Yale School of Forestry & Environmental Studies Management practices, Productivity and Biodiversity in Coffee Agroforestry Systems in Costa Rica Esteban Rossi, August Tropical Resources institute

Yale School of Forestry & Environmental Studies Agroforestry -The future of global land use Sustainable agroforestry? A working definition of sustainable forestry: “Sustainable forestry ensures that each ecosystem provides its fair share of values, neither depriving itself or other times and places of the ability to provide values” (Oliver, 2003)

Different people – different values

Can we manage for multiple values? Forests exist in different structures and different structures provide different values and provide habitat for different species. The challenge lies in finding the fair share of values, for the ecosystem. (Oliver, 2003) (Oliver and O’Hara 2004)

Coffee agroforestry research: Catie, Costa Rica Coffee Experimental agroforestry system Objectives: Increase productivity and quality. Reduce the need for chemical inputs and reduce costs. Describe the long term dynamics of the system. Establish the guidelines for “sustainable” coffee production in Costa Rica (Haggar, 2005).

?

AF experiment -Incomplete factorial design Shade tree species: Chloroleucon euryciclum Erythrina poeppigiana Terminalia amazonia 3 levels: No shade, 1sp & 2spp. Two kinds of inputs: Chemical (conventional) Organic

Shade tree speciesInput typeManagement Intensity Erythrina poeppigianaChemical (conventional)High & Medium OrganicMedium & Low Terminalia amazoniaChemicalHigh & Medium OrganicMedium & Low Chloroleucon eurycyclumChemicalMedium intensity OrganicMedium intensity T. amazonia + C. eurycyclumChemicalMedium intensity OrganicMedium intensity T. amazonia + E. poeppigianaChemicalMedium intensity OrganicMedium intensity C. eurycyclum + E. poeppigianaChemicalHigh & Medium OrganicMedium & Low Full sun (no shade)ChemicalHigh & Medium

Methods 1. Understory herb diversity surveys: 4m x 4m subplots with 3 replicates per treatment. Understory herb species richness and abundance. 2. Tree DBH 3.Tree height. 4. Coffee yield data.

Methods

Results Common herb species and number of occurrences. 4 x 4 m sampling plots. #FamilySpeciesFreq 1CaryophillaceaeDrymaria cordata30 2PoaceaePaspalum conjugatum30 3RubiaceaeCoffea arabica (sapl)30 4ApiaceaeSpananthe paniculata27 5PoaceaeDigitatia sanguinalis27 6PoaceaePaspalum conjugatum27 7ApiaceaeHydrocotyle umbellata26 8RubiaceaeBorreria laevis26 9CyperaceaeCyperus tenuis24 10EuphorbiaceaePhyllantus niruri24 11CyperaceaeCyperus luzulae23 12CyperaceaeCyperus tenuis23 13Leg-MimosaceaeMimosa pudica22 14CyperaceaeDichromena ciliata21 15Leg-FabaceaeErythrina poeppigiana (sapl)21 16AsteraceaePseudoelephantopus spicatus20 Taxonomic summary # Families 27 # Genera >50 # Species 58 Most abundant families Cyperaceae 8 spp Poaceae 6 spp Most abundant genera: Cyperus

Herb diversity and coffee productivity along the management intensification gradient (2007)

Historical mean yields of the Coffee AFS grouped for management practices for Organic treatments: thick lines. Chemical treatments: thin lines.

Coffee productivity and biodiversity grouped by shade type

Medium intensity management, a good compromise?

Shade tree basal area in single-species plots

Organic low T. amazonia collapsed (2009). Chloroleucon eurycyclum alone and in most combinations has potential for coffee AFS. Medium intensity management with different shade tree species is promising for Coffee AFS in Costa Rica. It is possible to manage coffee agroforestry systems for agricultural productivity and biodiversity conservation but… Lessons and Questions…

Steffan-Dewenter, et al, PNAS. 104: Aberdare National Park, Kenya, Naughton-Treves et al, (2005). …but “The Devil is in the details” Coffee Agroforestry systems have the potential to provide multiple values but the details have to be properly understood.

Associated Biodiversity

Acknowledgements Montagnini, F., De Melo E. & Elizondo, B. provided help, comments and discussion. This work was supported by the Tropical Resources Institute. Yale F&ES.

Basal area in two-species plots

Mean coffee yield Mg /ha Management intensity and shade type Herb richness Herb diversity and coffee productivity along the management intensification gradient (2007) a-organic low

Hypotheses, mechanisms & procedures in Biodiversity experiments using synthetic communities Loreau et al, Science. Biodiversity experiments in temperate grasslands

Experimental findings: Minnesota & EU Hector et al, Science. Tilman et al, Nature.

Historical perspective “It has been experimentally proved that if a plot of ground be sown with several distinct genera of grasses, a greater number of plants and a greater weight of dry herbage can thus be raised”. Darwin C, The Origin of species. (Hector & Hooper, 2002) The first ecological experiment. Woburn Abbey, UK (Vandermeer, The ecology of intercropping)

Findings After extensive debate it has been shown that: There is a positive, but complex, relation between diversity and productivity. Species composition is also important. The combined effects of composition and location can confound the interpretation of results. Increased traits- functional diversity groups also influences productivity. Community age effects: early dynamics sampling effects, late dynamics niche complementarity. Other variables (biotic & abiotic) correlate and affect productivity i.e., water, temperature, soil fertility