Karina Orozco – REU Experience

In 2022, I joined the Morton Arboretum’s Global Tree Conservation Program (GTCP) as a Research Experience for Post-baccalaureates (REP) participant. The fellowship provided me with a one-year term to conduct research as part of a conservation project for tropical montane cloud forest in Costa Rica, led by my mentor.

My work focused on the in situ establishment success of the endangered tropical oak Quercus insignis. Around 300 seedlings of this species were transplanted to six restoration sites in southern Costa Rica in collaboration with the local NGO Osa Conservation. I was able to visit our study region twice to collect survival and growth data six months and one year after transplant. Data was then analyzed using R to determine which site provided the best conditions for seedling growth and which had the lowest mortality rates. I mainly compared mortality rates and growth rates for height and diameter with percent canopy cover. I also collected 25 preliminary root samples 6 months after transplant to analyze for the presence of ectomycorrhiza, a type of fungi that forms a symbiotic relationship with plants by developing around their root tips.

rmbl in the field
insignis acorns in the field
ectomycorrhiza on seedling root

Left to right: Me with our collaborator Rodrigo in the field, insignis acorns in the nursery, and an example of ectomycorrhiza on seedling root tips under the microscope.

I found a few key takeaways from my analyses; average relative growth rate for height and diameter ranged between 0 and 0.1 cm and mm of growth per month, respectively, with some significant differences between sites. Total seedling mortality and sickness was generally higher for those with more exposure to sunlight (< 50% canopy cover). Root sample observation under a dissection microscope revealed that all samples showed evidence of ectomycorrhizal colonization, with some even presenting structures characteristic of arbuscular mycorrhiza, which live within plant roots. I plan to conduct further analysis of survival, growth, and ectomycorrhizal presence in relation to aspect, incline, rainfall, light exposure, and canopy cover.

Working in the GTCP has provided me with several opportunities in the field of conservation aside from developing my research skills. I acted as a coordinator for the project, which allowed me to meet with our partners, practice my Spanish, and organize a workshop on rare and threatened tree conservation. I also attended an IUCN Conservation Planning Specialist Group training to learn how to facilitate conservation planning workshops, hosted by the Georgia Aquarium in Atlanta.

tree identification course
cpsg training cohort
scouting expedition on Osa Peninsula

Left to right: A course on tree identification taught during the workshop, my CPSG training cohort, and a scouting expedition for Anthodiscus chocoensis, or Ajo negro, on the Osa Peninsula.

I have now presented my findings at Morton’s 2022 REU Symposium and the 2023 Center for Plant Conservation National Meeting. I am grateful for the support from NSF and the arboretum to gain such valuable research experience, as it was during this time I discovered my passion for tree science, fieldwork, and conservation. I have since been invited to continue working in the GTCP as a research coordinator beginning July 2023, and am excited to continue working in conservation to help protect threatened tree species!