Natural Regeneration Dynamics of Mora paraensis (Ducke) Ducke in Estuarine Floodplain Forests of the Amazon River

Marcelino Guedes,Diego Silva,Zenaide Miranda,Anderson Batista

doi:10.3390/f9020054

Abstract

The aim of this study was to evaluate the natural regeneration dynamics of Mora paraensis in floodplain forests in three regions of the eastern Amazon, and specifically, to explore the relationship between the abundance of regenerating trees and canopy openness. Tree height and circumference of all individuals of height >50 cm and diameter at breast height (DBH) <5 cm were measured in 2012, 2013 and 2015. A matrix of transitions was created and the natural regeneration (RR), demographic and dynamic rates were calculated. Hemispherical photos were used to measure canopy openness. There was no difference in the density of regenerating trees between the three study regions (mean = 2.957 ind. ha−1). The abundance of regenerating trees was highest in 2013, when 5614 individuals were inventoried, and as such the RR 2012–2013 was positive in all three regions (mean = 7.9%). Between 2013 and 2015, the RR was negative and above 50% in all regions. Canopy openness had no significant effect on the abundance of regenerating trees. The abundance of regenerating trees of M. paraensis was high in estuarine floodplain forests of the Amazon River, but the regeneration dynamics varied between years with more favourable years alternating with periods of high mortality and negative regeneration.

Highlights

Floodplain forests are the second most abundant vegetation type in the Amazon, covering75,880.8 km2
One dominant [4,5,6,7] and endemic [8] tree species in estuarine floodplain forests is Mora paraensis (Ducke) Ducke, or pracuúba, as it is commonly known. Timber exploitation in these forests began in the 1950s, at which time the first forestry studies were already drawing attention to the importance of the analysis of natural regeneration for understanding forest dynamics
In the floodplain forests, various timber species including M. paraensis are exploited commercially by local riverine populations and the timber is used in riverside sawmills [7,9,10,11]

Summary

Introduction

Floodplain forests are the second most abundant vegetation type in the Amazon, covering75,880.8 km (approximately 1.6% of the biome). In estuarine floodplain forests, the vegetation is subject to daily inundations owing to tidal flow, leading to various ecological, physiological and morphological adaptations [2], which in turn influence dominance [3]. One dominant [4,5,6,7] and endemic [8] tree species in estuarine floodplain forests is Mora paraensis (Ducke) Ducke, or pracuúba, as it is commonly known. Timber exploitation in these forests began in the 1950s, at which time the first forestry studies were already drawing attention to the importance of the analysis of natural regeneration for understanding forest dynamics. In the floodplain forests, various timber species including M. paraensis are exploited commercially by local riverine populations and the timber is used in riverside sawmills [7,9,10,11]

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Conclusion