Skip to Main content Skip to Navigation
Master Thesis

Influence of conspecific negative distance-dependence and fire events on recruitment of Brazil nut (Bertholletia excelsa) in the Peruvian Amazon

Abstract : The low natural regeneration of Brazil nut (Bertholletia excelsa) in the Madre de Dios region of Peru is a major concern for the conservation and sustainable use of this species which sustains one of the cornerstone non-timber forest product economies in Amazonia. Brazil nut is a gap-dependent long-lived pioneer species and has been shown previously to regenerate more effectively in fallows than in the mature forest. Aside from light and nutrient availability, recruitment success of the species might also be conditioned by negative conspecific distance-dependent processes as has been shown for a myriad of tropical tree species, but to date has not been studied in Brazil nut We measured Brazil nut recruitment in forty 150x10m2 transects (totaling 6 ha), proportionally laid out in mature forest and fallow land. We found a much higher likelihood of regeneration in fallow than in the mature forest, which was mainly due to more successful transitioning from seedling to sapling in fallows. Recruitment rates in fallow increased with the number of fire events occurred over the past 12 years, but this positive correlation was only observed up to three fire events. We observed conspecific negative distance-dependent recruitment of Brazil nut in the fallow but not mature forest. The absence of this pattern in the mature forest may be due to the lower light availability, combined with higher and more stable humidity levels in the mature forest compared to fallows, hampering the transition from seedling to sapling owing to pest and disease-driven mortality under these conditions. Furthermore, the sterilizing effect of fire in fallows might be an additional factor promoting the establishment of the relatively fire-resistant Brazil nut seedlings and saplings. Our findings suggest that a better management of fallow land and more controlled use of fire in land uses neighboring Brazil nut stands could be a cost-effective manner to increase recruitment rates.
Document type :
Master Thesis
Complete list of metadatas

Cited literature [62 references]  Display  Hide  Download

https://dumas.ccsd.cnrs.fr/dumas-01650803
Contributor : Agrocampus Ouest <>
Submitted on : Tuesday, November 28, 2017 - 2:40:14 PM
Last modification on : Monday, July 6, 2020 - 3:38:22 PM

File

2017_Porcher_Vincent.pdf
Files produced by the author(s)

Identifiers

  • HAL Id : dumas-01650803, version 1

Citation

Vincent Porcher. Influence of conspecific negative distance-dependence and fire events on recruitment of Brazil nut (Bertholletia excelsa) in the Peruvian Amazon. Life Sciences [q-bio]. 2017. ⟨dumas-01650803⟩

Share

Metrics

Record views

97

Files downloads

36