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.
Bibliographical noteFunding Information:
Financial support was provided by U.S. NSF DEB-0845071, DEB-1019436, and DEB-1558093 (to SAS), DEB-1019441 (to JSP), and the U.S. DOE Ameriflux Management Project Flux Core Site Agreement No. 7096915 (to GB).
© 2016 by the Ecological Society of America.
- Canopy structure
- Ground-based LiDAR
- Leaf area index (LAI)
- Light attenuation
- Plant area index (PAI)
- Secondary tropical forest
- Wood area index (WAI)