Whole tree responses to climate variation

Short-term, whole-tree physiological responses was assessed by xylem sap flow measurement (Granier 1987, Granier et al. 1990, 1992) on 10 of the dominant tree species at La Selva (O'Brien 2001).

4-8 trees of each species were measured for several days to weeks periods over a broad range of weather conditions in both seasons starting with well-watered wet season.

Family	Species	Leaves	Trees Sampled
Cecropiaceae	Cecropia insignis	S	5
	Cecropia obtusifolia	S	4
Euphorbiaceae	Hyeronima alchorneoides	S	4
Fabaceae	Balizia elegans	c	4
	Dipteryz panamensis	C	4
	Hymenolobium mesoamericanum	c	4
	Pentaclethra macroloba	c	8
Lecythidaceae	Lecythis ampla	s	4
Olacaceae	Minquartia guianensis	S	4
Simaroubaceae	Simarouba amara	C	4

C = large compound leaves, c = small compound, S = large simple, s = small simple

The data for each tree were used to develop response surfaces of tree performance in relation to microenvironment. We worked with trees with crowns at canopy level or higher and with dbh of 30-50 cm. We used meteorological data from the nearest met station, which for most trees was within 500m.

Whole-tree physiological response is compared with short term growth measured by band dendrometers.

O'Brien, J. J. 2001. The effects of climate on the growth and physiology of tropical rain forest canopy trees. Ph.D. Dissertation. Florida International University, Miami FL.