This study is based on the studies of herbaceous plants, birds and coleoptera that were carried out between 1998 and 2001 in the Lachay National Reserve, and is based on the interest of generating a biological early warning of the El Niño event. The present study incorporated two samples for beetles in 2002 and two samples for each group in 2010. The objective of the research was to evaluate the variation of the biotic variables of the three biological groups under the El Niño Event between 1998-2001 and 2010, to identify indicator variables of the El Niño Event. In the plots, composition, abundance, diversity, and functional groups were estimated. In addition, for herbaceous plants, vegetation cover, density, IVI and Cinv were evaluated. Some variables (Cinv Abundance, Cinv Coverage, Cinv IVI native and/or endemic and in vegetation coverage) suggest a positive relationship with the...