Claire Kremen, Professor

Closed (1) Insect Diversity in Agroecology Internship

Applications for Fall 2018 are now closed for this project.

Over the last half-century, conversion of land for agriculture has been a major driver of biodiversity loss. The tension between agriculture and biodiversity conservation will only become more acute in the near future, as human food demand is estimated to double by 2050. Beyond direct land use, conventional agriculture’s reliance on chemical pesticides negatively impacts both ecosystems and human health.

Monterey County, comprising much of California’s Central Coast, is not only one of the world’s most productive agricultural regions, it is also a pesticide hotspot. A recent report by the California Department of Public Health revealed that Monterey County has the highest percentage of public schools within a quarter-mile of the heaviest use of several categories of hazardous pesticides. Correlations between pesticide exposure and negative health impacts on farmworker families have been extensively documented in this region.

In a world of land scarcity, increasing food demand, and pesticide concerns, how can agricultural land use be balanced with conserving biodiversity and protecting human health?

The increased adoption of diversified farming practices is a potential solution. By promoting agricultural practices that simultaneously maintain high yields and support biodiversity, win-win solutions for humanity and the rest of nature may be achieved. Research shows that diversified farming systems with features such as non-crop plantings and complex landscape mosaics can positively influence ecosystem services, including soil retention, resilience to extreme weather, pollination, and pest control, although in some instances this can result in lower yields. This project studies the mechanisms underlying the effects of non-crop vegetation on biological pest control ecosystem services in organic strawberry fields. Clarifying these mechanisms will not only inform the management of agricultural lands for the dual goals of crop production and biodiversity maintenance, it may also contribute to reducing pesticide-related health risks and raising society’s valuation of pest control ecosystem services.


Students will be involved in specimen curation, cleaning and organizing plant and arthropod biodiversity data, as well as helping with statistical analysis. Students with experience in statistics and R-programming will have the chance to analyze existing data and contribute to writing up the results. There may also be opportunities to help with GIS software to quantify land cover data, depending on experience and interest.

Day-to-day supervisor for this project: Adrian Lu, Ph.D. candidate

Qualifications: Interest in agroecology, entomology, and/or botany is required. Must be detail-oriented, patient, and intellectually curious. Experience in botany, insect curation, statistics, R-programming, and GIS will be particularly useful.

Weekly Hours: to be negotiated

Closed (2) Agroecological improvements: a tropical pollination story /or/ Agroforestry & Biodiversity: a meta-analysis

Applications for Fall 2018 are now closed for this project.

There are two options under this project the first is a lab-based project (Agroecological Improvements) and the second is a literature/statistical project (Agroforestry & Biodiversity).

1) This project will be primarily lab work and will be focused on a project that examines the pollination biology of cultivated cacao in Ecuador. Theobroma cacao, an understory tree native to the Upper Amazon Basin, has an intriguing fly-based pollination system that is understudied even though cultivated varieties experience very low pollination rates. This study aims to determine how different management strategies and landscape contexts affect natural pollination levels in this globally important crop. We estimate pollination service to fields by comparing open and hand pollination treatments. In addition, we collected floral visitors to cacao in order to correlate pollination service to pollinator community composition.

2) Agriculture covers an estimated 40% of the Earth's terrestrial land surface, and demand for agricultural products is expected to increase in the near future. Deforestation and conversion of grasslands for agriculture are major conservation concerns disproportionately affecting tropical biomes, even as these ecosystems have a higher proportion of biodiversity than temperate biomes. Agroforestry and agroecological methods have been proposed as ways to reconcile biodiversity conservation and agriculture in tropical areas. After many years of individual studies, there is finally enough research to judge this sentiment on scientific grounds.

This project started with compiling a comprehensive list of all agroforestry papers focusing on biodiversity conservation in tropical ecosystems from the past 40 years and now has moved on to reviewing this body of literature in terms of methods, focus crops, and tropical biome. Data is also being harvested from these papers for a meta-analysis. I expect that this review/meta-analysis will reveal three major weakness: (1) A heavy focus on charismatic crops rather than crops important for food security or crops that cover the most land area; (2) A lack of sampling in reference habitats; (3) An incomplete consideration of landscape context and composition. This review will push the field of conservation biology further by highlighting the ways in which expanding the literature will be most effective in helping policymakers to achieve more effective conservation planning.

1) Under the supervision of a senior biologist, the undergraduate student will help with all aspects of lab processing of collected specimens. This is interesting but mostly repetitive laboratory tasks that include sorting and labeling specimen samples, pinning insects, identifying insects to order and family, using GIS software to quantify land cover data and entering data. If there is interest, the undergraduate could be involved in identifying some groups of insects to family or genus/species (most likely tropical ants). The student will be given time at the beginning of their tenure to read summaries, questions and review preliminary results in order to understand the project in a larger context.

2) Under the supervision of a senior biologist, the undergraduate student will help with all aspects of the meta-analysis. These interesting but mostly repetitive computer tasks include reading paper abstracts for inclusion criteria, reading included papers in order to harvest both qualitative and quantitative data, enter and analyze data. If there is interest, the undergraduate could be involved in a spin-off analysis project for a senior thesis that uses the same dataset. The student will be given time at the beginning of their tenure to read summaries, questions and review preliminary results in order to understand the project in a larger context.

This an excellent opportunity for students interested in gaining experience in reading scientific publications and learning new statistical skills.

Day-to-day supervisor for this project: Emily Kearney, Ph.D. candidate

Qualifications: For both projects, initiative, attention to detail, patience, and self-motivation are essential. 1) Interest in entomology, agroecology and conservation. -Working familiarity with insect orders and taxonomic keys preferred but not required. -Available hours need to be in blocks of 2 or more and students that can commit 6-8hr or more per week will be preferred. 2) Interest in agroforestry, conservation, and statistics. - Ability to critically read literature and experience harvesting data from scientific articles preferred but not required. - 6-8hrs/week preferred. Schedule is very flexible with one weekly meeting required. Other hours can be completed independently.

Weekly Hours: to be negotiated

Closed (3) Below- and aboveground connections in pollination

Applications for Fall 2018 are now closed for this project.

Belowground organisms influence pollinator behavior. Soil communities are extremely diverse, and when their interactions with plants influence floral characteristics, they have the potential to alter pollinator attraction and visitation. Plant–pollinator interactions have been neglected in studies of the direct and indirect effects of soil organism–root interactions.

Our research will explore these belowground interactions, focusing on the effects of arbuscular mycorrhizal fungi (AMF) and their effects on floral traits, specifically on strawberry plants. We will maintain strawberry plants inoculated with various AMF strains in the greenhouse and determine the effect of AMF on pollinator traits (floral display, pollen and nectar composition, and fruit and seed set). This study will further our understanding of ecological processes between soil microbes, plants, and pollinators that can inform land management strategies in agriculture and conservation biology.

Undergraduate students will be mostly involved in helping prepare and maintain the greenhouse experiment and collecting samples in the field. In addition, they will be required to collect various pollinator traits measurements (floral display, pollen and nectar composition, and fruit and seed set) and soil composition measurements (nutrients and mycorrhizal colonization) throughout the experiment. This an excellent opportunity for students interested in gaining experience in plant ecology research in controlled environments.

Day-to-day supervisor for this project: Aidee Guzman, Graduate Student

Qualifications: Interest in plant ecology, soil science, microbial ecology, and agroecology. Past experience in greenhouse management or field work is good but not required.

Weekly Hours: 6-8 hrs

Closed (4) Amphibian Acoustics: Implications for Tropical Conservation

Applications for Fall 2018 are now closed for this project.

Species respond differently to habitat conversion—even species in the same family or genus that share many functional traits (e.g. breeding strategy, diet, coloration). For example, in the family Centrolenidae (glass frogs), some species are extremely disturbance-adverse (e.g. Centrolene heloderma and C. lynchi) while others (e.g. Espadarana prosoblepon) are found in many habitat types along a disturbance gradient, from primary forest to pastures. These response differences may be driven by functional traits that are rarely considered, such as vocalization characteristics. This project aims to study how the acoustic characteristics of a species and its particular habitat(s) influence where amphibians are found.

Under the supervision of a senior biologist, the undergraduate student will help 1) compile a dataset of traditional functional traits (e.g. body size, breeding strategy) and/or 2) call characteristics across amphibian species in Ecuador. Functional traits and disturbance tolerance profiles will be compiled from ield guides and primary literature. Vocalizations for each species will be collected (when possible) from recording databases such as the Cornell Lab of Ornithology’s Macaulay Library of Natural Sounds, natural history museums, and personal recordings. Spectrogram analysis will be performed in Raven Software 2.0 (Cornell Lab of Ornithology). For each species, the student and I will categorize/bin each call characteristic (e.g. dominant frequency, diversity of notes, number of pulses per note) to create a call profile for each species. The student can work on the functional traits, vocalization analysis, or both depending on their interests.
This an excellent opportunity for students interested in wildlife acoustics, database generation, amphibian natural history, and conservation biology. All experience levels welcome.

Day-to-day supervisor for this project: Rebecca Brunner, Ph.D. candidate

Qualifications: Working familiarity with bioacoustics preferred but not required. Initiative, patience, attention to detail and self-motivation are essential.

Weekly Hours: to be negotiated