Sergio López
Phone: +52 9616170440 ext. 4240
Address: Instituto de Ciencias Biológicas, Ciudad Universitaria.
Libramiento Norte Poniente No. 1150, Colonia Potinaspak, CP 29018
Address: Instituto de Ciencias Biológicas, Ciudad Universitaria.
Libramiento Norte Poniente No. 1150, Colonia Potinaspak, CP 29018
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Papers by Sergio López
year, a total of 10 line transects were situated and recorded in the study area to determine relative abundance and density, and habitat type use (dry forest, Nanchal, grassland, riparian vegetation, and mangrove) by the species. This study reports a new C. oaxacana population on the Southeastern limit of species range. Although this species has a very restricted distribution and is in danger of extinction, C. oaxacana has a high population
density when compared to other Ctenosaura species. A total of 108 individuals were recorded throughout the study. Dry forest (33.75ind/ha) and Nanchal (18.75ind/ha) were the habitats with higher densities. Comparisons between habitat types showed no significant differences between dry forest and Nanchal (W=15, p=0.0808). Results between seasons were similar. The Oaxacan Spiny tailed Iguana preferred first the dry forest, and then
Nanchal, while avoided grassland, riparian vegetation, and mangroves. There was no difference in habitat use between males and females. Mean perch heights were 1.23±0.32 (n=30) in Nanchal, 2.11±0.30 (n=9) in grassland, 1.90±0.56 (n=54) in dry forest, 1.91±0.28 (n=9) in mangrove and 2.30±0.37 (n=6) in riparian vegetation. Species observed as refuge and perch were B. crassifolia (Nanchal); C. alata (grassland); Tabebuia sp., Genipa
americana, G. sepium, Acacia sp., Ficus sp. and Haematoxylon sp. (dry forest); G. sepium, Acacia sp. and Guazuma ulmifolia (riparian vegetation); and C. erecta (mangrove). Live trees hollows and branches were used by species. Main threats to the species are excessive hunting and habitat loss. Furthermore, grassland fires are still common in the study area during the dry season, which can result in habitat loss and territorial displacement of individuals.
We compared our results with several other studies on successional gradients elsewhere in the neotropics. Some Costa Rica mature forest has twice the number of species than El Triunfo. However, secondary forest in Costa Rica showed similar numbers to what we found in El Triunfo. These results suggest that secondary forest at El Triunfo could be more diverse than primary forest. The patterns on species diversity and species replacement along a successional gradient we obtained from this study would be of great help to design sound strategies for Cloud Forest restoration. This is very important since little is known on Cloud Forest dynamics and because this habitat is considered one of the most endangered all over the world.
species, environmental factors may influence evolutionary processes governing sex ratio variation and floral traits evolution. Kallstroemia grandiflora is an annual insectpollinated
gynodioecious herb with broad distribution from the Sonoran desert to the semiarid west coast of Mexico. In this study, we explored if female frequency
increases in harsh environments and the associated changes in floral morphology in female and hermaphrodite plants. We selected 23 populations along the pacific
coast of Mexico where we estimated female frequency and in eight of them we also measured flower size in hermaphrodite and female plants. The average decrease in
precipitation was correlated with the increase in female frequency, and a reduction in the flower size of hermaphrodite plants. Our results support the idea that harsh
environments may influence female frequency, but also flower size and possibly breeding system evolution.
year, a total of 10 line transects were situated and recorded in the study area to determine relative abundance and density, and habitat type use (dry forest, Nanchal, grassland, riparian vegetation, and mangrove) by the species. This study reports a new C. oaxacana population on the Southeastern limit of species range. Although this species has a very restricted distribution and is in danger of extinction, C. oaxacana has a high population
density when compared to other Ctenosaura species. A total of 108 individuals were recorded throughout the study. Dry forest (33.75ind/ha) and Nanchal (18.75ind/ha) were the habitats with higher densities. Comparisons between habitat types showed no significant differences between dry forest and Nanchal (W=15, p=0.0808). Results between seasons were similar. The Oaxacan Spiny tailed Iguana preferred first the dry forest, and then
Nanchal, while avoided grassland, riparian vegetation, and mangroves. There was no difference in habitat use between males and females. Mean perch heights were 1.23±0.32 (n=30) in Nanchal, 2.11±0.30 (n=9) in grassland, 1.90±0.56 (n=54) in dry forest, 1.91±0.28 (n=9) in mangrove and 2.30±0.37 (n=6) in riparian vegetation. Species observed as refuge and perch were B. crassifolia (Nanchal); C. alata (grassland); Tabebuia sp., Genipa
americana, G. sepium, Acacia sp., Ficus sp. and Haematoxylon sp. (dry forest); G. sepium, Acacia sp. and Guazuma ulmifolia (riparian vegetation); and C. erecta (mangrove). Live trees hollows and branches were used by species. Main threats to the species are excessive hunting and habitat loss. Furthermore, grassland fires are still common in the study area during the dry season, which can result in habitat loss and territorial displacement of individuals.
We compared our results with several other studies on successional gradients elsewhere in the neotropics. Some Costa Rica mature forest has twice the number of species than El Triunfo. However, secondary forest in Costa Rica showed similar numbers to what we found in El Triunfo. These results suggest that secondary forest at El Triunfo could be more diverse than primary forest. The patterns on species diversity and species replacement along a successional gradient we obtained from this study would be of great help to design sound strategies for Cloud Forest restoration. This is very important since little is known on Cloud Forest dynamics and because this habitat is considered one of the most endangered all over the world.
species, environmental factors may influence evolutionary processes governing sex ratio variation and floral traits evolution. Kallstroemia grandiflora is an annual insectpollinated
gynodioecious herb with broad distribution from the Sonoran desert to the semiarid west coast of Mexico. In this study, we explored if female frequency
increases in harsh environments and the associated changes in floral morphology in female and hermaphrodite plants. We selected 23 populations along the pacific
coast of Mexico where we estimated female frequency and in eight of them we also measured flower size in hermaphrodite and female plants. The average decrease in
precipitation was correlated with the increase in female frequency, and a reduction in the flower size of hermaphrodite plants. Our results support the idea that harsh
environments may influence female frequency, but also flower size and possibly breeding system evolution.