My name is Cassie Koerner and I am a senior in Natural Resource Conservation at the University of Montana in Missoula. I enjoy biology, forestry, and have a special interest in soils and entomology. Most of my work experience before my REU has been related to fire and its effects on forests and other parts of the environment.

La Selva is a biological station run by the Organization for Tropical Studies for the past 40 years or so. I arrived here on the 6th of June and fell in love immediately with my surroundings. There is so much diversity and beauty in the lowland tropical rainforest. No one is allowed to cross the Stone Bridge until registering in Reception and so I felt like I was crossing the threshold to my adventure the second I set foot on the bridge. It is a long walk to the River Station where we all live; especially with all of our luggage. But, it has been a great environment to get to know each other in such a non-private space. The entire country seems to stretch my idea of privacy because there are very few windows and many openings near the ceiling to let air flow through. All in all, it is difficult to keep much a secret around here.

Sunset over the soccer field.

June 30, 2005

I set out for a new adventure and was able to follow one of my dreams.  I have always been fascinated by ants and wanted to monitor their behavior here in the tropics.  I went to El Ceibo a part of the National Park we border called Braulio Carrillo.  El Ceibo is a species of tree, it is very beautiful...check out the picture below!  So, I went to Rachelle and Ximena (both pHD candidates at U of Texas, Austin) with Rachelle's project on Megalomyrmex species ants.  These little girls are very beautiful and can be found in many different places.  They are very elusive insects at times and lead you in all sorts of directions to keep you away from their nests and queens.  My main purpose in the trip was to collect ants for another study on alkaloids in ants that cause the poison dart frogs here to be toxic.  I was able to participate in a couple of ways.  For a period of over one hour, I sat in the same place and set out cookie crumbs...when the ants came to collect and eat I painted them neon green so it was easier for Rachelle to follow their path and find their nest.  I think that this really ticked them off, but it was fun anyways.  We were able to successfully collect 4 colonies over the weekend.  It was a very rare find because the species we found is a parasite to other colonies but is only found in 1:100 colonies.  We found this parasite in 2:4!  Rachelle was ecstatic to say the least.

June 14, 2005

The last few days I have been working like a dog!  Some mornings begin as early as 530 am and the day has not ended any earlier than midnight!  I am working really hard on establishing all my decomposition plots and getting all the 440 bags weighed, filled and marked for placement early next week.

Sunday was an awesome day for me. We took a trip from the Station down the river to the Sarapiqui.  We saw so many creatures!  The iguanas and birds were fabulous but the highlight was a giant crocodile.  We got really close and realized it was about 12 feet long and at least 2 feet wide!  It was so fat.  We also saw many locals along the river for a Sunday swim. (Dangerously close to the giant crock!)  I think that the ride was about 2 hours long and we saw a Giant Iguana, spider monkeys, vultures, caimen (alligatorish creature), and about a million other small creatures.  We stopped at a traveler's rest where there were hammocks and a couple of older men playing music.  They were awesome, but it was best to relax in the hammocks and walk through a butterfly garden of Morpha butterflies.  They are beautiful, bright blue and huge (about the size of your hand).  I tried to get some good photos but they move really fast. 

Yesterday I almost died of heat stroke.  It had not rained for 5 days and was getting progressively hotter and I had to ride my bike to my plots, 5km away (~3.3miles).  Bike riding down here is an entirely different sport though.  You have to wear long sleeve shirts, pants, and snake boots as well as a helmet.  Most of the ride to the plots is uphill and we gain ~2000 ft elevation.  It was very rewarding though because the area I work in is beautiful.  It used to be highly degraded pasture land but in 1988 they planted about ten native species plantation style.  Now, 17 years later it is a jungle of diversity and the trees are huge.  I am actually studying pine species.  At 17 years they are at 14-20 inches in diameter. I could not believe it!  We walked another couple of km laying out the plots and then went down near the Peje River for lunch.  This was the best part of the day!  We sat in the shade of many huge trees that extended out over the river and made a great sport of fishing for shrimp.  These guys were huge too!  You would think that my surprise would be supressing by now, but I am still constantly amazed by the size of things! 

June 11, 2005

Today was very intense as I began doing the work for my own research project here in La Selva.  There is a lot to get done before my advisers leave on Tuesday and so we are working very hard to get the study ready to go.  Today was spent marking litter bags to fill with roots and leaves for each of four sites.  There are six species and many different treatments.  In all we labled and tagged 440 bags and then began weighing each.  Tomorrow we will fill the bags with litter and the rest of the week will consist of weighing the full bags and depositing them at the sites.  This seems like a lot of work, but that is the bulk of the project.  I collect these bags at 0weeks, 2 weeks, 2 mos, 6 mos, and 10 mos.  The idea is to see how long it takes for the litter to break down according to site and species by limiting variables in a semi controlled atmosphere.  I will hopefully return to Costa Rica at either 6-10 mos to finish the project and write the paper.  The hypothesis is that by the time ten months arrives (possibly 6) that all the litter will be decomposed.

I am studying decomposition on Hyeronima alchorneoides, Vochysia guatemalensis, Vochysia ferruginea, Virola koschnyi , Pinus patula, and Pentaclethra macroloba and the differences in rates caused by substrate and decomposition environment. Below is a breif overview. For a more detailed description please see the link to my proposal and paper to the left.

Thank you to Ann Russell and Jim Raich for the opportunity to perform this project in Costa Rica. I am also grateful to the ECOS project for all of their hard work and the fun. Thank you to OTS for the funding and Costa Rica for the permits.