Appalachian State University organize Upward Bound for incoming students…this great bunch spent 5 days with us and helped on trail blazing, ditch digging, and erosion control and really got far on the forest road. You guys did an awesome job, we really appreciate your work!
A wonderful bunch of Globalworks teenagers stayed for 4 days and helped with road repairs and maintenance. Muchas gracias!
April 2004 was one of the driest seasons at Las Casas de la Selva which proved to be very fortunate for an exciting and busy session with the construction of a Wastewater Garden at the homestead. The team that gathered to complete this project in 15 days were: Dr. Mark Nelson, Chairman of the Institute of Ecotechnics, Mark ‘Laser’ Van Thillo, Abigail Alling, Gessie Houghton, Robert Townsend, Gregg Dugan, Chris ‘Dolphin’ Cook, Gilberto ‘Tingo’, Carmelo Torre, Javier Rojas, Sally Silverstone, 3t Vakil.
Wastewater Gardens® were developed by Dr. Mark Nelson, Chairman of the Institute of Ecotechnics and head of Wastewater Gardens International. The system was originally developed as part of the pioneering Biosphere 2 closed ecological system in Arizona. The system uses the technology of subsurface flow constructed wetlands so that there is never any exposed wastewater – thus preventing odor and accidental human contact.
Wastewater Gardens are an ecological, low cost, low maintenance solution to the problem of human waste. Improperly treated sewage causes ecological damage, pollutes drinking water supplies, and is literally a waste of potentially valuable freshwater enriched with nutrients in a world increasingly short of water resources. Using no mechanical or moving parts and no chemicals, all wastewater is recycled via a gravity system into elegant, biologically diverse gardens that produce lovely flowers as well as fruit and vegetables that can be eaten by humans, fodder crops for animal consumption or fuel-wood and fiber. The systems are carefully sealed so no wastewater contaminates the soil, ground water, rivers, lakes, or coastal waters.
Big Thanks to: Zabel Corporation, and Brian Borders for parts and filters for the Wastewater Garden. Firestone Corporation, and Marco Seiber for the donation of the liner for the Wastewater Garden and with all the help in getting it to us on time.
This Waste Water garden was built with a Grant from the Departamento de Recursos Naturales y Ambientales Puerto Rico. Gracious thanks to all those who made it possible.
We always appreciate the help that our volunteer groups provide, and help us get this project off the ground, sometimes literally!
Thank you to students of: Appalachian State University, Pepperdine University, Vanderbilt University, Northeastern University, and Northwestern University.
Frogging at Las Casas de la Selva! Patricia Caligari (center) is pursuing a Masters Degree at University of Puerto Rico. L-R: Rosangela, Michel, Naomi and Monica are her assistants in the field and they are taking credits as part of their bachelor degrees.
Geographic assessment of the response of three different endemic Puerto Rican anurans to the pathogenic fungus Batrachochytrium dendrobatidis (Bd)
ABSTRACT
Chytridiomycosis is a lethal infectious disease caused by the pathogenic chytrid fungus Batrachochytrium dendrobatidis (Bd), which is responsible for the extinction of many amphibians worldwide. In Puerto Rico three species of Eleutherodactylus disappeared potentially due to this pathogen, and many others are at risk. A synergistic effect between Bd and climate was shown for two species at El Yunque, but this relationship has not been tested in other species or forests. The purpose of this study is to evaluate the status of Bd in three endemic species, Eleutherodactylus wightmanae, Eleutherodactylus coqui, and Leptodactylus albilabris, which differ in conservation status, ecology and life history, in three highland forests across the island. Results from this study will enhance our understanding of the mechanisms of Bd under enzootic conditions.
Her advisor is Dr. Patricia Burrowes, who also co-authored our biodiversity and frog study paper.
Since February 2013, our new composting toilets have proved a huge success with everyone who has used them. Several Alternative Spring Break University groups in March 2013 made valuable deposits in our new humanure composting toilets, and we have one compost full and another already started. Up for a visit? Come have the splash-back free experience and leave a valuable resource behind. If you wrote a poem, be sure to leave it here too!
John Druitt and Sally Silverstone plant the first pine tree in 1984. Here is Sally in 2007 with the same tree.
SUMMARY
1984: In general the plantation design was to plant at approximately 3m (10 ft) spacing within the lines and 10m (32.5 ft) from line to line through the forest. In the process of line planting, larger trees and valuable native timber species were left in place and the lines continued with a gap left around them. This technique closely mimics a medium-sized tree fall gap, in which the forest floor litter and soils are undisturbed, but the above ground nearby competition is removed, such as vines and overhanging branches.
2000-2008 19 study plots, 1 acre (0.4 hectare) in size 16 plots of mahogany 3 plots of mahoe. 997 trees studied. Complete sets of reading taken twice. Range 24 to 42 mths between readings.
SURVIVAL RATE Mahogany plantings – 28% approx (dependent on plot aspect- see results, sw best) Initial planting approx. 370 trees per hectare (148 trees per acre) Mahoe plantings – 66%. Initial planting approx. 415 trees per hectare (166 trees per acre) DBH Mahogany trees are increasing in dbh by an average of 0.6 cm per year Mahoe are increasing by an average of 0.91 cm per year. HEIGHT since planting: Mahogany has grown in height at a rate of approximately half a meter per year. Mahoe at a rate of approximately one meter per year.
INDICATIONS The growth data indicate the Mahoe plantation has been far more successful than the mahogany in terms of wood production. At current rates of increase it would take the mahogany at Las Casas another 27 years to get 30 cm dbh trunks for logging, giving a total time from planting to harvest of 43 years. It is currently possible to harvest marketable wood from the mahoe at 15 years. Current conservative estimates for standing marketable wood for mahoe are approximately 58 cubic meters per hectare (25,000 board feet per hectare or 10,000 bd ft per acre). This makes the Mahoe a good candidate for sustainable forestry management where the aim is to get the trees on a cycle of harvesting and replanting to provide a continuous income. A final evaluation of this line planting method as a model for sustainable forestry will be possible when trees are being annually harvested selectively, replanting begins, and the wood and products successfully sold for profit. Future challenges with the Mahoe plantations will involve working out the best thinning and replanting strategies, (and dealing with issues of extraction on slopes, drying techniques, and forest road and bridge repairs after nearly thirty years and two hurricanes). The challenge is on.
Ongoing research on the Mahoe plantation: 2010 – 2012
Jimena Forero is pursuing a PhD Degree at the University of Puerto Rico, Rio Piedras campus. As part of her dissertation she is describing the stand density and the canopy structure of our mahoe enrichment plantation in order to make recommendations for its management. Using our three 1-acre permanent mahoe plots, she has, with the help of undergraduates and Earth Watch volunteers conducted a forest inventory over two years (2010-2012) of these plots at Las Casas de la Selva. Her academic supervisor is Dr. Jess K. Zimmerman, Environmental Sciences professor at University of Puerto Rico, Rio Piedras. Another part of her dissertation involves interviewing artisans all over the island, who use forest products.
NELSON MARK, SILVERSTONE SALLY, REISS KELLY, BURROWES PATRICIA, JOGLAR RAFAEL, ROBERTSON MOLLY, VAKIL THRITY, 2010. The impact of Hardwood Line-Planting on Tree and Amphibian Diversity in a Secondary Subtropical Wet Forest of Southeast Puerto Rico. Journal of Sustainable Forestry, 29(5): 503-516.
(Click link above to download 188KB PDF)
SUMMARY
2000-2004 Amphibians: Amphibians are especially useful as biological monitors of environmental health (Wake, 1991). Because in Puerto Rico frogs are the most important vertebrate nocturnal carnivores, a change in their population dynamics could have an important effect on the forest food web (Joglar, 1998). Thus, monitoring amphibians at Las Casas de la Selva was a suitable way to assess the impact of a line-planting forestry approach to tropical forest ecosystems. Main difference between the studied forested areas was that one had been disturbed to plant trees of potential economic value (line-planting), while the other area had been left undisturbed. There was no difference in species composition between the two areas studied. Eleutherodactylus coqui and E. wightmanae are the two most common species in both forests, with occasional sightings of E. portoricensis.
We were happy to note:
Analysis of variance (ANOVA) of mean relative abundance of the two most common species revealed no significant difference between forests.
This is encouraging data.
These results suggest that the degree of disturbance caused by planting economically valuable trees had no effect on amphibian diversity or density in Patillas, Puerto Rico. At a time when the impact of anthropogenic activities on amphibian populations are being evaluated (Stuart et al., 2005), it is important to show that the type of forestry enrichment practiced at “Las Casas de La Selva”, did not have a negative impact on frog abundance. Our work in Las Casas de la Selva is the first record of population densities of E. coqui in the central cordillera of Puerto Rico, and the first record of population densities for E. wightmanae.
At a time when amphibian populations are declining all over the globe, and populations of these two species are declining at El Yunque, these data from Patillas represent a very valuable baseline that will allow us to monitor population fluctuations and potential declines associated to climate change or disease. Chytrid fungus Since June 2004, various species of frogs at Las Casas de la Selva have been sampled for the incidence of a pathogenic chytrid fungus, Batrachochytrium dendrobatidis (Bd). This fungus is specific to amphibians and has been associated to their decline in various parts of the world (Longcore, 1999), including Puerto Rico (Burrowes et al. 2004). Tissue is taken from toe clippings and/or ventral skin scrapes, and analyzed for the chytrid DNA via specific PCR diagnostic methods. Results show the presence of chytrids in Patillas as early as 2005. At present, the level of incidence of Bd infection in Eleutherodactylus coqui is of 50 % and in E. wightmanae is 44 %. Biodiversity of Trees: Overall the line-planting program has resulted in a small increase in overall diversity of tree species in those areas. See results in the full paper, link above.
Ongoing Coqui frog research at Las Casas de la Selva: 2010 – 2012 Patricia Caligari (center) is pursuing a Masters Degree at University of Puerto Rico, and as part of her thesis is sampling for chytrid in three species of endemic frogs in different parts of Puerto Rico, including Las Casas de la Selva. Her crew of undergraduate students help in the field and lab with DNA extraction. Her advisor is Dr. Patricia Burrowes, co-author of our paper above. More info
All studies are a building block in the more complex strategy of developing techniques to both satisfying human needs and conserving the resource base.” Ariel Lugo
