In the context of the global amphibian crisis, biomonitoring constitutes a valuable assessment tool to provide critical up to date information on the status and health of amphibians worldwide. The aim of the current study was to evaluate the possible confounding effects of sex, size, and time since capture on enzymatic biomarkers and hematologic parameters of the South American frog Leptodactylus latrans. Frogs were collected by hand between 9 pm and 12 am on two consecutive nights. On the first night, captured frogs were transported for 2 h by car to laboratory installations, maintained overnight in plastic containers, and blood and tissue sampled on the next morning. In contrast, frogs collected on the second night were blood and tissue sampled in the field, immediately after the capture period. Hematological parameters were analyzed, and enzymatic activities of catalase, cholinesterase (ChE), and glutathione S-transferase (GST) were determined in the plasma, liver, kidney, and muscle. A sex difference was observed only for total white blood cell counts (WBC), females exhibiting significantly greater values than males. The packed cell volume (PCV), mean corpuscular hemoglobin concentration (MCHC), WBC, and muscle ChE activity were significantly correlated with snout-vent length (SVL). The correlation was inversed in the case of MCHC, WBC, and muscle ChE, while the correlation was positive between PCV and SVL. Most examined parameters presented similar values when frogs were sampled at night following capture or the next morning. Total red blood cells (RBCs) count, and plasma enzymatic activities of ChE and GST were the only parameters that presented significantly increased values in morning samplings compared with night samplings. Overall, the current study indicates that it is best to sample the frogs as soon as possible after capture if hematologic or plasmatic biomarkers are examined. Nevertheless, it is possible to sample on the next morning if tissular biomarkers are employed. | Instituto de Recursos Biológicos | Fil: Brodeur, Celine Marie Julie. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Recursos Bilológicos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. | Fil: Bahl, María Florencia. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de Química. Centro de Investigaciones del Medio Ambiente; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. | Fil: Natale, Guillermo S. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de Química. Centro de Investigaciones del Medio Ambiente; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. | Fil: Poliserpi, María Belen. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Recursos Biológicos; Argentina

We aim to differentiate the various visible leaf symptoms in the field survey with microscopical methods, and to better know, how the leaf, tissue and cell response differs between injury from ozone, heavy metals (both oxidative stress) and biotic infections

Results obtained by crown status estimation and branch structure transformation assessment methods are also applicable at forest stand level. By means of these methods we can reconstruct a scheme of probable stress response history for individual trees with possibility to distinguish three different types of stress response behaviour. The goal of our study was to describe a stress response history of single trees and corresponding forest stands, diverse in different level of multiple stress impact, and to localize investigated trees in the stress response scheme