Rainy season in Tarrazú

I’m back in San Marcos, Costa Rica, leading a few Earthwatch teams this month as we conduct more coffee sustainability research. This is a continuation of the work we started in April; the study is focused on better understanding the conservation value of forest fragments in and around coffee farms in the region in terms of an important ecosystem service: pollination. Building on recent research conducted elsewhere that indicates that having forests nearby coffee yields can enhance pollination, we are comparing pollinator diversity and abundance in both coffee farms that either have adjacent forest stands or are isolated from forest fragments. Coffee is able to self-fertilize, but can produce higher yields if it gets assistance from managed honeybees (imported European honeyebees, the same species commonly used in the U.S.) and other bees – these other bees, especially native stingless bees, are especially likely to be found nesting in forest fragments – hence the link between forest conservation and coffee yields. In April, we collected bees during coffee flowering season; now that the coffee flowering has ceased, we are trying to get a better idea of where the pollinators hang out during times when coffee is not flowering – hence we’re sampling in both coffee farms and nearby forest habitat.
This morning our first team of the month hit the field, helping set up yellow-pan traps to capture bees and wasps in both coffee fields and nearby forest areas. The team (six women from the U.S., Canada, and the U.K.) did a great job scrambling up and down the steeply terraced coffee fields…in addition to setting up bee traps, they also recorded timed observations of the number and type of pollinators flying through the fields, and measured ground cover (e.g., live plants, dead plants (mulch), and flowering plants that might serve as alternative resources for pollinators). Tomorrow we’ll go see what our traps have attracted; after we collected specimens from them, we’ll set up traps in another field – and then it’s back to the lab for an afternoon of sorting through specimens so that we can further identify the types of bees /wasps that we have captured.This afternoon, it is pouring rain, as is the norm for this time of year. As we head further into the rainy season, we’ll continue to do our work in the mornings, when we can generally expect at least a few hours of sunny, bee-friendly weather...

Yesterday as part of their orientation, the group was treated to a rare appearance of a male resplendent quetzal, famed trogon of Central America - lots of opportunity for close-up observation as he flitted from tree to tree alongside a dirt road we were descending after a hike through the forest at Fundacion Nubotropical - a terrific and auspicious start to the week!

Ecosystem services fieldwork in Tarrazu, Costa Rica

I've just arrived at the El Marques lab in San Marcos, Costa Rica, where I'll be leading volunteer teams from Earthwatch Institute in conducting fieldwork for the next month as part of an ongoing research project on sustainable coffee production across the central highland region known as Tarrazu. We've been working with farmers from CoopeTarrazu, a local cooperative of over 2600 coffee farmers in the Tarrazu region, for the past few years in a project linking farmer pratices to both coffee yields and the environment. This year we're focusing on pollinators - specifically, on the economic value of bees to coffee farmers in the region. Coffee normally self-fertilizes, so it is not as dependent on pollinating insects as much as some other well-known crops (e.g., almonds) - but there is some evidence that having native pollinators around may enhance yields as much as 20% under the right conditions. The Tarrazu region is, as are many agroecosystems, a patchwork of farms and forest fragments -- and one thing we'll be exploring is how useful those forest fragments are as habitat that can support important pollinators of the coffee - that is, to what extent forested areas are providing "ecosystem services" to coffee farms. To this end, we'll be looking at the diversity and abundance of native and non-native bees in coffee farms and adjacent forest fragments, as well as conducting manipulative experiments such as manually pollinating coffee flowers and comparing their yields with those of flowers that have netting placed on them to exclude pollinators. Data from these and other experiments we're conducting should give us a better understanding of the benefits of forest conservation in and around coffee farms - and more generally point the way to establishing best practices in agricultural ecosystems. The first volunteer team arrives in a few days; in the meantime, I'll be unpacking my equipment trunks and going through the field protocols with local colleagues today and tomorrow.

It's pouring rain as I'm writing - the kind of downpour typical of afternoons in the tropics - we'll be focusing on getting our fieldwork (capturing and observing bees) done in the mornings, and saving our lab work (sorting and preserving specimens) for the rainy afternoons!