Physiological ecology studies on chilean gelidiales

Abstract

In the exposed rocky habitats of Central Chile, four species of Gelidium occur along the vertical distance extending from the upper intertidal to the shallow subtidal. The present study was undertaken to characterize taxonomically confused species of Gelidium by differential responses to key ecological factors. In so doing, it was expected to better characterize ecophysiological differences between upper and lower intertidal species and to establish experimental bases on which to compare physiological responses of temperate and subtropical species of Gelidiaceae. The effects of temperature, water movement, salinity, photon flux density and photoperiod were tested on the growth rates of Gelidium pusillum (Stackh.) Le Jol., G. filicinum Bory, G. lingulatum (C. Agardh) J. Agardh and G. spinulosum Kützing prox. With the exception of salinity, specific differences are evident under the effects of all other factors tested.