A POPULATION OF LYCHNOPHORA ERICOIDES MART. (ARNICA) (ASTERACEAE) IS PRONE TO EXTINCTION IN A SAVANNA OF CENTRAL BRAZIL

Abstract

Lychnophora ericoides Mart. (Asteraceae), popularly known as arnica, is a plant species subjected to non-timber forest products extraction. Evidence is mounting that some local populations are on the brink of extinction. However, demographic studies of Lychnophora ericoides are rare. Therefore, as a step towards conservation, a remnant population of Lychnophora ericoides located in an area of the Cerrado (Brazilian Savanna) in Central Brazil was evaluated from 2010 through 2014. Disturbances such as wildfires and harvesting of Lychnophora ericoides were randomly distributed throughout the study period in this area. Four annual transition matrices (A1, A2, A3 and A4) were constructed, based on life stages. The main results of studies of population dynamics for this species are as follows: 1) population growth rates (λ) with 95% confidence intervals indicated a declining population in all periods from 2010 to 2014; 2) stochastic population growth rate considering the four matrices was < 1 with value λ = 0.358 and CI95% = (0.354–0.362); 3) survival with permanence at the same stage of reproductive adult individuals (46–80%) contributed most to population growth rate, based on elasticity analysis; 4) the population is much less likely to have increases in density, compared with reduction, for all intervals from 2010 to 2014, based on transient indices; 5) the low value of λ in the high-mortality year was caused by lower stasis of individuals in the seedling or sapling and juvenile life stages, as well as fecundity in the 2011–2012 and 2012–2013 intervals, as shown by a life table response experiment; and 6) 100% of the population will probably be extinct within 15 years. There is evidence that the main cause for local extinction of Lychnophora ericoides could be the effects of frequent wildfires. Based on these results, it is suggested that the time has come for significant conservation efforts to rescue this population, including monitoring, protection and education as the first steps towards protection of this vulnerable plant species.