Banco de sementes do solo em áreas ciliares em processo de restauração florestal na Zona da Mata Sul de Pernambuco

Abstract

This work aimed to evaluate the composition and diversity of soil seed bank species in riparian areas with different stages of forest restoration located in the municipality of Sirinhaém, Zona Sul Mata de Pernambuco. The present research was developed in two areas under restoration process, located at the Usina Trapiche S / A, in the municipality of Sirinhaém, in the region of Mata Sul in the State of Pernambuco. Sampling of the seed bank was performed in 40 plots of 250 m 2, 20 plots in each area, and two samples per plot were collected, totaling 80 samples. The soil was collected to a depth of 0-5 cm, using a square template with dimensions of 0.25 m x 0.25 m (0.03625 m²). The samples were stored in plastic bags and transported to the Forest Nursery of the Forest Science Department of UFRPE. The experiment was set up using 80 perforated plastic trays, with a volume of 0.0767m³. The trays were accommodated in two flowerbeds. On the bed was mounted two structures, one covered by white tulle - (full sun) and another covered by shade screen (70%), making it impossible to contaminate by external propagules. Among the soil trays were randomly arranged 10 trays with sterilized substrate to avoid contamination between the trays inside the structure. Germination was evaluated biweekly over the six-month period. All seedlings were identified to the lowest taxonomic level, quantified and then withdrawn from the trays. The emergent individuals were peeled to polyethylene bags that remained until their flowering, being the same herborizadas and deposited in the herbarium, for identification purposes. The species were classified when the dispersion syndrome, ecological group and its origin. The richness and phytosociological parameters, the Shannon diversity index (H '), the Pielou equability (J'), the Sorensen Similarity and the Hutcheson test were calculated by the MS-Excel 2016 program. The differences between the abundance of seeds of the two areas, their means and medians were obtained by software R °. The maximum seed density found in area 2 was represented by the Shading Screen of 70% (3,205.2 seeds / m²) and for area 1, it was the full sun (3,086.8 seeds / m²). Both areas had a high similarity index (Ss = 25.70%). The highest density in both areas was represented by herbaceous plants with a total of 10,916 seeds / m², of which 5,771.2 for area 2 and 5,144.8 for area 1. The species with the highest VIBS in the seed bank in area 1 and 2 were herbaceous (Lindernia crustacea (L.) F.Muell. And Ludwigia leptocarpa (Nutt.) H. Hara, area 1 and 2. Germinated a total of 19 species with 17 trees in area 2 and 10 in area 1, with 100% of pioneers. The species Solanum paniculatum L., Cecropia pachystachya Trécul and Piper aducum L. were the most representative. Among the total shrub and tree individuals present in area 1 (92.58%) are composed of species that present a zoocoric dispersion syndrome.