Nigel C. A. Pitman
A5030533662- Ecology and Vegetation Dynamics Studies
- Plant and animal studies
- Forest ecology and management
- Plant Diversity and Evolution
- Species Distribution and Climate Change
- Plant Water Relations and Carbon Dynamics
- Conservation, Biodiversity, and Resource Management
- Botany, Ecology, and Taxonomy Studies
- Forest Management and Policy
- Wildlife Ecology and Conservation
- International Relations in Latin America
- Environmental and Cultural Studies in Latin America and Beyond
- Remote Sensing in Agriculture
- Tree-ring climate responses
- Remote Sensing and LiDAR Applications
- African Botany and Ecology Studies
- Amazonian Archaeology and Ethnohistory
- Plant and Fungal Species Descriptions
- Fire effects on ecosystems
- Wildlife-Road Interactions and Conservation
- Forest Ecology and Biodiversity Studies
- Evolution and Paleontology Studies
- Geology and Paleoclimatology Research
- Indigenous Health and Education
- Genetic diversity and population structure
Field Museum of Natural History
2016-2025
Chicago Board of Education
2024
Duke University
2011-2021
John Wiley & Sons (United States)
2019
Ecological Society of America
2019
Wyoming Game and Fish Department
2019
Amazon National University of Madre de Dios
2017
Science Education Solutions (United States)
2017
University of Edinburgh
2016
Organization For Tropical Studies
2015
Amazon forests are a key but poorly understood component of the global carbon cycle. If, as anticipated, they dry this century, might accelerate climate change through losses and changed surface energy balances. We used records from multiple long-term monitoring plots across Amazonia to assess forest responses intense 2005 drought, possible analog future events. Affected lost biomass, reversing large sink, with greatest impacts observed where season was unusually intense. Relative pre-2005...
The high alpha-diversity of tropical forests has been amply documented, but beta-diversity—how species composition changes with distance—has seldom studied. We present quantitative estimates beta-diversity for trees by comparing plots in lowland terra firme forest Panama, Ecuador, and Peru. compare observations predictions derived from a neutral model which habitat is uniform only dispersal speciation influence turnover. find that higher Panama than western Amazonia patterns both areas are...
The vast extent of the Amazon Basin has historically restricted study its tree communities to local and regional scales. Here, we provide empirical data on commonness, rarity, richness lowland species across entire Guiana Shield (Amazonia), collected in 1170 plots all major forest types. Extrapolations suggest that Amazonia harbors roughly 16,000 species, which just 227 (1.4%) account for half trees. Most these are habitat specialists only dominant one or two regions basin. We discuss some...
Abstract Uncertainty in biomass estimates is one of the greatest limitations to models carbon flux tropical forests. Previous comparisons field‐based aboveground (AGB) trees greater than 10 cm diameter within Amazonia have been limited by paucity data for western Amazon forests, and use site‐specific methods estimate from inventory data. In addition, role regional variation stand‐level wood specific gravity has not previously considered. Using 56 mature forest plots across Amazonia, we...
Abstract The biomass of tropical forests plays an important role in the global carbon cycle, both as a dynamic reservoir carbon, and source dioxide to atmosphere areas undergoing deforestation. However, absolute magnitude environmental determinants forest are still poorly understood. Here, we present new synthesis interpolation basal area aboveground live old‐growth lowland across South America, based on data from 227 plots, many previously unpublished. Forest was analyzed terms two...
Abstract. Forest structure and dynamics vary across the Amazon Basin in an east-west gradient coincident with variations soil fertility geology. This has resulted hypothesis that may play important role explaining Basin-wide forest biomass, growth stem turnover rates. Soil samples were collected a total of 59 different plots analysed for exchangeable cations, carbon, nitrogen pH, several phosphorus fractions likely plant availability also quantified. Physical properties additionally examined...
The extent to which pre-Columbian societies altered Amazonian landscapes is hotly debated. We performed a basin-wide analysis of impacts on forests by overlaying known archaeological sites in Amazonia with the distributions and abundances 85 woody species domesticated peoples. Domesticated are five times more likely than nondomesticated be hyperdominant. Across basin, relative abundance richness increase around sites. In southwestern eastern Amazonia, distance strongly influences species....
Amazonian forests are the largest and most diverse in tropics, much of mystery surrounding their ecology can be traced to attempts understand them through tiny local inventories. In this paper we bring together a large number such inventories scattered across immense areas western Amazonia order address simple questions about distribution abundance tropical tree species lowland terra firme there. The goal is describe patterns commonness rarity at (1 ha), landscape (∼104 km2), regional (>106...
Abstract The net primary production of tropical forests and its partitioning between long‐lived carbon pools (wood) shorter‐lived (leaves, fine roots) are considerable importance in the global cycle. However, these terms have only been studied at a handful field sites, with no consistent calculation methodology. Here we calculate above‐ground coarse wood productivity for 104 forest plots lowland New World humid forests, using methodology that incorporates corrections spatial variations...
A previous study by Phillips et al . of changes in the biomass permanent sample plots Amazonian forests was used to infer presence a regional carbon sink. However, these results generated vigorous debate about sampling and methodological issues. Therefore we present new analysis change old–growth forest using updated inventory data. We find that across 59 sites, above–ground dry trees are more than 10 cm diameter (AGB) has increased since plot establishment 1.22 ± 0.43 Mg per hectare year...
Previous work has shown that tree turnover, biomass and large liana densities have increased in mature tropical forest plots the late twentieth century. These results point to a concerted shift ecological processes may already be having significant impacts on terrestrial carbon stocks, fluxes biodiversity. However, findings proved controversial, partly because rather limited number of permanent been monitored for short periods. The aim this paper is characterize regional–scale patterns ‘tree...
To assess how the decimation of large vertebrates by hunting alters recruitment processes in a tropical forest, we compared sapling cohorts two structurally and compositionally similar forests Rio Manu floodplain southeastern Peru. Large were severely depleted at one site, Boca (BM), whereas other, Cocha Cashu Biological Station (CC), supported an intact fauna. At both sites sampled small (≥1 m tall, <1 cm dbh) <10 saplings central portion 4-ha plots within which all trees ≥10 dbh mapped...
Abstract. Aboveground tropical tree biomass and carbon storage estimates commonly ignore height (H). We estimate the effect of incorporating H on tropics-wide forest in 327 plots across four continents using 42 656 diameter measurements harvested trees from 20 sites to answer following questions: 1. What is best H-model form geographic unit include models minimise site-level uncertainty destructive biomass? 2. To what extent does including derived (1) reduce all plots? 3. accounting for have...
Abstract Most of the planet's diversity is concentrated in tropics, which includes many regions undergoing rapid climate change. Yet, while climate‐induced biodiversity changes are widely documented elsewhere, few studies have addressed this issue for lowland tropical ecosystems. Here we investigate whether floristic and functional composition intact Amazonian forests been changing by evaluating records from 106 long‐term inventory plots spanning 30 years. We analyse three traits that...
Background and AimsWhen ecologically important plant traits are correlated they may be said to constitute an ecological 'strategy' dimension. Through identifying these dimensions understanding their inter-relationships we gain insight into why particular trait combinations favoured over others the implications of differences among species. Here investigated relationships several traits, thus strategy represented, across 2134 woody species from seven Neotropical forests.
The threats facing Ecuador's Yasuní National Park are emblematic of those confronting the greater western Amazon, one world's last high-biodiversity wilderness areas. Notably, country's second largest untapped oil reserves--called "ITT"--lie beneath an intact, remote section park. conservation significance may weigh heavily in upcoming state-level and international decisions, including whether to develop or invest alternatives.
Abstract The origin of modern disjunct plant distributions in the Brazilian Highlands with strong floristic affinities to distant montane rainforests isolated mountaintops northeast and northern Amazonia Guyana Shield remains unknown. We tested hypothesis that these unexplained biogeographical patterns reflect former ecosystem rearrangements sustained by widespread migrations possibly due climatic are very dissimilar from present-day conditions. To address this issue, we mapped presence...
The accurate mapping of forest carbon stocks is essential for understanding the global cycle, assessing emissions from deforestation, and rational land-use planning. Remote sensing (RS) currently key tool this purpose, but RS does not estimate vegetation biomass directly, thus may miss significant spatial variations in structure. We test stated accuracy pantropical maps using a large independent field dataset.Tropical forests Amazon basin. permanent archive plot data can be accessed at:...
Abstract While Amazonian forests are extraordinarily diverse, the abundance of trees is skewed strongly towards relatively few ‘hyperdominant’ species. In addition to their diversity, a key component global carbon cycle, assimilating and storing more than any other ecosystem on Earth. Here we ask, using unique data set 530 forest plots, if functions producing woody concentrated in small number tree species, whether most abundant species also dominate cycling, dominant characterized by...
Amazonia is the most biodiverse rainforest on Earth, and debate over how many tree species grow there remains contentious. Here we provide a checklist of all collected to date, describe spatial temporal trends in data accumulation. We report 530,025 unique collections trees Amazonia, dating between 1707 2015, for total 11,676 1225 genera 140 families. These figures support recent estimates 16,000 Amazonian based ecological plot from Tree Diversity Network. Botanical collection characterized...
Within the tropics, species richness of tree communities is strongly and positively associated with precipitation. Previous research has suggested that this macroecological pattern driven by negative effect water‐stress on physiological processes most species. This implies range limits taxa are defined their ability to occur under dry conditions, thus in terms distributions predicts a nested distribution from wet areas. However, ‘dry‐tolerance’ hypothesis yet be adequately tested at large...