Anatomical changes with needle length are correlated with leaf structural and physiological traits across five Pinus species.

Published

Journal Article

The genus Pinus has wide geographical range and includes species that are the most economically valued among forest trees worldwide. Pine needle length varies greatly among species, but the effects of needle length on anatomy, function, and coordination and trade-offs among traits are poorly understood. We examined variation in leaf morphological, anatomical, mechanical, chemical, and physiological characteristics among five southern pine species: Pinus echinata, Pinus elliottii, Pinus palustris, Pinus taeda, and Pinus virginiana. We found that increasing needle length contributed to a trade-off between the relative fractions of support versus photosynthetic tissue (mesophyll) across species. From the shortest (7 cm) to the longest (36 cm) needles, mechanical tissue fraction increased by 50%, whereas needle dry density decreased by 21%, revealing multiple adjustments to a greater need for mechanical support in longer needles. We also found a fourfold increase in leaf hydraulic conductance over the range of needle length across species, associated with weaker upward trends in stomatal conductance and photosynthetic capacity. Our results suggest that the leaf size strongly influences their anatomical traits, which, in turn, are reflected in leaf mechanical support and physiological capacity.

Full Text

Duke Authors

Cited Authors

  • Wang, N; Palmroth, S; Maier, CA; Domec, J-C; Oren, R

Published Date

  • May 2019

Published In

Volume / Issue

  • 42 / 5

Start / End Page

  • 1690 - 1704

PubMed ID

  • 30684950

Pubmed Central ID

  • 30684950

Electronic International Standard Serial Number (EISSN)

  • 1365-3040

International Standard Serial Number (ISSN)

  • 0140-7791

Digital Object Identifier (DOI)

  • 10.1111/pce.13516

Language

  • eng