title: Contribution of lianas to plant area index and canopy structure in a Panamanian forest.
abstract: Lianas are an important component of tropical forests, where they reduce tree growth, fecundity, and survival. Competition for light from lianas may be intense; however, the amount of light that lianas intercept is poorly understood. We used a large-scale liana-removal experiment to quantify light interception by lianas in a Panamanian secondary forest. We measured the change in plant area index (PAI) and forest structure before and after cutting lianas (for 4 yr) in eight 80 m × 80 m plots and eight control plots (16 plots total). We used ground-based LiDAR to measure the 3-dimensional canopy structure before cutting lianas, and then annually for 2 yr afterwards. Six weeks after cutting lianas, mean plot PAI was 20% higher in control vs. liana removal plots. One yr after cutting lianas, mean plot PAI was ~17% higher in control plots. The differences between treatments diminished significantly 2 yr after liana cutting and, after 4 yr, trees had fully compensated for liana removal. Ground-based LiDAR revealed that lianas attenuated light in the upper- and middle-forest canopy layers, and not only in the upper canopy as was previously suspected. Thus, lianas compete with trees by intercepting light in the upper- and mid-canopy of this forest.
authors.affiliation: Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin, 53203, USA.|Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin, 53211, USA.|Smithsonian Tropical Research Institute, Apartado 2072, Balboa, Panamá.
authors.forename: M Elizabeth
authors.initials: ME
authors.lastname: Rodríguez-Ronderos
authors.affiliation: Department of Civil, Environmental and Geodetic Engineering, The Ohio State University, Columbus, Ohio, 43210, USA.
authors.forename: Gil
authors.initials: G
authors.lastname: Bohrer
authors.affiliation: Department of Civil, Environmental and Geodetic Engineering, The Ohio State University, Columbus, Ohio, 43210, USA.|Department of Earth and Atmospheric Sciences and Alberta Centre for Earth Observation Sciences (CEOS), University of Alberta, Edmonton, Alberta, T6G 2E3, Canada.
authors.forename: Arturo
authors.initials: A
authors.lastname: Sanchez-Azofeifa
authors.affiliation: Smithsonian Tropical Research Institute, Apartado 2072, Balboa, Panamá.|Departments of Ecology, Evolution and Behavior and Plant Biology, University of Minnesota, St. Paul, Minnesota, 55108, USA.
authors.forename: Jennifer S
authors.initials: JS
authors.lastname: Powers
authors.affiliation: Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin, 53203, USA.|Smithsonian Tropical Research Institute, Apartado 2072, Balboa, Panamá.
authors.forename: Stefan A
authors.initials: SA
authors.lastname: Schnitzer
mesh_terms: D065928:Forests; D010176:Panama; D010944:Plants / Q000145:classification*; D014329:Tropical Climate
keywords: LAI-2000; Panama; canopy structure; competition; ground-based LiDAR; leaf area index (LAI); lianas; light attenuation; plant area index (PAI); secondary tropical forest; trees; wood area index (WAI)