Janne Soininen

Janne Soininen
University of Helsinki | HY · Department of Geosciences and Geography

PhD

About

210
Publications
91,339
Reads
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9,777
Citations
Introduction
I am a community ecologist with a special interest in large-scale biodiversity patterns of small aquatic organisms, especially benthic diatoms, phytoplankton and bacteria. I also like to investigate global patterns in biodiversity through meta-analyses.
Additional affiliations
February 2018 - present
University of Helsinki
Position
  • Professor (Full)
January 2015 - January 2018
University of Helsinki
Position
  • Professor (Associate)
January 2012 - January 2015
University of Helsinki
Position
  • Professor (Assistant)
Education
February 2000 - September 2004
University of Helsinki
Field of study
  • Aquatic Sciences

Publications

Publications (210)
Article
Climate effects and human impacts, that is, nutrient enrichment, simultaneously drive spatial biodiversity patterns. However, there is little consensus about their independent effects on biodiversity. Here we manipulate nutrient enrichment in aquatic microcosms in subtropical and subarctic regions (China and Norway, respectively) to show clear segr...
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Aquatic and terrestrial ecosystems are tightly linked through the fluxes of organisms and matter. However, aquatic and terrestrial ecologists have mainly studied these ecosystems separately, a “splendid isolation” historically fostered by disciplinary boundaries between institutes and funding schemes. Here, we synthesize the progress made in joint...
Article
Biological similartiy typically decreases with geographical distance. Despite the recent attention to the distance decay relationship, there is no consensus on how the relationship varies across organism groups, geographic gradients and environments. We first conducted a quantitative meta-analysis of 401 distance decay relationships across a wide r...
Article
Increasing evidence has emerged for non-random spatial distributions of microbes, but knowledge of the processes that cause variation in microbial assemblage among ecosystems is lacking. For instance, some studies showed that deterministic processes such as habitat specialization are important, while other studies hold that bacterial communities ar...
Article
Although elevational gradients in microbial biodiversity have attracted increasing attention recently, the generality in the patterns and underlying mechanisms are still poorly resolved. Further, previous studies focused mostly on species richness, while left understudied evenness, another important aspect of biodiversity. Here, we studied the elev...
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Urbanization is one of the major drivers of biotic homogenization (i.e., decrease in beta diversity) in freshwater systems. However, only a few studies have simultaneously examined how urbanization affects multiple facets (i. e., taxonomic, functional and phylogenetic) of beta diversity and its underlying ecological drivers in urban river macroinve...
Article
Distance-decay relationships (DDRs) represent a very useful approach to describing the spatial distribution of biological communities. However, plankton DDR patterns and community assembly mechanisms are still poorly understood at different spatial scales in reservoir ecosystems. We collected phytoplankton, zooplankton and water samples in 24 reser...
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Microbes regulate the composition and turnover of organic matter. Here we developed a framework called Energy-Diversity-Trait integrative Analysis to quantify how dissolved organic matter and microbes interact along global change drivers of temperature and nutrient enrichment. Negative and positive interactions suggest decomposition and production...
Article
Dissolved organic matter (DOM) is a large and complex mixture of molecules that fuels microbial metabolism and regulates biogeochemical cycles. Individual DOM molecules have unique functional traits, but how their assemblages vary deterministically under global change remains poorly understood. Here, we examine DOM and associated bacteria in 300 aq...
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Aim: Understanding the variation in community composition and species abundances (i.e., β-diversity) is at the heart of community ecology. A common approach to examine β-diversity is to evaluate directional variation in community composition by measuring the decay in the similarity among pairs of communities along spatial or environmental distance...
Article
Understanding large‐scale spatial distribution patterns is not only a central goal of ecology but is also essential for conservation planning. Nevertheless, the biogeographical patterns of diversity and composition remain unclear for microorganisms and the role of various factors in structuring their assemblages is still poorly known. Here, we test...
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Comparing spatio-temporal patterns between planktonic and benthic algae is helpful for understanding their associations and differences. However, such studies are still rare especially in large rivers. We used a dataset collected in the upper reach of the Jinsha River in different seasons to explore biodiversity and assembly processes of planktonic...
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Understanding the spatial variation in species richness and the mechanisms that limit species range sizes along geographical gradients belong to the central research issues in macroecology. Here, we aim to test the topographic and climatic effects on anuran species richness and community composition in mountainous regions in the Brazilian Atlantic...
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Global freshwater biodiversity is declining dramatically, and meeting the challenges of this crisis requires bold goals and the mobilisation of substantial resources. While the reasons are varied, investments in both research and conservation of freshwater biodiversity lag far behind those in the terrestrial and marine realms. Inspired by a global...
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The cover image is based on the Viewpoint A global agenda for advancing freshwater biodiversity research by Alain Maasri et al., https://doi.org/10.1111/ele.13931. Image Credit: Solvin Zankl. image
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Ecological studies on islands have provided fundamental insights into the mechanisms underlying biodiversity of larger organisms, but we know little about the factors affecting island microbial biodiversity and ecosystem function. We conducted a field experiment on five Baltic Sea islands where we placed aquatic microcosms with different levels of...
Article
Mountains are pivotal to maintaining habitat heterogeneity, global biodiversity, ecosystem functions and services to humans. They have provided classic model natural systems for plant and animal diversity gradient studies for over 250 years. In the recent decade, exploration of microorganisms on mountainsides has also achieved substantial progresse...
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The biodiversity–ecosystem functioning concept asserts that processes in ecosystems are markedly influenced by species richness and other facets of biodiversity. However, biodiversity–ecosystem functioning studies have been largely restricted to single ecosystems, ignoring the importance of functional links – such as the exchange of matter, energy,...
Article
1. Cold subarctic pond ecosystems will be threatened due to the increase in global temperatures. Therefore, it is important to gain more knowledge on how their biota may respond to global warming. The aim of this research was to illustrate the variability in diatom species richness and community composition along environmental gradients in northern...
Article
Diatom biogeography has attracted increased attention especially over the past two decades. However, due to covariance between space and environment, diatom biogeographical studies suffer from the fundamental problem of reliably evaluating the relative roles of dispersal processes versus local environment in shaping diatom distributions. Using betw...
Article
The analysis of community structure in studies of freshwater ecology often requires the application of dimensionality reduction to process multivariate data. A high number of dimensions (number of taxa/environmental parameters x number of samples), nonlinear relationships, outliers, and high variability usually hinder the visualization and interpre...
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Inland aquatic ecosystems, such as streams, rivers, ponds and lakes, play an important role in maintaining global aquatic biodiversity and ecosystem services. They have been increasingly influenced by environmental change such as global warming, dam construction, habitat fragmentation, eutrophication and urbanization. However, our understanding of...
Article
Body size descriptors and associated resemblance measurements may provide useful tools for forecasting ecological responses to increasing anthropogenic land‒use disturbances. Yet, the influences of agriculture and urbanisation on the size structure of biotic assemblages have seldom been investigated in running waters. Using a comprehensive dataset...
Preprint
Full-text available
Microbes play a critical role in regulating the size, composition, and turnover of dissolved organic matter (DOM), which is one of the largest pools of carbon in aquatic ecosystems. Global change may alter DOM-microbe associations with implications for biogeochemical cycles, although disentangling these complex interactions remains a major challeng...
Article
Coastal areas are facing biodiversity loss and degradation of habitats due to intensified human activities. However, our understanding of the relative contribution of natural gradients and human induced disturbance to biodiversity is limited. Here, we investigated the response of three facets of alpha and beta diversity of benthic ciliates to envir...
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This is an open access article under the terms of the Creat ive Commo ns Attri bution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. Abstract Local biodiversity has traditionally been estimated with taxonomic diversity metrics such as species richness. Recently, the concept of...
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Emergent neutrality (EN) suggests that species must be sufficiently similar or sufficiently different in their niches to avoid interspecific competition. Such a scenario results in a transient pattern with clumps and gaps of species abundance along the niche axis (e.g. represented by body size). From this perspective, clumps are groups of coexistin...
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Bacterioplankton community composition has become the center of research attention in recent years. Bacteria associated with toxic cyanobacteria blooms have attracted considerable interest. However, little is known about the environmental factors driving the bacteria community, including the impact of invasive cyanobacteria. Therefore, our aim has...
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Aim To examine how snow cover and permafrost affect plant species distributions at a subcontinental extent. Location Mountain realm of Fennoscandia, northern Europe. Time period Species data from 1 January 1990–25 February 2019. Major taxa studied Arctic-alpine and boreal vascular plants. Methods We examined the effect of snow persistence and p...
Preprint
Full-text available
Freshwater biodiversity is declining dramatically, and the current biodiversity crisis requires defining bold goals and mobilizing substantial resources to meet the challenges. While the reasons are varied, both research and conservation of freshwater biodiversity lag far behind efforts in the terrestrial and marine realms. We identify fifteen pres...
Preprint
Full-text available
Understanding the variation in community composition and species abundances, i.e., β-diversity, is at the heart of community ecology. A common approach to examine β-diversity is to evaluate directional turnover in community composition by measuring the decay in the similarity among pairs of communities along spatial or environmental distances. We p...
Article
Full-text available
Patterns in community composition are scale-dependent and generally difficult to distinguish. Therefore, quantifying the main assembly processes in various systems and across different datasets has remained challenging. Building on the PER-SIMPER method, we propose a new metric, the dispersal-niche continuum index (DNCI), which estimates whether di...
Preprint
Full-text available
Freshwater biodiversity is declining dramatically, and the current biodiversity crisis requires defining bold goals and mobilizing substantial resources to meet the challenges. While the reasons are varied, both research and conservation of freshwater biodiversity lag far behind efforts in the terrestrial and marine realms. We identify fifteen pres...
Article
Full-text available
The global biodiversity loss has increased the need to understand the effects of decreasing diversity, but our knowledge on how species loss will affect the functioning of communities and ecosystems is still very limited. Here, the levels of taxonomic and functional beta diversity and the effect of species loss on functional beta diversity were inv...
Article
Biotic groups usually have nonrandom cross-taxon relationships in their biodiversity or compositions across sites, but it is poorly known how such congruence varies across long-term ecosystem development, and what are the ecological processes underlying biodiversity patterns. Here, we examined the cross-taxon congruence in diversity and composition...
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1. The occupancy and abundance of species are jointly driven by local factors, such as environmental characteristics and biotic interactions, and regional‐scale factors, such as dispersal and climate. Recently, it has been shown that biotic interactions shape species occupancies and abundances beyond local extents. However, for small ectothermic an...
Article
Previous studies have found mixed results regarding the relationship between beta diversity and latitude. In addition, by influencing local environmental heterogeneity, land use may modify spatial taxonomic and functional variability among communities causing biotic differentiation or homogenization. We tested 1) whether taxonomic and functional be...
Preprint
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Climate change stands to have a tremendous impact on the world’s freshwater ecosystems. To understand how, researchers analyzed 15,289 functional genes related to nutrient cycling and stress processes gathered from biofilm microbes across mountainside streams in Norway, Spain, and China. With increasing elevation, microbial functional diversity ten...
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River damming reduces the dispersal rates of biota and filter species by altering the local environmental conditions. Although phytoplankton is a key biotic group to indicate changes in aquatic environments, the effects of river damming on the longitudinal distribution of phytoplankton communities are not widely addressed. Here we investigated the...
Article
Aim Global biodiversity loss has raised interest in understanding variation in diversity at different scales. In particular, studies conducted across large spatial gradients are crucial, because they can increase perspectives on how ecological patterns change relative to environmental factors and facilitate predictions of possible responses to envi...
Preprint
Full-text available
A bstract Emergent neutrality (EN) suggests that species must be sufficiently similar or sufficiently different in their niches to avoid interspecific competition. Such a scenario results in a transient pattern with clumps and gaps of species abundance along the niche axis (e.g., represented by body size). From this perspective, clumps are groups o...
Article
Full-text available
Background: Understanding the large-scale patterns of microbial functional diversity is essential for anticipating climate change impacts on ecosystems worldwide. However, studies of functional biogeography remain scarce for microorganisms, especially in freshwater ecosystems. Here we study 15,289 functional genes of stream biofilm microbes along...
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1. Mass effect, allowing species to persist in unfavourable habitats, and dispersal limitation, preventing species from reaching favourable habitats, are the two major dispersal processes. While dispersal limitation can be detected by experimental or modelling techniques, mass effect is more challenging to evaluate, which hampers our ability to dis...
Article
Community variation (i.e., beta diversity) along geographical gradients is a well-known ecological pattern, but the corresponding variation in beta diversity components (e.g., species turnover and nestedness) and underlying drivers remain poorly understood. Based on two alternative approaches (that is, the beta diversity partitioning proposed by Ba...
Article
Aim Idealized metacommunity structures (i.e. checkerboard, random, quasi-structures, nested, Clementsian, Gleasonian, and evenly spaced) have recently gained increasing attention, but their relationships with environmental heterogeneity and how they vary with organism groups remain poorly understood. Here we tested two main hypotheses: (1) gradient...
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Metacommunity theory provides a useful framework to describe the underlying factors (e.g., environmental and dispersal-related factors) influencing community structure. The strength of these factors may vary depending on the properties of the region studied (e.g., environmental heterogeneity and spatial location) and considered biological groups. H...
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Rapid shifts in biotic communities due to environmental variability challenge the detection of anthropogenic impacts by current biomonitoring programs. Metacommunity ecology has the potential to inform such programs, because it combines dispersal processes with niche-based approaches and recognizes variability in community composition. Using interm...
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A major challenge in community ecology is to understand the underlying factors driving metacommunity (i.e., a set of local communities connected through species dispersal) dynamics. However, little is known about the effects of varying spatial scale on the relative importance of environmental and spatial (i.e., dispersal related) factors in shaping...
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The global biodiversity loss has raised interest in the different facets of diversity, and the importance of diversity for ecosystem functions has been recognized. However, our knowledge on seasonal and inter-annual variation in the composition and diversity of communities is still poor. Here, we investigated the seasonal and inter-annual changes i...
Article
Ongoing climatic change and anthropogenic pressure highlight the importance of reliable assessment of the ecological status of freshwaters. Bioindicators are used widely in ecological assessments as biotic assemblages reflect the environmental conditions in current ecosystems. However, the robustness of bioindicators relies on the transferability o...
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Ecological drift can override the effects of deterministic niche selection on small populations and drive the assembly of some ecological communities. We tested this hypothesis with a unique dataset sampled identically in 200 streams in two regions (tropical Brazil and boreal Finland) that differ in macroinvertebrate community size by five‐fold. Nu...
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We investigated the relationships between exotic freshwater fish invasions, environmental factors and ecofunctional diversity (i.e. the combination of ecological traits in communities) in streams. We used data from 335 stream sites, belonging to 105 watersheds and 3 basins in Italy, to test whether the exotic species invasion was dominated by speci...
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Exotic species invasions often result in native biodiversity loss, i.e. a lower taxonomic diversity, but current knowledge on invasions effects underlined a potential increase of functional diversity. We thus explored the connections between functional diversity and exotic species invasions, while accounting for their environmental drivers, using a...
Article
Reliable biological assessments are essential to answer ecological and management questions but require well-designed studies and representative sample sizes. However, large sampling effort is rarely possible, because it demands large financial resources and time, restricting the number of sites sampled, the duration of the study and the sampling e...
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Community variation (i.e. beta diversity) along geographical gradients is of substantial interest in ecology and biodiversity reserves in the face of global changes. However, the generality in beta diversity patterns and underlying processes remains less studied across trophic levels and geographical regions. We documented beta diversity patterns a...
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Different metacommunity perspectives have been developed to describe the relationship between environmental and spatial factors and their relative roles for local communities. However, only little is known about temporal variation in metacommunities and their underlying drivers. We examined temporal variation in the relative roles of environmental...