Dinámica de la humedad del suelo y la fitomasa de raíces en ecosistemas de la Sierra del Rosario, Cuba

the dynamics of soil moisture and fine root phytomass (< 1,0 mm) was studied in seven ecosystems, with different soil conditions and vegetation types, of the sierra del rosario biosphere reserve, cuba. five sites were from tropical evergreen mesophyllous forests (prevailing vegetation in the reserve), another one belonged to a tropical evergreen microphyllous forest and a shrubby savanna was also included. soil moisture was determined to a depth of 0-5 cm, and 5-15 cm every week during a year. each week five samples were collected per site. for the determination of the root phytomass samplings were made in four months of the year under study (two in the dry season and two in the rainy season), in the same spots where soil moisture was studied. this last variable varied according to the site, and it was lower in the dry sites (i.e., microphyllous forest and savanna); among evergreen forests these differences were less pronounced. in general, the 0-5cm soil layer, in all sites, maintained higher humidity and fine root production than the 5-15 cm layer. root phytomass changed with season, and the highest values were found in the mycrophyllous forest where soil moisture is lower. the results showed the importance of the first soil layer in the dynamics of soil moisture and fine root phytomass.