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Rev. biol. trop ; 60(2): 843-856, June 2012. graf, tab
Article in Spanish | LILACS | ID: lil-657823


Phorophyte specificity and microenvironmental preferences of corticolous lichens in five phorophyte species from premontane forest of Finca Zíngara, Cali, Colombia). Lichenized fungi or lichens are organisms that have been little studied in the tropics and which distribution is affected by microenvironmental factors and substrate characteristics. The present study aimed to identify phorophyte specificity and microenvironmental preferences of corticolous lichens in five phorophyte species from premontane forest of the farm Finca Zingara in Cali, Colombia. For this, five individuals were selected from five tree species (phorophytes). Lichen species present in a 0.50x0.20m² quadrant located in the trunk of each tree at a height of 1.3m were identified. Substrate parameters such as bark pH, Diameter Breast Height (DBH) and bark structure were measured. Also, microenvironmental factors including temperature, humidity and irradiance were determined. In order to detect phorophyte preferences, a non-metric multidimensional scaling (NMS) and indicator species analysis were made. Spearman correlation analysis was used to assert the relationship between environmental variables and groupings found in the NMS. A total of 69 species of lichens were found, of which 37 were identified to species, 18 to genera and 14 were not determined because they were sterile or had no spores. NMS showed that some individuals of the same tree species were grouped alongside the analysis dimensions, and they were related with the factors of light intensity, temperature and DBH. Only three lichens with preference for certain tree species were found (Arthonia microsperma by Meriania sp., Cladonia ceratophylla and sorediado 8 by Clusia sp.), suggesting absence of phorophyte preferences. Thus, it can be concluded that lichens from the study area do not show phorophyte preference, but their distribution is affected by light, temperature and DBH. Rev. Biol. Trop. 60 (2): 843-856. Epub 2012 June 01.

El objetivo de este trabajo fue evaluar la especificidad de forófito y las preferencias microambientales de los líquenes cortícolas en el Bosque de la Finca Zíngara (Cali, Colombia). Asimismo, se seleccionaron cinco individuos de cinco especies de árboles. Además, se identificaron las especies de líquenes presentes en un cuadrante de 0.50x0.20m2 ubicado en el tronco de cada árbol a 1.3 m de altura. También, se midieron parámetros microambientales como pH de la corteza, diámetro a la altura del pecho (DAP), estructura de la corteza, humedad relativa e irradianza. Para detectar las preferencias de forófito, se realizó un escalamiento no métrico multidimensional (NMS) y un análisis de especies indicadoras. Luego se efectúo un análisis de correlación de Spearman para evaluar la relación entre las variables ambientales y los agrupamientos encontrados en el NMS. Se encontraron 69 especies de líquenes, de los cuales 37 fueron determinados hasta especie, 18 hasta género y 14 no fueron determinados. El resultado del NMS mostró que algunos individuos de la misma especie de árbol se agruparon a lo largo de las dimensiones del análisis, y están relacionados con los factores intensidad de luz, temperatura y DAP. Sólo tres especies mostraron preferencia por ciertas especies de árboles (Arthonia microsperma por Meriania sp., Cladonia ceratophylla y sorediado 8 por Clusia sp.), lo cual sugiere ausencia de preferencias de forófito.

Ecosystem , Lichens/physiology , Trees , Colombia , Lichens/classification
Indian J Exp Biol ; 2003 May; 41(5): 403-10
Article in English | IMSEAR | ID: sea-60294


The properties of biophoton signals emitted by samples of lichen species P. tinctorum are investigated. The shape of a light induced signal is determined from 5 ms onwards using successively the bin resolution of 1, 10 and 100 ms; 1000 measurements in successive bins are made at each resolution. The measurement of the shape is repeated at various temperatures in the range (1 degree-40 degrees C) in steps of 1 degree C. It is found that a biophoton signal is very sensitive to temperature and different portions of the signal show different sensitivity. The temperature dependence of the decaying part is even qualitatively different from that of the non-decaying part. The signal responds to temperature changes of 0.1 degrees C in less than 1 ms. The effect of monochromatic stimulation on the strengths of the signal and its red, blue and green spectral components are determined in the wavelength range (400-700) nm in steps of 10 nm. The signal and its broad spectral components have similar excitation curves. The relative strength of spectral component appears independent of the stimulating wavelength. The shape of the decaying portion of the signal and its red, blue and green components is also determined. The character of decay in all four cases is non-exponential. The measurements with various interference filters spanning the entire visible region are made with the bin size of 20 s. These measurements are qualitative because of large fluctuations but suggest that the spectral components of a biophoton signal are distributed in the entire visible region. The probabilities of detecting different number of photons in the non-decaying portion are determined by making 30,000 measurements in each set with the bin size of 50, 100, 200, 300, 400, 500 and 700 ms. The probabilities determine the parameters of a squeezed state of light--the magnitude of its displacement parameter is different but the phase of its displacement parameter and its squeezing parameter are same for different sizes of a bin. These measurements further indicate that the average signal strength remains constant for 19 hr.

Lichens/physiology , Photons