Fiona Hemstreet
Research Mentor(s): David Wilkerson-Lindsey
Mentor Department: Ecology & Evolutionary Biology
Authors: Fiona Hemstreet, Tasnova Adrita, David Wilkerson-Lindsey
Session: Session 1 (9:00am – 9:50am)
Presentation Type: Poster 78
Abstract
While many forms of industrial agriculture are known to reduce biodiversity, smaller-scale diversified agroecosystems can harbor large numbers of species. Incorporating trees into agroecosystems is one way to foster this. Trees increase structural diversity by creating a canopy that shades the understory and blankets the surface of soil with a layer of leaf litter. This leaf litter matrix becomes a zone where arthropods can thrive, breaking down the organic matter raining from above. To better understand the change in the surface-dwelling arthropod communities as the trees grow, we investigated a farm transitioning its coffee production methods by planting shade trees to develop a diverse commercial coffee polyculture. We hypothesized that both shade and litter would have a positive impact on arthropod biodiversity and richness. To test this, we designed an experiment utilizing a two-factorial design, manipulating shade and leaf litter. Over a six-week period, arthropods were collected using pitfall traps and leaf litter sifting from our four treatments: sun with litter, shade with litter, sun without litter, and shade without litter. Once collected, the arthropods were observed in the lab under a stereomicroscope and identified by morphospecies, size, and diet. Our results show that while we did see a significant shift in the arthropod community towards more detritivores, the overall diversity is not significantly greater in the shaded leaf litter microclimates than the current unshaded conditions of the farm today. A six-week period may not be enough time for the diversity of the litter-dwelling arthropod community to assemble. Future investigations on the farm will continue to study how these communities grow over longer time periods and link the populations to soil health metrics. This will better allow us to understand the dynamic process of arthropod community assembly within the agroecological transitions that are necessary for sustainable food production.
