How Bovine Livestock Affects Seed Rain in Subtropical Climate Forest

Seed rainfall may be one of the mechanisms most impacted by livestock production in forest remnants. The trampling and cattle grazing alter dynamics, structure and floristic composition of the forest. The present work characterized the seed rainin forest remnants and the possible impacts of the presence and the management regime with different cattle stocks in the Pampa biome, southern region of Brazil. We compared three areas in Seasonal Forest remnants with a management history of 43 years: cattle exclusion area (A1); area with a cattle stock of 0.5 ua ha-1 (A2); and area with cattle stock of 1.0 ua ha-1 (A3). The seed rain was collected quarterly in 16 collectors (1 × 1 m²) per area for 24 months. The seeds were counted and identified according to external morphological characteristics, habit and dispersion syndrome. Shannon diversity index, submitted to the Hutcheson test, Pielou evenness, expected diversity and floristic similarity were determined. The results indicated that the impacts caused by livestock to seed rain were more significant in A3 where a quantitative reduction in the number of seeds was observed, probably due to the low number of plant individuals that make up the community.