Jochen Schöngart

• PhD
• Researcher at Instituto Nacional de Ciência e Tecnologia de Adaptações da Biota Aquática da Amazônia

Over recent decades the Amazon region has been exposed to large-scale land-use changes and global warming. How these changes affect Amazonia’s hydrological cycle remains unclear as meteorological data are scarce. We use tree ring oxygen isotope records to confirm that the Amazon hydrological cycle has intensified since 1980. Diverging isotopic tren...

Background Volatile isoprenoids (VIs), such as isoprene, monoterpenes, and sesquiterpenes, participate in various forest-atmosphere processes ranging from plant cell regulation to atmospheric particle formation. The Amazon Forest is the greatest and most diverse source of VI emissions, but the lack of leaf-level studies and the logistical challenge...

Fish species characteristics and supply of food resources in Amazonian floodplain forests probably shape the trophic structure and composition of the fish community; however, this dynamic has rarely been studied in the context of trophic networks. In this study, we hypothesized that the main forces that structure the trophic web of the fish communi...

Plant responses to stress, inter-organismal signaling, and atmospheric chemistry are significantly influenced by leaf volatile isoprenoid (VI) emissions (e.g., isoprene and monoterpenes). Despite their critical roles in ecology and the atmosphere, we have little understanding of whether and how VI emissions vary with axes of plant functional variat...

Aim Fire significantly contributes to Amazonian degradation, with igapó forests (seasonally flooded by blackwater rivers) being especially vulnerable. Igapó forests support species adapted to seasonal flooding, making fire a critical threat to these specialised organisms. Birds, due to their habitat specialisation, can provide insight into fire's i...

Species identification in Amazonian forest inventories is challenging due to a shortage of taxonomists, high biodiversity, and morphological similarities leading to taxonomic errors. Near infrared spectroscopy (NIRS) is a promising tool for improving species identification efficiency and reliability. This study assessed the effectiveness of NIRS in...

The increasing severity of droughts and their direct impact on the health of Amazon forest ecosystems underscore the urgent need to understand this phenomenon and to develop tools for large-scale monitoring. Leaf water potential (ψ leaf) is a critical indicator of plant water status. However, traditional methods for measuring ψ leaf are often logis...

Plants cope with the environment by displaying large phenotypic variation. Two spectra of global plant form and function have been identified: a size spectrum from small to tall species with increasing stem tissue density, leaf size, and seed mass; a leaf economics spectrum reflecting slow to fast returns on investments in leaf nutrients and carbon...

Epiphytes are an important group for studies on conservation, as they are organisms sensitive to environmental changes and can serve as strong indicators of the ecosystem’s status. To avoid anthropogenic threats and reduce environmental degradation, protected areas (PAs) have been established and become crucial for maintaining ecological processes...

Unlike most rivers globally, nearly all lowland Amazonian rivers have unregulated flow, supporting seasonally flooded floodplain forests. Floodplain forests harbor a unique tree species assemblage adapted to flooding and specialized fauna, including fruit-eating fish that migrate seasonally into floodplains, favoring expansive floodplain areas....

Aquatic herbaceous plants play a crucial role in Amazonian wetland ecosystems which are characterized by their unique hydrological cycles and diverse plant life. However, the fragile balance of these ecosystems is facing unprecedented challenges due to anthropogenic activities and the impacts of climate change. In this chapter, we explore the profo...

The Amazon basin is undergoing an unprecedented transformation during recent decades driven by anthropogenic-dominated disturbance regimes and increasing hydroclimatic extremes. This affects the large Amazonian river-floodplains influenced by annual, regular and predictable flood pulses with high amplitudes, the várzeas and igapós, which cover an a...

Leaf and wood functional traits of trees are related to growth, reproduction, and survival, but the degree of phylogenetic conservatism in these relationships is largely unknown. In this study, we describe the variability of strategies involving leaf, wood and demographic characteristics for tree genera distributed across the Amazon Region, and qua...

This review discusses observed hydroclimatic trends and future climate projections for the Amazon. Warming over this region is a fact, but the magnitude of the warming trend varies depending on the datasets and length of the analyzed period. The warming trend has been more evident since 1980 and has further enhanced since 2000. Long-term trends in...

Épocas chuvosas e secas resultam em fortes mudanças do nível da água nos grandes rios amazônicos, que criam largas áreas alagáveis ao longo dos seus cursos. Essas áreas ao longo dos rios de água branca, ricos em sedimentos e nutrientes dissolvidos, são chamadas várzeas, e aquelas ao longo dos rios com água preta e clara, pobres em sedimentos e nutr...

Riachos de baixa ordem fluvial (nascentes, cabeceiras, córregos, igarapés) formam uma rede de drenagem na paisagem, que é acompanhada por Áreas Úmidas (AUs) ripárias que se estendem em cada lado dos riachos. A densidade dessa rede e a extensão das AUs ripárias dependem da precipitação, da geomorfologia, da geologia, e da cobertura vegetal nas respe...

We describe the geographical variation in tree species composition across Amazonian forests and show how environmental conditions are associated with species turnover. Our analyses are based on 2023 forest inventory plots (1 ha) that provide abundance data for a total of 5188 tree species. Within-plot species composition reflected both local enviro...

Las fuertes sequías en la Amazonía han ido aumentando en frecuencia e intensidad, de cuatro en un siglo , a cuatro en menos de 25 años, en sintonía con el aumento de la deforestación y el calentamiento global. La sinergia de sequías, deforestación, incendios y degradación forestal, tiene el potencial de llevar a la Amazonía a un punto de no retorno...

Tropical peatlands are among the most carbon-dense terrestrial ecosystems yet recorded. Collectively, they comprise a large but highly uncertain reservoir of the global carbon cycle, with wide-ranging estimates of their global area (441 025–1700 000 km²) and below-ground carbon storage (105–288 Pg C). Substantial gaps remain in our understanding of...

Inundations in Amazonian black‐water river floodplain result in the selection of different tree lineages, thus promoting coexistence between species. We investigated whether Amazonian tree communities are phylogenetically structured and distributed along a flooding gradient from irregularly flooded forests along streams embedded within upland (terr...

Environmental stress is a fundamental facet of life and a significant driver of natural selection in the wild. Gene expression diversity may facilitate adaptation to environmental changes, without necessary genetic change, but its role in adaptive divergence remains largely understudied in Neotropical systems. In Amazonian riparian forests, species...

Aim We test the hypothesis that wind dispersal is more common among emergent tree species given that being tall increases the likelihood of effective seed dispersal. Location Americas, Africa and the Asia‐Pacific. Time period 1970–2020. Major taxa studied Gymnosperms and Angiosperms. Methods We used a dataset consisting of tree inventories from...

Introduction Trees from flooded forests have to adjust their xylem hydraulic structure to face the annual flooding and the climatic conditions of the atmosphere. Usually, this adjustment of anatomical tissues in the tropics is driven by drought events inducing conservative behavior and can be recorded annually in tree rings. However, how the flood...

The emergence of alternative stable states in forest systems has significant implications for the functioning and structure of the terrestrial biosphere, yet empirical evidence remains scarce. Here, we combine global forest biodiversity observations and simulations to test for alternative stable states in the presence of evergreen and deciduous for...

Wood density (WD) is a key functional trait for its importance in tree performance and in biomass calculations of forests. Yet, the variation of WD among different woody tree parts, how this varies across ecosystems, and how this influences estimates of forest carbon stocks remains little understood, particularly for diverse tropical forests such a...

The Brazil Nut tree ( Bertholletia excelsa , Lecythidaceae) is a species of considerable historical, economic and ecological importance in South America. Radiocarbon dating indicates some individuals can live from hundreds to more than 1000 years, which means they have the potential to reconstruct deep time growth patterns and their relationship to...

In 2023 Amazonia experienced both historical drought and warm conditions. On October 26th 2023 the water levels at the port of Manaus reached its lowest record since 1902 (12.70 m). In this region, October monthly maximum and minimum temperature anomalies also surpassed previous record values registered in 2015 (+ 3 °C above the normal considering...

Amazonia’s floodplain system is the largest and most biodiverse on Earth. Although forests are crucial to the ecological integrity of floodplains, our understanding of their species composition and how this may differ from surrounding forest types is still far too limited, particularly as changing inundation regimes begin to reshape floodplain tree...

The density of wood is a key indicator of trees’ carbon investment strategies, impacting productivity and carbon storage. Despite its importance, the global variation in wood density and its environmental controls remain poorly understood, preventing accurate predictions of global forest carbon stocks. Here, we analyze information from 1.1 million...

Aim Amazonia hosts more tree species from numerous evolutionary lineages, both young and ancient, than any other biogeographic region. Previous studies have shown that tree lineages colonized multiple edaphic environments and dispersed widely across Amazonia, leading to a hypothesis, which we test, that lineages should not be strongly associated wi...

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 inve...

Aim To determine the relationships between the functional trait composition of forest communities and environmental gradients across scales and biomes and the role of species relative abundances in these relationships. Location Global. Time period Recent. Major taxa studied Trees. Methods We integrated species abundance records from worldwide f...

The Amazonian clearwater igapós are poorly studied floodplain ecosystems that are mainly covered by forests and are undergoing massive threats due to changes in land use and climate. Their hydrochemical characteristics and edaphic conditions fall between those of the eutrophic várzea floodplains on whitewater rivers and those of the oligotrophic ig...

Forests are a substantial terrestrial carbon sink, but anthropogenic changes in land use and climate have considerably reduced the scale of this system¹. Remote-sensing estimates to quantify carbon losses from global forests2–5 are characterized by considerable uncertainty and we lack a comprehensive ground-sourced evaluation to benchmark these est...

ARTICLE Mapping density, diversity and species-richness of the Amazon tree flora Using 2.046 botanically-inventoried tree plots across the largest tropical forest on Earth, we mapped tree species-diversity and tree species-richness at 0.1-degree resolution, and investigated drivers for diversity and richness. Using only location, stratified by fore...

Understanding what controls global leaf type variation in trees is crucial for comprehending their role in terrestrial ecosystems, including carbon, water and nutrient dynamics. Yet our understanding of the factors influencing forest leaf types remains incomplete, leaving us uncertain about the global proportions of needle-leaved, broadleaved, ever...

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. Mo...

Determining the drivers of non-native plant invasions is critical for managing native ecosystems and limiting the spread of invasive species1,2. Tree invasions in particular have been relatively overlooked, even though they have the potential to transform ecosystems and economies3,4. Here, leveraging global tree databases5-7, we explore how the phy...

Roraimaea aurantiaca Struwe, S.Nilsson & V.A.Albert, a white-sand endemic species, was previously known from only two specimens collected in Roraima state, Brazil. Our new field collections and re-identified herbarium specimens expand this species’ distribution and include the first records from the Brazilian state of Amazonas. Based on this effort...

Graphical abstract Highlights d Ecological metadata were compiled for 7,694 sites across the Brazilian Amazon d Accessibility and proximity to research facilities influenced research probability d Knowledge gaps are greater in uplands than in wetlands and aquatic habitats d Undersampled areas overlap predicted hotspots of climate change and defores...

1. Biodiversity is an important component of natural ecosystems, with higher species richness often correlating with an increase in ecosystem productivity. Yet, this relationship varies substantially across environments, typically becoming less pronounced at high levels of species richness. However, species richness alone cannot reflect all importa...

Given the speed at which humans are changing the climate, species with high degrees of endemism may not have time to avoid extinction through adaptation. We investigated through teleconnection analysis the origin of rainfall that determines the phylogenetic diversity of rainforest frogs and the effects of microclimate differences in shaping the mor...

A diverse group of invasive grasses from tropical and subtropical Africa and Asia has spread throughout the Neotropics over the last decades. Despite their strong ecological impact, current and future distribution patterns of these grasses in the region according to climate change is poorly investigated. We chose ten high potential invasive grass s...

In a time of rapid global change, the question of what determines patterns in species abundance distribution remains a priority for understanding the complex dynamics of ecosystems. The constrained maximization of information entropy provides a framework for the understanding of such complex systems dynamics by a quantitative analysis of important...

Early and skilful prediction of the Negro River maximum water levels at Manaus is critical for effective mitigation measures to safeguard lives and livelihoods. Using dynamical seasonal prediction hindcasts, from six prediction centres, we investigate extending the lead time of previously developed statistical models, which issue forecasts in March...

Introduction The productivity of the Amazon Rainforest is related to climate and soil fertility. However, the degrees to which these interactions influence multiannual to decadal variations in tree diameter growth are still poorly explored. Methods To fill this gap, we used radiocarbon measurements to evaluate the variation in tree growth rates ov...

This book gives positive examples how humans and rivers have been, and are still in some places, living in harmony. It analyses how this knowledge can be transferred into modern river management schemes and thereby it attempts to mitigate the deplorable trend of the decline of biological and cultural heritages and diversities in and along rivers. A...

Seed transport by hydrochory is a key mechanism of long‐distance dispersal constrained by attributes of the seed and hydrodynamics of the river, influenced by seasonal precipitation and hydrological pulses. However, the extent to which a hydrodynamic model can predict seed dispersal influenced by a tributary is unknown. The study was conducted alon...

on the semi-arid Caatinga is lacking, but ~ 3% of the area may be occupied by riparian wetlands and other small wetland types, many of which are periodically dry. Riparian vegetation includes a very large richness in tree species. The amount and species richness of herbaceous plants depend on light availability. In-streams of the semi-arid region o...

Aim To investigate the geographic patterns and ecological correlates in the geographic distribution of the most common tree dispersal modes in Amazonia (endozoochory, synzoochory, anemochory and hydrochory). We examined if the proportional abundance of these dispersal modes could be explained by the availability of dispersal agents (disperser‐avail...

Amazonian floodplain forests along large rivers consist of two distinct floras that are traced to their differentiated sediment- and nutrient-rich (várzea) or sediment- and nutrient-poor (igapó) environments. While tree species in both ecosystems have adapted to seasonal floods that may last up to 270–300 days year⁻¹, ecosystem fertility, hydrogeom...

Extant climate observations suggest the dry season over large parts of the Amazon Basin has become longer and drier over recent decades. However, such possible intensification of the Amazon dry season and its underlying causes are still a matter of debate. Here we used oxygen isotope ratios in tree rings (δ18OTR) from six floodplain trees from the...

The latitudinal diversity gradient (LDG) is one of the most recognized global patterns of species richness exhibited across a wide range of taxa. Numerous hypotheses have been proposed in the past two centuries to explain LDG, but rigorous tests of the drivers of LDGs have been limited by a lack of high-quality global species richness data. Here we...

This work reports on the concentration of dissolved ions and identifies water chemistry patterns by the analysis of 79 water samples from rivers and streams in the Jaú and Uatumã basins, Negro and Solimões/Amazon rivers in the Brazilian Amazon central part. This dataset was analyzed by means of a principal component analysis (PCA) followed by a one...

Epiphytes are still an understudied plant group in Amazonia. The aim of this study was to identify distributional patterns and conservation priorities for vascular epiphyte assemblages (VEA) across Amazonia. We compiled the largest Amazonian epiphyte plot database to date, through a multinational collaborative effort of 22 researchers and 32 field...

This Report provides a comprehensive, objective, open, transparent, systematic, and rigorous scientific assessment of the state of the Amazon’s ecosystems, current trends, and their implications for the long-term well-being of the region, as well as opportunities and policy relevant options for conservation and sustainable development.

Studying the patterns of dominance and species composition of legumes can contribute to more precise models for nutrient cycling, especially the N-cycle. Leguminosae is the most important family in Central Amazonian floodplain forests surrounding large rivers. The floodplains are classified as nutrient-poor (igapó) and nutrient-rich (várzea) ecosys...

Interannual variability in the global land carbon sink is strongly related to variations in tropical temperature and rainfall. This association suggests an important role for moisture-driven fluctuations in tropical vegetation productivity, but empirical evidence to quantify the responsible ecological processes is missing. Such evidence can be obta...

The consensus is that Amazonian white-sand ecosystems (campinaranas) shelter several endemic plant species. How ever, recent studies have shown that most species are generalists, and they also occur in other Neotropical ecosystems. To investigate this issue, we analyzed the proportion of endemic/specialist species in a checklist of trees, palms, an...

The harvesting of açaí berries (palm fruits from the genus Euterpe) in Amazonia has increased over the last 20 years due to a high local and global market demand and triggered by their widely acclaimed health benefits as a ‘superfood’. Although such increase represents a financial boom for local communities, unregulated extraction in Amazonia risks...

Little is known about the life history and environmental factors that regulate the growth rate of hyperdominant trees in flooded Amazonian forests. Pentaclethra macroloba is a hyperdominant tree, and it is widely explored in the Amazon, because its seed oil is a powerful herbal medicine. We evaluated the demographic structure and growth patterns of...

Tropical wetlands vegetation is highly diverse and fundamental for ecosystem functioning supporting a huge associated biota including human populations. Wetland vegetation developed specific adaptations to cope with the reduction or absence of oxygen when flooded by freshwater. Over time, the riverine human populations on all continents have develo...

Tropical large rivers are crucial vectors of cultural, economic, and political development. Their floodplains and associated wetlands provide important ecosystem services related to water, rainforest and savanna flora and fauna. In addition, they accrete sediment in deltas and along coastlines, which results in one of the highest combined values of...

The Amazon basin is being increasingly affected by anthropogenic fires, however, most studies focus on the impact of fires on terrestrial upland forests and do not consider the vast, annually inundated floodplains along the large rivers. Among these, the nutrient-poor, blackwater floodplain forests (igapós) have been shown to be particularly suscep...

In June 2021 a new extreme flood was reported in the Amazon Basin, the largest hydrological system on Earth. During this event water level was above 29 m (the emergency threshold) for 91 days at Manaus station (Brazil), surpassing even the previous historical flood of 2012. Since the late 1990s, 9 extreme floods occurred, while only 8 events were r...

This Report provides a comprehensive, objective, open, transparent, systematic, and rigorous scientific assessment of the state of the Amazon’s ecosystems, current trends, and their implications for the long-term well-being of the region, as well as opportunities and policy relevant options for conservation and sustainable development.

More frequent and stronger flood hazards in the last two decades have caused considerable environmental and socioeconomic losses in many regions of the Amazon basin. It is therefore critical to advance predictions for flood levels, with adequate lead times, to provide more effective and earlier warnings to safeguard lives and livelihoods. Water-lev...

Key message Tree growth of Nectandra amazonum (Lauraceae) in the Central Amazonian floodplains does not respond to the annual long-term flooding but responds to variation of minimum temperature and potential evapotranspiration. Abstract During the last two decades, the Central Amazon region has been impacted by increasingly frequent and more sever...

Aquatic herbaceous plants are especially suitable for mapping environmental variability in wetlands, as they respond quickly to environmental gradients and are good indicators of habitat preference. We describe the composition of herbaceous species in two oligotrophic wetland ecosystems, floodplains along black-water rivers (igapó) and wetlands upo...

Incremental coring of trees is the key method used in non-destructive dendrochronological sampling. Despite the advances in developing such methods, the sampling of large, high-density trees still poses a challenge in remote tropical forests. Manually operated incremental drills, while easy to transport across difficult terrain, limit sample size a...