Sonia Trujillo-argueta - Academia.edu (original) (raw)
Uploads
Papers by Sonia Trujillo-argueta
Background/Question/Methods It is commonly believed that habitat degradation and fragmentation de... more Background/Question/Methods It is commonly believed that habitat degradation and fragmentation decrease genetic variation within plant populations. This hypothesis needs to be tested for those species that can withstand the harsh conditions left by desertification, a worldwide process in semiarid lands. Malacomeles denticulata is a common shrub in the Rosaceae, which can grow in a large variety of habitats, including severely degraded and eroded areas, and displays a large phenotypic variation among populations. We study the nature of such variations by means of a common garden experiment and single nucleotide polymorphisms (SNPs). For the garden experiment we used a half-sib design. Three phenotypic characters were examined: leaf area, leaf indentation and relative growth rate in total leaf area per plant (RGR). For the SNP study, an assay was designed from a partial M. denticulata DNA sequence 5.8S ITS 1-2 ribosomal RNA gene. The sequence was analysed with the Repeat Masker and Ba...
Biodiversity loss and conservation in fragmented forest landscapes: the forests of montane Mexico and temperate South America, 2007
A population of the threatened conifer Fitzroya cupressoides that has been heavily degraded by ti... more A population of the threatened conifer Fitzroya cupressoides that has been heavily degraded by timber extraction, and continues to be affected by harvesting of fuelwood and livestock browsing. Photo: Adrian Newton A.C. Premoli et al.
Ecology and Evolution, 2013
Climate change, habitat loss, and harvesting are potential drivers of species extinction. These f... more Climate change, habitat loss, and harvesting are potential drivers of species extinction. These factors are unlikely to act on isolation, but their combined effects are poorly understood. We explored these effects in Catopsis compacta, an epiphytic bromeliad commercially harvested in Oaxaca, Mexico. We analyzed local climate change projections, the dynamics of the vegetation patches, the distribution of Catopsis in the patches, together with population genetics and demographic information. A drying and warming climate trend projected by most climate change models may contribute to explain the poor forest regeneration. Catopsis shows a positive mean stochastic population growth. A PVA reveals that quasi-extinction probabilities are not significantly affected by the current levels of harvesting or by a high drop in the frequency of wet years (2%) but increase sharply when harvesting intensity duplicates. Genetic analyses show a high population genetic diversity, and no evidences of population subdivision or a past bottleneck. Colonization mostly takes place on hosts at the edges of the fragments. Over the last 27 years, the vegetation cover has being lost at a 0.028 years À1 rate, but fragment perimeter has increased 0.076 years À1 . The increases in fragment perimeter and vegetation openness, likely caused by climate change and logging, appear to increase the habitat of Catopsis, enhance gene flow, and maintain a growing and highly genetically diverse population, in spite of harvesting. Our study evidences conflicting requirements between the epiphytes and their hosts and antagonistic effects of climate change and fragmentation with harvesting on a species that can exploit open spaces in the forest. A full understanding of the consequences of potential threatening factors on species persistence or extinction requires the inspection of the interactions of these factors among each other and their effects on both the focus species and the species on which this species depends.
New Phytologist, 2007
Inbreeding depression is common among plants and may distort mating system estimates. Mating syst... more Inbreeding depression is common among plants and may distort mating system estimates. Mating system studies traditionally ignore this effect, nonetheless an assessment of inbreeding depression that may have occurred before progeny evaluation could be necessary. • In the neotropical Pinus chiapensis inbreeding depression was evaluated using regression analysis relating progeny F-values with seed germinability, the mating system was analysed in three populations with contrasting size, using isozymes, obtained a corrected outcrossing rate.
Journal of Evolutionary Biology, 2009
Evolutionary Applications, 2011
Pioneer species are essential for forest regeneration and ecosystem resilience. Pinus chiapensis ... more Pioneer species are essential for forest regeneration and ecosystem resilience. Pinus chiapensis is an endangered pioneer key species for tropical montane cloud forest regeneration in Mesoamerica. Human activities have severely reduced some P. chiapensis populations, which exhibited a small or null colonization potential suggesting the involvement of genetic factors associated with small populations. We explored the relationships between (i) population genetic diversity (allozymes) and population size, including sampling size effects, (ii) fitness estimates associated with colonization potential (seed viability and seedling performance) in a common environment and population size, and (iii) fitness estimates and observed heterozygosity in populations with sizes spanning five orders of magnitude. All the estimates of genetic diversity and fitness increased significantly with population size. Low fitness was detected in progenies of small populations of disturbed and undisturbed habitats. Progenies with the lowest observed heterozygosity displayed the lowest fitness estimates, which, in turn, increased with heterozygosity, but seed viability peaked at intermediate heterozygosity values suggesting inbreeding and outbreeding depression. Inbreeding depression appears to be the most immediate genetic factor in population decline. Conservation efforts should try to maintain large and genetically diverse populations, enhance gene flow by restoring connectivity between adjacent populations, and avoid genetically distant individuals.
eco.confex.com, 2010
Sonia Trujillo-Argueta, Rafael F. Del Castillo and Raul Rivera-García, CIIDIR Oaxaca, Instituto P... more Sonia Trujillo-Argueta, Rafael F. Del Castillo and Raul Rivera-García, CIIDIR Oaxaca, Instituto Politecnico Nacional, Oaxaca, Mexico ... and Reynoso in the Santa Catarina Ixtepeji municipality, where the vegetation is a dry fragmented shrub and disturbed oak forest respectively. ...
Dry forests are currently the focus of conservation and restoration efforts. This is because one-... more Dry forests are currently the focus of conservation and restoration efforts. This is because one-billion people live in dry regions of the world that cover nearly 40 per cent of the Earth's surface. These regions have all in common a reliance on natural resources -including biodiversity, which is declining at a rate unprecedented in recorded history (UNDP, 2004). The objectives of the ReForLan project were to identify and promote approaches for the sustainable management, conservation, and restoration of arid and semi-arid forest ecosystems. In particular, the focus of this chapter is to assess the impact of forest loss, fragmentation, and degradation on genetic variability within socioeconomically important tree species of conservation concern. Also to provide recommendations for restoration of dryland forest resources based on the understanding of processes influencing genetic variation.
American Journal of Botany, 2009
Background/Question/Methods It is commonly believed that habitat degradation and fragmentation de... more Background/Question/Methods It is commonly believed that habitat degradation and fragmentation decrease genetic variation within plant populations. This hypothesis needs to be tested for those species that can withstand the harsh conditions left by desertification, a worldwide process in semiarid lands. Malacomeles denticulata is a common shrub in the Rosaceae, which can grow in a large variety of habitats, including severely degraded and eroded areas, and displays a large phenotypic variation among populations. We study the nature of such variations by means of a common garden experiment and single nucleotide polymorphisms (SNPs). For the garden experiment we used a half-sib design. Three phenotypic characters were examined: leaf area, leaf indentation and relative growth rate in total leaf area per plant (RGR). For the SNP study, an assay was designed from a partial M. denticulata DNA sequence 5.8S ITS 1-2 ribosomal RNA gene. The sequence was analysed with the Repeat Masker and Ba...
Biodiversity loss and conservation in fragmented forest landscapes: the forests of montane Mexico and temperate South America, 2007
A population of the threatened conifer Fitzroya cupressoides that has been heavily degraded by ti... more A population of the threatened conifer Fitzroya cupressoides that has been heavily degraded by timber extraction, and continues to be affected by harvesting of fuelwood and livestock browsing. Photo: Adrian Newton A.C. Premoli et al.
Ecology and Evolution, 2013
Climate change, habitat loss, and harvesting are potential drivers of species extinction. These f... more Climate change, habitat loss, and harvesting are potential drivers of species extinction. These factors are unlikely to act on isolation, but their combined effects are poorly understood. We explored these effects in Catopsis compacta, an epiphytic bromeliad commercially harvested in Oaxaca, Mexico. We analyzed local climate change projections, the dynamics of the vegetation patches, the distribution of Catopsis in the patches, together with population genetics and demographic information. A drying and warming climate trend projected by most climate change models may contribute to explain the poor forest regeneration. Catopsis shows a positive mean stochastic population growth. A PVA reveals that quasi-extinction probabilities are not significantly affected by the current levels of harvesting or by a high drop in the frequency of wet years (2%) but increase sharply when harvesting intensity duplicates. Genetic analyses show a high population genetic diversity, and no evidences of population subdivision or a past bottleneck. Colonization mostly takes place on hosts at the edges of the fragments. Over the last 27 years, the vegetation cover has being lost at a 0.028 years À1 rate, but fragment perimeter has increased 0.076 years À1 . The increases in fragment perimeter and vegetation openness, likely caused by climate change and logging, appear to increase the habitat of Catopsis, enhance gene flow, and maintain a growing and highly genetically diverse population, in spite of harvesting. Our study evidences conflicting requirements between the epiphytes and their hosts and antagonistic effects of climate change and fragmentation with harvesting on a species that can exploit open spaces in the forest. A full understanding of the consequences of potential threatening factors on species persistence or extinction requires the inspection of the interactions of these factors among each other and their effects on both the focus species and the species on which this species depends.
New Phytologist, 2007
Inbreeding depression is common among plants and may distort mating system estimates. Mating syst... more Inbreeding depression is common among plants and may distort mating system estimates. Mating system studies traditionally ignore this effect, nonetheless an assessment of inbreeding depression that may have occurred before progeny evaluation could be necessary. • In the neotropical Pinus chiapensis inbreeding depression was evaluated using regression analysis relating progeny F-values with seed germinability, the mating system was analysed in three populations with contrasting size, using isozymes, obtained a corrected outcrossing rate.
Journal of Evolutionary Biology, 2009
Evolutionary Applications, 2011
Pioneer species are essential for forest regeneration and ecosystem resilience. Pinus chiapensis ... more Pioneer species are essential for forest regeneration and ecosystem resilience. Pinus chiapensis is an endangered pioneer key species for tropical montane cloud forest regeneration in Mesoamerica. Human activities have severely reduced some P. chiapensis populations, which exhibited a small or null colonization potential suggesting the involvement of genetic factors associated with small populations. We explored the relationships between (i) population genetic diversity (allozymes) and population size, including sampling size effects, (ii) fitness estimates associated with colonization potential (seed viability and seedling performance) in a common environment and population size, and (iii) fitness estimates and observed heterozygosity in populations with sizes spanning five orders of magnitude. All the estimates of genetic diversity and fitness increased significantly with population size. Low fitness was detected in progenies of small populations of disturbed and undisturbed habitats. Progenies with the lowest observed heterozygosity displayed the lowest fitness estimates, which, in turn, increased with heterozygosity, but seed viability peaked at intermediate heterozygosity values suggesting inbreeding and outbreeding depression. Inbreeding depression appears to be the most immediate genetic factor in population decline. Conservation efforts should try to maintain large and genetically diverse populations, enhance gene flow by restoring connectivity between adjacent populations, and avoid genetically distant individuals.
eco.confex.com, 2010
Sonia Trujillo-Argueta, Rafael F. Del Castillo and Raul Rivera-García, CIIDIR Oaxaca, Instituto P... more Sonia Trujillo-Argueta, Rafael F. Del Castillo and Raul Rivera-García, CIIDIR Oaxaca, Instituto Politecnico Nacional, Oaxaca, Mexico ... and Reynoso in the Santa Catarina Ixtepeji municipality, where the vegetation is a dry fragmented shrub and disturbed oak forest respectively. ...
Dry forests are currently the focus of conservation and restoration efforts. This is because one-... more Dry forests are currently the focus of conservation and restoration efforts. This is because one-billion people live in dry regions of the world that cover nearly 40 per cent of the Earth's surface. These regions have all in common a reliance on natural resources -including biodiversity, which is declining at a rate unprecedented in recorded history (UNDP, 2004). The objectives of the ReForLan project were to identify and promote approaches for the sustainable management, conservation, and restoration of arid and semi-arid forest ecosystems. In particular, the focus of this chapter is to assess the impact of forest loss, fragmentation, and degradation on genetic variability within socioeconomically important tree species of conservation concern. Also to provide recommendations for restoration of dryland forest resources based on the understanding of processes influencing genetic variation.
American Journal of Botany, 2009