PARENT SESSION
Poster Session 6: Physiology.
Monday, August 2 Presentations from 5:00 PM to 6:30 PM, Exhibit Hall A 1.
Morpho-functional attributes of four tree species in two contrasting environments at a Mexican tropical dry forest.
Quijas Fonseca, Sandra1, Balvanera, Patricia*,1, 1 Centro de Investigaciones en Ecosistemas, Morelia, Michoacán, Mexico
ABSTRACT- Changes in morpho-functional traits associated to differences in environmental conditions and resource availability, such as water or nutrient gradients, have been widely explored among species, but much less within species. In the tropical dry forest differences in water availability are a major factor driving plant establishment, growth, survival and reproduction. In this work we explore whether morpho-functional traits change in two environments that contrast heavily on soil water availability. The selected species are Plumeria rubra, Guapira macrocarpa, Bursera instabilis and Pirhanea mexicana (previously Celaenodendron mexicanum), all very abundant. The morpho-functional traits selected operate on medium (> 1 year) to long-term (> 10 years). They include two foliar traits, total leaf area and specific leaf area, two performance related traits, total height, crown area and number of leaves, two architectural traits, crown depth/width ratio, and one resource use related trait, stem dry matter content. Eight trees from each species were measured for these traits at two replicate locations for two contrasting environments (drier and more messic sites), at the Chamela-Cuixmala Biosphere Reserve, along the Pacific Coast of Mexico. Selected results show that total leaf area and total tree height did not respond to contrasting environmental conditions, and showed effects of site for two of the four species. Specific leaf area was significantly larger in more messic conditions than in drier ones only for P. rubra, G. macrocarpa. Number of leaves was significantly larger for P. mexicana and P. rubra in more messic conditions than in drier ones. We conclude that traits that operate over the long-term show clearer differences than those that operate on medium term, that are likely to be affected by the strong inter-annual variability in climatic conditions.
Key words: water availability, functional traits, tropical dry forest