These pages provide information on the STRI Canopy Crane Access Systems and on the activities of the Tropical Canopy Biology Program at STRI. STRI has installed two tower construction cranes which provide convenient access to the canopy at one seasonally dry forest, Parque Natural Metropolitano (PNM) near Panama City, and at one moist forest, Parque Nacional San Lorenzo (PNSL, formerly known as Fort Sherman) near Colon.
STRI maintains meteorological stations at both cranes. For information about these stations and access to data, summaries and reports, click on the following links: Parque Natural Metropolitano, Parque Nacional San Lorenzo
Views of the San Lorenzo canopy crane in Colon
Situation map of the two canopy cranes in Panama, PNSL and PNM. Image by GoogleEarth
In a nutshell:
The construction cranes lift researchers above the forest in a small gondola and then lower them at desired study sites within the canopy. In this way, the cranes allow safe, easy and three-dimensional access to the forest. The crane operator, who receives orders by radio from the researchers on where to position the gondola, controls the crane movements. The gondola can easily accommodate up to four researchers, including heavy equipment, for hours at a time.
The canopy crane at Parque Natural Metropolitano is located within a lowland semi-deciduous forest on the Pacific coast of the Isthmus. This 80-year-old forest receives on average 1,740 mm of rain per year. The crane is 42 meters tall, with a boom length of 51 meters, and gives access to almost 1 hectare of forest and to approximately 80 species of trees and lianas.
The second crane facility is installed in a wet evergreen forest at Parque Nacional San Lorenzo on the Caribbean coast. This forest receives about 3,300 mm of rainfall per year. Hence, a steep rainfall gradient occurs between the two crane locations and the species composition of the two forests are very different. The PNSL crane is 52 meters tall with a radius of 54 meters, and can reach approximately 180 species of trees and lianas.
Both cranes are located in forest dynamics plots, in which trees have been mapped, measured and identified. The plot at the Parque Natural Metropolitano crane is 1 ha in area and all trees larger than 10cm in diameter at breast height (DBH) are mapped. The plot at the Parque Nacional San Lorenzo crane is 6 ha in area and all trees larger than 1cm in diameter at breast height (DBH) are mapped. For more information, please see a detailed description of the two crane sites.
The cranes facilitate in-situ studies on a range of research topics, including plant phenology, pollination biology, the ecophysiology of canopy trees and lianas (including gas exchange, water transport and light limitation), the diversity and feeding behavior of canopy arthropods, biotic interactions, food web ecology, etc. These studies can all take place directly in the canopy. For more information, please see examples of research projects, as well as possible future canopy research.
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