Zooplankton Metacommunities Research Articles

Zooplankton functional diversity as a bioindicator of freshwater ecosystem health across land use gradient

Zooplankton are critical indicators of pressures impacting freshwater ecosystems. We analyzed the response of zooplankton communities across different sub-catchment types—headwaters, natural, urban, urban-agricultural, and agricultural—within the Łyna river–lake system in Northern Poland. Using taxonomic groups and functional traits (body size, feeding strategies), we applied Partial Least Squares Regression (PLS-R) to elucidate the relationships between environmental conditions, land use, and zooplankton metacommunity structure. Two-Way Cluster Analysis (TWCA) identified local subsets with characteristic patterns, while Indicator Species Analysis (ISA) determined area-specific taxa. The natural river zone exhibited significant habitat heterogeneity and feeding niches, whereas urban areas created functional homogenization of zooplankton, dominated by small, broad-diet microphages. Agricultural areas promoted diversity among large filter feeders (Crustacea), active suctors (Rotifera), and amoebae (Protozoa). However, intensified agricultural activities, substantially diminished the zooplankton population, biomass, taxonomic richness, and overall ecosystem functionality. The impact of land cover change is more pronounced at small-scale sub-catchments than at the catchment level as a whole. Therefore, assessing these impacts requires detailed spatial and temporal analysis at the sub-catchment level to identify the most affected areas. This study introduces a new sub-catchment-based perspective on ecosystem health assessment and underscores the zooplankton's role as robust indicators of ecological change.

Past community data are consistent predictors of zooplankton metacommunity structure in small reservoirs

Past community data are consistent predictors of zooplankton metacommunity structure in small reservoirs

Seasonal and flow regime differences should be considered in explaining zooplankton metacommunity assembly

Environmental and spatial filtering collectively regulate zooplankton communities, while their relative contributions to community structure may change with seasonal variations and flow regime differences. However, there is a lack of research on the combined effect of these two factors. To explore these differences, we studied zooplankton populations as well as environmental and geographical data from different seasons in rivers with variable flows in the Shaying River basin. According to our results, the assembly mechanisms for intermittent river (IR) communities fluctuated more and were more responsive to geographical factors than were the assembly mechanisms of perennial river (PR) communities during the wet and dry seasons. We discovered that the rotifer/protozoan assemblage was more vulnerable to spatial influences, whereas the composition of the crustacean group was heavily impacted by the environment. Our findings contribute to a better understanding of metacommunity assembly mechanisms in highly dynamic ecosystems.

Assessing the Zooplankton Metacommunity (Branchiopoda and Copepoda) from Mediterranean Wetlands in Agricultural Landscapes

Mediterranean wetlands are suitable ecosystems for studying metacommunity theory, since they are isolated ecosystems within a land matrix with well-established limits, often with watersheds destined for agricultural uses. The zooplankton community of wetlands in agricultural landscapes is the result of processes that operate in a different multiscale context. We selected 24 ponds in Alto Guadalquivir region (SE Spain) with different local environmental variables (biological, limnological and land uses). The zooplankton community of the wetlands under study consists of a total of 60 species: 38 branchiopods and 22 copepods. This community (total, branchiopods and copepods) was analysed through two different and complementary metacommunity approaches. The pattern approach determines the species distribution along environmental gradients, and the mechanistic approach considers the involved processes, such as environmental control and dispersal limitation. The results indicated a nested metacommunity, in which five limnological variables, three land uses and six spatial variables are the main drivers that explain zooplankton distribution in these wetlands. In conclusion, species sorting and dispersal processes play a role in the structuring of the zooplankton metacommunity. This conclusion has implications for the development of adequate management policies on Mediterranean wetland protection and diversity conservation in agricultural contexts.

Species portfolio effects dominate seasonal zooplankton stabilization within a large temperate lake.

Portfolio effects (PEs) in ecology refer to the suite of phenomenon where the temporal variation of aggregate ecosystem properties (i.e., abundance) is lower than that of their ecosystem components. An example of this is where differential responses of species to environmental variation generate stability at higher levels of ecological organization (e.g., local community, metapopulation, metacommunity). Most of the research examining such PEs has focused on spatial or interannual variation of ecosystems; however, as global change continues to alter seasonality and ecosystem functioning, understanding the underlying food web structures that help maintain stability at multiple spatial and temporal scales is critical to managing ecological systems. Recent advances investigating diversity-stability relationships has led to the development of frameworks that incorporate a metacommunity perspective which allows for the partitioning of PEs across organizational scales (i.e., local community, metapopulation, cross-community, metacommunity) from local population dynamics (total). This partitioning yields insights into the mechanisms that generate observed PEs in nature. Here, we employed one of these recently developed frameworks on a temporally (1986-1999, 2008-2019) and spatially (five sampling stations, local communities) extensive data set of zooplankton abundance (e.g., density) within a large temperate lake to investigate how temporal (seasonal) and spatial (among site) PEs influence stability within the zooplankton metacommunity. We found that seasonal asynchrony of different zooplankton species within local communities and across communities generated the vast majority of stabilization, while spatial (i.e., metapopulation) dynamics were more synchronous and contributed little to overall system stability. Furthermore, significantly positive diversity-asynchrony relationships at the total, local- and cross-community scales were found as asynchrony was positively correlated with local Shannon diversity. Last, a comparison of PEs over the time periods, during which significant local and global changes (i.e., climate warming, invasive species) have occurred suggests that PEs may be eroding, as increasingly synchronous dynamics and declining diversity in recent years have led to a rise in metacommunity variability. We end by arguing for the critical importance of understanding seasonally driven stabilizing mechanisms as local and global changes threaten to fundamentally alter seasonal signals with potentially strong implications for the structures that lend stability to ecosystems.

DNA metabarcoding reveals impact of local recruitment, dispersal, and hydroperiod on assembly of a zooplankton metacommunity.

Understanding the environmental impact on the assembly of local communities in relation to their spatial and temporal connectivity is still a challenge in metacommunity ecology. This study aims to unravel underlying metacommunity processes and environmental factors that result in observed zooplankton communities. Unlike most metacommunity studies, we jointly examine active and dormant zooplankton communities using a DNA metabarcoding approach to overcome limitations of morphological species identification. We applied two-fragment (COI and 18S) metabarcoding to monitor communities of 24 kettle holes over a two-year period to unravel (i) spatial and temporal connectivity of the communities, (ii) environmental factors influencing local communities, and (iii) dominant underlying metacommunity processes in this system. We found a strong separation of zooplankton communities from kettle holes of different hydroperiods (degree of permanency) throughout the season, while the community composition within single kettle holes did not differ between years. Species richness was primarily dependent on pH and permanency, while species diversity (Shannon Index) was influenced by kettle hole location. Community composition was impacted by kettle hole size and surrounding field crops. Environmental processes dominated temporal and spatial processes. Sediment communities showed a different composition compared to water samples but did not differ between ephemeral and permanent kettle holes. Our results suggest that communities are mainly structured by environmental filtering based on pH, kettle hole size, surrounding field crops, and permanency. Environmental filtering based on specific conditions in individual kettle holes seems to be the dominant process in community assembly in the studied zooplankton metacommunity.

Influence of spatial and environmental factors on the structure of a zooplankton metacommunity in an intermittent river

Influence of spatial and environmental factors on the structure of a zooplankton metacommunity in an intermittent river

Mechanistic approach and elements of metacommunity structure of the zooplankton of palm swamps in the Neotropical region

AbstractStudies of metacommunities are of great importance for ecological knowledge because they assess how the processes related to the species' niche and the dispersion processes structure the communities. In this context, the objective of the present study was to investigate the main assembly mechanisms responsible for the structuring of the zooplankton community in a complex of neotropical palm swamps (“veredas”), consisting of sets of small common ponds in the Brazilian savannah, similar to swamps. Zooplankton were sampled in the pelagic region of 15 veredas in April 2018. The zooplankton total community showed a distribution related to spatial and environmental factors. For Rotifera the relative importance of environmental factors was greater, while Cladocera and Copepoda were more structured by space. The community was still structured according to the Gleasonian model of distribution, where Rotifera presented a Gleasonian structure, Cladocera quasi‐Gleasonian, and Copepoda quasi‐nested random. The influence of environmental and spatial factors and the resulting structure of the zooplankton metacommunity seem to be directly related to the dispersal capacity in each group. Differences in relative importance of the factors that shaped the community highlight the idiosyncratic characteristics of zooplankton species. Thus, we emphasize the importance of using the two approaches of metacommunity studies to help to elucidate the processes that govern the structuring of metacommunities.

Zooplankton β diversity dynamics and metacommunity structure depend on spatial and temporal scales in a Neotropical floodplain

Abstract Both β diversity and metacommunity structure vary in time and space. It is necessary to examine different scales, especially in the face of extreme hydrological conditions. We investigated seasonal variation in β diversity and Elements of Metacommunity Structure [EMS] of zooplankton during four years (two years of prolonged drought and two years with extreme flood events) and at two spatial scales (sub‐basins and floodplain; smaller and larger spatial scale, respectively). We sampled 29 lakes quarterly during four years in the Upper Paraná River floodplain, Brazil. We estimated the replacement component of β diversity using the Jaccard dissimilarity index. We also used EMS to determine the metacommunity pattern of zooplankton distribution in each period and spatial scale. The flood peak observed in the snapshot sampling drove the homogenization of zooplanktonic assemblages. However, β diversity was not reduced in the two years with extreme flood events compared to the period of prolonged drought at either of the spatial scales (floodplain and sub‐basins), except for a single sub‐basin. This finding shows the importance of longer‐term ecological studies to better capture the dynamics of the zooplanktonic metacommunity. Regardless of the hydrological period and spatial scale zooplanktonic metacommunity structure remained practically constant throughout the four years, with a predominance of species range turnover (Clementsian). At the smallest spatial scale (sub‐basins), we found quasi‐structural patterns (quasi‐Clementsian and quasi‐Gleasonian). The predominance of the Clementsian pattern suggests that the associations of zooplankton species in the floodplain responded similarly to the environmental gradient and that the responses differed among species groups. Over time, the smaller spatial scale (sub‐basin) better represents the dynamics of β diversity than the larger spatial scale (floodplain), and better represents the structure of the zooplankton metacommunity. However, we emphasize the need for further studies to consider different biological groups and larger spatial scale over time to maximize the understanding of aquatic metacommunities dynamics. ​

Contrasting the assembly of phytoplankton and zooplankton communities in a polluted semi-closed sea: Effects of marine compartments and environmental selection

Understanding the underlying mechanisms of community assembly is a major challenge in microbial ecology, particularly in communities composed of diverse organisms with different ecological characteristics. However, very little is known about the effects of marine compartments in shaping marine planktonic communities; primarily, how they are related to organism types and environmental variables. In this study, we used multiple statistical methods to explore the mechanisms driving phytoplankton and zooplankton metacommunity dynamics at the regional scale in the Bohai Sea, China. Clear geographic patterns were observed in both phytoplankton and zooplankton communities. Zooplankton showed a stronger distance-decay of similarity than phytoplankton, which had greater community differences between locations with further distances. Our analyses indicated that the zooplankton communities were primarily governed by species sorting versus dispersal limitation than the phytoplankton communities. Furthermore, we detected that zooplankton exhibited wider habitat niche breadths and dispersal abilities than phytoplankton. Our findings also showed that environmental pollution affected high trophic organisms via food webs; the presence of heavy metals in the Bohai Sea altered the abundance of some phytoplankton, and thus modified the zooplankton that feed on them.

Diversity of dormant and active zooplankton stages: spatial patterns across scales in temperate riverine floodplains

AbstractIn dynamic systems, many species use dormancy as a strategy to survive harsh periods and disperse through time, a fundamental aspect scarcely explored in metacommunities studies. We compared spatial patterns of resting egg bank and active zooplankton diversity across scales (rotifers and cladocerans), explored relationships between diversity and environmental and spatial factors and compared their species composition in riverine floodplains of the Danube River. The egg bank was similarly or even more heterogeneous than the active communities, and signals of community homogenization detected for active communities were not observed for the egg bank. The strong relationships detected between rotifers egg bank diversity and local hydrological parameters suggest that floods would not weaken diversity–environment relationships, as observed for the active communities. These results imply that spatial patterns of resting and active stages are affected by different processes and that the egg bank would not contribute to the homogenizing tendencies observed for the active communities. Our study contributes to a more thorough understanding of zooplankton metacommunities in riverine floodplains and shows the need to further investigate the spatial and temporal patterns of the egg banks within the framework of metacommunities.

The interaction between spatial variation in habitat heterogeneity and dispersal on biodiversity in a zooplankton metacommunity

It is hypothesized that biodiversity is maintained by interactions at local and regional spatial scales. Many sustainability plans and management practices reflect the need to conserve biodiversity, yet once these plans are implemented, the ecological consequences are not well understood. By learning how management practices affect local environmental factors and dispersal in a region, ecologists and natural resource managers can better understand the implications of management choices. We investigated the interaction of local and regional scale processes in the built environment, where human-impacts are known to influence both. Our goal was to determine how the interaction between spatial variation in habitat heterogeneity in algal management of urban ponds and dispersal shape biodiversity at local and regional spatial scales. A twelve-week mesocosm study was conducted where pond management and dispersal were manipulated to determine how spatial variation in habitat and dispersal from various source pools influence zooplankton metacommunities in urban stormwater ponds. We hypothesized that dispersal from managed or unmanaged source pools will lead to community divergence and local management practices will act as an environmental filter, both reducing beta diversity between managed ponds and driving compositional divergence. Our results suggest that zooplankton dispersal from managed or unmanaged source pools was important to explaining divergence in community composition. Furthermore, local management of algae marginally reduced compositional turnover of zooplankton among ponds but did not lead to significant divergence in community composition. Management practices may act as strong environmental filters by reducing beta diversity between ponds. As hypothesized, source pool constraints led to compositional divergence and local management practices resulted in reduced compositional turnover between ponds. The results of this study suggest that sustainability and management plans may have complex effects on biodiversity both within and across spatial scales.

The relative influence of the environment, land use, and space on the functional and taxonomic structures of phytoplankton and zooplankton metacommunities in tropical reservoirs

Disentangling the effects of space and the environment on species distribution is one of the current goals of ecology and biogeography. In this study, we aimed to determine the relative influence of local, spatial (directional and non-directional), and land-use predictors on the taxonomic and functional trait compositions of phytoplankton and zooplankton assemblages. We collected data from 25 sampling points within shallow artificial water reservoirs in the central-western region of Brazil. This study was conducted in an area with a small spatial extent (<50 km between sampling sites) and in a reservoir of a typical hierarchical branching river network. The explanatory variables included 8 environmental features, 2 land-use predictors, and 2 spatial proxies (non-directional and directional spatial eigenvectors). We used a partial redundancy analysis to evaluate the relative influence of each predictor. Only spatial predictors, mainly directional, were important in explaining the phytoplankton and zooplankton metacommunity structure (functional and taxonomic). According to the metacommunity perspective, our results indicated that the phytoplankton and zooplankton metacommunities could be classified as species sorting with high dispersal, that is, a mass-effect perspective. We expected to see mass-effect processes in our study area, in which highly-dispersive species occur in a small-scale, highly-connected area where upstream reservoirs act as sources for dispersing species downstream. Moreover, some functional traits and morphofunctional attributes of phytoplankton (presence of flagella and small size) and zooplankton (suspensivore, carnivore, and littoral habitats) were associated with an increase in dispersal. Finally, this study contributes to the understanding of how environment, space, and land-use components structure plankton metacommunities.

Environmental and spatial influences on stream zooplankton communities of the Brazilian Cerrado

The integration of species dispersal dynamics with environmental predictors has become indispensable to understanding the pattern of communities’ organization. Thus, we evaluated the relative importance of environmental and spatial variables on the structure of zooplankton metacommunities in 20 Brazilian Cerrado streams. In multivariate models, we used the Partial Redundancy Analysis and found that space is mostly responsible for determining the structuring of the zooplankton community. However, the environmental predictors did not present a significant explanation. Our results indicate that space might act as a co-variable that explains and filters spatial variation when tested between species distributions and environmental factors. We understand that metacommunity studies with stream zooplankton demand more attention because space explained only a minor part of the variation of the zooplankton community. Therefore, advances in the research for environmental variables that can predict zooplankton in the Cerrado streams are important to understand the effects of anthropogenic change on aquatic communities.

Rainfall leads to habitat homogenization and facilitates plankton dispersal in tropical semiarid lakes

Although some efforts have been made to understand the role of hydrology in structuring aquatic systems, little is known about how rainfall affects the relative roles of local environmental and spatial processes in structuring plankton metacommunities in tropical drylands. We hypothesize that the role played by spatial variables is more important in the dry than in the rainy season, because drought increases lakes isolation in semiarid regions. To test our hypothesis, we compared the variation in plankton structure between seasons attributable to local and spatial predictors by using variation-partitioning techniques. We used data for phytoplankton and zooplankton communities as a whole and separately by their size groups (nanoplankton, microplankton and mesoplankton) from 40 man-made lakes in northeastern Brazil. Our results showed that rainfall homogenized limnological variables and reduced total phytoplankton and nanophytoplankton beta diversity, but no effect of season was observed for microphytoplankton and zooplankton communities. Overall, in the dry season, both environmental and spatial variables were important structuring factors for the total phytoplankton, total zooplankton and microzooplankton communities, concurring with both niche- and neutral-based models. In the rainy season, spatial variables were neither important for shaping the phytoplankton nor the zooplankton metacommunities, confirming our hypothesis. The main ecological implication of our findings is that both niche- and neutral-based processes might play an important role on phytoplankton and zooplankton metacommunities dynamics in a future warmer and drier climate in tropical semiarid regions.

Zoochory of zooplankton: seasonality and bird morphological diversity can influence metacommunity dynamics of temporary ponds

Abstract Harsh and unstable aquatic environments present selective forces that influence environmental heterogeneity, dispersal capacity and specific life history strategies that, in turn, affect species distribution and metacommunity dynamics. To date, relatively few studies have examined the potential of bird-mediated dispersal to connect isolated ephemeral habitats. We used zooplankton from temporary ponds to examine the effects of bird morphological diversity and water availability on microcrustacean diversity in temporary ponds. Three bird feet models were constructed based on small, large and webbed anisodactylous forms in order to simulate bird walking on the pond shore. Bird and zooplankton communities were sampled in two temporary ponds and experimentally simulated zooplankton dispersal by bird on dry sediments. We surveyed in two contrasting seasonal periods. Overall, water availability does affect zooplankton composition, and birds with large feet have higher dispersal capacity. In addition, birds with different feet size and shape carry distinct zooplankton species. During the dry season, sediments hold 100% more species than in the wet season, which indicates that birds have higher potential for dispersing zooplankton in drought conditions. Our findings suggest that bird diversity can maintain zooplankton metacommunities by rescuing dormant organisms from dry ponds and connecting to any available aquatic habitats.

Environmental and spatial filters of zooplankton metacommunities in shallow pools in high‐elevation peatlands in the tropical Andes

Abstract Understanding metacommunity organisation in freshwater ecosystems is particularly important at high elevation in the tropical Andes, as this region is considered an important biodiversity hotspot with many endemic species threatened by climate change. High levels of dispersal at the regional scale and strong environmental filters at the local scale are thought to structure aquatic communities in these systems. However, metacommunity organisation patterns at the limit of aquatic life (&gt;4,500 m a.s.l.) remain largely unknown. Given the extreme environmental conditions experienced by organisms at high elevation, environment filters would be expected to play a greater role than spatial filters in community assemblages. We assessed the effects of environmental and spatial filters on zooplankton (Cladocera), to gain insight into metacommunity organisation in the shallow high‐elevation pools of the tropical Andes. We sampled zooplankton communities and assessed nine environmental variables, for 200 pools from 20 peatlands in the Cordillera Real of Bolivia. We performed redundancy and variation partitioning analyses on both abundance and presence/absence data, to evaluate the contribution of environmental and spatial processes (geographic and elevation distances) to cladoceran metacommunity assembly at different spatial scales. We identified 18 cladoceran species, eight of which were endemic to the Andes. We found that both environment and spatial filters made a significant contribution to the structuring of cladoceran communities at higher spatial scales (i.e. intervalleys and within valleys), whereas only the environmental filter operated at small spatial scales (i.e. within peatlands). Elevation had a significant effect on cladoceran community variation (e.g. 6.9% within valleys, for abundance data), but not on species diversity. Similar patterns were obtained with presence/absence data. Macrophyte cover, pool area and pH were the most important variables explaining community variation and the species diversity of cladocerans at pool level. These results suggest that species sorting is probably the main process generating variation in cladoceran communities at all spatial scales. At larger spatial scales (intervalleys and within valleys), limited dispersal may also filter species composition. We identified factors significantly contributing to the variation observed, but their overall explanatory power was low. This finding highlights the difficulties involved in evaluating the response of aquatic organisms to their environment and suggests that other environmental variables should be considered. Moreover, frequent and unpredictable disturbances and high stochasticity probably operate simultaneously with environmental filters to structure zooplankton organisation in these unique and harsh aquatic systems.

Scale-dependent effects of natural environmental gradients, industrial emissions and dispersal processes on zooplankton metacommunity structure: Implications for the bioassessment of boreal lakes

Environmental controls were traditionally considered as sole determinants of community assembly for freshwater bioassessment studies, whereas potential importance of dispersal processes and spatial scale have received limited attention. We conducted a bioassessment of lakes across northeast Alberta, Canada using crustacean zooplankton to develop a framework for evaluating if and how atmospheric emissions from the nearby Athabasca Oil Sands Region could impact their community assemblages. We quantified the effects of environmental gradients and spatially contingent dispersal processes for determining zooplankton community composition of 97 lakes at two spatial scales (regional and sub-regional) using constrained ordination, spatial modeling and variance partitioning techniques. Our findings indicated that effects of both environmental gradients and dispersal processes on species composition were scale-dependent. Zooplankton community composition was significantly correlated to environmental parameters that are directly and indirectly sensitive to industrial deposition including nitrate, sulphate, dissolved organic carbon, base cation, chloride, trace metal concentrations and predation regime, indicating their potential to track future environmental impacts. The relative importance of these environmental predictors varied with spatial scale, yet unraveling the effects of natural environmental heterogeneity vs. industrial deposition on this scale-dependency was not possible due to lack of regional baseline information. Dispersal processes were not important in shaping zooplankton communities at the sub-regional scale, but had limited, yet significant influence on species composition at the regional scale, emphasizing the need for cautious interpretation of broad-scale community patterns. Beyond establishing crucial regional baselines, our study highlights the necessity for explicit incorporation of dispersal effects and spatial scale in bioassessment of lakes across landscapes.

Ecosystem flux and biotic modification as drivers of metaecosystem dynamics.

The fluxes of energy, matter, and organisms are important structuring forces of metaecosystems. Such ecosystem fluxes likely interact with environmental heterogeneity and differentially affect the diversity of multiple communities. In an aquatic mesocosm experiment, we tested how ecosystem flux and patch heterogeneity affected the diversity of bacteria, phytoplankton, and zooplankton metacommunities, and the structure and functioning of metaecosystems. We built metaecosystems consisting of three mesocosms that were either connected by flux of living organisms, organic material, and nutrients (alive ecosystem flux) or only by flux of organic material and nutrients (dead ecosystem flux). The three patches of each metaecosystem were either homogeneous or heterogeneous in nutrient loading. We found that the three groups of organisms responded differently to our treatments: flux of living organisms increased bacterial diversity irrespective of nutrient heterogeneity, while flux effects on phytoplankton diversity depended on nutrient heterogeneity, potentially indicating source-sink effects. Although zooplankton diversity was largely unaffected by our manipulations, subtle changes of community composition in response to ecosystem flux had strong effects on lower trophic levels, highlighting the importance of indirect flux effects via alterations in trophic interactions. Furthermore, differential effects of communities on the mean and spatial variability of local abiotic environments influenced the development of metaecosystem heterogeneity through time. Despite identical nutrient loading at the scale of the metaecosystem, abiotic conditions diverged between homogeneous and heterogeneous metaecosystems. For example, concentrations in dissolved organic carbon (DOC) were higher in homogeneous than heterogeneous metaecosystems, possibly because of differential responses of the algal community to local environmental conditions. Similarly, we found that flux effects on organisms translated into effects on DOC concentrations at the patch level, suggesting that flux-mediated changes in abundances of species can alter abiotic conditions. Our study shows that the dynamics of biotic and abiotic compartments of spatially structured ecosystems are intricately linked, highlighting the importance of integrating metacommunity and metaecosystem perspectives.

Ordination obscures the influence of environment on plankton metacommunity structure

AbstractThe composition of plankton communities in individual habitats is often influenced by environmental conditions like pH or hydroperiod. At larger scales, environmental gradients can influence community structure across interconnected local communities. Detecting the role of environmental and spatial factors on metacommunity structure depends on the ordering of sites and species prior to analysis. We investigated this ordination in two wetland metacommunities; a well‐sampled, hyper‐diverse zooplankton metacommunity, and a Central American phytoplankton metacommunity. We calculated coherence, turnover, and boundary clumping to classify the structure of the metacommunity, and we propose a statistic that responds to variation in both coherence and turnover. Traditional ordination approaches failed to discern metacommunity structure, while significant structure existed along abiotic gradients in both zooplankton and phytoplankton systems. This shows that abiotic controls on community composition may not be detectable with traditional analyses, and suggests an alternative of ordering sites by known abiotic gradients.