Hopkins Marine Station Student Paper

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(full paper is archived in the Miller Library)

Title: Photosynthetic response and acclimation of two supralittoral lichens to various salt condtions
Student Author(s): Stallard, Donald J. Jr.
Faculty Advisor(s): Abbott, I.A.
Pages: 17
Location: Final Papers Biology 175H
Date: June 1982
Keywords: upper intertidal
splash zone
Abstract: Salt tolerance and acclimation ability of two seashore lichens, Lecanora pinguis and Niebla homalea, were examined to determine to what extent they are actually marine adapted. Photosynthetic rate was used as an indicator of the lichens' response to different conditions. Tolerance was tested by soaking samples in distilled and various salt water concentrations for various lengths of time, and acclimation ability was determined by giving preliminary treatments of distilled or salt water and then observing their effects on responses to later treatments. L pinguis was found to be more tolerant of salt water than N. homalea, but N. homalea showed ability to acclimate to either marine or terrestrial conditions, while L. pinguis could not adapt to terrestrial conditions. Thus, L. pinguis is a true marine lichen, while N. homalea is more accurately described as a salt-tolerant terrestrial lichen. Typical photosynthetic rates for this study were 150 ul/g-hr for L. pinguis and 75 ul/g-hr for N. homalea as measured on a Gilson model IGRP 14 differential respirometer.