Crown fragmentation assessment in tropical trees: Method, insights and perspectives

• Published in: Forest ecology and management Vol. 261; no. 3; pp. 400 - 407
• Main Authors: Rutishauser, Ervan, Barthélémy, Daniel, Blanc, Lilian, Eric-André, Nicolini
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 01-02-2011; [Amsterdam]: Elsevier Science; Elsevier
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Assessments; Biodiversity and Ecology; Biological and medical sciences; branches; Canopies; Crown assessment; Crown fragmentation; drought; Environmental Sciences; experimental design; field experimentation; Forest dynamics; forest trees; Forestry; Forests; Fragmentation; Fundamental and applied biological sciences. Psychology; growth decline; lianas; Management; Mortality; new methods; overstory; plant architecture; shape; species differences; Synecology; Terrestrial ecosystems; tree crown; tree crown fragmentation; tree growth; Tree mortality; Trees; Tropical forests; water stress; French Guiana; Crown assessment; Tree mortality; Crown fragmentation; Forest dynamics; Evaluation; Forests; Dynamic characteristic; Mortality; Tropical zone; Forest ecology; Woody plant; Method; Fragmentation; Crown; Forestry; Tree
• ISSN: 0378-1127; 1872-7042
• DOI: 10.1016/j.foreco.2010.10.025

[Display omitted]
▶ Tree vulnerability to extreme climatic events remains difficult to study in tropical forests. ▶ A new method that allows assessing tree decline through crown fragmentation is proposed. ▶ Severe crown fragmentation was related to low growth rates and high probability of death. ▶ Crown assessment provides a new tool to study tropical forest response to climate change.
Decreasing growth rate (Feeley et al., 2007) and large die-back due to drought (Phillips et al., 2009) suggest that tropical forests are suffering recent climate changes. Forest vulnerability to external factors (e.g. air pollution, acid rain) is widely studied in northern countries, while only a few attempts have investigated crown integrity in the Tropics. The method needs to be generic enough to account for the large number of species and crown shapes encountered in tropical forests. In the present study, we developed and tested a novel field method that estimates crown fragmentation (main branch mortality (MB) and secondary branch mortality (SB)), liana infestation (LI) and crown position (CP) in the canopy. The relationship between crown fragmentation and annual growth rate (agr) was investigated through multiple regression. Six out of eight canopy tree species showed significant growth decline with increasing crown fragmentation. Higher probability of death was also found in trees with severe crown fragmentation. The capacity of such crown assessment to depict tree vitality in a forest stand is discussed along with potential applications in both forest science and management.