Evaluation of the IKEU programme. An evaluation of the programme’s organization, its organs, financing and contributions

Prosjektleder: Øyvind KasteIKEU (Integrated Studies of the Effects of Liming Acidified Waters) is the national monitoring programme for long-term effects of liming in Sweden. The main focus of IKEU is to study the long-term effects of liming on lakes and streams in order to improve the knowledge base for the liming activity. The main aim of this report is to evaluate the current programme structure and IKEU’s fulfilment of the four main objectives since the last evaluation in 2009. The evaluation includes an assessment of scientific quality, the usefulness of the long-term monitoring series produced by the programme, whether the programme produces relevant knowledge for decision making, and to what extent decisionmakers implement the knowledge produced by the programme.The Swedish Agency for Marine and Water ManagementpublishedVersio

Metoder for beregning av vannets syrenøytraliserende kapasitet (ANC) for klassifisering av forsuringstilstand

ANC er nøkkelparameteren for å vurdere endringer i kjemisk vannkvalitet med endringer i sur nedbør, klima og arealbruk. Imidlertid har parameteren lav presisjon, siden den er basert på ladningsbalansen mellom mange målte verdier. Det er derfor ønskelig å utlede alterna tive måter å beregne ANC. ANC er et estimat for overskuddet av svake syrers baser i vannet. I naturlig vann er dette tilnærmet lik differansen mellom konsentrasjonen av H + og summen av bikarbonat og organiske anioner i løsning. Titrert alkalitet er et mål for det samme, men som en erstatning for ANC, må verdien korrig eres for operasjonelle kilder til avvik. Her utledes og testes to teoretiske modeller og en empirisk tilpasset modell for ANC basert på målinger av alkalitet. I de fleste vann anbefales modellen basert på bikarbonat betegnet som ALK02. I svært forsuringsfølsomt vann (nær kvantifise ringsgrense for titrert alkalitet), anbefales imidlertid en empirisk tilpasset modell som erstatning for beregnet ANC.publishedVersio

Metoder for beregning av vannets syrenøytraliserende kapasitet (ANC) for klassifisering av forsuringstilstand

publishedVersio

Naturregnskap og økologisk tilstand. Samsvar mellom fagsystemet for økologisk tilstand, vannforskriften, FNs rammeverk og EUs forslag til naturregnskap

Framstad, E., Czúcz, B, Schartau, A.K., Simensen, T., Nybø, S. & Sandvik, H. 2023. Naturregnskap og økologisk tilstand: Samsvar mellom fagsystemet for økologisk tilstand, vannforskriften, FNs rammeverk og EUs forslag til naturregnskap. NINA Rapport 2327. Norsk institutt for naturforskning. Et naturregnskap er et statistisk rammeverk for å systematisere, beskrive og kvantifisere data om status og endringer i naturens goder samt økosystemenes tilstand og romlige fordeling. FN har i 2021 vedtatt en standard for naturregnskap (SEEA EA). Et økologisk tilstandsregnskap er en vesentlig del av et slikt naturregnskap. Eurostat har i etterkant utviklet en metodikk som bruker FN-standarden som et rammeverk for å sammenstille ulike vurderinger av økologisk tilstand knyttet til EU-lovverk og tilhørende datarapportering. Klima- og miljødepartementet ønsker å få på plass et naturregnskap med god forvaltningsnytte og i tråd med internasjonale standarder innen 2026. Denne rapporten utreder i hvilken grad eksisterende datagrunnlag, variabler og systemer for vurdering av økologisk tilstand i terrestriske, limniske og kystnære marine økosystemer kan videreutvikles slik at dette kan utgjøre et grunnlag for tilstandsregnskap på regionalt nivå i Norge. Rapporten presenterer innledningsvis de relevante nasjonale og internasjonale rammeverkene: fagsystemet for økologisk tilstand, vannforskriften, naturindeks, SEEA EA, JRCs EU-metodikk og Eurostats tilnærming. Deretter gjøres en del konseptuelle avklaringer som inngår i grunnlaget for selve problembesvarelsen, nemlig kriterier for gode tilstandsvariabler, måter å tilordne variabelverdier til økosystemforekomster på, måter å fastsette referanseverdier på, en avklaring av økosystemtypologien som legges til grunn, muligheten for å gjennomføre et tilstandsregnskap på finere romlig skala enn regioner og viktige aspekter ved skalering og romlig aggregering. Selve problembesvarelsen består av fire deler: 1) En vurdering av om og hvordan fagsystemet for økologisk tilstand kan brukes i et tilstandsregnskap etter FN-standarden. Rammeverkene har overensstemmelser på de fleste punkt, men vi påpeker også flere tilpasningsbehov, som bl.a. omfatter en utvidelse til sterkt menneskepåvirkete økosystemer og endringer i økosysteminndelingen. Flere sider ved geografisk aggregering og tematisk sammenstilling av tilstandsvariabler bør undersøkes nærmere. 2) En vurdering av om og hvordan tilstandsvurderinger etter vannforskriftens klassifiseringssystem kan brukes i et tilstandsregnskap etter FN-standarden. Rammeverkene er nokså sammenfallende på de fleste områder, men vi påpeker flere tilpasningsbehov, som bl.a. omfatter avgrensningen i vannforekomster og geografisk aggregering av indikatorverdier. 3) En vurdering av hvilke økosystemtyper som kan ha tilstrekkelig datagrunnlag for relevante variabler til å kunne tilstandsvurderes for 2024. Dette gjøres ved først å vurdere for hver variabel om den har god sammenheng med økosystemets tilstand, henger sammen med påvirkningsfaktorer, har et tilstrekkelig datagrunnlag, har en tilgjengelig referanseverdi og har tilfredsstillende matematiske egenskaper. Deretter gjøres det en samlet vurdering for hver økosystemtype om variabelsettet er dekkende for økosystemenes ulike egenskaper. 4) En illustrasjon av hvordan et tilstandsregnskap kan struktureres og visualiseres. Dette inkluderer eksempler på hvordan et tilstandsregnskap kan se ut i praksis

Spatial and temporal variation in Arctic freshwater chemistry—Reflecting climate-induced landscape alterations and a changing template for biodiversity

Freshwater chemistry across the circumpolar region was characterised using a pan-Arctic data set from 1,032 lake and 482 river stations. Temporal trends were estimated for Early (1970-1985), Middle (1986-2000), and Late (2001-2015) periods. Spatial patterns were assessed using data collected since 2001.Alkalinity, pH, conductivity, sulfate, chloride, sodium, calcium, and magnesium (major ions) were generally higher in the northern-most Arctic regions than in the Near Arctic (southern-most) region. In particular, spatial patterns in pH, alkalinity, calcium, and magnesium appeared to reflect underlying geology, with more alkaline waters in the High Arctic and Sub Arctic, where sedimentary bedrock dominated.Carbon and nutrients displayed latitudinal trends, with lower levels of dissolved organic carbon (DOC), total nitrogen, and (to a lesser extent) total phosphorus (TP) in the High and Low Arctic than at lower latitudes. Significantly higher nutrient levels were observed in systems impacted by permafrost thaw slumps.Bulk temporal trends indicated that TP was higher during the Late period in the High Arctic, whereas it was lower in the Near Arctic. In contrast, DOC and total nitrogen were both lower during the Late period in the High Arctic sites. Major ion concentrations were higher in the Near, Sub, and Low Arctic during the Late period, but the opposite bulk trend was found in the High Arctic.Significant pan-Arctic temporal trends were detected for all variables, with the most prevalent being negative TP trends in the Near and Sub Arctic, and positive trends in the High and Low Arctic (mean trends ranged from +0.57%/year in the High/Low Arctic to -2.2%/year in the Near Arctic), indicating widespread nutrient enrichment at higher latitudes and oligotrophication at lower latitudes.The divergent P trends across regions may be explained by changes in deposition and climate, causing decreased catchment transport of P in the south (e.g. increased soil binding and trapping in terrestrial vegetation) and increased P availability in the north (deepening of the active layer of the permafrost and soil/sediment sloughing). Other changes in concentrations of major ions and DOC were consistent with projected effects of ongoing climate change. Given the ongoing warming across the Arctic, these region-specific changes are likely to have even greater effects on Arctic water quality, biota, ecosystem function and services, and human well-being in the future

Multitrophic biodiversity patterns and environmental descriptors of sub-Arctic lakes in northern Europe

1. Arctic and sub-Arctic lakes in northern Europe are increasingly threatened by climate change, which can affect their biodiversity directly by shifting thermal and hydrological regimes, and indirectly by altering landscape processes and catchment vegetation. Most previous studies of northern lake biodiversity responses to environmental changes have focused on only a single organismal group. Investigations at whole-lake scales that integrate different habitats and trophic levels are currently rare, but highly necessary for future lake monitoring and management. 2. We analysed spatial biodiversity patterns of 74 sub-Arctic lakes in Norway, Sweden, Finland, and the Faroe Islands with monitoring data for at least three biological focal ecosystem components (FECs)—benthic diatoms, macrophytes, phytoplankton, littoral benthic macroinvertebrates, zooplankton, and fish—that covered both pelagic and benthic habitats and multiple trophic levels. 3. We calculated the richnessrelative (i.e. taxon richness of a FEC in the lake divided by the total richness of that FEC in all 74 lakes) and the biodiversity metrics (i.e. taxon richness, inverse Simpson index (diversity), and taxon evenness) of individual FECs using presence–absence and abundance data, respectively. We then investigated whether the FEC richnessrelative and biodiversity metrics were correlated with lake abiotic and geospatial variables. We hypothesised that (1) individual FECs would be more diverse in a warmer and wetter climate (e.g. at lower latitudes and/or elevations), and in hydrobasins with greater forest cover that could enhance the supply of terrestrial organic matter and nutrients that stimulated lake productivity; and (2) patterns in FEC responses would be coupled among trophic levels. 4. Results from redundancy analyses showed that the richnessrelative of phytoplankton, macrophytes, and fish decreased, but those of the intermediate trophic levels (i.e. macroinvertebrates and zooplankton) increased with decreasing latitude and/ or elevation. Fish richnessrelative and diversity increased with increasing temporal variation in climate (temperature and/or precipitation), ambient nutrient concentrations (e.g. total nitrogen) in lakes, and woody vegetation (e.g. taiga forest) cover in hydrobasins, whereas taxon richness of macroinvertebrates and zooplankton decreased with increasing temporal variation in climate. 5. The similar patterns detected for richnessrelative of fish, macrophytes, and phytoplankton could be caused by similar responses to the environmental descriptors, and/or the beneficial effects of macrophytes as habitat structure. By creating habitat, macrophytes may increase fish diversity and production, which in turn may promote higher densities and probably more diverse assemblages of phytoplankton through trophic cascades. Lakes with greater fish richnessrelative tended to have greater average richnessrelative among FECs, suggesting that fish are a potential indicator for overall lake biodiversity. 6. Overall, the biodiversity patterns observed along the environmental gradients were trophic-level specific, indicating that an integrated food-web perspective may lead to a more holistic understanding of ecosystem biodiversity in future monitoring and management of high-latitude lakes. In future, monitoring should also focus on collecting more abundance data for fish and lower trophic levels in both benthic and pelagic habitats. This may require more concentrated sampling effort on fewer lakes at smaller spatial scales, while continuing to sample lakes distributed along environmental gradients.publishedVersio

Multitrophic biodiversity patterns and environmental descriptors of sub-Arctic lakes in northern Europe

Arctic and sub-Arctic lakes in northern Europe are increasingly threatened by climate change, which can affect their biodiversity directly by shifting thermal and hydrological regimes, and indirectly by altering landscape processes and catchment vegetation. Most previous studies of northern lake biodiversity responses to environmental changes have focused on only a single organismal group. Investigations at whole-lake scales that integrate different habitats and trophic levels are currently rare, but highly necessary for future lake monitoring and management. We analysed spatial biodiversity patterns of 74 sub-Arctic lakes in Norway, Sweden, Finland, and the Faroe Islands with monitoring data for at least three biological focal ecosystem components (FECs)—benthic diatoms, macrophytes, phytoplankton, littoral benthic macroinvertebrates, zooplankton, and fish—that covered both pelagic and benthic habitats and multiple trophic levels. We calculated the richnessrelative (i.e. taxon richness of a FEC in the lake divided by the total richness of that FEC in all 74 lakes) and the biodiversity metrics (i.e. taxon richness, inverse Simpson index (diversity), and taxon evenness) of individual FECs using presence–absence and abundance data, respectively. We then investigated whether the FEC richnessrelative and biodiversity metrics were correlated with lake abiotic and geospatial variables. We hypothesised that (1) individual FECs would be more diverse in a warmer and wetter climate (e.g. at lower latitudes and/or elevations), and in hydrobasins with greater forest cover that could enhance the supply of terrestrial organic matter and nutrients that stimulated lake productivity; and (2) patterns in FEC responses would be coupled among trophic levels. Results from redundancy analyses showed that the richnessrelative of phytoplankton, macrophytes, and fish decreased, but those of the intermediate trophic levels (i.e. macroinvertebrates and zooplankton) increased with decreasing latitude and/or elevation. Fish richnessrelative and diversity increased with increasing temporal variation in climate (temperature and/or precipitation), ambient nutrient concentrations (e.g. total nitrogen) in lakes, and woody vegetation (e.g. taiga forest) cover in hydrobasins, whereas taxon richness of macroinvertebrates and zooplankton decreased with increasing temporal variation in climate. The similar patterns detected for richnessrelative of fish, macrophytes, and phytoplankton could be caused by similar responses to the environmental descriptors, and/or the beneficial effects of macrophytes as habitat structure. By creating habitat, macrophytes may increase fish diversity and production, which in turn may promote higher densities and probably more diverse assemblages of phytoplankton through trophic cascades. Lakes with greater fish richnessrelative tended to have greater average richnessrelative among FECs, suggesting that fish are a potential indicator for overall lake biodiversity. Overall, the biodiversity patterns observed along the environmental gradients were trophic-level specific, indicating that an integrated food-web perspective may lead to a more holistic understanding of ecosystem biodiversity in future monitoring and management of high-latitude lakes. In future, monitoring should also focus on collecting more abundance data for fish and lower trophic levels in both benthic and pelagic habitats. This may require more concentrated sampling effort on fewer lakes at smaller spatial scales, while continuing to sample lakes distributed along environmental gradients.Peer reviewe

A hitchhiker's guide to European lake ecological assessment and intercalibration

The Water Framework Directive is the first international legislation to require European countries to establish comparable ecological assessment schemes for their freshwaters. A key element in harmonising quality classification within and between Europe's river basins is an "Intercalibration" exercise, stipulated by the WFD, to ensure that the good status boundaries in all of the biological assessment methods correspond to similar levels of anthropogenic pressure. In this article, we provide a comprehensive overview of this international comparison, focusing on the assessment schemes developed for freshwater lakes. Out of 82 lake ecological assessment methods reported for the comparison, 62 were successfully intercalibrated and included in the EC Decision on intercalibration, with a high proportion of phytoplankton (18), macrophyte (17) and benthic fauna (13) assessment methods. All the lake assessment methods are reviewed in this article, including the results of intercalibration. Furthermore, the current gaps and way forward to reach consistent management objectives for European lakes are discussed. (C) 2015 The Authors. Published by Elsevier Ltd.Peer reviewe