Reintroduction of native species has become increasingly important in conservation worldwide for ... more Reintroduction of native species has become increasingly important in conservation worldwide for recovery of rare species and restoration purposes. However, few studies have reported the outcome of reintroduction efforts in plant species. Using data from the literature combined with a questionnaire survey, this paper analyses plant species reintroduction trials worldwide by assessing the methods used and the results obtained from these reintroduction experiments. The objectives were: (1) to examine how successful plant species reintroductions have been so far in establishing or significantly augmenting viable, self-sustaining populations in nature; (2) to determine the conditions under which we might expect plant species reintroductions to be most successful; (3) to make the results of this survey available for future plant reintroduction trials. Results indicate that survival, flowering and fruiting rates of reintroduced plants are generally quite low. Furthermore, our results show a downward trend with time. We identified various parameters influencing plant reintroduction outcomes, e.g., material type, number of individuals reintroduced, provenance of material introduced, demographic status of source population, introduction method and manipulations in the field. The detection of the effects of these variables on reintroduction success is of considerable importance for conservation management. This study also revealed shortcomings of common experimental designs that greatly limit the interpretation of plant reintroduction studies. We therefore conclude by suggesting improvements for the design of future reintroductions.
Natural hybrids between rare and common sympatric species are commonly eradicated to avoid the po... more Natural hybrids between rare and common sympatric species are commonly eradicated to avoid the potential extinction of the rare species, although there is currently no clear predictive framework to quantify this risk. As hybrids can have intrinsic value as new evolutionary pathways, further knowledge on the factors controlling hybridization is needed. In this study we evaluated the role of pollination patterns in hybridization events in two sympatric populations of Narcissus cavanillesii and N. serotinus in Portugal. Narcissus cavanillesii is a rare species, while N. serotinus is widely distributed across the Mediterranean. The hybrid, N. 3perezlarae, is quite frequent in southeastern Spain but is scarce in Portugal. Reciprocal manual crossings confirmed compatibility between the two species, although hybridization was more successful when N. cavanillesii participated as female. Narcissus cavanillesii and N. serotinus only shared one pollinator, Megachile sp. (Hymenoptera), which had low visitation rates and high flower constancy. No single isolation mechanism was fully effective in preventing hybridization. Temporal displacement of flowering peaks, strong pollinator specificity, and high flower constancy in the shared pollinator all contributed to limiting hybridization in this site. In other sympatric occurrences, different phenological windows and pollination assemblages may allow greater frequency of the hybrid.
Mutualistic communities have an internal structure that makes them resilient to external perturba... more Mutualistic communities have an internal structure that makes them resilient to external perturbations. Late research has focused on their stability and the topology of the relations between the different organisms to explain the reasons of the system robustness. Much less attention has been invested in analyzing the systems dynamics. The main population models in use are modifications of the r-K formulation of logistic equation with additional terms to account for the benefits produced by the interspecific interactions. These models have shortcomings as the so-called r-K formulation diverges under some conditions. In this work, we introduce a model for population dynamics under mutualism that preserves the original logistic formulation. It is mathematically simpler than the widely used type II models, although it shows similar complexity in terms of fixed points and stability of the dynamics. We perform an analytical stability analysis and numerical simulations to study the model behavior in general interaction scenarios including tests of the resilience of its dynamics under external perturbations. Despite its simplicity, our results indicate that the model dynamics shows an important richness that can be used to gain further insights in the dynamics of mutualistic communities.
The main purpose of this study was to evaluate the influence of the breeding system in the reprod... more The main purpose of this study was to evaluate the influence of the breeding system in the reproductive success of Narcissus cavanillesii A. Barra & G. López (Amaryllidaceae), a species listed under Annexes II and IV of European Community Habitat and Species Directive. This taxon, which occurs in only two populations in Portugal, is of conservation interest in this country due to its low area of occupancy and population size, and fragmentation. Hand-pollinations were carried out to evaluate the performance of self-and cross-pollination offspring. Results show that xenogamous pollinations produce more fruits and seeds than autogamous ones. However, no significant differences were detected neither in seed weight nor in seed germination percentage between treatments. Germination rate (T 50) was significantly higher in autoga-mous crosses whereas radicle vigour as well as the number of days until the appearance of the first leaf were lower. A fitness coefficient was estimated for each of these parameters by comparing the results obtained from selfing and outcrossing treatments. These results are important for the formulation of effective management strategies in the conservation of this scarce geo-phyte in Portugal. This study was promoted by EDIA, S. A. and co-financed by EDIA, S. A. and European Regional Development Funds (ERDF).
Parra-Quijano, M., Draper, D. & Iriondo, J. M.: GIS-based evaluation of the in situ conservation ... more Parra-Quijano, M., Draper, D. & Iriondo, J. M.: GIS-based evaluation of the in situ conservation of a Crop Wild Relative: the case of Spanish lupins. — Bocconea 21: 000-000. 2007. — ISSN 1120-4060. The six Lupinus species that grow naturally in Spain were used as a model of how GIS and gap analysis can be used in the assessment of the conservation status of a crop wild relative (CWR). Data on the geographic location of Lupinus populations was compiled along with relevant environmental data for Peninsular Spain. This information was used to generate predictive distribution models, to identify areas of high richness in Lupinus species and to assess whether the current network of protected areas holds sites of high richness in Lupinus species that might be utilized to establish genetic reserves.
Natural hybrids between rare and common sympatric species are commonly eradicated to avoid the po... more Natural hybrids between rare and common sympatric species are commonly eradicated to avoid the potential extinction of the rare species, although there is currently no clear predictive framework to quantify this risk. As hybrids can have intrinsic value as new evolutionary pathways, further knowledge on the factors controlling hybridization is needed. In this study we evaluated the role of pollination patterns in hybridization events in two sympatric populations of Narcissus cavanillesii and N. serotinus in Portugal. Narcissus cavanillesii is a rare species, while N. serotinus is widely distributed across the Mediterranean. The hybrid, N. 3perezlarae, is quite frequent in southeastern Spain but is scarce in Portugal. Reciprocal manual crossings confirmed compatibility between the two species, although hybridization was more successful when N. cavanillesii participated as female. Narcissus cavanillesii and N. serotinus only shared one pollinator, Megachile sp. (Hymenoptera), which had low visitation rates and high flower constancy. No single isolation mechanism was fully effective in preventing hybridization. Temporal displacement of flowering peaks, strong pollinator specificity, and high flower constancy in the shared pollinator all contributed to limiting hybridization in this site. In other sympatric occurrences, different phenological windows and pollination assemblages may allow greater frequency of the hybrid.
Reintroduction of native species has become increasingly important in conservation worldwide for ... more Reintroduction of native species has become increasingly important in conservation worldwide for recovery of rare species and restoration purposes. However, few studies have reported the outcome of reintroduction efforts in plant species. Using data from the literature combined with a questionnaire survey, this paper analyses plant species reintroduction trials worldwide by assessing the methods used and the results obtained from these reintroduction experiments. The objectives were: (1) to examine how successful plant species reintroductions have been so far in establishing or significantly augmenting viable, self-sustaining populations in nature; (2) to determine the conditions under which we might expect plant species reintroductions to be most successful; (3) to make the results of this survey available for future plant reintroduction trials. Results indicate that survival, flowering and fruiting rates of reintroduced plants are generally quite low. Furthermore, our results show a downward trend with time. We identified various parameters influencing plant reintroduction outcomes, e.g., material type, number of individuals reintroduced, provenance of material introduced, demographic status of source population, introduction method and manipulations in the field. The detection of the effects of these variables on reintroduction success is of considerable importance for conservation management. This study also revealed shortcomings of common experimental designs that greatly limit the interpretation of plant reintroduction studies. We therefore conclude by suggesting improvements for the design of future reintroductions.
Natural hybrids between rare and common sympatric species are commonly eradicated to avoid the po... more Natural hybrids between rare and common sympatric species are commonly eradicated to avoid the potential extinction of the rare species, although there is currently no clear predictive framework to quantify this risk. As hybrids can have intrinsic value as new evolutionary pathways, further knowledge on the factors controlling hybridization is needed. In this study we evaluated the role of pollination patterns in hybridization events in two sympatric populations of Narcissus cavanillesii and N. serotinus in Portugal. Narcissus cavanillesii is a rare species, while N. serotinus is widely distributed across the Mediterranean. The hybrid, N. 3perezlarae, is quite frequent in southeastern Spain but is scarce in Portugal. Reciprocal manual crossings confirmed compatibility between the two species, although hybridization was more successful when N. cavanillesii participated as female. Narcissus cavanillesii and N. serotinus only shared one pollinator, Megachile sp. (Hymenoptera), which had low visitation rates and high flower constancy. No single isolation mechanism was fully effective in preventing hybridization. Temporal displacement of flowering peaks, strong pollinator specificity, and high flower constancy in the shared pollinator all contributed to limiting hybridization in this site. In other sympatric occurrences, different phenological windows and pollination assemblages may allow greater frequency of the hybrid.
Mutualistic communities have an internal structure that makes them resilient to external perturba... more Mutualistic communities have an internal structure that makes them resilient to external perturbations. Late research has focused on their stability and the topology of the relations between the different organisms to explain the reasons of the system robustness. Much less attention has been invested in analyzing the systems dynamics. The main population models in use are modifications of the r-K formulation of logistic equation with additional terms to account for the benefits produced by the interspecific interactions. These models have shortcomings as the so-called r-K formulation diverges under some conditions. In this work, we introduce a model for population dynamics under mutualism that preserves the original logistic formulation. It is mathematically simpler than the widely used type II models, although it shows similar complexity in terms of fixed points and stability of the dynamics. We perform an analytical stability analysis and numerical simulations to study the model behavior in general interaction scenarios including tests of the resilience of its dynamics under external perturbations. Despite its simplicity, our results indicate that the model dynamics shows an important richness that can be used to gain further insights in the dynamics of mutualistic communities.
The main purpose of this study was to evaluate the influence of the breeding system in the reprod... more The main purpose of this study was to evaluate the influence of the breeding system in the reproductive success of Narcissus cavanillesii A. Barra & G. López (Amaryllidaceae), a species listed under Annexes II and IV of European Community Habitat and Species Directive. This taxon, which occurs in only two populations in Portugal, is of conservation interest in this country due to its low area of occupancy and population size, and fragmentation. Hand-pollinations were carried out to evaluate the performance of self-and cross-pollination offspring. Results show that xenogamous pollinations produce more fruits and seeds than autogamous ones. However, no significant differences were detected neither in seed weight nor in seed germination percentage between treatments. Germination rate (T 50) was significantly higher in autoga-mous crosses whereas radicle vigour as well as the number of days until the appearance of the first leaf were lower. A fitness coefficient was estimated for each of these parameters by comparing the results obtained from selfing and outcrossing treatments. These results are important for the formulation of effective management strategies in the conservation of this scarce geo-phyte in Portugal. This study was promoted by EDIA, S. A. and co-financed by EDIA, S. A. and European Regional Development Funds (ERDF).
Parra-Quijano, M., Draper, D. & Iriondo, J. M.: GIS-based evaluation of the in situ conservation ... more Parra-Quijano, M., Draper, D. & Iriondo, J. M.: GIS-based evaluation of the in situ conservation of a Crop Wild Relative: the case of Spanish lupins. — Bocconea 21: 000-000. 2007. — ISSN 1120-4060. The six Lupinus species that grow naturally in Spain were used as a model of how GIS and gap analysis can be used in the assessment of the conservation status of a crop wild relative (CWR). Data on the geographic location of Lupinus populations was compiled along with relevant environmental data for Peninsular Spain. This information was used to generate predictive distribution models, to identify areas of high richness in Lupinus species and to assess whether the current network of protected areas holds sites of high richness in Lupinus species that might be utilized to establish genetic reserves.
Natural hybrids between rare and common sympatric species are commonly eradicated to avoid the po... more Natural hybrids between rare and common sympatric species are commonly eradicated to avoid the potential extinction of the rare species, although there is currently no clear predictive framework to quantify this risk. As hybrids can have intrinsic value as new evolutionary pathways, further knowledge on the factors controlling hybridization is needed. In this study we evaluated the role of pollination patterns in hybridization events in two sympatric populations of Narcissus cavanillesii and N. serotinus in Portugal. Narcissus cavanillesii is a rare species, while N. serotinus is widely distributed across the Mediterranean. The hybrid, N. 3perezlarae, is quite frequent in southeastern Spain but is scarce in Portugal. Reciprocal manual crossings confirmed compatibility between the two species, although hybridization was more successful when N. cavanillesii participated as female. Narcissus cavanillesii and N. serotinus only shared one pollinator, Megachile sp. (Hymenoptera), which had low visitation rates and high flower constancy. No single isolation mechanism was fully effective in preventing hybridization. Temporal displacement of flowering peaks, strong pollinator specificity, and high flower constancy in the shared pollinator all contributed to limiting hybridization in this site. In other sympatric occurrences, different phenological windows and pollination assemblages may allow greater frequency of the hybrid.
This book details the methodology used by all research groups in the data gathering for the publi... more This book details the methodology used by all research groups in the data gathering for the publication of the "Atlas y Libro Rojo de la Flora Vascular Amenazada de España" (Atlas and Red Book of Threatened Vascular Flora of Spain)
Description Bipartite provides functions to visualise webs and calculate a series of indices comm... more Description Bipartite provides functions to visualise webs and calculate a series of indices commonly used to describe pattern in ecological webs. It focusses on webs consisting of only two trophic levels, eg pollination webs or predator-prey-webs. Visualisation is important to get an idea of what we are actually looking at, while the indices summarise different aspects of the webs topology.
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Papers by J. Iriondo