G. Varbiro

G. Varbiro
Hungarian Academy of Sciences | HAS · Danube Research Institute

PhD

About

181
Publications
67,309
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Introduction
I am an ecologist- hydrobiologist at the Hungarian Centre for Ecology. My research interests focus on ecosystem ecology, aquatic macroinvertebrates and ecological assessment.
Additional affiliations
January 2011 - October 2014
Hungarian Academy of Sciences
Position
  • Researcher

Publications

Publications (181)
Article
Full-text available
Flow intermittency and poor environmental conditions can occur separately or simultaneously, affecting the occurrence of trait states in stream macroinvertebrate assemblages. Within the framework of limiting similarity theory, we investigate whether environmental filtering or limiting similarity serves as the primary driver force under three enviro...
Article
Land use system has a great impact on soil properties. The effect of land use on soil chemical, microbiological properties and soil moisture of salt-affected soils was investigated in India. Soil samples were collected from Solonetz soils under different land uses such as arable land (SnA), bare land (SnB) and pasture land (SnP). Results of the stu...
Article
Full-text available
Aim To determine which riverine invertebrate traits respond consistently to anthropogenic impacts across multiple biogeographic regions. Location Europe. Time Period 1981–2021. Major Taxa Studied Riverine invertebrates. Methods We compiled a database of riverine invertebrate community time series for 673 sites across six European countries span...
Article
As flow intermittency increases globally, understanding how macroinvertebrates respond at a functional level in streams becomes crucial for effective water management. This study investigates the functional response of macroinvertebrates to flow intermittency in Hungarian lowland streams over a 10-month period, comparing intermittent and perennial...
Article
Full-text available
Freshwater macroinvertebrates are a diverse group and play key ecological roles, including accelerating nutrient cycling, filtering water, controlling primary producers, and providing food for predators. Their differences in tolerances and short generation times manifest in rapid community responses to change. Macroinvertebrate community compositio...
Article
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Inland navigation in Europe is proposed to increase in the coming years, being promoted as a low-carbon form of transport. However, we currently lack knowledge on how this would impact biodiversity at large scales and interact with existing stressors. Here we addressed this knowledge gap by analysing fish and macroinvertebrate community time series...
Article
Full-text available
Transitioning from perennial to non-perennial flow regimes causes ecological shifts in aquatic communities. Aquatic macroinvertebrates deploy resistance and resilience strategies to cope with flow intermittency, crucial in rivers with long-term seasonal dry episodes. Less is known, about how these strategies support community persistence in streams...
Technical Report
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The Water Framework Directive requires member states to determine thresholds for a range of supporting chemical quality elements that will support good ecological status. This is a fundamental step in maintaining natural biodiversity as well as ensuring ecosystem service provision. All countries have defined thresholds, which have been used to re...
Technical Report
Full-text available
This report summarises approaches to setting robust criteria to achieve Water Framework Directive (WFD) objectives for the Annex V physico-chemical supporting elements: transparency, oxygenation, temperature, salinity and acidification. Nutrients have been considered in previous reports. This work is intended to complement existing guidance on stat...
Article
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Humans impact terrestrial, marine and freshwater ecosystems, yet many broad-scale studies have found no systematic, negative biodiversity changes (for example, decreasing abundance or taxon richness). Here we show that mixed biodiversity responses may arise because community metrics show variable responses to anthropogenic impacts across broad spat...
Article
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The zebra mussel Dreissena polymorpha is one of the most successful, notorious, and detrimental aquatic invasive non-native species worldwide, having invaded Europe and North America while causing substantial ecological and socioeconomic impacts. Here, we investigated the spatiotemporal trends in this species' invasion success using 178 macroinvert...
Article
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In this study, we aim to investigate how the functional properties of microalgae help to delineate the major groups of aquatic habitats. Using functional trait-based and Reynolds’ functional group-based approaches similarities of the microalgal flora of all aquatic habitats occurring in Hungary were compared. The habitats covered the whole size spe...
Article
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Defining nutrient thresholds that protect and support the ecological integrity of aquatic ecosystems is a fundamental step in maintaining their natural biodiversity and preserving their resilience. With increasing catchment pressures and climate change, it is more important than ever to develop clear methods to establish thresholds for status class...
Article
Full-text available
Phytoplankton is one of the five biological quality elements used to assess the ecological status of lakes within the Water Framework Directive. Classical morphological Utermöhl method and eDNA metabarcoding by Ilumina sequencing the hypervariable V9 region of the eukaryotic SSU rRNA gene were used to analyse the qualitative and quantitative compos...
Preprint
Full-text available
Freshwater navigation is expected to increase in the coming years, being promoted as a low-carbon form of transport. However, we currently lack knowledge on how this will impact biodiversity at large scales and interact with existing stressors. We addressed this knowledge gap by analyzing fish and macroinvertebrate community time series spanning th...
Article
Non-native species introductions have been acknowledged as one of the main drivers of freshwater biodiversity decline worldwide, compromising provided ecosystem services and functioning. Despite growing introduction numbers of non-native species, their impacts in conjunction with anthropogenic stressors remain poorly documented. To fill this gap, w...
Article
Full-text available
The mixing regime, the spatial distribution of nutrients and light determine the distribution of phytoplankton in lakes to a large extent. Linear stratification is a unique phenomenon among the various forms the lakes can stratify, representing a continuous and gradual water temperature decrease with depth. Here, we aimed to understand how mixing,...
Article
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Owing to a long history of anthropogenic pressures, freshwater ecosystems are among the most vulnerable to biodiversity loss¹. Mitigation measures, including wastewater treatment and hydromorphological restoration, have aimed to improve environmental quality and foster the recovery of freshwater biodiversity². Here, using 1,816 time series of fresh...
Article
Full-text available
The use of long-term datasets is crucial in ecology because it provides a comprehensive understanding of natural fluctuations, changes in ecosystems over extended periods of time, and robust comparisons across geographical scales. This information is critical in detecting and analysing trends and patterns in species populations, community dynamics,...
Article
Full-text available
Soil organic matter is a biological system that functions as an integrated whole. These assemblies have different properties, functions, and decomposition times. SOM is one of the main determinants of soil productivity. Our studies were carried out in a temperate deciduous oak forest on Luvisols soil. In the DIRT Project (Detritus Input and Removal...
Conference Paper
The water quality evaluation and monitoring are crucial for water resource management programs that need regulation and monitoring. As a result of this it is necessary to assess the quality of the water as part of the ecosystem such as analyzing the enrichment of nutrients in the water bodies (based on category, type and geographical location), con...
Article
Full-text available
As alien invasive species are a key driver of biodiversity loss, understanding patterns of rapidly changing global species compositions depends upon knowledge of invasive species population dynamics and trends at large scales. Within this context, the Ponto-Caspian region is among the most notable donor regions for aquatic invasive species in Europ...
Article
Full-text available
(1) Bioclimatic factors have a proven effect on species distributions in terrestrial, marine, or freshwater ecosystems. Because of anthropogenic effects, the changes in these variables are accelerated; thus, the knowledge of the impact has great importance from a conservation point of view. Two endemic dragonflies, the Balkan Goldenring (Cordulegas...
Article
Full-text available
Carbon in soil is one of the most important indicators of soil fertility. Part of the carbon stored in them is returned to the atmosphere during soil respiration. Climate change and inappropriate land use can accelerate these processes. Our work aimed to determine how soil CO2 emissions change over ten years as a result of litter manipulation treat...
Article
Soil organic matter content is a main driver of soil functions and ecosystem services. Various quantity of litter inputs was studied in a Quercetum-petraeae-cerris forest in northeastern Hungary at the Síkfőkút DIRT (Detritus Input and Removal Treatment) experimental site. The goal of the project was to assess how rates and sources of plant litter...
Article
Climate change and human-induced habitat degradations result in loss of species diversity in natural ecosystems. While the extinction of macroscopic organisms has been well documented in both the scientific literature and the public media, we have only limited knowledge on the loss of microscopic elements of the ecosystems. Since rarity coincides w...
Article
Full-text available
Body metrics are considered as master traits that regulate physiological, behavioural and life history features of planktic cyanobacteria and microalgae. Although the distribution of their morphological traits reflects the various trade‐offs and strategies needed for survival in pelagic habitats, previous methods for quantifying phytoplankton body...
Article
Full-text available
Aim Invasive alien species are a growing problem worldwide due to their ecological, economic and human health impacts. The “killer shrimp” Dikerogammarus villosus is a notorious invasive alien amphipod from the Ponto‐Caspian region that has invaded many fresh and brackish waters across Europe. Understandings of large‐scale population dynamics of hi...
Article
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The monitoring of biological indicators is required to assess the impacts of environmental policies, compare ecosystems and guide management and conservation actions. However, the growing availability of ecological data has not been accompanied by concomitant processing tools able to facilitate data handling and analysis. Multiple common challenges...
Article
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Cyanobacteria are notorious bloom formers causing various water quality concerns, such as toxin production, extreme diurnal variation of oxygen, pH, etc., therefore, their monitoring is essential to protect the ecological status of aquatic systems. Cyanobacterial cell counts and biovolumes are currently being used in water management and water qual...
Conference Paper
Rivers are one of the most essential natural resources for living beings, with cultural, social, economic, and historical significance. The water quality evaluation and monitoring are crucial for water resource management programs that need regulation and monitoring. As a result of this, it is necessary to assess the quality of the water as part of...
Preprint
Full-text available
As alien invasive species are a key driver of biodiversity loss, understanding patterns of rapidly changing global species compositions depends upon knowledge of biological invasion dynamics and trends. The Ponto-Caspian region is among the most notable donor regions for aquatic invasive species in Europe. Using macroinvertebrate time series collec...
Poster
Full-text available
Whilst being small and shallow, permanent ponds provide valuable habitats for a multitude of organisms as well as provide habitats for animals like aquatic insects and others, including many rare species. These ponds, which were often neglected in limnological studies, were the core of our joint project, the 3rd freshwater project - EUROPONDS in or...
Article
Full-text available
Globalization has led to the introduction of thousands of alien species worldwide. With growing impacts by invasive species, understanding the invasion process remains critical for predicting adverse effects and informing efficient management. Theoretically, invasion dynamics have been assumed to follow an “invasion curve” (S-shaped curve of availa...
Conference Paper
The water quality evaluation and monitoring are crucial for water resource management programs that need regulation and monitoring. As a result of this it is necessary to assess the quality of the water as part of the ecosystem such as analyzing the enrichment of nutrients in the water bodies (based on category, type and geographical location), con...
Article
Full-text available
Climate change is putting increasing pressure on flowing waters. Drastic water level fluctuations in rivers or drying up of small and medium-sized streams all contribute to the biodiversity crisis threatening freshwater ecosystems. Benthic diatoms are important elements of biofilm in small streams. However, knowledge on the relationship between ben...
Article
Full-text available
Nutrient targets based on pressure-response models are essential for defining ambitions and managing eutrophication. However, the scale of biogeographical variation in these pressure-response relationships is poorly understood, which may hinder eutrophication management in regions where lake ecology is less intensively studied. In this study, we de...
Preprint
Full-text available
Cyanobacteria are notorious bloom formers causing various water quality concerns, such as toxin production, extreme diurnal variation of oxygen, or pH, etc., therefore, their monitoring is essential to protect the ecological status of aquatic systems. Cyanobacterial cell counts and biovolumes are currently being used in water management and water q...
Article
Full-text available
Rivers are dynamic ecosystems in which both human impacts and climate‐driven drying events are increasingly common. These anthropogenic and natural stressors interact to influence the biodiversity and functioning of river ecosystems. Disentangling ecological responses to these interacting stressors is necessary to guide management actions that supp...
Article
Full-text available
Diatoms are widely applied in the ecological status assessment of aquatic ecosystems using indices calculated from pollution sensitivity and indicator values of species. Traditional, morphology-based identification of species requires in-depth taxonomic knowledge and expertise. Identifying taxa according to their barcode sequences obtained with hig...
Article
Full-text available
Phytoplankton is one of the key Biological Quality Elements within the Water Framework Directive, used to assess the ecological status of surface water bodies. Water samples for phytoplankton identification were collected from April to September at a total of eight sampling sites in all six Croatian natural karstic lakes with an area greater than 0...
Article
Full-text available
Dominant floating and submerged rootless vegetation can be regarded as alternative stable states world-wide. The competition between these two vegetation types can be strongly influenced by epiphytic algae. These algae, on the other hand, are partially controlled by grazers like snails. However, how this interaction between snails and epiphyton aff...
Article
Full-text available
Eutrophication caused by an excessive presence of nutrients is affecting large portions of European waters with more than 60% of the surface water bodies failing to achieve the primary ambition of water management in Europe, that of good ecological status (GES) with diffuse emission from agriculture being the second most important pressure affectin...
Article
One key component of any eutrophication management strategy is establishment of realistic thresholds above which negative impacts become significant and provision of ecosystem services is threatened. This paper introduces a toolkit of statistical approaches with which such thresholds can be set, explaining their rationale and situations under which...
Article
This study was conducted with the aim to assess the effect of land use on chemical properties (organic carbon; pH; electrical conductivity; available P, K, Ca, Mg, Na), microbiological properties (basal soil respiration, microbial biomass carbon, dehydrogenase activity and phosphatase activity), and physical property (moisture content) of salt-affe...
Article
Full-text available
We managed to create a self-developed sensor system, which is based on the simultaneous reflectance measurements at a 660 and 940 nm wavelength. The ratio of the reflectance refers to the concentration of the soil organic carbon (SOC). This instrument has a calibration range of 1.19 to 6.05 SOC%. The SOC content of twenty-six soil samples was measu...
Article
Full-text available
Diatoms, eukaryotic algae with silica cell wall have been proved to be reliable bioindicators and are applied in ecological status assessment of aquatic ecosystems using indices calculated from pollution sensitivity and indicator values of species. Traditional method of identification of diatom species is based on morphological features of frustule...
Article
Full-text available
The aim of this pilot study was to investigate the potential of eDNA techniques to detect the presence of the two dragonfly species Cordulegaster heros and Cordulegaster bidentata. Both species are classified as “near threatened” according to the IUCN Red List and are strictly protected in several countries. Monitoring these species with traditiona...
Technical Report
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The task group on supporting physico-chemical elements have reviewed information reported by Member States to WISE on the standards for general physico-chemical quality elements including nutrients. A wide range of supporting physico-chemical elements are used by Member States. This report focusses on those that are ecologically most relevant for i...
Article
Full-text available
Freshwater ecosystems are threatened by the global change‐induced extreme climatic events worldwide. The unpredictable changes in water supply create strongly disturbed environments and ultimately result in diversity changes. Here, we studied the formation of benthic algal and cyanobacterial assemblages under intermediately disturbed (IDC) and high...
Article
Full-text available
Stream macroinvertebrates, as non-target organisms, may face with either a single or a complex stressor during a restoration treatment. We quantified the structural, phylogenetic, and functional responses to both single (water retention) and complex (water retention and grazing) stressors and analysed how the ecological quality changes, in order to...
Article
Full-text available
Morphology and spatial dimensions of microalgal units (cells or colonies) are among of the most relevant traits of planktic algae, which have a pronounced impact on their basic functional properties, like access to nutrients or light, the velocity of sinking or tolerance to grazing. Although the shape of algae can be approximated by geometric forms...
Article
Full-text available
Global warming is accompanied by increasing water stress across much of our planet. We studied soil biological processes and changes in soil organic carbon (SOC) storage in 30 Hungarian oak forest sites in the Carpathian Basin along a climatic gradient (mean annual temperature (MAT) 9.6–12.1 °C, mean annual precipitation (MAP) 545–725 mm) but on si...
Article
Full-text available
The initial online publication contained a typesetting mistake in the author information. The original article has been corrected.
Article
Full-text available
Nutrient pollution remains one of the leading causes of river degradation, making it important to set thresholds that support good ecological condition, which is the main objective of managing Europe's aquatic environment. A wide range of methods has been used by European member states to set river nutrient thresholds in the past, and these vary gr...
Article
Full-text available
Environmental filtering and limiting similarity are those locally acting processes that influence community structure. These mechanisms acting on the traits of species result in trait convergence or divergence within the communities. The role of these processes might change along environmental gradients, and it has been conceptualised in the stress...
Article
Full-text available
Reduced body size is among the universal ecological responses to global warming. Our knowledge on how altered body size affects ecosystem functioning in ectothermic aquatic organisms is still limited. We analysed trends in the cell size structure of phytoplankton in the middle Danube River over a 34-year long period at multiple levels: (i) average...
Article
Full-text available
Climatic extreme events such as droughts (unpredictable), dry periods (predictable) or even flush floods, threaten freshwater ecosystems worldwide. The filtering mechanisms of these events and their strength on communities, however, can be different among regions. While time-for-adaptation theory defines whether or not water scarcity can be conside...
Article
Full-text available
Assigning species to functional response groups in phytoplankton ecology reduces the number of functional units, which helps understand the processes that shape diversity and functioning of planktonic assemblages. Although the concept has become widespread in recent years, numerical characterization of the groups’ positions in the niche space remai...
Article
Full-text available
The Sakarya River basin is one of the largest basins in Turkey, and encompasses the Kocaeli, Düzce, Sakarya, Bursa, Bilecik, Bolu, Kütahya, Eskişehir, Ankara, Afyon, and Konya provinces. In this study, the water quality status of the basin was investigated using 18 diatom indices, calculated in Omnidia software. For this purpose, a total of 46 stat...
Article
Full-text available
(1) Urbanization significantly influences the ecosystems of rivers in various ways, including the so-called loading effect of wastewater production. Benthic diatoms are used in ecological status assessments of waters. Beside species composition, traits can be used as indicators. We aimed to evaluate how the loading of the large city of Budapest man...
Data
Tau and significance levels (in brackets) are given, as well as bootstrap confidence interval calculations based on 10,000 bootstrap replicates at 99% CI (in the second line). Significant trends are bold and italic. N.s.: non-significant, *: p < 0.05, **: p < 0.01, ***: p < 0.001. (DOCX 45 kb)
Data
The relationship shows three discrete periods: (1) before 1990—stable phase; (2) between 1990 and 2000—transitional phase; and (3) after 2000—dispersed phase. The Figure is based on once a week sampling frequency from the middle Danube section, Göd (N-Budapest) Hungary, from the period 1979 to 2012 (n = 1434). (PNG 211 kb)