Leandro Juen

Universidade Federal do Pará, Belém, Brazil · Instituto de Ciências Biológicas

The diverse ecosystems of the Amazon biome play a vital role in the maintenance of biodiversity and delivering essential ecosystem services at both local and global levels. Small-bodied generalist insects, such as those from the order Odonata, contribute significantly to these services and are recognized as sensitive bioindicators of environmental...

More than one-third of the world’s high-biodiversity areas are inhabited by traditional communities, which possess deep knowledge and a unique relationship with the environment, resulting in sustainable management of natural resources. However, the importance of these communities is not always highlighted; therefore, this study conducts a mapping o...

Heteroptera are aquatic insects sensitive to environmental impacts that are frequently used in biomonitoring programs. Resolving families and genera provides consistent responses and can be a useful alternative to accelerate monitoring results and simplify protocols. Our objective was to evaluate which taxonomic levels may be more effective in asse...

Motivation: Freshwater ecosystems have been heavily impacted by land-use changes, but data syntheses on these impacts are still limited. Here, we compiled a global database encompassing 241 studies with species abundance data (from multiple biological groups and geographic locations) across sites with different land-use categories. This compilation...

Estimates of dark diversity, species that belong to a given species pool but are not present locally, can help to understand how environmental conditions influence species distribution. However, it remains uncertain whether dark diversity can predict the absence of indicator species in preserved environments after environmental changes. We explored...

to access the manuscript for free -> https://authors.elsevier.com/a/1k1b6B8cd0Xe1 //// Integrating the physicochemical characteristics of aquatic environments with their biotas is essential for the conservation and monitoring of biodiversity, given the sensitivity of both the biotic and the abiotic components to environmental changes linked to wa...

Motivation: Freshwater ecosystems have been heavily impacted by land-use changes, but data syntheses on these impacts are still limited. Here, we compiled a global database encompassing 241 studies with species abundance data (from multiplebiological groups and geographic locations) across sites with different land-use categories. This compilation...

Motivation: Freshwater ecosystems have been heavily impacted by land-use changes, but syntheses on the impacts on freshwater ecosystems are still limited. Here, we compiled a global database encompassing 248 studies with species abundance data (from multiple taxon groups and geographic locations) across sites with different land-use categories. Thi...

Motivation: Freshwater ecosystems have been heavily impacted by land-use changes, but syntheses on the impacts on freshwater ecosystems are still limited. Here, we compiled a global database encompassing 248 studies with species abundance data (from multiple taxon groups and geographic locations) across sites with different land-use categories. Thi...

Wallacean shortfalls in knowledge about biodiversity, especially in the Amazon biome, can only be addressed by increasing sampling efforts in focal areas. The objective of this study was to describe the fish fauna of streams associated with four protected areas in the Eastern Amazon. These areas include the Tapajós (Parque Nacional da Amazônia,...

The aim of this study was to investigate the effects of oil palm (Elaeis guineensis) plantations on the water quality and physical structure of streams in the Amazon region and on the diversity of adult odonates (Insecta: Odonata). We tested the hypotheses: (1) that streams draining palm oil monocultures have low water quality and physical integrit...

During a field expedition in the municipality of Araquari, state of Santa Catarina, southern Brazil, adults of the damselfly Cyanallagma demoiselle Denck, Ehlert & Pinto 2023 (Odonata, Zygoptera, Coenagrionidae) were collected. This species was recently described and reported to date for the southeastern Atlantic Forest in Brazil. Here, we recorded...

Environmental architecture and body temperature drive the distribution of ectothermic species, especially those with specific ecophysiological requirements or narrow ecological niches. In this study, we evaluated the connection between thorax temperature and niche specialization concerning the abundance and species contribution to the beta diversit...

Aim We address the relative importance of biogeographic regions (areas of endemism), regional climate and spatial factors on taxonomic, functional and phylogenetic beta diversity of bird assemblages in upland terra‐firme forests in the Amazon. Location Amazon biome. Taxon Birds. Methods We gathered 27,498 occurrence records of 873 bird species f...

We describe, illustrate and diagnose two hitherto unknown females of the genus Epipleoneura Williamson, 1915: E. capilliformis (Selys, 1886) and E. albuquerquei Machado, 1964. Both females are diagnosed based on the prothoracic hind lobe morphology: in E. capilliformis, the hind lobe is trilobed, with an elevated median portion, unique within the k...

Understanding the effects of mining activities on Amazonian streams and their impact on aquatic communities is of paramount importance in the current context of resource overexploitation in society. In this study, we assessed the significance of the environment and interspecific interactions on the organization patterns of semiaquatic insect specie...

Environmental and spatial variables can act as filters in species distribution, thereby structuring biological communities. Our study aims to analyze the effects of environmental and spatial factors on the structuring of Odonata assemblages in Cerrado. Testing the hypotheses: (1) the structuring of Odonata larvae and adult assemblages is more influ...

The biological diversity of a region may not be fully sampled due to the low abundance or rarity of species, or the absence of species determined by their niche specificity. Investigating these species is essential for understanding the unrealized ecological potential in different habitats, identifying gaps in local and regional communities, and ga...

Incorporating insects into ecotourism activities increases awareness of their importance in ecosystems. However, the inclusion of this group in ecotourism activities is still rare. In this context, we identified the perception of indigenous and non-indigenous leaders and residents about the potential of Odonata (dragonflies and damselflies) as key...

Over time, the species comprising aquatic communities disperse and form new communities and/or alter existing ones. These changes are a result of environmental factors that directly influence the niche breadth for each taxon. Therefore, understanding the dynamics of aquatic communities to better comprehend the effects of anthropogenic activities. I...

Freshwater crabs play a crucial role in aquatic ecosystems by contributing to decomposition of organic matter and facilitating energy flow in food webs. They also serve as sensitive indicators of habitat modification, pollution, and other anthropogenic activities. We assessed the relationship between the integrity of Amazonian stream habitats and t...

In the Brazilian Eastern Amazon, an area with high biological endemism, oil palm plantations rapidly expand, presenting ongoing challenges to prevent deforestation and biodiversity loss. This study was developed in the Belém Endemism Area and assessed the impacts of oil palm expansion on biological and social aspects. The biological impact analysis...

The various ecosystems of the Amazon biome play a vital role in the maintenance of biodiversity, as well as providing important ecosystem services at local and global levels. Small-bodied generalists include a number of important groups, such as the insects of the order Odonata. Given their sensitivity to environmental alterations, odonates are als...

Aquatic ecosystems are among the most affected by anthropogenic impacts, and the rapid detection and measurement of these impacts are of great importance for the maintenance of such environments. The order of aquatic insects Odonata has emerged as an important bioindicator of environmental quality due to its sensitivity to environmental changes and...

Various factors, including environmental variables, influence the behavior of aquatic insects. However, our understanding of insect behavior and their relationships with these variables remains limited. One important variable is water turbidity, which may be exacerbated by soil erosion, directly impacting visibility in the water and potentially aff...

Niche and dispersal‐based processes govern freshwater communities, such as aquatic insects, shaping their distribution and establishment in the environment. So, we aimed to address the relative influence of niche and dispersal‐based processes on Odonata diversity in Amazonian freshwater systems, and the influence of species dispersal functional tra...

Freshwater ecosystems, under the influence of human activities, are subject to multiple environmental stressors that lead to biodiversity loss, and the habitat modification. In recent years, different various organisms have been used as bioindicators to detect environmental changes by their ability to perceive changes in community attributes. A goo...

The landscape of the Brazilian Cerrado has been modified by human actions in the last decade with a significant increase in fires. Despite efforts to delimit an area for biodiversity conservation, human pressure on the landscape surrounding these units can affect the local environmental condition. We assessed the effect of landscape factors and fir...

One of the primary challenges in biodiversity conservation is the limited knowledge of the taxonomy and geographical distribution of species, particularly in megadiverse regions such as the Amazon In this context, the present study aimed to mitigate the Linnean and Wallacean shortfalls within the Family Leptophlebiidae (Ephemeroptera: Insecta) in t...

Studies that assess the contribution of sites (LCBD) and species (SCBD) to total beta diversity (BDtotal) along environmental/spatial gradients are of fundamental importance for biodiversity knowledge, species conservation and for environmental restoration. We analyzed which spatial, environmental and environmental heterogeneity (LCEH) predictors w...

Anthropogenic activities highly threaten neotropical freshwater habitats. Aquatic insects are sensitive to environmental alterations and thus considered under great risk due to such pressures. However, large‐scale gaps regarding the knowledge of the distribution of aquatic insect species remain in the Neotropics, particularly in the South American...

Insect monitoring is pivotal for assessing biodiversity and informing conservation strategies. This study delves into the complex realm of insect monitoring in the Global South—world developing and least-developed countries as identified by the United Nations Conference on Trade and Development—highlighting challenges and proposing strategic soluti...

Discerning the impact of anthropogenic impacts requires the implementation of bioindicators that quantify the susceptibilities and vulnerabilities of natural terrestrial and aquatic ecosystems to perturbation and transformation. Although legal regulations in Brazil recognize the value of bioindicators in monitoring water quality, the depreciation o...

Diverse abiotic and biotic factors drive the ecological variation of communities across spatial and temporal dimensions. Within the Amazonian landscape, various freshwater environments exhibit distinct physicochemical characteristics. Thus, our study delved into the fluctuations of Odonata assemblages amidst distinct water bodies within Amazonia, e...

Experiments are useful scientific tools for testing hypotheses by manipulating variables of interest while controlling for other factors that can bias or confuse the results and their interpretation. To ensures accuracy and reproducibility, experiments must have transparent and repeatable methodologies. Due to the importance of shredder invertebrat...

Understanding the distribution patterns of biodiversity is a pivotal challenge in ecology, exacerbated by the escalating frequency of anthropogenic events with severe consequences. This urgency underscores the need for comprehensive investigations, as exemplified by our study, which focuses on evaluating the effects of environmental and spatial var...

The Brazilian Cerrado is a biodiversity hotspot that has suffered significant vegetation loss in the states that make up the so-called MATOPIBA region in recent years an area currently experiencing soybean cultivation expansion in Brazil. This expansion can change the environmental conditions of freshwater streams, as they receive the impacts of ac...

Context Global change, including land-use change and habitat degradation, has led to a decline in biodiversity, more so in freshwater than in terrestrial ecosystems. However, the research on freshwaters lags behind terrestrial and marine studies, highlighting the need for innovative approaches to comprehend freshwater biodiversity. Objectives We i...

For more than six decades, ecologists have been investigating how biological communities are structured and the implications for conservation. The Niche and Island Biogeography theories stand out as the basis for predictions related to diversity-environmental heterogeneity and diversity-area relationships, respectively. Although positive relationsh...

1. The African species Cloeon smaeleni is one of the three Ephemeroptera species recorded as exotic and was introduced in Brazilian port areas. The records of this exotic species do not have a pattern, making it challenging to propose control measures and impact investigations. 2. We utilized Species Distribution Models (SDMs) to address: (i) What...

Abstract Aquatic insects of the orders Ephemeroptera, Plecoptera, and Trichoptera (EPT) have a wide distribution and play an important ecological role in aquatic ecosystems, primarily in nutrient cycling in lotic systems. They also exhibit high morphological and functional diversity. Although there are numerous studies evaluating the morphological...

The evaluation of environmental and spatial influence in freshwater systems is crucial for the conservation of aquatic diversity. So, we evaluated communities of Odonata in streams inside and outside sustainable use areas in the Brazilian western Amazon. We predicted that these streams would differ regarding habitat integrity and species α and β di...

Aim Insects are one of the least studied taxa, with most species lacking basic ecological and biogeographical information. This problem is particularly acute in the tropics, where low sampling effort hampers accurate estimates of species richness at scale and potentially confounds efforts to identify the drivers of biogeographical gradients. Here,...

One area of animal behaviour of growing interest is related to the behavioural traits that favour species' survival in rapidly changing environments (e.g. cities). In this regard, one animal group that is resilient to urbanization is that of odonate insects. These animals are formidable generalist predators that exhibit large behavioural flexibilit...

Human land-use is changing Earth’s surface, causing a decline in biodiversity and altering ecosystem functioning. However, most of the empirical evidence of land-use impacts in the Neotropics comes from studies investigating isolated land-use types, and the pathways by which intensified land-uses affect ecosystem functioning are largely unknown. Us...

Oil palm plantations are rapidly expanding in the Brazilian Eastern Amazon with high endemism but still are facing deforestation and biodiversity loss. This study in the Belém Endemism Area assessed the impacts of oil palm expansion on both biological and social aspects. The biological impact analysis compared biodiversity in seven taxonomic groups...

The Brazilian Amazon is one of Earth’s most biodiverse and ecologically important regions. However, research investments for biodiversity in the biome are disproportionately low compared with other regions of Brazil. In 2022, the Amazon received 13% of master's, doctoral and postdoctoral scholarships and hosted 11% of all researchers working in bio...

Brazil hosts a wide range of Odonata species, including many hitherto undescribed ones, especially in remote and unexplored regions where logistics are difficult. The northwestern Brazilian Amazon is an example of this situation, and many locations still need to be sampled there and have their taxonomic inventories compiled. Against this background...

The male and female imago stage and a new species of the Hermanella complex are described based on material from Pará State, Northern Brazil: Hydromastodon cf. mikei (Thomas & Boutonnet, 2004) and Paramaka froehlichi sp. nov. The male imago of Hydromastodon cf. mikei can be distinguished from Hydromastodon sallesi by the following combination of ch...

For more than six decades, ecologists have been investigating how biological communities are structured and the implications for conservation. The Niche and Island Biogeography theories stand out as the basis for predictions related to diversity-environmental heterogeneity and diversity-area relationships, respectively. Although positive relationsh...

Protected areas are hugely important for preserving freshwater systems, given their importance for the human well-being and aquatic diversity. Our main objective in the present study was to investigate the diversity of adult Odonata species in streams inside a national park, and in streams located outside this protected area, under different human...

Understanding the effects of mining activities on Amazonian streams and their impact on aquatic communities is of paramount importance in the current context of resource overexploitation in society. In this study, we assessed the significance of the environment and interspecific interactions on the organization patterns of semiaquatic insect specie...

estuaries using biotic indicators. We aimed (1) to describe the current landscape of the scientific production on the topic; (2) to characterize the most productive/influential authorships and the organization of scientific collaboration; (3) to analyze the most used biotic integrity indices, metrics and methods. After the survey process, separatio...

Changes in water quality and stream habitats can significantly impact Odonata larvae dynamics as a result of their specific ecological requirements. This study investigated the effects of water quality and microhabitats on the structure of Odonata larval communities. During the same period, substrate types, water variables, and Odonata larvae were...

The final-instar larva of Psaironeura tenuissima is described based on reared specimens from Amazonas and Pará states in the Brazilian Amazon. Psaironeura larvae are grouped with Neoneura and Protoneura larvae by having nodated caudal lamellae, however, they can be differentiated by the number of labial palp setae. Psaironeura tenuissi­ma are morph...