Abstract Detail

Wood: Biology of a Living Tissue

Pratt, R. Brandon [1].

Carbohydrate storage in sapwood of chaparral shrubs: the associations with parenchyma and dehydration tolerance.

The vascular system of woody plants performs three basic functions: transport of water, mechanical support of the plant body, and storage of nutrients. Most work has focused on water transport and mechanical support and less on storage. We examined the interdependence of these functions hypothesizing that wood that is proficient at one function is necessarily poor at another due to tradeoffs that have their basis in xylem structure. To examine this, carbohydrate content of stems was measured in 32 species of chaparral shrubs along with cell type percentages and functional traits related to dehydration tolerance. The plants were measured in undisturbed and naturally occurring shrublands in southern California in regions with a semi-arid Mediterranean-type climate. We found that carbohydrate content of wood was not strongly associated with parenchyma area of the tissue. Many sampled species had living fibers that were important for storing starch. There was not an association between mechanical strength of wood tissue and carbohydrate storage, which may be partially due to living fibers that can support both mechanical and storage functions. There was a significant relationship between carbohydrate storage and dehydration tolerance (cavitation resistance and minimum seasonal water potential) with more dehydration tolerant species (greater cavitation resistance and lower minimum seasonal water potential) having lower levels of carbohydrate storage. This finding was supported by phylogenetic independent contrasts. We conclude that evolutionary forces have led to the association of carbohydrate storage in woody tissues and dehydration tolerance because of they are part of an adaptive suite of traits as opposed to arising due to tradeoffs between xylem structure and function.

1 - CALIFORNIA STATE UNIVERSITY BAKERSFIELD, DEPARTMENT OF BIOLOGY, 9001 Stockdale Highway, Bakersfield, CA, 93311-1099, USA

Keywords:
chaparral
cavitation
drought
xylem.

Presentation Type: Symposium Presentation
Session: SY09, Wood: Biology of a Living Tissue
Location: Oglethrope Auditorium/Savannah International Trade and Convention Center
Date: Wednesday, August 3rd, 2016
Time: 11:15 AM
Number: SY09008
Abstract ID:930
Candidate for Awards:None