceives from the environmental benefits of these areas as well as to the valuable information for management for public administrators with the aim of checking the budget that they manage.Area of study: Calares del Mundo and Sima Natural Park (Albacete, Castilla-La Mancha).Material and methods: With the purpose of determining consumer surplus, 410 surveys were made in August, 2009 and the individual travel cost method was used.Main results: The value the visitor conceded for the recreational use of the park was 12.58 € and the annual consumer surplus value added for recreational use reached almost 3.5 million euros.Research highlights: This research emphasizes that the results are along the same lines as those from similar studies carried out in natural areas of Spain as well as in natural areas of other countries.Key words: natural areas; travel cost method; consumer surplus; Castilla-La Mancha