Sporophyte production and population structure of two species of Pottiaceae in an Atlantic Forest remnant in Pernambuco, Brazil

Populations of Hyophila involuta (Hook.) Jaeg. and Barbula agraria Hedw. are found fruiting in an Atlantic Forest remnant in Recife, Pernambuco, Brazil. In order to verify the relationship between sporophyte production and population parameters, ten populations of each species were studied. The sporophyte production, sex ratios, shoot densities, and the proportion and spatial distribution of fertile females, fruiting females, males and sterile shoots were measured. The predominance of females over males was significant for both species. The proportion of sterile and sexual shoots, however, was almost 1:1. Average shoot density was 19 per cm2 for H. involuta and 27 per cm2 for B. agraria. Finally, the sporophyte production of 48% for H. involuta and of 55% for B. agraria; this variation was not related to any of the other population parameters measured. Therefore, sporophyte production in H. involuta and B. agraria must withstand the variations in population parameters without being influenced. The non-clumped spatial distribution of female and male shoots favors sporophyte production.