Effect of urban landscape configuration on the structural dynamics of myxogastrids (Finished)
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Period: 2017

Team: Carlos Rojas, Pedro Rojas and research team.

Objetive: The main goal of this project was to characterize the myxomycete assemblages associated with different urban configuration as a proxy to understand landscape-level effects on microorganisms.

Context: Urban centers may have different types of configurations. In this study we have selected towns and cities shaped like blocks (very compact and almost circular) and others shaped like spiders (very spread and with typical "branches" of conurbation). We are trying to assess if such configurations do have an effect over myxomycetes assemblages or not in order to understand the effect of landscape level urban arrangements on microbial communities.

What have we done thus far?
We have selected a series of collecting areas in different urban centers in Costa Rica, Mexico, Peru and the United States and have already obtained some information using lab protocols. So far, we have created a series of rings of different radius size around the cities and analyzed the data. Results have shown that only when the distance with the city cetroid exceeds 5 times the size of the centroid-edge radius, it is that myxomycete assemblages start looking different to those "inside of the city". Since a number of other variables may play a role in shaping those differences, we are still working on the generation of more data and analyzing satellite information to produce the expected multiscale analysis that we proposed. 
A smaller scale dataset looking at two cities within Costa Rica was  investigated and provided information showing that greater landscape level characteristics may be responsible for differences between the outer and inner areas of the cities. A manuscript in currently (Dec 2017) under development.

Exploring new areas for research with Dr. Carlos Lado from Spain

Comparative monitoring of myxogastrids in tropical and temperate areas (Finished)
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Period: 2017

Team: Carlos Rojas, Adam W. Rollins (Lincoln Memorial University) and research team.

Objetive: The main goal of this project was to quantify a series of microenvironmental parameters and correlate them with classical biodiversity data in order to understand the extent of "site-effect" interactions toward the generation of data on myxomycetes.

Context: Researchers in all parts of the world produce data on myxomycetes without taking in consideration that some site-effect interactions with the organisms under study may play a role in determining the final datasets, results, analysis and conclusions. Using a standard protocol, we are trying to design simple experiments to understand the extent of these interactions and the level at which, they shape those datasets used for publication. 

What have we done thus far?
We have generated two datasets for tropical myxomycetes using two different labs located in very different conditions (one in Costa Rica and one in the United States). Results have shown that general patterns do not change but specific ones differed between labs. We have also seen, one more time, that drier areas tend to be more productive than moister ones and that general results also depend upon other research conditions such as handling techniques and process of curation. During 2017, also ran a separate experiment within Costa Rica, in two sites only separated by a mountain and found the same pattern mentioned above. Even though a series of environmental conditions between laboratories may be different, it seems that both temperature and atmospheric humidity are the key variables explaining the patterns obtained in the experiments. A manuscript is currently (Dec 2017) under development.

Barba Volcano crater

Isotrop: Carbon and Nitrogen movement in two forest systems in Costa Rica (Finished)

Period: 2015-2017

Team: Carlos Rojas, Karina Rodriguez, Randall Valverde, Erik Pollock (University of Arkansas), Georges Govaere and lab assistants

Objetive: The main goal of this project was to characterize chemical, physical and biological changes associated with wood decomposition as a way to evaluate dynamic processes of nutrient recycling in tropical forests.

Context:There is vast information on tropical forest dynamics. However, most of the data used to understand processes in these forests has not been obtained through local efforts and thus, the raw information is usually not available to most people in the respective areas. This project, designed to be an international collaboration effort between researchers from the University of Costa Rica and from the University of Arkansas, is aimed to obtain quantified public data on nutrient recycling in two forest systems in Costa Rica. Both forest types have been characterized extensively by our lab during the last three years, so we expect to count on a nice dataset by the time this project is over.

What have we done thus far?
Wood pieces were set in reseach sites at the Juan Castro Blanco National Park and assessments of physico-chemical properties have been performed during 24 months. Both isotopic signals and structural data showed that during the first year the wood that has been exposed to the climate in the forest did not changed significantly and that it took about 20 months to show differences. This is very interesting in a tropical context where humidity is a very important factor enhancing decay, but since our data showed that soil moisture tends to stay low (contrary to air moisture which tends to be high), this can be an indication that nutrient dynamics and climate dependent in some way.  As such, our data shows that wood degradation and chemical movement occurred slower than expected in the premontane wet forest under scrutiny. 
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PNJCB´s Research Station in San José de la Montaña

Publication

​Umaña S, Rodríguez K, Rojas C. 2017. ¿Do mountain microorganisms (MM) really work as a biofertilization strategy? A Biosystems Engineering Approach. Revista de Ciencias Ambientales 51(2), 133-144.

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​Mixotico: Protocol for isolation of soil myxomycetes from soils (Finished)

Period: 2015-2016

Team: Carlos Rojas, Randall Valverde with conceptual help from Carlos Lado (Royal Botanical Garden of Madrid) and lab assistants

Objetive: The goal of this project is to help design a protocol for isolation of myxogastrid fruiting bodies using soils in order to support the initiatives of scientific development on soil microorganisms. 

Context: Up to this point, there is no standard protocol for isolation of fruiting bodies of myxogastrids using soil as the primary source of propagules. Our idea is to evaluate a series of soil types (both tropical and temperate) and isolation protocols in order to come up with a good enough design that we can use a starting point to refine a true isolation lab protocol. 

What have we done thus far?
A matrix of twenty two different soil types (eleven from the tropics and eleven from temperate forests) and eight different substrate types was used in order to determine the best combination of parameters to be used for diversity/abundance analyses. Results showed that the history of land use may be an important determinant of myxogastrid presence using the best isolation combination found in the present study. A second experiment, using different growing media and soils across a latitudinal gradient from the northern USA to Costa Rica, resulted in dictyostelids and myxomycetes showing inverse patterns of presence being the first ones more recorded in the tropics. Also, we were able to determine that crop selection may have an impact on the myxomycete and dictyostelid assemblages when agricultural fields were examined. This constitued a Master´s thesis in the Department of Biosystems Engineering by the student Reyner Sibaja. 

Primary isolation cultures using soil

Publications

​Guyer HE, Rojas PA, Rollins AW, Rojas C. 2017. Mycetozoan incidence in soils and their potential for ecosystem quality assessment. Manuscript submitted to CREAM Journal (in review).

Sibaja-Matarrita R, Barboza-Chinchilla L, Rojas C. 2017. Can mycetozoans be used as health indicators of soil in the agricultural context of Costa Rica? Manuscript submitted to Revista de Ciencias Ambientales (in review).

​Mixotico: Myxogastrid dynamics in different forest systems representing a degradation continuum (Finished)

Period: 2015-2016

Team: Carlos Rojas, Randall Valverde, Adam W. Rollins (Lincoln Memorial University) and lab assistants

Objetive: The goal of this project is to compare the dynamics of myxogastrid assemblages associated with different degrees of forest degradation as a strategy to determine guild similarity at the landscape level.

Context:  The need for specific-site long term projects has driven some researchers to design myxomycete studies that can be useful for answering questions related to ecological strategies. In this context, we have designed the present project in different areas of the north and northwestern parts of Costa Rica. The idea is then, to collect long term information about myxogastrid dynamics in the same study areas in order to monitor trends that somehow may have been underestimated in previous research.

What have we done thus far?
Study areas were selected and suveyed for myxomycetes in the Arenal Tempisque Conservation Area. As expected, results show that drier areas such as the Palo Verde National Park, tend to yield higher number of records than moister ones. Also, our results seem to show significant differences among stages of degradation, being the less degraded areas the more productive ones. However, a number of interesting and even new records for Costa Rica and the Central American region have come up from the isolation chambers made with material from the most degraded zones. In the context of previous research, our results show that even though there are species that occur across a broad gradient of environmental conditions, there seems to be a guild of species that perform better in harder conditions. This project will generate a scientific paper within the 2017 year. However, with parallel results obtained for a specific guild of myxomycetes, we were able to publish a multiscale paper on the assemblage structure between an urban and a rural location when looking at flowers and inflorescences as niches for these organisms. 

Researchers after collecting in Miravalles Volcano

Publication

​Rojas C, Valverde R, Rollins AW, Murillo-Roos M. 2016. What can myxomycetes tell us about floricolous microbial systems? Nova Hedwigia 104: 211-220. 

Mixotico: Myxogastrid distribution in the first vertical kilometer in Costa Rica (Finished)

Period: 2015

Team: Carlos Rojas, Randall Valverde and lab assistants

Objetive: To document changes in species assemblages, species diversity and abundance patterns using fruiting bodies of myxogastrids in the first vertical kilometer in Costa Rica in order to understand the ecological forces determining distribution and biogeography of this group of organisms in tropical areas.

Context: There is some information on vertical distribution of myxogastrids already published in the scientific literature. However, a true comprehensive study on the topic has never been carried out in the Neotropics and so, our team decided to evaluate this issue in Costa Rica. Even though it is very likely that the distribution of fruiting bodies actually responds to a number of variables that we will no quantify, it is also likely that an elevational distribution pattern may show associations with particular plant species, morphology and/or structural changes in the forest. Taking advantage of Costa Rica´s geographical position, we are studying the effect on the dry Pacific slope and on the wet Caribbean slope in order to account for some macroenvironmental varition as well. 

What have we done thus far?
Four transects of one kilometer in vertical change ranging from 1100 m to 100 m above sea level have been established in Costa Rica. The two Pacific slope transects correspond to the Teruel de Acosta-Parrita region (Central Pacific) and the Fila de Cal region (South Pacific) whereas the Caribbean transects correspond to the Guayabo de Turrialba-Herediana de Siquirres region (East-facing Caribbean) and the Cinchona-La Virgen de Sarapiquí region (North-facing Caribbean). A series of collections of dead plant material have been made and studied in the lab for one of the two proposed rounds and some interesting distributional patterns have already been recorded. The composition of species between the Pacific and Caribbean transects is different, as expected, but the degree of variation in the elevational transect also shows interesting contrasting patterns suggesting that different species have different abilities to deal with external forces in order to survive in one area. 

During a field trip in the Costa Rica-Panama border

Publication

​Rojas C, Valverde R, Solano E. 2016. Does elevation influence the distributional patterns of tropical myxomycetes? A case study in Costa Rica. Mycology http://dx.doi.org/10.1080/21501203.2016.1168885