Torbjørn Haugaasen

Norwegian University of Life Sciences (NMBU) · Faculty of Environmental Sciences and Natural Resource Management (MINA)

Selective logging is a major form of land use in tropical rainforests, with more than half of the world's tropical forest already explored. In the Brazilian Amazon, most logging operations are illegal and highly damaging to forests. However, the effects of illegal logging on wildlife are poorly studied. Here we investigate the effects of illegal lo...

The persistent high deforestation rate and fragmentation of the Amazon forests are the main threats to their biodiversity. To anticipate and mitigate these threats, it is important to understand and predict how species respond to the rapidly changing landscape. The short-eared dog Atelocynus microtis is the only Amazon-endemic canid and one of the...

Flying foxes play keystone ecological roles in plant reproduction. Yet, they face numerous threats, including persecution for eating commercial fruits. This human-wildlife conflict has recently escalated to culling campaigns of a threatened flying fox on Mauritius. Finding non-lethal solutions to this human-wildlife conflict on the island is theref...

The conversion of natural habitats to farmland is a major driver of the global extinction crisis [1, 2]. Two strategies are promoted to mitigate the impacts of agricultural expansion on biodiversity: land sharing integrates wildlife-friendly habitats within farmland landscapes, and land sparing intensifies farming to allow the offset of natural res...

The rise in species richness with area is one of the few ironclad ecological relationships. Yet, little is known about the spatial scaling of alternative dimensions of diversity. Here, we provide empirical evidence for a relationship between the richness of acoustic traits emanating from a landscape, or soundscape richness, and island area, which w...

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...

The transformation of natural habitats for farming is a major driver of tropical biodiversity loss. To mitigate impacts, two alternatives are promoted: intensifying agriculture to offset protected areas (land sparing) or integrating wildlife‐friendly habitats within farmland (land sharing). In the montane and dry tropics, phylogenetic and functiona...

The dietary ecology of a species can provide information on habitat requirements, food resources and trophic interactions, important to guide conservation efforts of wildlife populations in endangered habitats. In this study, we investigated the dietary ecology of bearded capuchin monkeys (Sapajus libidinosus) in Brasilia National Park, in the enda...

In the face of global ecosystem changes driven by anthropogenic activities, effective biomonitoring strategies are crucial for mitigating impacts on vulnerable aquatic habitats. Time series analysis underscores a great significance in understanding the dynamic nature of marine ecosystems, especially amidst climate change disrupting established seas...

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 w...

Birds nesting on riverine beaches are exposed to large temperature fluctuations, while changing water levels pose flooding risks. We used miniature temperature loggers ( i Buttons®) placed in nests and on the beach surface combined with time‐lapse photography to study incubation behaviour in the black skimmer ( Rynchops niger ) on the Manu River, P...

Two strategies are central to the debate regarding agricultural development: one integrates farming and conservation (land sharing), and the other separates farming and conservation, intensifying production to allow the offset of natural habitat (land sparing). The role of wildlife‐friendly habitat in the wider surrounding landscape (landscape wild...

A new species from the southwest Brazilian Amazon, Isocopris rossinii Arias-Buriticá, Bach, and Vaz-de-Mello, new species, is described along with a diagnosis, illustrations, and discussion of its taxonomic position in the genus. This new species is readily distinguished by a deep depression in the frons, a large and trapezoidal ventral clypeal pro...

The Brazilian state of Acre is located in the southwestern Amazon and it is characterized by a humid tropical forest vegetation that covers plains and mountains. Up to this point, the composition of termite species in the state is not known. The aim of this study was to provide a checklist of termite species or recognizable taxonomic units for the...

Palingonalia Young, 1977 is a small, poorly known genus of Neotropical leafhoppers comprising only three described species. Here, we describe for the first time the female genitalia of Palingonalia and provided the first record of P. subta Freytag & Vargas, 2007 from Amazonas state, Brazil. Additionally, a distributional map for the genus, discussi...

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...

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...

The wildlife trade is a billion‐dollar global business, involving millions of people, thousands of species, and hundreds of millions of individual organisms. Unravelling whether trade targets reproductively distinct species and whether this preference varies between captive‐ and wild‐sourced species is a crucial question. We used a comprehensive li...

Species relative abundance (SRA) is an essential attribute of biotic communities, which can provide an accurate description of community structure. However, the sampling method used may have a direct influence on SRA quantification, since the use of at-tractants (e.g., baits, light, and pheromones) can introduce additional sources of variation in t...

The rise in species richness with area is one of the best-studied patterns in ecology. Yet, little is known about the spatial scaling of alternate dimensions of diversity. Here, we provide empirical evidence for a relationship between the richness of acoustic traits emanating from the landscape, or soundscape richness, and the island area, which we...

The Amazon is one of the most diverse biomes around the globe, currently threatened by economic and industrial development and climate change. Large mammals are keystone species, playing an important role in ecosystem structure and function as ecological engineers, while being highly susceptible to deforestation, habitat degradation , and human exp...

The seasonal flood pulse in Amazonia can be considered a primary driver of community structure in floodplain environments. Although this natural periodic disturbance is part of the landscape dynamics, the seasonal inundation presents a considerable challenge to organisms that inhabit floodplain forests. The present study investigated the effect of...

Global warming is a great threat to biodiversity with negative impacts spanning the entire biological hierarchy. One of the main species’ traits determining survival at higher temperature is the thermal point at which an animal loses its ability to escape from deadly conditions (critical thermal maximum—CTmax). Variation in CTmax across species is...

Habitat conversion is a major driver of tropical biodiversity loss, but its effects are poorly understood in montane environments. While community‐level responses to habitat loss display strong elevational dependencies, it is unclear whether these arise via elevational turnover in community composition and interspecific differences in sensitivity o...

Ecologists often seek to infer patterns of species occurrence or community structure from survey data. Hierarchical models, including multi‐species occupancy models (MSOMs), can improve inference by pooling information across multiple species via random effects. Originally developed for local‐scale survey data, MSOMs are increasingly applied to lar...

Fruits and seeds are key food resources for most Amazonian mammals and birds. Selective logging is an increasingly dominant land use in the region that can deplete these resources over large areas. However, this potential impact remains poorly studied. Here we assess potential losses of animal-dispersed (endozoochorous and synzoochorous) trees resu...

The ‘Critically Endangered’ Black-winged Trumpeter Psophia obscura is endemic to the Belém Centre of Endemism in extreme eastern Amazonia and has a declining population and range. Here we report on a five-year (2016–2020) systematic camera-trap (n = 61) study of the species in Gurupi Biological Reserve, one of its most important conservation areas....

Soundscape studies are increasingly used to capture landscape‐scale ecological patterns. Yet, several aspects of soundscape diversity remain unexplored. Although some processes influencing acoustic niche usage may operate in the 24‐hr temporal domain, most acoustic indices only capture the diversity of sounds co‐occurring in sound files at a specif...

Rapid development of remote sensing and LiDAR technology has refined estimates of tree architecture and extrapolation of biomass across large spatial scales. Yet, current biomass maps show significant discrepancies and mismatch to independent ground data. A potential obstacle to accurate biomass estimation is the loss of information on wood density...

The domestic cat ( Felis catus ) is among the most popular companion animals and most abundant carnivores globally. It is also a pet with an immense ecological footprint because even non-feral and food-subsidized cats can be prolific predators. Whereas knowledge about the spatial behavior of individual domestic cats is growing, we still know little...

The Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) regulates international legal trade to prevent the detrimental harvest of wildlife. We assess the volumes of threatened and non-threatened bird, mammal, amphibian, and reptile species in the CITES-managed trade and how this trade responded to category change...

1. Soundscape studies are increasingly common to capture landscape-scale ecological patterns. Yet, several aspects of soundscape diversity quantification remain unexplored. Although some processes influencing acoustic niche usage may operate in the 24h domain, most acoustic indices only capture the diversity of sounds co-occurring in sound files at...

The domestic cat (Felis catus) is the most popular companion animal and the most abundant carnivore globally. It is also a pet with an immense ecological footprint, because even non-feral and food-subsidized cats are prolific predators. Whereas knowledge about the spatial behavior of individual domestic cats is growing, we still know little about h...

Amazonia encompasses extensive forests in areas that are periodically inundated by overflowing rivers. The inundation depth and duration vary according to the slope of the terrain and distance to major water bodies. This creates a flooding gradient from the lowest lying seasonally flooded forest up into the unflooded forest, which directly affects...

Ecologists often seek to infer patterns of species occurrence or community structure from survey data. Hierarchical models, including multi-species occupancy models (MSOMs), can improve inference by pooling information across multiple species via random effects. Originally developed for local-scale survey data, MSOMs are increasingly applied to lar...

Significance Sustainable-use protected areas (PAs) have contributed to tropical biodiversity conservation by deterring deforestation in multiple countries, yet their social and economic benefits to local stakeholders remain poorly understood. Amazonia hosts the largest tropical PA system on Earth, which is intended to safeguard its rich biological...

Production forests are a dominant feature of most tropical forest landscapes and it is therefore important to understand the effects of timber extraction on the resident fauna. Here we investigate the effects of reduced-impact logging (RIL) on medium-to large-sized terrestrial mammals in two Jamari National Forest logging concessions, southwestern...

The annual flooding in the Amazon basin transforms the understory of floodplain forests into an aquatic environment. However, a great number of non-aquatic bird species occupy the understory and midstory of these forests. In general, these birds are thought to be sedentary and territorial, but the way they adapt to this dramatic seasonal transforma...

Amazonia comprises a mosaic of contrasting habitats, with wide environmental heterogeneity at local and regional scales. In central Amazonia, upland forest (terra firme) is the predominant forest type and seasonally flooded forests inundated by white- and black-water rivers (várzea and igapó, respectively) represent around 20% of the forested areas...

Animal coloring serves several functions, including camouflage and thermoregulation. However, some individuals have anomalous coloring patterns due to excess (melanism) or deficiency (albinism, leucism, or piebaldism) in melanin production. Although these anomalies occur in several species, there are few cited cases. Here, we report the occurrence...

An understanding of a species' geographic distribution is essential to assess, plan, and develop strategies for its conservation. The geographic distribution of the bald uakari, Cacajao calvus, and its component subspecies has been poorly investigated, with disjunct distributions being reported in Brazil and Peru. In this study, we reveal new recor...

Amazonia encompasses forests that grow in areas that are periodically inundated by overflowing rivers. The inundation depth and duration vary according to the slope of the terrain, creating a flooding gradient. This gradient directly affects the biota, but the effect on soil organisms remains elusive. Here, we use DNA metabarcoding to estimate prok...

Meeting rising demand for oil palm whilst minimizing the loss of tropical biodiversity and associated ecosystem functions is a core conservation challenge. One potential solution is focusing the expansion of high-yielding crops on presently low-yielding farmlands alongside protecting nearby tropical forests that can enhance provision of ecosystem f...

The wildlife trade is worth billions of dollars annually and affects most major taxonomic groups. Despite this, a global understanding of the trade’s impacts on species populations is lacking. We performed a quantitative meta-analysis of the wildlife trade that synthesized 506 species-level effect sizes from 31 studies, estimating trade-driven decl...

Effectively managing farming to meet food demand is vital for the future of biodiversity.¹,² Increasing yields on existing farmland can allow the abandonment (sparing) of low-yielding areas that subsequently recover as secondary forest.2, 3, 4, 5 A key question is whether such “secondary sparing” conserves biodiversity more effectively than retaini...

Research Highlights: Rare, or sparsely distributed, species drive the floristic diversity of upland, terra firme and seasonally flooded forests in the central Juruá-a remote and hitherto floristically poorly known area in the Brazilian Amazon. Background and Objectives: Floristic inventories are critical for modelling and understanding the role of...

The tropical rainforests of Sundaland are a global biodiversity hotspot increasingly threatened by human activities. While parasitic insects are an important component of the ecosystem, their diversity and parasite-host relations are poorly understood in the tropics. We investigated parasites of passerine birds, the chewing lice of the speciose gen...

For tropical tree species, wood density can vary greatly both within and between species depending on environmental conditions. In Amazonian seasonally flooded forests, yearly flood pulses influence tree growth and floodplain trees have developed specialised strategies to cope with prolonged submersion during flooding. We therefore hypothesised tha...

Global warming is having impacts across the Tree of Life. Understanding species’ physiological sensitivity to temperature change and how they relate to local temperature variation in their habitats is crucial to determining vulnerability to global warming. We ask how species’ vulnerability varies across habitats and elevations, and how climatically...

We investigated short-eared dog habitat associations on two spatial scales. First, we used the largest record database ever compiled for short-eared dogs in combination with species distribution models to map species habitat suitability, estimate its distribution range and predict shifts in species distribution in response to predicted deforestatio...

For arboreal primates, ground use may increase dispersal opportunities, tolerance to habitat change, access to ground-based resources, and resilience to human disturbances, and so has conservation implications. We collated published and unpublished data from 86 studies across 65 localities to assess titi monkey (Callicebinae) terrestriality. We exa...

Natural regeneration of abandoned farmland provides an important opportunity to contribute to global reforestation targets, including the Bonn Challenge. Of particular importance are the montane tropics, where a long history of farming, frequently on marginal soils, has rendered many ecosystems highly degraded and hotspots of extinction risk. Ants...

The ecological impacts of meeting rising demands for food production can potentially be mitigated by two competing land‐use strategies: off‐setting natural habitats through intensification of existing farmland (land sparing), or elevating biodiversity within the agricultural matrix via the integration of ‘wildlife‐friendly’ habitat features (land s...

The importance of tropical forests in regulating global carbon stocks is well known. However, the role of abiotic variables related to climate conditions and edaphic parameters for patterns of above-ground woody biomass (AGWB) are still under debate. For Amazonian forests subjected to periodic floods, these patterns are even more uncertain. This st...

Secondary forests are promoted as having pivotal roles in reversing the tropical extinction crisis. While secondary forests recover carbon and species over time, a key question is whether phylogenetic diversity—the total evolutionary history across all species within a community—also recovers. Conserving phylogenetic diversity protects unique pheno...

Floodplain forests cover extensive areas of the Amazon basin, but the number of tree inventories is low. Vast floodplain regions therefore remain floristically unknown. We present a quantitative inventory of floodplain forests from four Amazon river basins (Jutaí, Juruá, Tefé and Purus), investigate within- and between-basin floristic similarity, a...

Given the dramatic loss of tropical forests and accelerating climate change, secondary forest regeneration is increasingly recognised as being an important method for reversing losses in biodiversity and carbon stocks. The recolonisation of biodiversity within secondary forests depends in part upon the recovery of forest structure, including the ra...

Most terrestrial species on Earth are ectothermic and track temperature at small spatial scales, from sun flecks to cool shaded spots. Current assessments of thermal heterogeneity in complex environments are predominately characterized by ambient temperature. This omission of solar radiation may lead to inaccurate conclusions regarding thermoregula...