To date, the spatial distribution pattern and density of Brazil nut trees in logged forest stands is unclear across the Amazon basin. We asked the following questions: (1) What are the densities and spatial distributions of Brazil nut juveniles (10 = dbh < 40 cm) and adults (= 40 cm dbh) in three selectively logged Brazil nut concessions (1413 ha sampled) in Madre de Dios, Peru; (2) What is the spatial relationship between adults and juveniles (10 = dbh < 30 cm); and (3) What is the spatial relationship between juveniles (10 = dbh <30 cm) and cut stumps (= 10 y)? Spatial analyses were conducted using statistics derived from Ripley's K function. Juveniles were aggregated in all three concessions. Results for adult populations rejected the null hypothesis of a random distribution among trees = 40 cm dbh. We did not find an attraction between juveniles and cut-stump locations, nor between adults and juveniles. The strong peaks of aggregation for juveniles and adult Brazil nuts in this study occurred at long distances (300-900 m), suggesting multiple tree canopy gaps as drivers of spatial distribution patterns, either via natural or anthropogenic sources. Our data contribute to a more thorough understanding of Brazil nut population structure in disturbed forests in south-western Amazonia.
Topic: forests, trees, spatial distribution, multiple use forestry, seeds, distribution
Publication Year: 2017
Source: Journal of Tropical Ecology 33(2): 114-127