The impact of agro-biodiversity and eco-system services in development or A new vision for a just, sustainable and productive agriculture

In this presentation I challenge the assumption that increasing yields should be a priority under all circumstances. Today we produce enough food to feed the world but still there are 1 billion people that are hungry. The problem is not that there isn’t enough food but the poor people don’t have access to that food. Then I examine the relationship between biodiversity and agriculture and the idea that biodiversity provides ecosystem services. I describe an example showing that complex ecological interaction result in the control of insect pests. Then I discuss the debate between two paradigms regarding agriculture and conservation of biodiverisy: separation (land sparing) versus integration (land sharing), and argue that the separation paradigm is flawed. I finish with a discussion of what I perceived is needed to solve the biodiversity and food crises in the world: a focus on small-scale agroecological farms with strong social and ecological relationships

Spatial Pattern And Ecological Process In The Coffee Agroforestry System

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/116922/1/ecy2008894915.pd

The ghost of ecology in chaos, combining intransitive and higher order effects

Historically, musings about the structure of ecological communities has revolved around the structure of pairwise interactions, competition, predation, mutualism, etc. . . Recently a growing literature acknowledges that the baseline assumption that the pair of species is not necessarily the metaphorical molecule of community ecology, and that certain structures containing three or more species may not be usefully divisible into pairwise components. Two examples are intransitive competition (species A dominates species B dominates species C dominates species A), and nonlinear higher-order effects. While these two processes have been discussed extensively, the explicit analysis of how the two of them behave when simultaneously part of the same dynamic system has not yet appeared in the literature. A concrete situation exists on coffee farms in Puerto Rico in which three ant species, at least on some farms, form an intransitive competitive triplet, and that triplet is strongly influenced, nonlinearly, by a fly parasitoid that modifies the competitive ability of one of the species in the triplet. Using this arrangement as a template we explore the dynamical consequences with a simple ODE model. Results are complicated and include include alternative periodic and chaotic attractors. The qualitative structures of those complications, however, may be retrieved easily from a reflection on the basic natural history of the system.Comment: 29 pages, 15 figure

Cuban science democratic and not tied to profit

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/62931/1/437192a.pd

Biodiversity Conservation in Tropical Agroecosystems

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/74765/1/annals.1439.011.pd

Coexistence of Aphid Predators in Cacao Plants: Does Ant-aphid Mutualism Play a Role?

Mutualism between ants and hemipterans that produce honeydew has important implications for biological control because hemipterans defended against predators can reach economic injury levels. We tested the hypothesis that ant-aphid mutualism can mediate competition and promote the coexistence of aphid natural enemies. A quadrate in the field measuring 30 x 30 meters (10 plants in 10 rows = 100 plants) was established in a cacao plantation and a whole quadrate survey was carried out in vegetative shoot flushings from the trunk. The number of ants and predators, the identity of ant and natural enemy species and colony occupancy by ants were recorded. Spatial association indexes were used to evaluate the degree of overlap in ant-ant and ant-predator spatial distributions. The ant Crematogaster victima F. Smith was selected for a test on differences in its attack behavior against larvae of the syrphid Ocyptamus antiphates (Walker) and a species of ladybird beetle (Coleoptera: Coccinelidae). Five species of ants were found tending aphids more frequently and their level of spatial association was slightly negative with remarkable mutual exclusion from aphid colonies. Two of them, Cr. victima and Cr. erecta Mayr, were potential defendants of aphids and were selected to study their spatial association with the distribution of natural enemies. It was found that spatial association between ants and aphid predators is slightly positive. The results suggest that the occurrence of attack behavior of Cr. victima against syrphids, but not against coccinellids, can increase coexistence of predators by generating independent spatial distribution

Reduced Diversity and Complexity in the Leaf-Litter Ant Assemblage of Colombian Coffee Plantations

Coffee agroecosystems have recently undergone a dramatic intensification in Colombia, a megadiverse country, especially in terms of the nature of shade cover. We tested for changes in the composition, ecological associations, and diversity of ants (Hymenoptera: Formicidae) along a gradient of intensification of coffee production in the Colombian Andes. We surveyed 16 farms in two regions, classified into four management types: (1) forest (no agriculture), (2) organic polygeneric shaded coffee, (3) monogeneric shaded coffee, and (4) sun coffee (unshaded). Forty sampling units (20 1-m 2 plots on the ground and 20 coffee bushes) were established at each farm between 2001 and 2002. We sampled with a mini-winkler litter extraction technique and through visual searching. Organic polygeneric shaded-coffee plantations contained significantly higher ant species richness, and their ant assemblages resembled the forest patches more than any other management type. The number of statistically significant associations among ant species dropped with production intensification, as did the number of ant species involved in such associations. The network of ant associations in shaded systems transformed into an extremely simplified network in sun coffee, with a few dominant ants extending almost entirely throughout the crop. Intensification of coffee agriculture not only caused loss of litter ant species (especially forest species) but also a reduction in the complexity of the ant assemblage in the leaf litter of this agroecosystem.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/74649/1/j.1523-1739.2005.00062.x.pd

Insights from excrement: invasive gastropods shift diet to consume the coffee leaf rust and its mycoparasite

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154946/1/ecy2966.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154946/2/ecy2966_am.pd

Avian Foraging Behavior in Two Different Types of Coffee Agroecosystem in Chiapas, Mexico

This study describes the foraging ecology of birds during summer and winter in two different types of coffee agroecosystems in Chiapas, Mexico. Avian foraging behavior is documented in two agroecosystems of differing management intensity, structurally similar but with different levels of floristic diversity, during summer and winter seasons. The distribution of tree species used by birds was more even, and birds used a greater diversity of tree species, in the more diverse coffee shade system. Much of the variation in resource use derived from shifts in the use of flowers and fruit, highlighting the importance in resource phenology for birds. Insectivory was more frequent in winter than summer for the coffee layer, and in summer for the shade layer. Given the vegetative structural similarity of the two coffee agroecosystems included in this study, floristic differences probably accounted for much of the difference in the bird communities between the management systems, especially given the strong seasonal response to flowering and fruiting. This work suggests that plentiful and diverse food resources associated with the high diversity of plant species may facilitate coexistence of the high number of bird species found in shade-grown coffee agroecosystems.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72797/1/j.1744-7429.2006.00248.x.pd

Agroforests as Model Systems for Tropical Ecology1

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/117179/1/ecy2008894913.pd