scholarly journals Zooplankton functional complementarity between temporary and permanent environments

2021 ◽  
Vol 33 ◽  
Author(s):  
Rayanne Barros Setubal ◽  
Reinaldo Luiz Bozelli

Abstract: Aims This study aims to evaluate the functional complementarity of the zooplankton community between temporary ponds and permanent lagoons. We hypothesize that temporary environments will be functionally more diverse than permanent environments and will have different functional composition. Methods Five temporary ponds and five permanent lagoons were compared regarding their limnological characteristics, species richness, functional diversity indices and functional trait composition. Results No differences between ponds and lagoons were found regarding mean species richness and functional diversity. However, a larger number of species was found in the set of temporary environments i.e., although the mean richness was the same, the species' identity varied from one pond to another. Ponds showed greater variability in functional trait composition, resulting in significant differences in zooplankton functional dispersion. Ponds also presented a greater range of limnological characteristics. Conclusions Temporary and permanent environments present high limnological and functional complementarity, which make them important for maintaining biodiversity on a regional scale. Temporary environments seem to be refugees for species that do not settle in more stable environments because these species are more likely to colonize environments that periodically restart their successional trajectory. Therefore, actions that seek to preserve complementary environments are essential and urgent, especially those related to small and temporary environments.

2019 ◽  
Vol 70 (11) ◽  
pp. 1611 ◽  
Author(s):  
Xiaoyun Bai ◽  
Congcong Guo ◽  
Mamun Abdullah Al ◽  
Alan Warren ◽  
Henglong Xu

Multifunctional trait analysis is increasingly recognised as an effective tool for assessing ecosystem function and environmental quality. Here, a baseline study was performed at four depths (i.e. 1, 2, 3.5 and 5m) in Yellow Sea coastal waters of northern China in order to determine the optimal depth for bioassessment using biological traits of biofilm-dwelling ciliates. Community-weighted means (CWM) from functional traits system were used to summarise the trait distribution and functional diversity of ciliates among the four depths during a 1-month colonisation period. Functional trait distribution revealed a clear temporal variation among the four depths. In total, 3 of 17 functional traits (i.e. feeding type, body size and flexibility) showed significant temporal patterns. Bootstrapped averaging and permutational multivariate analysis of variance (PERMANOVA) tests demonstrated that the colonisation pattern of biofilm-dwelling ciliates as expressed by CWM at 1 and 2m differed significantly from those at 3.5 and 5m. Functional diversity indices showed lower variability at 1 and 2m than at 3.5 and 5m. These results suggest that 1 and 2m are the preferred sampling depths for bioassessment of marine water quality using biological traits of biofilm-dwelling ciliates.


2015 ◽  
Author(s):  
Jonathan S Lefcheck ◽  
J. Emmett Duffy

The use of functional traits to explain how biodiversity affects ecosystem functioning has attracted intense interest, yet few studies have a priori altered functional diversity, especially in multitrophic communities. Here, we manipulated multivariate functional diversity of estuarine grazers and predators within multiple levels of species richness to test how species richness and functional diversity predicted ecosystem functioning in a multitrophic food web. Community functional diversity was a better predictor than species richness for the majority of ecosystem properties, based on general linear mixed effects models. Combining inferences from 8 traits into a single multivariate index increased prediction accuracy of these models relative to any individual trait. Structural equation modeling revealed that functional diversity of both grazers and predators was important in driving final biomass within trophic levels, with stronger effects observed for predators. We also show that different species drove different ecosystem responses, with evidence for both sampling effects and complementarity. Our study extends experimental investigations of functional trait diversity to a multilevel food web, and demonstrates that functional diversity can be more accurate and effective than species richness in predicting community biomass in a food web context.


2015 ◽  
Author(s):  
Jonathan S Lefcheck ◽  
J. Emmett Duffy

The use of functional traits to explain how biodiversity affects ecosystem functioning has attracted intense interest, yet few studies have a priori manipulated functional diversity, especially in multitrophic communities. Here, we manipulated multivariate functional diversity of estuarine grazers and predators within two levels of species richness to test how species richness and functional diversity predicted ecosystem functioning in a multitrophic food web. Community functional diversity was a better predictor than species richness for the majority of ecosystem properties, based on general linear mixed effects models. Combining inferences from 8 traits into a single multivariate index increased prediction accuracy of these properties relative to any individual trait. Structural equation modeling revealed that functional diversity of both grazers and predators was important in driving final biomass within and between trophic levels, with stronger effects observed for predators. We also show that different species drove different ecosystem responses, with evidence for both sampling effects and complementarity. Our study extends experimental investigations of functional trait diversity to a multilevel food web, and demonstrates that functional diversity can be more accurate and effective than species richness in predicting community biomass in a food web context.


2021 ◽  
Author(s):  
Angélica Vilas Boas da Frota ◽  
Breno Dias Vitorino ◽  
Sara Miranda Almeida ◽  
Josué Ribeiro da Silva Nunes ◽  
Carolina Joana Da Silva

Abstract Hydrological dynamics of the Pantanal wetland drive the availability of resources and niche for aquatic and terrestrial fauna. We consider that changes in the hydrological regime of this floodplain can affect species richness, abundance and functional structure of waterbirds, wetland birds and non-wetland birds. Our study aimed to assess whether the degree of wetland dependence influences the response of bird groups to the flood pulse. We conducted the bird survey in the Paraguay River floodplain system, in five sampling sites, covering the periods of drought, flooding, full flood and ebb of the 2017–2018 hydrological cycle. Species richness and abundance were higher for non-wetland birds than waterbirds and wetland birds. On the other hand, we found that the higher the degree of wetland dependence by birds, the higher the differences in the functional-trait values. Species richness, abundance and all metrics of functional diversity varied significantly when there was an interaction between the degree of wetland dependence and the hydrological period. In all hydrological periods, bird groups occupied distinct niches. Traits such as foraging around or below the water surface were among the dominant functional traits in all hydrological periods. We emphasize the need to consider the functional traits of species in ecological studies of wetlands since measuring only species richness may not reflect the characteristics inherent to this type of ecosystem. In addition, the conservation of wetlands directly implies the maintenance of various niches throughout the hydrological periods, either for dependent or non-dependent bird species in wetlands.


2021 ◽  
Author(s):  
Matt Davis

Continuous indices of functional diversity are popular in studies examining community structure and ecosystem function across a wide range of subfields from paleontology to range management. These indices were designed to replace the use of more arbitrary, discrete functional groups or guilds; however, the effect of typical methodological decisions on these new continuous measures has not been fully investigated. To test the effect of using ordinal traits in functional diversity analysis, I first calculated relative functional diversity index values in real plant communities with real continuous trait data and Euclidean distances. I then compared these original values to "treatment" functional diversity index values obtained by discretizing the trait data and using Gower's distance. Agreement between original and treatment values was highly unpredictable and often abysmal. Small methodological choices, such as whether to treat a functional trait as continuous (mm) or ordinal ("small", "medium", "large"), could completely change a perceived functional diversity relationship along an environmental gradient. Some parameter combinations returned results that were no better than random noise. Because simple methodological choices can have such a large impact on continuous functional diversity indices, it is ambiguous whether analyses using ordinal traits are actually measuring an underlying functional diversity relationship between communities or just reflecting the arbitrary parameter choices of researchers.


2021 ◽  
Vol 11 ◽  
Author(s):  
Daniela Aros-Mualin ◽  
Sarah Noben ◽  
Dirk N. Karger ◽  
César I. Carvajal-Hernández ◽  
Laura Salazar ◽  
...  

Functional traits determine how species interact with their abiotic and biotic environment. In turn, functional diversity describes how assemblages of species as a whole are adapted to their environment, which also determines how they might react to changing conditions. To fully understand functional diversity, it is fundamental to (a) disentangle the influences of environmental filtering and species richness from each other, (b) assess if the trait space saturates at high levels of species richness, and (c) understand how changes in species numbers affect the relative importance of the trait niche expansion and packing. In the present study, we determined functional diversity of fern assemblages by describing morphological traits related to resource acquisition along four tropical elevational transects with different environmental conditions and species richness. We used several functional diversity indices and their standardized effect size to consider different aspects of functional diversity. We contrasted these aspects of functional diversity with climate data and species richness using linear models and linear mixed models. Our results show that functional morphological trait diversity was primarily driven by species richness and only marginally by environmental conditions. Moreover, increasing species richness contributed progressively to packing of the morphological niche space, while at the same time decreasing morphological expansion until a saturation point was reached. Overall, our findings suggest that the density of co-occurring species is the fundamental driving force of morphological niche structure, and environmental conditions have only an indirect influence on fern resource acquisition strategies.


2018 ◽  
Author(s):  
Lise Bacouillard ◽  
Noémie Baux ◽  
Jean-Claude Dauvin ◽  
Nicolas Desroy ◽  
Katja Juliana Geiger ◽  
...  

In the eastern Bay of Seine, which is a representative area of coastal zones exposed to numerous anthropogenic disturbances, data from a long-term monitoring program of the benthic macrofauna based on a framework of 60 stations sampled during 7 cruises from 1988 to 2016 were used to investigate the link between species and functional diversity at different scales and assess how long-term changes in the community structure may have altered the ecosystem functioning. To cover the different facets of α-diversity, a selection of species and functional diversity indices were calculated and the links between these metrics were determined from a Principal Component Analysis. The β-diversity was analysed by applying multivariate methods on both species and traits composition matrices. Population fluctuations of a few very abundant species led to the major variations observed in the structure of the community in both taxonomic and functional aspects. A certain redundancy was found among species and functional diversity indices in terms of richness, evenness and heterogeneity. Likewise, at regional scale, similar patterns were reported on the spatial structure of the community in terms of species and trait composition. These patterns persist over time suggesting that the community structure and its functioning are rather resilient.


Plants ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 778
Author(s):  
Yesica Pallavicini ◽  
Fernando Bastida ◽  
Eva Hernández-Plaza ◽  
Sandrine Petit ◽  
Jordi Izquierdo ◽  
...  

Arable field margins are valuable habitats providing a wide range of ecosystem services in rural landscapes. Agricultural intensification in recent decades has been a major cause of decline in plant diversity in these habitats. However, the concomitant effects on plant functional diversity are less documented, particularly in Mediterranean areas. In this paper, we analyzed the effect of margin width and surrounding landscape (cover and diversity of land use and field size), used as proxies for management intensity at local and landscape scales, on plant species richness, functional diversity and functional trait values in margins of winter cereal fields in southern Spain. Five functional traits were selected: life form, growth form, seed mass, seed dispersal mode and pollination type. RLQ and fourth-corner analyses were used to link functional traits and landscape variables. A total of 306 plant species were recorded. Species richness and functional diversity were positively related to margin width but showed no response to landscape variables. Functional trait values were affected neither by the local nor landscape variables. Our results suggest that increasing the margin width of conventionally managed cereal fields would enhance both taxonomic and functional diversity of margin plant assemblages, and thus the services they provide to the agro-ecosystem.


Author(s):  
Karl A. Lamothe ◽  
Justin A. G. Hubbard ◽  
D. Andrew R. Drake

Abstract The Niagara River, which connects two Great Lakes (Erie and Ontario) and forms a border between Canada and the United States, has experienced decades of abiotic and biotic disturbance as well as long-term restoration efforts. Given the iconic riverscape and importance as a binational fisheries resource, a biodiversity assessment of the mainstem Niagara River fish assemblage is overdue. Here, fish assemblage and habitat data from a standardized boat electrofishing program of the Niagara River were combined with species trait data related to substrate associations, diet preferences, reproductive strategies, and body size to quantify biodiversity patterns among river sections (sites above and below Niagara Falls), seasons (spring, summer, fall), and years (2015–2017). Sixty-five species were captured representing a variety of trait combinations. Significant differences in functional dispersion and divergence (i.e., functional diversity) were observed between river sections, seasons, and (or) years. The fish community captured in the lower river in spring 2015 had both the highest average functional dispersion (2.08 ± 0.32 SD) and divergence (0.88 ± 0.04 SD) compared to the other seasonal sampling efforts, but relatively few fishes were captured (n = 686). Although non-native fishes represented a small portion of the catch over the 3 years (8.6% of catch), the seasonal presence (spring and fall) of mostly introduced large-bodied salmonids expanded functional trait space in the lower river during these periods. The importance of rare species on functional diversity metrics suggests further insight on local species detection probabilities is needed to understand if differences in functional diversity reflect ecological patterns or are driven by sampling design.


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