Scientific Journals of INIA (Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria)
Not a member yet
3042 research outputs found
Sort by
What comes first, origin or production method? An investigation into the relative importance of different attributes in the demand for eggs
Get PDFThis paper analyses consumer preferences for different eggs attributes to assess the importance placed by consumers on the origin and method of production when shopping. The data comes from an experiment conducted in Spain during 2009. An Error Component Random Parameter Logit model is used to estimate the effect of different eggs characteristics on consumers’ utility and derive their willingness to pay. Results suggest that consumers positively value the free-range and organic method of production and the local and regional origin and that they are willing to pay an additional € 0.85 for each package of six free-range or organic eggs, € 0.77 for locally produced and € 0.27 for regional produced eggs. Hence, the least valued eggs for consumers are those produced in cages and outside the region. Relative to this product, the highest willingness to pay corresponds to free-range or organic eggs followed by locally produced eggs and finally, by the regional eggs. Thus, we can conclude that Spanish consumers give more importance when shopping for eggs to the method of production than to the origin of production
Microsatellite variation in potato landraces from the island of La Palma
Get PDFNineteen microsatellite markers were used to fingerprint a set of 19 potato landraces from the island of La Palma (Canary Islands). These landraces represent relicts of early introductions from South America, although most are commonly cultivated by local farmers. The SSR primers detected 62 polymorphisms, 13 of which were present in all landraces. Several accession- and group-specific markers were detected. Jaccard similarity coefficients were estimated from the molecular data and UPGMA cluster analysis was performed. Some cultivars with related common names clustered together. In some cases, e.g., for the ‘Conejera’ landrace, the molecular patterns were discrepant with previous species assignments, suggesting the need for a more detailed morphological and comparative study of these accession
Spatiotemporal variation in acorn production and damage in a Spanish holm oak (Quercus ilex) dehesa
Get PDFAim of study. There is a lack of knowledge about spatio-temporal patterns of acorn production in dehesas, especially regarding the influence of different agents causing acorn damage. We examined the spatial and temporal variability on acorn production and damage in four stands within a dehesa farm in 1997, 1998 and 1999.Area of study. The study was carried out in a 1800 ha dehesa farm of Cáceres province, western Spain.Material and Methods. Acorns were sampled by means of seed traps placed in the canopy of six holm oak trees per stand. Acorn collected in it were counted and assessed for damage by Curculio weevils, Cydia moths and the bacterial pathogen Brenneria quercina.Main results. Mean acorn production for the whole study period was 44.60 acorns m-2, which did not vary significantly either among stands or among years. The variability among individual trees was very high (0-300 acorns m-2). The rate of infestation by Curculio was 7.64 ± 10.72 %, by Cydia was 1.76 ± 3.33 %, whereas 10.29 ± 16.12 % of acorns were infested by Brenneria. We found no significant spatial differences, but the rates of acorn loss by insects varied among years. These rates were independent of annual acorn production and there was no correlation among damages by different pests, except between Curculio and Cydia in two crop years.Research highlights. It can be concluded that acorn crops are synchronized at the within-farm level and that the temporal variation in acorn damages can be independent of crop size.Keywords: Acorn production; Brenneria; Curculio; Cydia; dehesa; Quercus ilex; spatio-temporal variation
Short-term dynamics of Quercus ilex advance regeneration in a Pinus nigra plantation after the creation of small canopy gaps
Get PDFAim of the study: The aim of the research is to analyse the role of Quercus ilex advance regeneration in the stand regeneration of pine plantations after small-sized canopy openings, and to assess the influence of the forest stand and the canopy opening. The performance of the advance regeneration under the pine plantation is also examined.Area of study: A Pinus nigra plantation in dry Continental Mediterranean climate in eastern Spain.Materials and Methods: The tree regeneration of ten canopy openings of 0.17-0.43 ha was monitored during five years after treatment. It was also sampled in 0.12 ha-plots in the non-treated pine plantation surrounding the openings.Main results: An important increase in the height of Q. ilex regeneration was observed in the openings, unlike what was found in the intact pine plantation. In the pine plantation, stand density showed a moderate positive influence on the density of Q. ilex regeneration, whereas in the canopy gaps Q. ilex height was negatively influenced by stand density before the opening.Research highlights: The canopy opening triggered a response in Q. ilex advance regeneration, although height growth rates seemed to reduce over time. The results support the view that promoting Q. ilex in pine plantations may require different management strategies depending on the characteristics of the pine overstorey and on the density and size of the advance regeneration.Key words: Mediterranean forest; stand initiation; seedling resprout; group selection cutting; truffl
Modelling stand biomass fractions in Galician Eucalyptus globulus plantations by use of different LiDAR pulse densities
Get PDFAims of study: To evaluate the potential use of canopy height and intensity distributions, determined by airborne LiDAR, for the estimation of crown, stem and aboveground biomass fractions.To assess the effects of a reduction in LiDAR pulse densities on model precision.Area of study: The study area is located in Galicia, NW Spain. The forests are representative of Eucalyptus globules stands in NW Spain, characterized by low-intensity silvicultural treatments and by the presence of tall shrub.Material and methods: Linear, multiplicative power and exponential models were used to establish empirical relationships between field measurements and LiDAR metrics.A random selection of LiDAR returns and a comparison of the prediction errors by LiDAR pulse density factor were performed to study a possible loss of fit in these models.Main results: Models showed similar goodness-of-fit statistics to those reported in the international literature. R2 ranged from 0.52 to 0.75 for stand crown biomass, from 0.64 to 0.87 for stand stem biomass, and from 0.63 to 0.86 for stand aboveground biomass. The RMSE/MEAN · 100 of the set of fitted models ranged from 17.4% to 28.4%.Models precision was essentially maintained when 87.5% of the original point cloud was reduced, i.e. a reduction from 4 pulses m–2 to 0.5 pulses m–2.Research highlights: Considering the results of this study, the low-density LiDAR data that are released by the Spanish National Geographic Institute will be an excellent source of information for reducing the cost of forest inventories.Key words: Eucalypt plantations; airborne laser scanning; aboveground biomass; carbon stocks; remote sensing; forest inventory
Stand dynamics, spatial pattern and site quality in Austrocedrus chilensis forests in Patagonia, Argentina
Get PDFAim of study: The objective of this study was to analyze the stand structure and spatial pattern of two A. chilensis stands with contrasting soil conditions and different site qualities in order to explore if these differences lead to patterns similar to the ones observed under different precipitation conditions.Area of study: The study was carried out in two stands located near the city of El Bolsón (41° 56’S - 71° 33’ W), Rio Negro, Argentina.Material and Methods: We evaluated age difference between canopy strata (upper and lower) in two stands with different site qualities by means of a Mann-Whitney test. Dead individuals by diameter class were compared by means of a chi square test. Spatial distribution pattern was analyzed using the pair-correlation function and the mark-correlation function.Main results: Both sites exhibited a random spatial distribution of A. chilensis but different processes seem to underlie the patterns. In the low-quality site facilitation and continuous establishment led to a transient clumped spatial pattern. Mortality mediated by competition occurred mainly on small trees resulting in the current random pattern. On the other hand, spatial pattern in the high-quality site does not reflect a facilitation mediated recruitment. The upper strata established synchronously and subsequent regeneration was episodic.Research highlights: The results show that the differences in site quality may lead to different establishment spatial patterns, showing the importance of facilitation processes in sites with drier soil conditions and lower quality, although results may be site specific, due to the lack of replications.Keywords: Spatial analysis; regeneration; mortality; competition; facilitation.Abbreviations used: LQ: low-quality site; HQ: high-quality site
A participatory approach to design a toolbox to support forest management planning at regional level
Get PDFAim of the study: Forest management planning in a region typically involves multiple stakeholders. Decisions processes are idiosyncratic, driven by individual goals and supported by segmented forest-based information. Nevertheless, stakeholders’ decisions do impact one another leading to complex interaction networks where communication, cooperation and negotiation play a key role. This research addresses the need to develop decision tools to support these roles. Emphasis is on the integration of participatory planning tools and techniques in the architecture of a regional decision support toolbox.Area of the study: The proposed approach was applied in the Chamusca County in Central Portugal although it is easily extended to other regions.Material and methods: This research proposes an Enterprise Architecture methodological approach to design a toolbox that may address distinct stakeholders’ interests and decision processes, while enabling communication, cooperation, negotiation and information sharing among all those involved in the regional interactions network.Main results: the proposed approach was tested in a regional network involving decision processes and information shared by 22 entities clustered into 13 stakeholders groups, including industrial owners, and non-industrial private forestland owners (NIPF) - acting individually or grouped into associations and federations -, national and regional offices of the forest authority, forest services providers, non-governmental organizations and research centers. Results suggest that the proposed approach may provide a toolbox that may effectively address stakeholders’ decision processes and goals and support the regional interaction network.Key-words: forest management; multiple stakeholders; decision support systems; enterprise architecture; participatory process
In vitro plant regeneration of Albizia lebbeck (L.) from seed explants
No full textObjectives: An efficient and reproducible regeneration protocol for rapid multiplication of Albizia lebbeck (L.) was developed by using intact seed explants.Methods: Murashige and Skoog's (MS) medium supplemented with different hormones (BA, Kn, GA3 and TDZ) was used for the induction of multiple shoots from the seed explants. Ex-vitro rooting was performed by using pulse treatment method in auxins (IBA and NAA) and the complete plantlets were transferred to the field.Results: High frequency direct shoot induction was found in aseptic seed cultures of A. lebbeck on Murashige and Skoog medium supplemented with 5.0 µM TDZ (Thiadiazuron). Seeds were germinated after 7 days of culture and induced maximum 8 shoots from the region adjacent to the apex of the primary shoot of the seedling upto 25 days of incubation. Proliferating shoot cultures with increased shoot length was established by sub-culture of excised sprouting epicotyls on MS medium supplied with reduced concentrations of TDZ. Maximum shoot regeneration frequency (76 %) with highest number of shoots (21) and shoot length (5.1 cm) per sprouting epicotyl was observed in the MS medium supplemented with 0.5 µM TDZ after 8 weeks of culture. Different concentrations of Indole-3-butyric acid (IBA) and α-naphthalene acetic acid (NAA) were tested to determine the optimal conditions for ex-vitro rooting of the microshoots. The best treatment for maximum ex-vitro root induction frequency (81 %) was accomplished with IBA (250 µM) pulse treatment given to the basal end of the microshoots for 30 min followed by their transfer in plastic cups containing soilrite and eventually established in normal garden soil + soilrite (1:1) with 78 % survival rate. In addition, histological study was undertaken to gain a better understanding of the regenerated shoots from the epicotyl region.Conclusion: The findings will be fruitful in getting a time saving and cost effective protocol for the in vitro propagation of Albizia lebbeck.Keywords: Woody legume; TDZ; multiplication; epicotyl segment; shoot stumps.Abbreviations used: GA3 (Gibberellic acid); BA (6-Benzyladenine); Kn (Kinetin); TDZ (Thidiazuron); MS (Murashige and Skoog Medium); IBA (Indole-3-butyric acid); NAA (α-Naphthalene acetic acid)
Trends in hunters, hunting grounds and big game harvest in Spain
Get PDFAim of study: Game species are considered a scarce natural resource and therefore they are subject to economic analysis. Current studies on factors affecting big game trends have mostly emphasized the impact of ecological supply variables. This study intends to expand this analysis by considering two important supply and demand economic parameters.Area of study: We use big game hunting in Spain from 1972 until 2007 as a case study since it has an important role in the European hunting activity. Material and Methods: Different linear models were fitted to explain big game harvest as a function of two parameters not previously used: hunting grounds areas and big game firearm hunting licenses.Main results: Our main results show that up to 1989 the decrease in the area of open access territories significantly explains the increase in big game harvests, and that afterwards, once the hunting property rights were strengthen in most of the Spanish territory, the number of big game firearm licenses best explain big game harvests increments.Research highlights: This work shows an upward trend in Spanish harvests of big game, which can be attributed in part to (1) a shift to the right of big game demand, measured by an increase in big game firearm licenses, and (2) a change in the nature of big game supply (from a backward to an ordinary upward supply curve) due to the strengthening of hunting property rights of Spanish hunting grounds.Keywords: hunting license; firearm license; hunting bag; hunting sector; property rights; wildlife
Carbon and nitrogen accumulation in forest floor and surface soil under different geographic origins of Maritime pine (Pinus pinaster Aiton.) plantations
Get PDFAim of study : To determine if plantations consisting of different geographic origins of the Maritime pine (Pinus pinaster Aiton.) could have altered C and N stocks in the forest floor and surface soils.Area of study : Forest floor and mineral soil C and N stocks were measured in four adjacent plantations of different geographic origins of Maritime pine (Gironde, Toulon, Corsica and Spain) and adjacent primary native Sessile oak (Quercus petraea L.) at Burunsuz region in Belgrad Forest where is located in the Istanbul province in the Marmara geographical region between 41°09' -41°12' N latitude and 28°54' - 29°00' E longitude in Turkey.Material and Methods : Plots were compared as common garden experiments without replications. 15 surface soil (0-10 cm) and 15 forest floor samples were taken from each Maritime pine origins and adjacent native Sessile oak forest. C and N contents were determined on LECO Truspec 2000 CN analyzer. The statistical significance of the results was evaluated by one-way Analysis of Variance (ANOVA).Research highlights : Forest floor carbon mass, nitrogen concentration and nitrogen mass of forest floor showed a significant difference among origins. Soil carbon mass and nitrogen mass did not significantly differ among investigated plots.Keywords: carbon sequestration; C/N ratio; decomposition; exotic; tree provenance