Soil Seed Bank in the Tropical Rainforest Inserted in Agricultural Matrix, Northeast Region of Brazil

Abstract

This research aimed to evaluate under two conditions of luminosity the floristic composition of the seed bank the soil of a remnant of Atlantic Forest inserted in an agricultural matrix located in the northeastern region of Brazil. Sixty samples of superficial soil were collected, with a distance, of approximately, 50 meters. The samples were placed in polyethylene bags, identified and transported to the forest nursery of the Federal Rural University of Pernambuco where they were placed under two conditions of luminosity, full sun and 70% shading. Count of emerged seedlings was performed daily. They were considered as emerged after the opening of the protophyllum. At 120 days, the seedlings were removed and transplanted into polyethylene bags and left in beds and the soil was stirred to facilitate the germination of some viable seeds that might still exist. To compare the richness and number of seedlings emerged in the two light conditions, ANOVA was performed. There were 3,965 seedlings, belonging to 15 botanical families and 29 morphospecies. In full sun, 524 emerged and under shading 70%, 3,441 seedlings. Considering the richness and number of emerged seedlings, there was a significant difference in the F test (P=.05), because it presented a higher mean for the analyzed variables, the 70% shade presented better results, providing better conditions for seedling emergence. The seed bank as a potential source to produce seedlings of shrub-tree/tree-tree species, as they are responsible for the propagation of species of plant species, for the most part, for example, the beginning of degraded succession or colonization of clearings, with the worst result being under shading 70%.