Ecological applications of differences in the hydr

Authors: L M T Aparecido J dos Santos N Higuchi N Kunert

Publish Date: 2015/05/22

Volume: 29, Issue: 5, Pages: 1431-1445

PDF Link

Abstract

We studied the hydraulic efficiency of palms and broadleaved tropical tree species from a moist tropical lowland forest in the Central Brazilian Amazon Therefore we harvested 34 trees and 10 açai palms and measured vessel size and frequency at diameter at breast height and additionally at the base of the crown shaft for the palms Further we assessed the active xylem area to estimate the hydraulic conductivity through Hagen Poiseuille’s adapted theoretical equation Mean vessel diameter in dicot trees was 12762 ± 4922 μm with an average 909 ± 650 vessels per mm2 Mean conduits sizes at the base h = 010 m of palm trees were larger with 28820 ± 3296 μm and less frequent with 140 ± 046 vessels per mm2 Hydraulic conductivity was on average 331 ± 459 kg m−1 s−1 MPa−1 for dicot trees Mean hydraulic conductivity in açai palms was 2045 ± 106 kg m−1 s−1 MPa−1 at the base and increased to 12473 ± 552 kg m−1 s−1 MPa−1 at the crown base Hydraulic conductivity at the base of the crown was higher than in the base of the trunk due to the high density of vessels in a small crosssection in this height Furthermore we found a speciesindependent relationship between vessel diameter and frequency We conclude that the differences found in the hydraulic efficiency give some evidence that palms have a lower occurrence of embolism and cavitation than trees which is due to stiffer and stronger conduit pathways and efficient droughtavoiding strategies The differences in hydraulic architecture between palms and trees imply different water use patterns thus varying niche differentiation but this does not consequently need to be an excluding factor for coexistence in the same environmentWe would like to thank CAPES Coordination for the Improvement of Higher Level Personal for financing the first author’s master program CNPq National Council for Scientific and Technological Development for their program INCT—Madeiras da Amazônia that provides financial support for Forest Management Laboratory and ZF2 camp site infrastructure and INPA/CFT Brazilian National Institute for Research in the Amazon/Tropical Forest Science Department for their infrastructure faculty and staff and for choosing and giving the first author the title of MSc This present manuscript is based on partial data from the first author’s master thesis We would also like to thank all the manual operations done by the workers at Forest Management ZF2 camp site Many thanks to Fernando Silva and Rempei Suwa for the palm tree harvesting Further we would like to thank Jorge Freitas Francisco José Vasconcellos INPA Xylotheque and Claudete Catanhede do Nascimento INPA Laboratory of Wood Artifacts Engineering for giving access to laboratory equipment and facilitating the wood anatomy analyses

Keywords: