Publications by authors named "Robert Ewers"

To protect and restore ecosystems at the speed and scale required to meet current environmental challenges, a greater understanding of how conservation initiatives spread from existing to new adopters is required. According to the diffusion of innovation theory, positive adopter-to-peer communication is a powerful driver of innovation spread, whereas negative communications hinder innovation spread. Aware of this, businesses regularly survey customers and respond accordingly to maximize company growth.

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Modeling complex, nonlinear ecosystem processes across different timescales presents a significant challenge. We identify two key issues: selecting a representative timestep that captures interconnected processes across various timescales, and simulating these processes in an appropriate sequence. By synthesizing existing ecosystem frameworks, we find shared compromises between biological realism and computational performance.

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The impacts of degradation and deforestation on tropical forests are poorly understood, particularly at landscape scales. We present an extensive ecosystem analysis of the impacts of logging and conversion of tropical forest to oil palm from a large-scale study in Borneo, synthesizing responses from 82 variables categorized into four ecological levels spanning a broad suite of ecosystem properties: (i) structure and environment, (ii) species traits, (iii) biodiversity, and (iv) ecosystem functions. Responses were highly heterogeneous and often complex and nonlinear.

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  • Insects are declining globally, especially in tropical forests, which have high biodiversity but are also experiencing significant biodiversity loss.
  • Most predictions about insect biodiversity rely on well-studied species, leaving many undescribed species unaccounted for, particularly in hyper-diverse tropical environments.
  • A study in Borneo found that 76% of collected staphylinid beetle species were undescribed, showing that these unknown species are more negatively affected by environmental changes caused by logging.
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Stem respiration constitutes a substantial proportion of autotrophic respiration in forested ecosystems, but its drivers across different spatial scales and land-use gradients remain poorly understood. This study quantifies and examines the impact of logging disturbance on stem CO efflux (EA) in Malaysian Borneo. EA was quantified at tree- and stand-level in nine 1-ha plots over a logging gradient from heavily logged to old-growth using the static chamber method.

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  • New digital technology could change the way we take care of nature, but we need a better plan to use it!
  • Focusing on special areas called 'super-sites' can help us create better systems for understanding and managing ecosystems!
  • By using real-time data and simulations, we can make smarter choices for protecting nature that can change as needed!
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  • Logged and disturbed forests, often seen as degraded, actually harbor significant biodiversity and should not be dismissed in conservation efforts.
  • A study in Sabah, Malaysia examined the effects of logging intensity on 1,681 species, revealing two important conservation thresholds.
  • Lightly logged forests (less than 29% biomass removed) can recover well, while heavily degraded forests (over 68% biomass removed) may need more intensive recovery efforts, highlighting the varying conservation values of logged forests.
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Along with propagating the input toward making a prediction, Bayesian neural networks also propagate uncertainty. This has the potential to guide the training process by rejecting predictions of low confidence, and recent variational Bayesian methods can do so without Monte Carlo sampling of weights. Here, we apply sample-free methods for wildlife call detection on recordings made via passive acoustic monitoring equipment in the animals' natural habitats.

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Although eco-acoustic monitoring has the potential to deliver biodiversity insight on vast scales, existing analytical approaches behave unpredictably across studies. We collated 8,023 audio recordings with paired manual avifaunal point counts to investigate whether soundscapes could be used to monitor biodiversity across diverse ecosystems. We found that neither univariate indices nor machine learning models were predictive of species richness across datasets but soundscape change was consistently indicative of community change.

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  • This study looks into how to keep track of endangered species by using photos of their unique markings, which is cheaper and easier than traditional methods.
  • They created a system that automatically picks suitable photos and compares three software programs to see which one identifies animals the best.
  • The findings showed that while one program worked really well overall, it had trouble with a specific group of animals from Kenya, showing that more work is needed for accurate monitoring in different regions.
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  • Many tropical forests that have been logged and damaged are believed to absorb carbon, but this may not be true.
  • A study in Malaysian Borneo shows that instead of helping with carbon absorption, these forests are actually releasing a lot of carbon from the soil and dead plants.
  • The research found that after logging, these forests can produce more carbon than they absorb, challenging the common belief that they are good for the environment.
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Old-growth tropical forests are widely recognized as being immensely important for their biodiversity and high biomass. Conversely, logged tropical forests are usually characterized as degraded ecosystems. However, whether logging results in a degradation in ecosystem functions is less clear: shifts in the strength and resilience of key ecosystem processes in large suites of species have rarely been assessed in an ecologically integrated and quantitative framework.

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Tropical forests are some of the most biodiverse ecosystems in the world, yet their functioning is threatened by anthropogenic disturbances and climate change. Global actions to conserve tropical forests could be enhanced by having local knowledge on the forests' functional diversity and functional redundancy as proxies for their capacity to respond to global environmental change. Here we create estimates of plant functional diversity and redundancy across the tropics by combining a dataset of 16 morphological, chemical and photosynthetic plant traits sampled from 2,461 individual trees from 74 sites distributed across four continents together with local climate data for the past half century.

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Changes in land-use and the associated shifts in environmental conditions can have large effects on the transmission and emergence of mosquito-borne disease. Mosquito-borne disease are particularly sensitive to these changes because mosquito growth, reproduction, survival and susceptibility to infection are all thermally sensitive traits, and land use change dramatically alters local microclimate. Predicting disease transmission under environmental change is increasingly critical for targeting mosquito-borne disease control and for identifying hotspots of disease emergence.

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Landscape changes disrupt environmental, social and biological systems, altering pathogen spillover and transmission risks. This study aims to quantify the impact of specific land management practices on spillover and transmission rates of zoonotic and vector-borne diseases within Malaysian Borneo. This protocol describes a cohort study with integrated ecological sampling to assess how deforestation and agricultural practices impact pathogen flow from wildlife and vector populations to human infection and detection by health facilities.

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  • Landscape ecology aims to understand how habitat transformation affects biodiversity, but it faces challenges due to variability in observations across different contexts and times.
  • Current research indicates that the way species respond to habitat changes is influenced by larger ecological factors, such as historical disturbances and climate conditions.
  • By integrating landscape ecology with macroecological perspectives, we can resolve contradictory findings and improve predictions to address the biodiversity crisis.
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  • Research discusses how current global climate models are based on air temperatures but fail to capture the soil temperatures beneath vegetation where many species thrive.
  • New global maps present soil temperature and bioclimatic variables at 1-km resolution for specific depths, revealing that mean annual soil temperatures can differ significantly from air temperatures by up to 10°C.
  • The findings indicate that relying on air temperature could misrepresent climate impacts on ecosystems, especially in colder regions, highlighting the need for more precise soil temperature data for ecological studies.
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Acoustic indices derived from environmental soundscape recordings are being used to monitor ecosystem health and vocal animal biodiversity. Soundscape data can quickly become very expensive and difficult to manage, so data compression or temporal down-sampling are sometimes employed to reduce data storage and transmission costs. These parameters vary widely between experiments, with the consequences of this variation remaining mostly unknown.

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Fine roots constitute a significant component of the net primary productivity (NPP) of forest ecosystems but are much less studied than aboveground NPP. Comparisons across sites and regions are also hampered by inconsistent methodologies, especially in tropical areas. Here, we present a novel dataset of fine root biomass, productivity, residence time, and allocation in tropical old-growth rainforest sites worldwide, measured using consistent methods, and examine how these variables are related to consistently determined soil and climatic characteristics.

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The past 40 years in Southeast Asia have seen about 50% of lowland rainforests converted to oil palm and other plantations, and much of the remaining forest heavily logged. Little is known about how fragmentation influences recovery and whether climate change will hamper restoration. Here, we use repeat airborne LiDAR surveys spanning the hot and dry 2015-16 El Niño Southern Oscillation event to measure canopy height growth across 3,300 ha of regenerating tropical forests spanning a logging intensity gradient in Malaysian Borneo.

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Soil respiration is the largest carbon efflux from the terrestrial ecosystem to the atmosphere, and selective logging influences soil respiration via changes in abiotic (temperature, moisture) and biotic (biomass, productivity, quantity and quality of necromass inputs) drivers. Logged forests are a predominant feature of the tropical forest landscape, their area exceeding that of intact forest. We quantified both total and component (root, mycorrhiza, litter, and soil organic matter, SOM) soil respiration in logged (n = 5) and old-growth (n = 6) forest plots in Malaysian Borneo, a region which is a global hotspot for emission from forest degradation.

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In Southeast Asia, biodiversity-rich forests are being extensively logged and converted to oil palm monocultures. Although the impacts of these changes on biodiversity are largely well documented, we know addition to samples we collected in 201 little about how these large-scale impacts affect freshwater trophic ecology. We used stable isotope analyses (SIA) to determine the impacts of land-use changes on the relative contribution of allochthonous and autochthonous basal resources in 19 stream food webs.

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Natural habitats are being impacted by human pressures at an alarming rate. Monitoring these ecosystem-level changes often requires labor-intensive surveys that are unable to detect rapid or unanticipated environmental changes. Here we have developed a generalizable, data-driven solution to this challenge using eco-acoustic data.

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