Papers by Andrea Cruz-Angon
Environmental Science & Policy
Sociedad y Ambiente
Se presenta un análisis de las trayectorias, retos y oportunidades de los Estudios de biodiversid... more Se presenta un análisis de las trayectorias, retos y oportunidades de los Estudios de biodiversidad estatal que son promovidos por la Comisión Nacional para el Conocimiento y Uso de la Biodiversidad, en el marco de la iniciativa de las Estrategias Estatales de Biodiversidad. Tras 20 años de esta iniciativa, se han publicado 24 Estudios de Estado con un perfil técnico-científico y biologicista a través de procesos que han involucrado a los distintos actores federales, estatales y académicos de la conservación en México. Su incidencia en el desarrollo de políticas y estrategias de conservación ha tenido un papel relevante para escalar el discurso conservacionista internacional desde los lineamientos del Convenio sobre la Diversidad Biológica, pasando por la Estrategia Nacional sobre Biodiversidad de México, hasta las Estrategias para la Conservación y el Uso Sustentable de la Biodiversidad de los Estados y la conformación de corredores de conservación. Aunque los Estudios de Estado ha...
Se presentan las principales conclusiones derivadas del análisis de la información de los capítul... more Se presentan las principales conclusiones derivadas del análisis de la información de los capítulos precedentes del Estudio de Estado sobre la Biodiversidad de Guanajuato, donde se plantean algunas estrategias y acciones necesarias para mejorar el conocimiento y aprovechamiento de la biodiversidad en el estado de Guanajuato. Se incluyen algunas de las barreras más importantes y condiciones habilitadoras que formaron la base para la formulación de la Estrategia para la Conservación y Uso Sustentable de la Biodiversidad del Estado de Guanajuato
2016. Hacia la estrategia para la conservación y el uso sustentable. En: La biodiversidad en la C... more 2016. Hacia la estrategia para la conservación y el uso sustentable. En: La biodiversidad en la Ciudad de México, vol. iii. conabio/sedema, México, pp.374-386.
... Martha Lucía Baena, Clementina González Zaragoza, Peter Bichier Garrido y Benjamin Lorr me as... more ... Martha Lucía Baena, Clementina González Zaragoza, Peter Bichier Garrido y Benjamin Lorr me asistieron en distintas fases del proyecto, también gracias ... A la comuna, mis vecinitos (Ivan, Astrid, Camilo, Dario, Marisa, Octavio, Valeria, Rosario y Rita,) ya Rosa María, que me ...
Agriculture, Ecosystems & Environment, 2007
We studied the relationships of bird and small mammal species richness, composition, and abundanc... more We studied the relationships of bird and small mammal species richness, composition, and abundance to vegetation structure and economic profitability across a coffee intensification gradient in central Veracruz, Mexico. We conducted 2 years of point count censuses for summer resident birds, 2 years of Sherman live trapping for small mammals, and gathered vegetation structure data at 147 sampling points distributed over 16 sites spanning a cultivation intensification gradient. We calculated net annual revenue per hectare as an index of profitability from economic and management data collected during interviews with plantation owners/managers. Both the species richness and abundance of forest-affiliated birds were significantly greater in floristically and structurally diverse 'bajo monte' coffee and forest compared with commercial polyculture coffee, which was, in turn, significantly richer than statistically indistinguishable specialized shade and sun coffee. Mammal capture rates were extremely low at all but two sites. Forest bird species richness and abundance were explained by multiple linear regression models that included statistically significant effects of shade cover, percent of trees with epiphytes, and canopy height. We found no clear relationship between profitability and biodiversity, with biodiverse bajo monte coffee plantations ranking among the most profitable under all price scenarios. The high profitability of biodiverse bajo monte coffee systems was not dependent on the inclusion of long-term environmental costs or premium pricing systems. Our results demonstrate that high-biodiversity coffee cultivation can be compatible with high profitability, and has significant potential for conserving biodiversity in coffee-growing regions, but only as a substitute for lowbiodiversity coffee cultivation, not forest. #
Animal Conservation, Apr 30, 2000
We surveyed birds in cacao (Theobroma cacao) plantations in the state of Tabasco, Mexico. The sha... more We surveyed birds in cacao (Theobroma cacao) plantations in the state of Tabasco, Mexico. The shade canopy was planted by farmers and consisted of approximately 60 species of trees with no single dominant species. Canopy height averaged 15 m and the structure was multi-storied. We conducted 220 ten minute, 25 m radius point counts for birds and detected 1550 individuals from 81 species. The average number of birds/point and the expected diversity in a fixed number of individuals within the cacao surveyed were well within the range of other lowland habitats, including agricultural sites, that we have surveyed previously in neighbouring Chiapas. In the Tabascan cacao, the migrant group was composed, in part, of forest species, and dimorphic species were represented primarily by males, which in other areas are known to dominate forest or forest-like habitats. In contrast to the composition of migrant species, we found few resident forest specialists in Tabascan cacao. Instead, the tropical resident group was composed of large-bodied generalist species that use small patches of trees in open habitats. These results (moderate diversity, low numbers of forest specialists) differ from the few studies completed in 'rustic' cacao systems located near large tracts of forest. The planted shade cacao agroecosystem -at least in the absence of nearby forest -may have a limited value for conserving lost tropical forest bird diversity, but it provides habitat for woodlandassociated migratory species. Our results also indicate that the planted shade cacao plantations supported few small omnivorous or frugivorous species, probably because cacao itself, as well as the dominant shade trees, produce primarily mammal or wind dispersed fruit and seeds.
E l Estado de México por su situación geográfica, variado relieve y diversidad de áreas climática... more E l Estado de México por su situación geográfica, variado relieve y diversidad de áreas climáticas es una entidad con gran biodiversidad. Los registros establecen que dentro del Estado existen al menos 3,524 especies de plantas y 125 especies de mamíferos y 490 de aves, lo que es solo un ejemplo de la magnitud de la riqueza biológica con que cuenta el Estado. La “Diversidad Biológica del Estado de México: Estudio de Estado”, representa el trabajo coordinado de distintos grupos de investigación, cuya importante labor ofrece una herramienta invaluable para definir políticas publicas encaminadas a la protección y conservación de la biodiversidad en el Estado de México. La pérdida de la diversidad biológica es uno de los grandes problemas que enfrentamos. Sin embrago, el estudio de las condiciones locales, como trata esta obra, representa una valiosa contribución al conocimiento de la biodiversidad nacional y mundial, que será de gran utilidad como referencia en la implementación de las...
Annals of botany, 2005
Dioon angustifolium was considered within D. edule. Recent morphometric and allozyme studies on D... more Dioon angustifolium was considered within D. edule. Recent morphometric and allozyme studies on D. edule have shown that D. angustifolium has originated from geographic isolation and is therefore considered to be a separate species. This cycad is endemic to north-eastern Mexico and is known only from three populations in the Sierra Madre Oriental mountain chain. Its populations are small when compared with its southern relative D. edule. In this study, genetic variation was determined within and between populations of D. angustifolium and the genetic consequences of habitat fragmentation and isolation of populations of this species were assessed. Allozyme electrophoresis of 14 presumptive loci was used. The data were analysed with statistical approximations for estimating genetic diversity, structure, gene flow and recent genetic bottlenecks. Means and standard deviations of genetic diversity estimators were: number of alleles per locus (A = 1.67 +/- 0.23), percentage of polymorphic...
Journal of Tropical Ecology, 2009
The abundance of epiphytes has been assumed to be important in explaining the high diversity of t... more The abundance of epiphytes has been assumed to be important in explaining the high diversity of tropical canopy arthropods. In this study we assessed the possible role that the presence of epiphytes may have on the diversity and abundance of canopy insects in an experimental study conducted in a coffee plantation in Coatepec, Veracruz, Mexico. Epiphytes were removed from trees in one of two plots in two sites of the coffee plantation. In each plot we collected insects from three Inga jinicuil trees by knockdown insecticide fogging. Insects were sorted to morphospecies, counted and measured. Trees with epiphytes had significantly higher numbers of species and individuals and insects larger than 5 mm were also more species-rich and abundant in trees with epiphytes. The magnitude of the enhancement was surprisingly large with the epiphyte plot samples having on average 90% more individuals and 22% more species than plots without epiphytes. These differences were even greater for large (>5 mm) insects (184% and 113% respectively). Our results support the tenet that epiphytes provide valuable resources to arthropods, which we have illustrated for canopy insects in shade trees of coffee plantations.
Journal of Applied Ecology, 2005
Coffee is produced in tropical regions of the world, largely in Latin America. Coffee cultivation... more Coffee is produced in tropical regions of the world, largely in Latin America. Coffee cultivation techniques range from traditional systems, where coffee grows under a diverse canopy of shade trees (shade-coffee plantations), to modern systems, where coffee grows without any type of shade (sun-coffee plantations). Shade-coffee plantations provide refuge for forest fauna in otherwise deforested landscapes. The conservation value of these agro-ecosystems depends upon their structural and floristic diversity. 2. The way coffee producers manage the vegetation, including the epiphytic component, may profoundly affect the value of plantations for conserving biological diversity. Shadecoffee certification programmes have emerged to verify that coffee advertised as 'shade grown' is actually grown on highly biodiverse plantations. Although these programmes universally encourage epiphyte protection from pruning (a common practice), there has been no experimental evaluation of the importance of epiphytes in supporting faunal diversity. We report the effect of experimentally removing epiphytes on the bird assemblage in a shade-coffee farm near Coatepec, Veracruz, Mexico. 3. We established two matching pairs of epiphyte removal and control plots. We compared bird diversity and abundance, based on daily censuses during the breeding and non-breeding season. We used existing information on the way in which birds use epiphytes as foraging and nesting substrates to explain the presence of different species in plots with epiphytes. 4. Plots without epiphytes tended to be less diverse than plots with epiphytes, but rarefaction analysis and showed no significant differences in species richness between treatments in any of the seasons. Mean bird abundance was significantly higher in plots with epiphytes during both seasons, and a multidimensional scaling analysis showed that bird community structure differed between the two treatments. 5. Eighteen forest bird species were significantly more abundant in plots with epiphytes. Three non-forest species were more common in plots without epiphytes. Resident bird species that used epiphytes as a nesting substrate were significantly more abundant in plots with epiphytes. 6. When epiphytes are removed, canopy cover, foraging substrates, nest sites and nest materials are eliminated and microclimatic conditions change. This could increase predation on adult birds and nests, increase intra-and interspecific competition, and decrease individual survivorship. 7. Synthesis and applications. This is the first experimental assessment of the importance of epiphytes for birds. Shade-coffee plantations with epiphytes maintain higher abundance and diversity of the inhabitant bird fauna than plantations without epiphytes. This study reinforces the value of positive epiphyte management as an important factor in shade-grown coffee certification, where the goal is to promote biodiversity conservation.
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Papers by Andrea Cruz-Angon