6 research outputs found

    Testing convergent validity in choice experiments: Application to public recreation in Spanish stone pine and cork oak forests

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    We perform two convergent validity tests in a choice experiment applied to public recreation in Spanish stone pine and cork oak forests. Results show convergent validity between a choice and a ranking recoded as a choice format in an experiment with three alternatives plus status quo. We also find significant differences between two payment vehicles (increased trip expenditures and entrance fee) that are included simultaneously in the choice sets. We estimate aggregated recreation values using compensating variation and simulated exchange value (maximum benefits from a potential market) measures. The latter measures account for 35–51% of the former values.This research was supported by INIA (grant number CPE03-001-C5) and by the National R&D Plan of the Spanish Government (DYNOPAGROF (grant number SEJ2005-05085/ECCON), ACBPA (grant number ECO2012-35432) and VEABA (grant number ECO2013-42110) projects). Itziar Ruiz-Gauna Ph.D's contract is funded by the Programa Predoctoral de Formación de Personal Investigador No Doctor provided by the Basque Regional Government.Peer reviewe

    Modeling the potential distribution and conservation status of three species of oak gall wasps (Hymenoptera: Cynipidae) in the Iberian range

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    Cynipids (Hymenoptera: Cynipidae) induce a wide variety of complex galls on plants of different botanical families, particularly on Quercus species. Cynipid galls are well known to host large communities of insects, providing fundamental ecological niches for different animal taxa, which are organized in structured and relatively isolated communities at the microhabitat level. Gall communities of Quercus woodlands could be a conservation concern considering some risks, which affect several species of the Parasitica group of Hymenoptera, within which gall wasps and their parasitoids and inquilines are included. These risks concerning Parasitica species are mainly due to three causes: their high trophic level, high host specialization and the lack of knowledge of their biology. In this paper, a preliminary approach to this issue is presented for the Iberian–Balearic range. We model and study the ecological niche of three cynipid gall species that induce galls on Quercus species (Andricus quercustozae, Biorhiza pallida and Plagiotrochus quercusilicis). The cynipid gall species were selected for their different sets of host species and life cycle. The Ecological Niche Factor Analysis and two niche models built for each species (MAXENT and Mahalanobis Distances) support the interpretation that the bioclimatic variables considered have effects on cynipids through their respective sets of host plants. In addition, the results regarding A. quercustozae are consistent with the hypothetical existence of cryptic sexual generation (exposed in other works) parasitizing cork oak (Quercus suber), which could have another key role in its conservation
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