More than 10,000 pre-Columbian earthworks are still hidden throughout Amazonia

Indigenous societies are known to have occupied the Amazon basin for more than 12,000 years, but the scale of their influence on Amazonian forests remains uncertain. We report the discovery, using LIDAR (light detection and ranging) information from across the basin, of 24 previously undetected pre-Columbian earthworks beneath the forest canopy. Modeled distribution and abundance of large-scale archaeological sites across Amazonia suggest that between 10,272 and 23,648 sites remain to be discovered and that most will be found in the southwest. We also identified 53 domesticated tree species significantly associated with earthwork occurrence probability, likely suggesting past management practices. Closed-canopy forests across Amazonia are likely to contain thousands of undiscovered archaeological sites around which pre-Columbian societies actively modified forests, a discovery that opens opportunities for better understanding the magnitude of ancient human influence on Amazonia and its current state

Consistent patterns of common species across tropical tree communities

Trees structure the Earth’s most biodiverse ecosystem, tropical forests. The vast number of tree species presents a formidable challenge to understanding these forests, including their response to environmental change, as very little is known about most tropical tree species. A focus on the common species may circumvent this challenge. Here we investigate abundance patterns of common tree species using inventory data on 1,003,805 trees with trunk diameters of at least 10 cm across 1,568 locations1,2,3,4,5,6 in closed-canopy, structurally intact old-growth tropical forests in Africa, Amazonia and Southeast Asia. We estimate that 2.2%, 2.2% and 2.3% of species comprise 50% of the tropical trees in these regions, respectively. Extrapolating across all closed-canopy tropical forests, we estimate that just 1,053 species comprise half of Earth’s 800 billion tropical trees with trunk diameters of at least 10 cm. Despite differing biogeographic, climatic and anthropogenic histories7, we find notably consistent patterns of common species and species abundance distributions across the continents. This suggests that fundamental mechanisms of tree community assembly may apply to all tropical forests. Resampling analyses show that the most common species are likely to belong to a manageable list of known species, enabling targeted efforts to understand their ecology. Although they do not detract from the importance of rare species, our results open new opportunities to understand the world’s most diverse forests, including modelling their response to environmental change, by focusing on the common species that constitute the majority of their trees

Fornecimento de volumoso para bezerros pré-ruminantes Roughage for pre-ruminant calves

O presente trabalho avaliou a performance de bezerros mestiços HolandêsxZebu, do nascimento aos 90 dias de idade, desaleitados aos 56 dias, com acesso ou não a volumoso. O ensaio foi conduzido na Estação Experimental de Itaguaí da PESAGRO-RIO, em Seropédica, RJ, no período de janeiro a abril de 2000. Foram utilizados 27 bezerros, distribuídos em blocos ao acaso, de acordo com o peso ao nascer e com o sexo, nos seguintes tratamentos experimentais: (1) Concentrado; (2) Concentrado+pasto de capim-estrela (Cynodon nhenfluensis), e (3) Concentrado+feno de alfafa (Medicago sativa). Os animais foram separados das mães 24 horas após o nascimento e mantidos em baias individuais. Todos os animais receberam colostro até o 3º dia de vida e, a partir daí, quatro litros de leite integral/animal/dia, além de concentrado comercial (18%PB), até o máximo de 2,0kg/animal/dia, a partir da segunda semana de vida. Os animais do tratamento 2 tiveram acesso aos piquetes, manejados em rodízio, a partir do 15º dia de vida, no período das 8h às 14h, e aqueles do tratamento 3 receberam feno de alfafa (18%PB) picado, à vontade, a partir do 8º dia de vida. Não houve diferença (P>0,05) entre os tratamentos 1 e 3; entretanto, aqueles submetidos ao tratamento 2 consumiram menor (P<0,05) quantidade de concentrado. Não houve diferença (P>0,05) para consumo total de matéria seca e eficiência alimentar entre os tratamentos 1 e 3 e para ganho de peso médio diário, perímetros abdominal e torácico, incidência de diarréias e corrimento nasal entre os três tratamentos. O fornecimento de volumoso para bezerros pode ser feito a partir da 8ª semana de idade, sem prejuízos para o seu desenvolvimento, desde que os animais tenham à sua disposição concentrado inicial desde a segunda semana de idade.<br>This experiment aimed to evaluate the growth of Holstein Zebu crossbred calves, from birth to 90 days of age, early weaned, with or without available roughage from the second week of age on. The trial was carried out at the Itaguaí Experimental Station, from PESAGRO-RJ, from January up to April, 2000. Twenty-seven calves were used, randomly assigned to blocks according to sex and birth weight, in the following experimental treatments: (1) only starter; (2) starter plus Cynodon nhenfluensis paddocks grazed from the 15th day of age on; and, (3) starter plus Medicago sativa hay. Calves were separated from their dams twenty-four hours after birth and kept to individual pens. All animals received colostrum up to the 3rd day of age and, from there on, four litters of whole milk/animal/day, up to the 56th day of age, and commercial starter (18%CP) up to a maximum of 2.0kg/animal/day from the second week of age on. Animals from treatments 1 and 3 were kept on their pens up to 70 days of age, those from treatment 3 received, in separated feeders, chopped alfalfa hay (18%CP, particle size of 5cm), ad libitum, from the 8th day on. Animals in treatment 2 had access to paddocks from 8:00 to 14: 00h. Milk, starter and hay intakes, as well as diarrhoea and nasal flow incidences were measured daily up to 70 days of age. Body weight and barrel and heart girth were taken weekly. There were no difference (P>0.05) between calves fed roughage (treatments 2 and 3) for starter intake; however, animals allowed to graze showed lower (P<0.05) starter intake. Average total dry matter intake and feed efficiency were similar (P>0.05) for treatments 1 and 3. There were no differences (P>0.05) among treatments for average daily weight gain, as well as diarrhea, nasal flow incidences and barrel and heart girth. It was concluded that roughage may be supplied to calves from day 56th of age on, without impairing their development, when starter is offered since the second week of age

Data from: Over 10,000 Pre-Columbian earthworks are still hidden throughout Amazonia

Dataset: This set of data and R computer codes were used to create the predictive model, figures, and develop analysis on the manuscript "Over 10,000 Pre-Columbian earthworks are still hidden throughout Amazonia" submitted to Science journal as a research article (DOI: ...ade2541). Please read the materials and methods sections on the manuscript supplementary materials, along with the data provided in the "Database" folder, to ensure reproducibility. Earthwork Predictive Model: The Inhomogeneous Poisson Process (IPP) model fit was performed using the 'fit_bayesPO' function of the 'bayesPO' library in R version 4.0.2. The model was developed by the author of the package Guido Alberti Moreira. Figures: Figures created from R computer codes presented on the Main text are inside the "MainText_figures" folder, and Supplementary material figures are inside the "SuppMaterial_figures" folder. Please utilize the instructions in the supplementary material in conjunction with the data in the "database" folder to ensure reproducibility. Dataset usage: It is free to use, but if you use this dataset in your work, please make sure to cite the repository and our paper properly. We also welcome users to invite us for collaboration. For the use of this dataset, please cite: Peripato, V. et al. Data from: Over 10,000 Pre-Columbian earthworks are still hidden throughout Amazonia (2023). DOI: 10.5281/zenodo.7750985. https://doi.org/10.5281/zenodo.775098