Liana regeneration in secondary and primary forests of central Amazonia

Background: Lianas are considered to be particularly abundant in tropical forests after disturbance; however, information on their regeneration by seedlings, saplings, and sprouts is scarce. Aim: We assessed how primary and secondary forest types with different land use history are related to the density and diversity of liana regeneration. Methods: Liana regeneration (≤ 1.7 m in length) was identified and counted in primary and secondary forest plots in Amazonia, near Manaus, Brazil. The primary forest was non-inundated evergreen tropical lowland forest. Secondary forest types were Vismia (on land formerly clear felled, used for pasture and intensively burned) and Cecropia (on land formerly clear felled, no pasture usage nor intensive fires), with distances between 0.03 and 1.2 km to the primary forest edge. Results: The density of woody regeneration (trees, lianas, palms and shrubs) was 50% lower in the secondary forests than in the primary forest. The share of lianas of woody regeneration (10–13%) hardly differed among forest types. Liana species richness per plot was highest in the primary forest and lowest in the Vismia forest. Accumulated species richness in the Cecropia forest was similar to that in the primary forest. With increasing distance from the primary forest, species richness and the proportion of lianas of woody regeneration decreased. Conclusion: Our results indicate that secondary forest type/land use history influenced liana regeneration diversity but not density. Distance to primary forest influenced both.