title: Do subtoxic levels of chlorate influence the desiccation tolerance of Egeria densa?
abstract: Among the different factors hypothesized to be responsible for the virtual disappearance of Egeria densa, once a dominant aquatic macrophyte in a southern Chile wetland ecosystem, are the negative effects of certain chemical compounds (mainly chlorate) and harsh environmental conditions (desiccation caused by prolonged atmospheric exposure). The authors performed an integrated experiment in which E. densa plants were first exposed for four weeks inside a mesocosm system to levels of chlorate that existed in the wetland at the time of the plant's demise and then exposed to desiccation conditions that also resembled those that the system had experienced. Hence, the authors tested the hypothesis that E. densa plants exposed to sublethal levels of chlorate are more susceptible to the deleterious effect of desiccation compared with plants that had not been exposed to chlorate. This hypothesis was tested by means of quantifying physiologically related parameters in plants right after the four weeks under water and then after the desiccation period of 6 h. Their results rejected this hypothesis, because all plants, regardless of their history, are equally affected by desiccation.
authors.affiliation: Ecology Department, Catholic University of Chile and Center for Advanced Studies in Ecology and Biodiversity, Santiago, Chile. apalma@bio.puc.cl
authors.forename: Alvaro T
authors.initials: AT
authors.lastname: Palma
authors.forename: Alex
authors.initials: A
authors.lastname: Schwarz
authors.forename: Luís A
authors.initials: LA
authors.lastname: Henríquez
authors.forename: Ximena
authors.initials: X
authors.lastname: Alvarez
authors.forename: José M
authors.initials: JM
authors.lastname: Fariña
authors.forename: Qimiao
authors.initials: Q
authors.lastname: Lu
mesh_terms: D002677:Chile; D002704:Chlorates / Q000032:analysis / Q000633:toxicity*; D003890:Desiccation; D055864:Droughts; D017753:Ecosystem; D031321:Hydrocharitaceae / Q000502:physiology*; D013312:Stress, Physiological; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000633:toxicity*; D053833:Wetlands
chemical_list: D002704:Chlorates; D014874:Water Pollutants, Chemical