Monteverde Institute: Tropical Ecology and Conservation

Follow

• 

  Biological treatment of Monteverde gray water using effective microorganisms and mountain microorganisms, December 2017

  Sierra Raby

  As in many rural or less structurally developed areas, homeowners and businesses in Monteverde, Costa Rica filter grey water through grease traps or biojardineras or release it directly into their yards. This study evaluates the efficacy of two concentrations of Effective Microorganisms (EM) and Mountain Microorganisms (MM) in improving local grey water. These solutions contain biologically beneficial bacteria, yeast, and fungi. I collected grey water from six residential and commercial sources, treated each source with EM and MM in different concentrations, and gathered water quality metrics from each group for seven days. The metrics included surface cover, sedimentation, layering, smell, percent Total Dissolved Solids (%TDS), Dissolved Oxygen (%DO), and pH. After seven days, all treated containers had more surface cover than the control containers. All treatment groups reduced %TDS significantly more than the control group. Percent dissolved oxygen for all treatments decreased compared to the control, and continued decreasing until day seven, indicating that the microbes remained active until the last day of measurements . Both EM and MM solutions have a low pH, which may explain the higher acidity in treatment groups than control groups. EM concentrate performed best in the categories of sedimentation and smell. Therefore, addition of similar ratios of EM would best enhance grey water system efficacy and pleasantness, improving the quality of life of those who use them.

• 

  Color change in Dolabrifera dolabrifera (sea hare) in response to substrate change, December 2017

  Jennay Argiris

  Dolabrifera dolabrifera is an Opisthobranch (sea slug) known for its cryptic coloration. This coloration is an important defense mechanism, but D. dolabrifera have never been studied to see if they change colors to increase their cryptic nature. After photographing 12 D. dolabrifera on different substrates, the color of the slugs and their substrate were determined. These colors were then depicted as hue values. Each D. dolabrifera was photographed three times, in different tide pools and over time. Every D. dolabrifera was graphed with the hue value found for the slug, substrate and reference for the three photographs taken. After analyzing the graphs, I found a correlation between the slug and substrate hue in eight out of the twelve trials. D. dolabrifera changes its color based on its substrate.

• 

  Diet of frugivorous birds and bats in Monteverde: Potential seed dispersal in naturally disrupted areas, December 2017

  Yibing Yu

  After a natural disruption clears away the previous plant community, plants from the new vegetation succession will exploit the newly opened up spaces and start growing in this area. Seed dispersal by aerial animals is important in the new vegetation succession because it allows seeds from places relatively far away to access the area. In early October the storm Nate caused flash floods and landslildes, which disturbed many natural habitats in Monteverde. In this study I investigated plant species that naturally grow in disrupted areas by looking at what kind of seeds are dispersed by the frugivorous birds and bats in Monteverde, and what seeds actually land in an area opened up by the storm recently. I collected fecal samples from birds and bats, and also set seed traps in a newly opened area caused by a flash flood. By analyzing the samples, I found nine species of bird dispersers and two species of bat dispersers, dispersing 19 species seeds from 12 plant families. Throughout my samples I found that both birds and bats can contribute to the diversity in a new vegetation succession. Large amount of seeds in the family Passifloraceae, Piperaceae, Solanaceae and Primulaceae are distributed by birds and bats. One species in particular, Myrsine coriacea, are dispersed by a varied of birds, and were found in the seed traps too. Therefore Myrsine coriacea in the family Primulaceae, has a high potential of growing in new vegetation succession after this major natural disruption.

• 

  Differences in heterospecific pollen deposition across pollination syndromes in the Monteverde area, December 2017

  Kara Powell

  Pollination is an important ecosystem service, increasing the ability of plants to adapt to changing environments through the process of sexual reproduction. The efficiency of pollination can be reduced due to the transfer of heterospecific pollen, which is pollen from another species. Flower characteristics vary in order to attract certain types of pollinators. This phenomenon is classified in groups of flower morphology characteristics known as pollination syndromes. Little research exists that summarizes heterospecific pollen transfer within these pollination syndromes. I investigated pollen deposition across pollination syndromes in Monteverde, Costa Rica in two different sites: San Gerardo and Curi Cancha. I mounted stigmas from each reserve onto microscope slides in order to count the amounts of both conspecific and heterospecific pollen. I then classified each species into a certain pollination syndrome using characteristics defined by the USDA. I divided the plant species in my data into two categories based on their strategy for attracting pollinators: generalist and specialist. I found that there was no significant difference in the amount of conspecific and heterospecific pollen deposition between generalist and specialist plant species. Pollen deposition is likely more affected by floral traits that are indistinguishable when classifying plants into generalist and specialist categories. Thus, heterospecific pollen transfer (HPT) is affected by more factors than the specialization of floral morphology.

• 

  Differential maternal defense behavior in three species of treehoppers (Hemiptera: Membracidae), December 2017

  Mackenzie Kui

  Maternal care in the animal kingdom can vary immensely from species to species, but the reason for its ubiquity underlies an evolutionary impulse to pass on favorable genes to the next generation. In treehoppers, maternal care increases the rate of offspring survival through species-specific levels of protection from both predation and parasitism. To investigate the factors that influence maternal care, I introduced a variety of animate and inanimate stimuli to both brooding and non-brooding treehoppers in three species: Antianthe expansa, Alchisme grossa, and Umbonia crassicornis. By quantifying their responses as proxies for energy output, I concluded that maternal defense is a species-specific phenomenon that is distinct from personal defense, relies primarily on kinesthetics rather than visual input, and is stimulus-dependent. This type of species-specificity is likely governed by different types of environmental pressures that necessitate the evolution of direct defense behaviors or inter-species mutualisms.

• 

  Evidence for aposematic coloration of the sea urchin Astropyga pulvinata, December 2017

  Nathan Howell

  Astropyga pulvinata is a brightly colored urchin found in some tropical pacific waters including the coast of Costa Rica. The aim of this study was to test a possible explanation for the coloration of A. pulvinata. I tested the hypothesis that the coloration of A. pulvinata is aposematic. I tested this by poking A. pulvinata and another species of urchin, the uniformly black Diadema mexicanum, then comparing their reactions. The results indicated that A. pulvinata were more likely to move as a response to the poking stimulus than D. mexicanum, which was contrary to the predicted hypothesis. 100% of A. pulvinata urchins moved after being poked, but only 60% of D. mexicanum urchins moved. However, after further investigation and observations, this behavior does not disprove the warning coloration hypothesis. Another test involved placing both species of urchin in the feeding garden of the territorial giant damselfish. The results showed that the damselfish bit D. mexicanum significantly more than A. pulvinata. After 9 trials with 120 minutes of video, damselfish bit D. mexicanum a total of 314 times and A. pulvinata only twice. The best explanation for such behavior is that A. pulvinata exhibits aposematic coloration.

• 

  Growing Trichoderma asperellum, a natural fungicide, on coffee pulp and husks, December 2017

  Amber DeVries and Georgia Van Tyne

  Coffee farms often rely on chemical fungicides to control fungal crop diseases such as ojo de gallo (Mycena citricolor) and red rust (Hemileia vastatrix). Trichoderma is a genus of fungus known to parasitize other fungi and it can be used to treat these crop diseases. Research has already proved that Trichoderma spp. can be cultivated on various organic substrates. Our goal was to help coffee farmers discover which coffee waste products could grow Trichoderma asperellum best. To do this, we collected three coffee by-products from Café de Monteverde: “young” coffee pulp, “old” coffee pulp, and coffee husks. We mixed these coffee waste byproducts into different ratios to create eight different coffee material test substrates. In addition to these test substrates, we chose goat waste and rice as test substrates. The three test substrates that had the highest percent colonization of T. asperellum, in order, were: (1) 50% old pulp and 50% coffee husk, (2) 75% old pulp and 25% coffee husk, and (3) 50% young pulp and 50% coffee husk. We saw conidial pigmentation indicating a more mature stage of Trichoderma growth in rice only. The pH had an optimal range of percent colonization of T. asperellum from about 5.5-7.5. Meanwhile, moisture had no observed correlation with percent colonization. Due to the colonization success of our T. asperellum, we know it is possible for T. asperellum to grow on coffee byproducts in a non-laboratory setting. Future research should study how long the T. asperellum needs to grow on the test substrates discussed in this experiment before it is concentrated enough for use as a fungicide and also how to make this procedure more effective for use on a larger scale.

• 

  Insect communities across forest fragments of different sizes in Monteverde, December 2017

  Jesse Laine

  Forest fragmentation creates numerous boundaries and microclimates that affect organisms of all taxa. I studied the composition of insect communities across two forest fragments of different sizes, as well as continuous forest and pasture. Pitfall traps and sweep netting techniques were used to sample 888 insects overall. The fragments had similar numbers of insects and morphospecies, regardless of size. The pasture had the most morphospecies present. In addition, Forest edges consistently showed higher abundance and diversity than forest cores. This indicates that reduction of habitable land does not always reduce the numbers of individuals and species, and in some cases can increase them. Only four of the total 145 morphospecies sampled were found living in every site. This means 2.8% of morphospecies were resilient and generalist enough to exist across the different habitats. This research shows that the differences in habitat created by fragmentation are exceptionally difficult for insects to manage. Future research should do similar samples in different regions and climates.

• 

  Medicinal herbs and mosquitoes: A study of plant-based insect repellents, December 2017

  Miguel Alejandro Ochoa

  Mosquito-borne illnesses present a great threat to human health, and result in millions of cases and hundreds of thousands of deaths annually. This study aimed to determine the effectiveness of extracted essential oils from three neotropical plants traditionally used in Costa Rican folk medicine as mosquito repellents. I extracted the essential oils of Siparuna decipiens (Monimiaceae), Gliricidia sepium (Fabaceae), and Neuroloena lobata (Asteraceae) via simple steam distillation. The extracted oils were then examined and compared to a negative control in the field on live volunteers, focusing on the mosquitoes in the Monteverde Zone, Puntarenas Province, Costa Rica. After a total exposure 18 hours and 12 trials over the course of 4 days, I found no significant evidence with relation to the effectiveness of any of the plants. DEET was the only treatment to significantly exhibit a deterrence towards mosquitoes.

• 

  Microhabitat influences morphospecies richness on Costa Rican rocky reefs, December 2017

  Brooke Hawkins and Eric Medina

  Microhabitat can be important in understanding small-scale habitat use of marine populations. This study examines the role of microhabitat, defined as a combination of substrate feature, as well as spatial heterogeneity on the biodiversity of rocky reefs off the coast of Cuajiniquil, Guanacaste, Costa Rica. We surveyed twenty quadrats from three sites, recording the benthic animal morphospecies we observed, the microhabitats they occupied, and measured physical attributes of each habitat. We found that stony caves harbor more morphospecies in a given area than other microhabitats, but that rocky flats and stony pools host more unique morphospecies in total. We also found that sandy substrates have lower morphospecies diversity than other substrates. There was a positive correlation between microhabitat diversity and morphospecies diversity within a quadrant. Our results suggest that microhabitats contribute to reef diversity in different ways. For instance, some have a higher density of morphospecies richness, while others contribute more unique morphospecies to reefs overall. Spatial heterogeneity also plays a key role. While heights and widths are poor indicators for biodiversity, the number of microhabitats present have a positive relationship with diversity.

• 

  Possible effects of long-term weather changes and extreme weather events on mice population abundances in Monteverde, Costa Rica, December 2017

  Emily S. Parker

  Mice and rat abundance is determined by a multitude of factors, including, but not limited to: climate change, predation, and food availability. In this study, I analyzed the effects of daily and long-term weather on rodent populations to understand a possible decrease in abundance from 2016 to 2017 in Monteverde, Puntarenas, Costa Rica. I took observations of individuals from four different sites: Santa Elena, Bajo del Tigre, Dwight and Rachel Crandell Memorial Reserve, and the Estación Biológica Monteverde. While a considerable number of specimens were captured in Bajo del Tigre, I observed the total abundance of rodents to be significantly lower than that observed one year prior in the fall of 2016 in the same sites. Due to this disparity, I hypothesized that climate change and weather could be affecting the populations. I obtained rainfall data taken from the time period around each study period and monthly totals of both 2016 and 2017. I tested this data as a control against the number of rodents caught for each respective study. For both years, the amount of daily rainfall was not statistically correlated to the number of rodents captured daily. These results indicated that low catch rates were not caused by daily rainfall in 2017; therefore, it is possible the population levels have been decreasing over the past year. I went on to explore new hypotheses of long-term climate change, coati interference, and food availability as possible explanations for a decreasing rodent population.

• 

  Presence and prevalence of microplastics in the water and marine organisms of the Gulf of Santa Elena, Guanacaste, Costa Rica, December 2017

  Eliot Headley

  Marine environments are sinks for microplastic pollution. Microplastics are widely dispersed through the world’s Ocean and can be fibrous. Synthetic microfibers shed from clothing, wash into rivers, and eventually into the Ocean. These microplastic pieces can be deleterious to marine organisms and the humans that consume them. My aim was to investigate the presence and prevalence of microplastics in the Gulf of Santa Elena, Costa Rica. Microplastics were collected through a plankton net and through dissection of fish guts from local fishermens’ catch. Microplastics, most of which microfibers, were observed in every plankton net sample and in six of the seven fish samples collected. Calculated from this data, there are about 1.03 microplastics in every 10,000L Gulf of Santa Elena water.

• 

  Relating wing loading and ear size to bat diet types, December 2017

  Shilah McGuinness

  Bats have one of the widest diet varieties in the animal kingdom. With these varying diet niches, each bat species experiences a different set of evolutionary pressures from its ecological interactions. This study assessed the variation in wing and ear morphology in bats and how these values compare with their varying diet types, in order to assess the ecological specificity that these species have evolved. I set up mist nets over a series of two weeks and captured a total of 17 bats from 9 species, conducting a series of measurements to calculate the total wing area and ear/weight ratio of each bat. The results showed statistical significance in the larger ear sizes found in insectivores when compared to other diet types captured. Additionally, the wingloading of the insectivores was significantly smaller than those of nectarivorous and small fruit eaters, and the high wingloading of the large fruit eater was also shown to be significant. Overall, these results correlated with the known ecology of these bat species, as insectivores need less agility to forage for prey in the open than frugivorous and nectarivorous bats searching in the vegetation. Furthermore, because insectivore prey is in motion, it makes sense that their echolocation abilities are heightened in comparison to those species with diets involving sessile food sources.

• 

  Species abundance of fungi is greater in landslide areas compared to undisturbed areas of the forest in Monteverde, Puntarenas, Costa Rica, December 2017

  Sunshine Lopez

  Fungi plays an important role in the ecosystem by decomposing dead plants, and other organic matter. Without this process, there would be an accumulation of organic material in the forest which would go un-decomposed. Fungi which are saprotrophic macrofungi from the phyla Basidioycota and Ascomycota have the vital job of recycling nutrients from dead plant material in the forest back into the soil. The abundance of organic material created by the landslides on the reserve behind Estación Biológica in Monteverde, Puntarenas, Costa Rica may have given rise to nearly twice the amount of different species of fungi (n=31) compared to those alongside undisturbed trails (n=18) where there was not an abundance of organic material. I found more basidiomycetes compared to ascomycetes in both the landslides and the undisturbed areas. Some types of fungi require a succession of decomposition to take place before establishing mycelium, whereas I found others which were substrate specific. Species of fungi which were very common were Agaricales sensu lato, Coprinellus disseminatus, and Scutellinia scutellata. Other species were substrate specific, such as the red mushrooms of Hygrocybe coccinea.

• 

  Species distribution of the rocky intertidal zone organisms at La Islita in Cuajiniquil, Costa Rica, December 2017

  John La Bonte

  The rocky intertidal zone is an area of the seashore between the high and low tide marks with a hard substrate for organisms to move on. The organisms in this habitat face biotic and abiotic factors that determine their distribution and abundance through a biological mechanism called vertical zonation. I studied the rocky intertidal zone of La Islita near Cuajiniquil, Costa Rica in an effort to find the species that are present in this habitat and their relative abundance throughout the zone. I surveyed five transects that spanned the majority of La Islita to find where and in what abundance each species is present. There are a total of 28 species that I found, with most showing distinct distributional patterns of where they live in the rocky intertidal zone. I divided my results into the class’s bivalvia, gastropoda, and anthozoa and also looked at the distributions of two species: Diadema mexicanum, and Chthamalus anisopoma. Species within each class all showed different distributions even though these species have very similar physical characteristics. Microhabitats created by the terrain in different littoral zones allows species to expand into other littoral areas they would normally be excluded from due to abiotic factors. This densely populated habitat shows the prominence that biotic and abiotic factors play in influencing species distributions.

• 

  Synchronized male cricket calls in choruses of the cricket Anaxipha sp., December 2017

  Michael Morales

  In Monteverde, there is a species of cricket within the Genus Anaxipha where males sing in loud choruses at night. I wanted to explore the purpose of this behavior by looking at the call and response activity between individual males. In this experiment, I looked at male responses to manipulations of the species male song, which is composed of two elements. I conducted a series of playback experiments on captive crickets. Responses of test subjects were documented while presenting playbacks of manipulated songs. Each playback treatment had a unique response from the crickets being tested. However, overall, it appears that the crickets were either trying to copy the composition the recordings, or keep pace with their speed. Results show that males within this species of cricket are actively listening and responding to each other.

• 

  The effectiveness of cover crops as a control for root knot nematodes (Meloidogyne spp.) in coffee (Coffea arabica), December 2017

  Joyce Silva

  Root Knot Nematodes are members of the family Meloidognidae and can be detrimental to the overall health and productivity of infected crops. Evidence of the presence of these nematodes can be seen by the galls or “swollen nodules” that form where these worms have been feeding. In order to avoid the use of harmful nematicides some farms have chosen to use cover crops as a more sustainable approach to combating these pests. For my study I decided to test if the cover crops used at LIFE Monteverde were effective in reducing the prevalence of root knot nematodes in the roots of their coffee trees. Using two different plots of coffee I was able to analyze a total of 235 roots from 56 trees. After extracting these roots, they were taken back to the lab, examined, and then categorized by the number of galls found on each individual root collected. The first plot that was sampled lacked evidence of root knot nematodes regardless if cover crops were used on the tree or not. The second plot’s roots were clearly infested with root knot nematodes from both trees that used cover crops and those who did not. Both plots clearly indicated that cover crops did not affect the presence of nematodes. This data also suggested that perhaps age, proximity to neighboring farms, and topography play a role in the soil’s suitability for root knot nematodes. In addition to these results, I also noticed that the coffee trees were the only roots being parasitized. The roots of the cover crops used showed no signs of nematode infestation and were found in the same soil of the roots that were severely affected by these parasites. This evidence could suggest that this species of root knot nematodes are a specialized species that feed only on the roots of Coffea arabica.

• 

  The effects of reforestation on mammal diversity and abundance in Monteverde, Costa Rica, December 2017

  Noelle Pruett

  Reforestation is an important mechanism in helping previously deforested landscapes recover. However, reforested areas tend to have less diversity in vegetation, due to the fact that humans are not able to replicate the same diversity or pattern of regeneration that would occur naturally. I investigated whether or not these changes in forest types and vegetation affect the diversity and abundance of mammals that inhabit these areas. I used both camera traps and Sherman traps to survey mammals from areas with reforestation and with natural regeneration. I observed a total of 72 mammals from five species in the camera traps. I found that while there were no significant differences in the number of species present, there was a significantly larger number of individual mammal appearances on camera traps in locations with natural regeneration. I captured a total of 28 individual rodents over five species in the Sherman traps. Though I found more individual rodents in areas with reforestation, there was not a significant difference between areas with reforestation and natural regeneration. These results indicate that three of the five larger mammal species observed in the cameras (Nasua narica, Dasyprocta punctata, and Puma concolor) were significantly more abundant in areas with natural regeneration than reforestation. Though more research is needed to determine the specific reasons these species are less abundant in reforested areas, I speculate that it is due to dietary changes.

• 

  Variability of mycorrhizal colonization amongst varieties of Coffea arabica in Monteverde, Costa Rica, December 2017

  McKenzie Sime

  Mycorrhizae are a kind of fungus that forms symbiotic relationships with plants. They help plants deal with environmental stressors such as drought and disease. Almost all plants have this symbiosis with mycorrhizae, coffee being included in this group. Coffea arabica, a species of coffee, is grown in tropical regions and multiple varieties have been developed to increase the productivity of the plants. However, tropical regions, like Monteverde, Costa Rica where this study was conducted, are going to be some of the hardest areas hit by climate change. Plants are going to be depending more and more on their mycorrhizae as these environmental stressors become stronger as the climate changes. I looked at the variability of mycorrhizal colonization amongst different coffee varieties. I also tested the effects of vermicompost on mycorrhizal colonization in an effort to find a simple and possibly applicable method to increase colonization in plants. There was a significant difference in mycorrhizal abundance between varieties, with the Catuaí variety of coffee showing almost twice as much colonization as the Venecia variety (6.67% as opposed to 3.33%). There was also a significant change in the colonization of plants that were vermicomposted while control plants that were given no vermicompost did not see a significant change (13.06% as opposed to 7.78%). These results might indicate that vermicompost is a viable method of increasing mycorrhizal colonization in Coffea arabica.

• 

  Vertical stratification of web-building spiders in strangler fig trees?, December 2017

  Justin N. Daniel

  Web building spiders rely on their silk structures to capture prey. The morphologies of the webs produced by spiders vary greatly and they provide insight into spiders’ behavior and ecology. Strangler fig trees, due to a life history that results in trunks with complicated structures, host a great diversity of web-building spiders. I studied the vertical distribution of the web-building spiders that inhabit strangler figs. I used a Single Rope method of canopy access to climb five strangler fig trees to record webs and web-building spiders. Whether a vertical stratification of these spiders exists remains unclear. Apparent patterns, which were observed on four trees, among 12 morphospecies and 7 families, here are analyzed and discussed. Web types, families and species were not stratified with the exceptions of the species Tengella radiata and the family Agelenidae.

• 

  Vocalizations and associated behaviors of the white-nosed coati, Nasua narica, December 2017

  Jeremy Giampaoli

  Vocalizations emitted by mammals in a social context can be linked to behavioral states. These different states may exhibit specific acoustic characteristics, such as long call duration, harmonics, and wide frequency range. My objective in this study was to describe the different vocalizations of White-Nosed Coatis (Nasua narica) according to their behavioral context. I recorded vocalizations of ten individual males and a social group of coatis in Monteverde, Costa Rica. Based on the associated behaviors, I grouped the calls into three behavioral states: aggressive, relaxed, and alarmed. After analyzing the acoustic characteristics of the vocalizations using spectrograms, I further discriminated the calls into sub-states. I quantitatively and qualitatively described a variety of vocalizations (chirps, squawks, squeaks, trills, and grunts). Each behavioral sub-state exhibited a significantly different vocalization, demonstrating a clear relationship between vocalization characteristics and associated behavior. The quantitative acoustic traits I found align with Morton’s motivational-structure rules: that aggressive vocalizations exhibit a lower minimum frequency and wider frequency range than those of non-aggressive contexts. Additionally, inter-individual variation was prominent and could provide a method of individual identification within the species.

• 

  Zooplankton morphospecies and abundance in relation with tide in mangroves of Cuajiniquil, Costa Rica, December 2017

  Stephanie Li

  In two decades, at least 35% of the world’s mangroves have been lost, which is more than both tropical rain forests and coral reefs (Valiela et al. 2001). Mangroves act as an important habitat and feeding grounds for fish (Sasekumar et al. 1992). Zooplankton are abundant in the mangroves and are important organisms to study to get an understanding of the foundation of ecosystem’s food chain. Zooplankton eat phytoplankton and get eaten by small fish and other sea animals, providing a food source and extending the food chain. I aimed to ask and answer the following question: is there a difference in the abundance and morphospecies of zooplankton present in the mangroves of Cuajiniquil, Costa Rica, depending on the tide? Using a student plankton net, I collected a total of fifteen samples at varying tides between 17 November and 21 November 2017, all during the daytime. After collecting a sample, I looked through each sample in its entirety under a dissecting microscope, separated zooplankton by morphospecies, and recorded the quantity of each morphospecies. I found 36 morphospecies with copepods and crustaceans being the most abundant. More zooplankton morphospecies were present during incoming tide rather than outgoing tide. The greatest abundance of morphospecies were present during middle tide with shrimp being most abundant at low tide, but zooplankton excluding shrimp being most abundant at middle tide. I found a positive correlation between zooplankton abundance and morphospecies versus salinity. Future studies could look at the zooplankton’s tolerance for change in salinity to determine whether the zooplankton specialize in a certain salinity or if they are physically brought in and out of the mangrove estuary with the tide.

• 

  Higher abundance and species richness at lower elevations in Monteverde altitudinal survey on euglossine bee diversity, June 2017

  Liora Huebner

  In many Neotropical areas, Orchid bees are the primary bee pollinators, so knowing their biogeographical and altitudinal distribution in Monteverde, Costa Rica could be useful for understanding ecosystem health. The Orchid bees’ optical uniqueness, large biodiversity and accessibility serve as useful and easily identifiable bioindicators of farm and ecosystem health. The biogeographical distribution of Orchid bees has been thoroughly researched, but there are few scientific papers conducting surveys on their altitudinal distribution. I caught a total of 138 bees from six different species: Euglossa viridissima, Euglossa imperialis, Euglossa mixta, Euglossa maculilabris, Exaerete smaragdina and Eulaema bombiformis using methyl salicylate, cineole and eugenol in four different locations of altitudes ranging from about 1200 m to 1800m. I spent two mornings and three hours each day at Bajo del tigre, the Crandell reserve, la Estación Biológica and the TV towers. The region of lowest elevation had the highest abundance and species richness. I found five species and 66 individuals at Bajo del Tigre and only two species and six individuals at the TV towers. Surprisingly, a site at medium elevation, la Estación Biológica had the highest Shannon diversity due to possessing the most heterogeneous species composition and a presence of four species. Since my results show that bee biodiversity does vary with altitude, they would make useful indicators of ecosystem change over time as climate change causes locations of lower elevations to heat up and become less habitable.

• 

  Microbial diversity in compost, its efficacy against pathogenic fungus Mycena citricolor, and soil erosion at Life Monteverde, June 2017

  Naomi Hood and Mason Thurmond

  The incidence of Mycena citricolor on coffee plants and soil erosion threaten the productivity of coffee farms in the Monteverde region. Mycena citricolor, commonly known as ojo de gallo, is a pathogenic fungus that causes defoliation and loss of fruit in Coffea arabica. The fungus lives on coffee leaves and in the soil. As soil erodes, fertile material for plant growth is lost and ojo de gallo is given the opportunity to spread across the farm. This study investigated the possibility of novel sustainable practices in maintaining healthy coffee plants at Finca Life Monteverde by applying compost to ojo de gallo. We also compared soil erosion in areas of differing vegetation cover and found that there was not a significant relationship between percent vegetation cover and soil erosion. We compared the inhibition and reduction in number of colonies of Mycena citricolor after application of various composts produced by the farm, a synthetic fungicide called Opus, and the commonly used biocontrol called Trichoderma asperellum (Trichoderma). We found that a compost containing rice and coffee skins, goat and chicken manure, whey, molasses, and carbon produced by the farm significantly inhibited growth of Mycena citricolor the most, and all composts inhibited more so than the synthetic fungicide Opus. Composts have the potential to effectively inhibit the growth of ojo de gallo because their microbial diversity can outcompete the pathogenic fungus. The use of vegetation cover as a means of preventing soil erosion should be further investigated to limit the spread of pathogenic fungi.