Flood disturbance and shade stress shape the population structure of açaí palm Euterpe precatoria, the most abundant Amazon species

Abstract

Euterpe precatoria Mart. is the most abundant plant species in the Amazon basin, and one of the main non-timber forest products on the continent. A thorough understanding of the ecology of this species is needed to support sustainable management initiatives. Resource availability, disturbance regime, and human management are some of the main factors influencing population structure. We described the species’ life stages, evaluated its allometric relationships, and assessed the effects of habitat type (floodplain and upland) and proximity to human settlements on population size distribution in the Central Amazon near the Purus River. The height:diameter ratio increased from Seedlings to Juvenile 2, but decreased from Juvenile 2 to Reproductive 2, indicating changing height investment for any given diameter along these life stages. There was a marked habitat dependency in both the density and population size distribution, with populations in upland forests dominated by juveniles, whereas populations in the floodplains were dominated by reproductive palms. Proximity to human settlements was not related to population structure parameters. Our results suggest that the disturbance regime may have opposite meanings in várzea forests, where it limits recruitment under increased light levels, and in terra firme forests, where it may stimulate recruitment under limited light conditions.

Secondary Succession Altered the Diversity and Co-Occurrence Networks of the Soil Bacterial Communities in Tropical Lowland Rainforests

“…Forests with different disturbance histories have different vegetation recovery speeds and patterns. Natural disturbances such as floods or volcanic eruptions can affect forest ecosystems for hundreds of years, and these disturbances may cause long-term changes in biodiversity patterns by causing the extinction of some plant species [ 26 , 27 ]. For forests disturbed by slash-and-burn cultivation, the plant types that appeared in the early stage of forest succession were basically herbs, and then a forest plant community with arbor plants as the dominant species gradually developed.…”

“…Three tropical lowland rainforests disturbed by deforestation with different natural secondary succession stages were selected in Hainan, China, namely early successional stage (33 years), early-mid successional stage (60 years), and mid successional stage (73 years) according to the definition of previous scholars [ 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 ]. Within each of the 3 kinds of successional stage rainforest, 10 plots (20 × 20 m) were established for soil sampling and plant community surveying.…”