Browsing by Subject "Bioindicators"

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  • Rainio, J.; Niemelä, J. (Kluwer Academic Publishers, 2003)
    One of the primary goals of research on bioindicators is to identify species or other taxonomic units that would reliably indicate disturbances in the environment, and reflect the responses of other species or the overall biodiversity. However, there is no perfect bioindicator and selecting the most suitable one depends to a great extent on the goal of the survey. In this paper we examine the suitability of carabids as bioindicators. Carabids are frequently used to indicate habitat alteration. They have been used in grasslands and boreal forests where species number and/ or abundances have been noted to change along a habitat disturbance gradient. A common trend is that large, poorly dispersing specialist species decrease with increased disturbance while small generalist species with good dispersal ability increase. Some species are not affected by moderate disturbance. There is, however, not enough research to determine how suitable carabids are for biodiversity studies, or how well they represent the response of other species. We conclude that carabids are useful bioindicators, but as crucial understanding of their relationship with other species is incomplete, they should be used with caution.
  • Ovaskainen, Otso Tapio; Weigel, Benjamin Matthias; Potyutko, Oleg; Buyvolov, Yury (2019)
    Scale-related assessment strategies are important contributions to successful ecosystem management. With varying impact of environmental drivers from local to regional scales, a focal task is to understand scale-de- pendent responses when assessing the state of an ecosystem. In this study we use large-scale monitoring data, spanning 40 years and including four aquatic bioindicator groups (phytoplankton, zooplankton, periphyton, zoobenthos) to expose the long-term changes of water quality across Russia. We include four hierarchical spatial scales (region, basin, waterbody and observation point) to identify the relative importance of different spatio- temporal scales for the variation of each bioindicator and patterns of co-variation among the bioindicators at different hierarchical levels. We analysed the data with Hierarchical Modelling of Species Communities (HMSC), an approach that belongs to the framework of joint species distribution models. We performed a cross validation to reveal the predictive power of modelled bioindicator variation, partitioned explained variance among the fixed effects (waterbody type, and influence of human population density) and the random effects (spatial and spatio-temporal variation at the four hierarchical scales), and examined the co-variation among bioindicators at each spatio-temporal scale. We detected generally decreasing water quality across Russian freshwaters, yet with region and bioindicator specific trends. For all bioindicators, the dominating part of the variation was attributed the largest (region) and smallest (observation point) hierarchical scales, the region particularly important for benthic and the observation point for pelagic bioindicators. All bioindicators captured the same spatial variation in water quality at the smallest scale of observation point, with phytoplankton, zooplankton and periphyton being associated positively to each other and negatively to zoobenthos. However, at larger spatial scales and at spatio-temporal scales, the associations among the bioindicators became more complex, with phytoplankton and zooplankton showing opposite trends over time. Our study reveals the sensitivity of bioindicators to spatial and temporal scales. While delivering unidirectional robust water quality assessments at the local scale, bioindicator co-variation is more complex over larger geographic scales and over time.
  • Popov, S.; Milicic, M.; Diti, I.; Marko, O.; Sommaggio, D.; Markov, Z.; Vujic, A. (2017)
    Spatial and temporal differences in landscape patterns are of considerable interest for understanding ecological processes. In this study, we assessed habitat quality by using the Syrph The Net database and data on decreasing species richness over a 25-year period for the two largest phytophagous hoverfly genera (Merodon and Cheilosia). Furthermore, within this time frame, we explored congruence between ecological responses (species richness and Biodiversity Maintenance Function for these two genera) and landscape structural changes through correlation analysis. Our results indicate that landscapes have experienced changes in aggregation, isolation/connectivity and landscape diversity, with these parameters being significantly correlated with Cheilosia species richness loss and habitat quality. We conclude that the genus Cheilosia is a good bioindicator that can highlight not only the current quality of an area but also temporal changes in landscape patterns.
  • Whittle, Alex; Amesbury, Matthew J.; Charman, Dan J.; Hodgson, Dominic A.; Perren, Bianca B.; Roberts, Stephen J.; Gallego-Sala, Angela V. (2019)
    Unicellular free-living microbial eukaryotes of the order Arcellinida (Tubulinea; Amoebozoa) and Euglyphida (Cercozoa; SAR), commonly termed testate amoebae, colonise almost every freshwater ecosystem on Earth. Patterns in the distribution and productivity of these organisms are strongly linked to abiotic conditions—particularly moisture availability and temperature—however, the ecological impacts of changes in salinity remain poorly documented. Here, we examine how variable salt concentrations affect a natural community of Arcellinida and Euglyphida on a freshwater sub-Antarctic peatland. We principally report that deposition of wind-blown oceanic salt-spray aerosols onto the peatland surface corresponds to a strong reduction in biomass and to an alteration in the taxonomic composition of communities in favour of generalist taxa. Our results suggest novel applications of this response as a sensitive tool to monitor salinisation of coastal soils and to detect salinity changes within peatland palaeoclimate archives. Specifically, we suggest that these relationships could be used to reconstruct millennial scale variability in salt-spray deposition—a proxy for changes in wind-conditions—from sub-fossil communities of Arcellinida and Euglyphida preserved in exposed coastal peatlands.
  • Pajunen, Virpi; Kahlert, Maria; Soininen, Janne (2020)
    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 of indices and models outside the regions they were derived from. We tested the reliability of stream diatom assemblages as indicators of water chemistry and climatic factors in a cross-regional assessment by developing a predictive model with diatom assemblage data from Sweden and using it to model stream conditions in Finland. The inference models and predictions were performed using the Boosted Regression Trees (BRT) method, separately in species and genus levels. The predictive performance of the calibration models in Sweden were good or moderate for both water chemistry and climatic variables, both at species and genus levels. The most important climatic (growing degree days, r(2) = 0.57) and water chemistry variables (pH, r(2) = 0.65; and total phosphorus (TP), r(2) = 0.52) could be inferred from diatom assemblages relatively well. However, predictive performances of the cross-regional models were low (r(2)