Madrigal, L.A. and Vargas, V. 2016. Density of the herbaceous layer and its relationship to light, pH and amount of litter in the Alberto Brenes Reserve, Costa Rica. UNED Research Journal. 8, 2 (Oct. 2016), 195–199. DOI:https://doi.org/10.22458/urj.v8i2.1561.