62 p. Recurso Electr?nicoEn Colombia los incendios forestales contribuyen a la degradaci?n de los bosques, uno
de los m?s afectados es el bosque seco tropical (BST). Dado que los microorganismos
son componentes fundamentales del suelo, son empleados como bio-indicadores pues
reflejan los cambios en ?ste. El objetivo del presente trabajo fue evaluar el efecto de un
incendio forestal sobre la microbiota de un suelo de BST en la reserva Santaf? de los
Guaduales. Se evaluaron dos ?reas, una quemada (Q) y una control (C). Se estim? la
actividad (biomasa-C, respiraci?n y actividad enzim?tica), la abundancia (total y de los
grupos funcionales mediante medios selectivos, la abundancia de bacterias tambi?n se
evalu? por qPCR) y la estructura de la comunidad microbiana (bacterias y oxidantes de
amonio con la t?cnica de DGGE); adem?s, se determinaron los par?metros
fisicoqu?micos de: pH, humedad ed?fica, carbono org?nico, nitr?geno total, f?sforo
disponible y amonio La mayor?a de los valores en los par?metros analizados
disminuyeron en el ?rea afectada por el incendio; siendo el nitr?geno (-56%) y el carbono
org?nico (-43%) los que m?s se vieron afectados de los par?metros fisicoqu?micos, y de
los par?metros microbiol?gicos, la estructura de la comunidad bacteriana y la densidad
de los grupos funcionales fueron los m?s sensibles ante la quema. Se concluye que el
incendio afect? de forma negativa el ambiente ed?fico del BST estudiado, adem?s,
teniendo en cuenta la relaci?n observada entre algunos par?metros se sugiere que la
comunidad microbiana tambi?n responde de forma sensible a la cantidad y calidad del
sustrato disponible.
Palabras clave: bioindicadores, par?metros microbiol?gicos, comunidad microbiana,
quema, amonificantes.Forest fires contributed to the degradation of woodlands in Colombia, one of the most
affected is the dry tropical forest. Since microorganisms are fundamental components of
the soil, they are used as biological indicators because they reflect alterations in the soils.
The main goal of this study was to evaluate the effect of a forest fire in the microbiota on
dry tropical forest soils in the Santaf? de los Guaduales reserve. Two areas were
evaluated, one of them was burned (Q) and the other one was used as a control (C). The
activity (biomass-C, respiratory and enzymatic activity), the abundance (total and
functional groups by selective mediums, abundance of bacteria was also assessed by
qPCR) and the microbial community structure (bacteria and ammonium oxidizing bacteria
with the DGGE technique) were determined; besides physicochemical parameters, pH,
soil moisture, organic carbon, total nitrogen, available phosphorus and ammonium were
determined too. Most of the values in the analyzed parameters decreased in the area
affected by fire; being the nitrogen (-56%) and organic carbon (-43%) the most affected
of the physicochemical parameters and of the microbiological parameters, the bacterial
community structure and the functional groups density were the ones that showed greater
sensitivity by burning. We concluded that fires affects in negative way the edaphic
environment of the dry tropical forest studied, moreover, considering the relation found
between some parameters, we suggest that microbial community responds too in a
sensitive way to the quantity and quality of the available substratum.
Keywords: bioindicators, microbiological parameters, microbial communities, burning,
ammonifiers
