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Linking environmental and biological data using ecological models can provide crucial knowledge about the effects of water quality parameters on freshwater ecosystems. However, a model can only be as reliable as its input data. Here, the influence of sampling frequency of temporal variable environmental input data on the reliability of model results when linked to biological data was investigated using Threshold Indicator Taxa Analysis (TITAN) and species sensitivity distributions (SSDs). Large-scale biological data from benthic macroinvertebrates and matching water quality data including four metals and four nutrients of up to 559 site-year combinations formed the initial data sets. To compare different sampling frequencies, the initial water quality data sets (n = 12 samples per year, set as reference) were subsampled (n = 10, 8, 6, 4, 2 and 1), annual mean values calculated and used as input data in the models. As expected, subsampling significantly reduced the reliability of the environmental input data across all eight substances. For TITAN, the use of environmental input data with a reduced reliability led to a considerable (1) loss of information because valid taxa were no longer identified, (2) gain of unreliable taxon-specific change points due to false positive taxa, and (3) bias in the change point estimation. In contrast, the reliability of the SSD results appeared to be much less reduced. However, closer examination of the SSD input data indicated that existing effects were masked by poor model performance. The results confirm that the sampling frequency of water quality data significantly influences the reliability of model results when linked with biological data. For studies limited to low sampling frequencies, the discussion provides recommendations on how to deal with low sampling frequencies of temporally variable water quality data when using them in TITAN, in SSDs, and in other ecological models.
Denise Babitsch; Elisabeth Berger; Andrea Sundermann. Linking environmental with biological data: Low sampling frequencies of chemical pollutants and nutrients in rivers reduce the reliability of model results. Science of The Total Environment 2021, 772, 145498 .
AMA StyleDenise Babitsch, Elisabeth Berger, Andrea Sundermann. Linking environmental with biological data: Low sampling frequencies of chemical pollutants and nutrients in rivers reduce the reliability of model results. Science of The Total Environment. 2021; 772 ():145498.
Chicago/Turabian StyleDenise Babitsch; Elisabeth Berger; Andrea Sundermann. 2021. "Linking environmental with biological data: Low sampling frequencies of chemical pollutants and nutrients in rivers reduce the reliability of model results." Science of The Total Environment 772, no. : 145498.
Water is essential to human societies and a prerequisite for flourishing nature, especially in arid regions. Yet, climate change and socio-economic developments are expected to exacerbate current and future stresses on water resources, demanding innovative approaches to balance water needs for society and nature conservation. In this study, we use the IPBES conceptual framework to combine ecological and socio-economic insights and analyse the connections between people and nature in the water scarce Draa River Basin, southern Morocco. We study the diversity of desert benthic macroinvertebrates as one component of nature using DNA barcoding and their potential to serve as bioindicators of human impact by relating species occurrences to environmental parameters. Furthermore, based on 87 interviews with farmers and key institutional stakeholders, we investigate how farmers perceive water related changes and how water is managed in the basin. Regarding benthic macroinvertebrates, 41 families were identified, 475 DNA barcodes generated and assigned to 118 putative species (Barcode Index Numbers) of which 60 were first records. This indicates a lack of reference sequences for known, but also a potentially high number of undescribed species. Environmental parameters, which are partly influenced by human activities, such as aquatic stages, salinity and intermittency, were the most important variables explaining invertebrate richness and community composition in generalized linear models. We further describe farmers' perceptions of decreasing water quality and quantity. Farmers generally believe that they are able to cope with water related changes, although perceptions are regionally differentiated with farmers downstream being less optimistic. With growing concerns, water policies currently focus on increasing water supply and less on reducing water demands. Based on these findings, the usefulness of the IPBES framework for understanding social-ecological system dynamics is reflected, and recommendations for future freshwater management and research are derived.
Elisabeth Berger; Lisa Bossenbroek; Arne J. Beermann; Ralf B. Schäfer; Mohammed Znari; Sina Riethmüller; Nanki Sidhu; Nils Kaczmarek; Hassan Benaissa; Mohamed Ghamizi; Sabrina Plicht; Souad Ben Salem; Fadoua El Qorchi; Mohamed Naimi; Florian Leese; Oliver Frör. Social-ecological interactions in the Draa River Basin, southern Morocco: Towards nature conservation and human well-being using the IPBES framework. Science of The Total Environment 2021, 769, 144492 .
AMA StyleElisabeth Berger, Lisa Bossenbroek, Arne J. Beermann, Ralf B. Schäfer, Mohammed Znari, Sina Riethmüller, Nanki Sidhu, Nils Kaczmarek, Hassan Benaissa, Mohamed Ghamizi, Sabrina Plicht, Souad Ben Salem, Fadoua El Qorchi, Mohamed Naimi, Florian Leese, Oliver Frör. Social-ecological interactions in the Draa River Basin, southern Morocco: Towards nature conservation and human well-being using the IPBES framework. Science of The Total Environment. 2021; 769 ():144492.
Chicago/Turabian StyleElisabeth Berger; Lisa Bossenbroek; Arne J. Beermann; Ralf B. Schäfer; Mohammed Znari; Sina Riethmüller; Nanki Sidhu; Nils Kaczmarek; Hassan Benaissa; Mohamed Ghamizi; Sabrina Plicht; Souad Ben Salem; Fadoua El Qorchi; Mohamed Naimi; Florian Leese; Oliver Frör. 2021. "Social-ecological interactions in the Draa River Basin, southern Morocco: Towards nature conservation and human well-being using the IPBES framework." Science of The Total Environment 769, no. : 144492.
In many dry parts of the world, salinization of water resources threatens freshwater biodiversity and the livelihood of people. However, ecological impact studies remain scarce. Here, we review field-observations of salinity impacts on ecosystem processes such as leaf decomposition, metabolism, biomass production and nutrient cycling, with a special emphasis on dryland ecosystems. In addition, we discuss the potential linkages of these processes to ecosystem service delivery—the benefits that humans derive from ecosystems—as additional nature conservation arguments and the challenges associated with this endeavour. This article is part of the theme issue ‘Salt in freshwaters: causes, ecological consequences and future prospects'.
Elisabeth Berger; Oliver Frör; Ralf B. Schäfer. Salinity impacts on river ecosystem processes: a critical mini-review. Philosophical Transactions of the Royal Society B: Biological Sciences 2018, 374, 20180010 .
AMA StyleElisabeth Berger, Oliver Frör, Ralf B. Schäfer. Salinity impacts on river ecosystem processes: a critical mini-review. Philosophical Transactions of the Royal Society B: Biological Sciences. 2018; 374 (1764):20180010.
Chicago/Turabian StyleElisabeth Berger; Oliver Frör; Ralf B. Schäfer. 2018. "Salinity impacts on river ecosystem processes: a critical mini-review." Philosophical Transactions of the Royal Society B: Biological Sciences 374, no. 1764: 20180010.
Monitoring of macroinvertebrate communities is frequently used to define the ecological health status of rivers. Ideally, biomonitoring should also give an indication on the major stressors acting on the macroinvertebrate communities supporting the selection of appropriate management measures. However, most indices are affected by more than one stressor. Biological traits (e.g. size, generation time, reproduction) could potentially lead to more stressor-specific indices. However, such an approach has rarely been tested. In this study we classify 324 macroinvertebrate taxa as vulnerable (decreasing abundances) or tolerant (increasing abundances) along 21 environmental gradients (i.e. nutrients, major ions, oxygen and micropollutants) from 422 monitoring sites in Germany using Threshold Indicator Taxa Analysis (TITAN). Subsequently, we investigate which biological traits and taxonomic groups are associated with taxa classified as vulnerable or tolerant with regard to specific gradients. The response of most taxa towards different gradients was similar and especially high for correlated gradients. Traits associated with vulnerable taxa across most gradients included: larval aquatic life stages, isolated cemented eggs, reproductive cycle per year 2-4cm. Our results question whether stressor-specific indices based on macroinvertebrate assemblages can be achieved using single traits, because we observed that similar taxa responded to different gradients and also similar traits were associated with vulnerable and tolerant taxa across a variety of water quality gradients. Future studies should examine whether combinations of traits focusing on specific taxonomic groups achieve higher stressor specificity.
Elisabeth Berger; Peter Haase; Ralf Schäfer; Andrea Sundermann. Towards stressor-specific macroinvertebrate indices: Which traits and taxonomic groups are associated with vulnerable and tolerant taxa? Science of The Total Environment 2018, 619-620, 144 -154.
AMA StyleElisabeth Berger, Peter Haase, Ralf Schäfer, Andrea Sundermann. Towards stressor-specific macroinvertebrate indices: Which traits and taxonomic groups are associated with vulnerable and tolerant taxa? Science of The Total Environment. 2018; 619-620 ():144-154.
Chicago/Turabian StyleElisabeth Berger; Peter Haase; Ralf Schäfer; Andrea Sundermann. 2018. "Towards stressor-specific macroinvertebrate indices: Which traits and taxonomic groups are associated with vulnerable and tolerant taxa?" Science of The Total Environment 619-620, no. : 144-154.