Greener rivers in a changing climate?—Effects of climate and hydrological regime on benthic algal assemblages in pristine streams

Excessive biomass development of benthic algae is often considered undesirable, but understanding the causes is confounded by complex interactions among driving factors. Pristine rivers allow a benchmark where human interference should be limited to climate change. In this study a time series comprising >20 years of annual benthic algae surveys from two pristine, soft water, boreal stream sites is used to determine whether year-to-year variations in benthic algal assemblages and cover were related to climate (temperature, precipitation, North Atlantic Oscillation) or hydrological regime. Total benthic algal cover ranged from 6 to 100% at Atna (the outflow of the Atna River from Lake Atnasjø), and from 3 to 50% at the headwater stream Li. Climate and hydrological regime explained 18 - 74% of the variability in benthic algal assemblages and cover. Generally, more variance was explained at Li than at Atna, possibly because (i) aquatic bryophytes blurred nutrient-mediated effects of climate and hydrology at Atna, and (ii) the upstream lake buffered hydrological variation. Temperature was more important for explaining benthic algal assemblages and cover at Atna, while hydrology was more important at Li. Climate and hydrological regime had no major impact on benthic algal taxon richness. High temperatures were associated with high benthic algal cover, particularly at Atna, while high suspended particle concentrations were associated with reduced benthic algal cover at Li, possibly due to scouring. Cover of the cyanobacterium Phormidium sp. increased at Li with increasing temperature, and decreased with prolonged periods of high discharge. Current predictions of climate change would lead to a “greener” Atna (increased cover of benthic algae), while Li would become more “bluegreen” (more Phormidium sp. but less filamentous green algae). It would also lead to a slightly more “eutrophic” algal assemblage at Atna (as indicated by the PIT-index for ecological status assessment), while a possible drift of the PIT-index is less clear at Li. The differences between Atna and Li likely reflect differences among river types, and it seems possible to make some generalizations: climate will likely affect benthic algae in lake outlets primarily via temperature, while headwater streams will primarily be affected via altered hydrology and particle concentrations.acceptedVersio

Ecological status assessment of clay rivers with naturally enhanced water phosphorus concentrations

The species composition of benthic algae changes as water phosphorus concentrations increase, and these changes can be used for ecological status assessment according to the Water Framework Directive. Natural background phosphorus concentrations in rivers and streams that are unaffected by anthropogenic impacts are usually low. Running waters draining catchments with deposits of marine clay, however, may have enhanced phosphorus concentrations, because the clay is naturally rich in apatite. Almost all clay rich areas have been cultivated for centuries, however, and fertilization has increased the soil phosphorus levels. It has, therefore, been difficult to disentangle natural from anthropogenically enhanced phosphorus in streams draining clay rich areas. We compared water phosphorus concentrations, and the Periphyton Index of Trophic Status PIT, between clay and non-clay, impacted and unimpacted rivers in Norway. We found that water phosphorus concentrations and the PIT index were higher in unimpacted clay rivers than in unimpacted non-clay rivers, indicating that natural phosphorus concentrations in clay rivers are indeed enhanced compared to rivers without deposits of marine clay. In addition, phosphate-P contributed 18–23% to total phosphorus in unimpacted clay rivers, but 33–37% in unimpacted and impacted non-clay rivers and clay rivers affected by agriculture. This indicates that the total phosphorus in unimpacted clay rivers is less bioavailable than in non-clay rivers and in impacted clay rivers. Water total phosphorus concentrations in unimpacted clay rivers significantly increased with catchment clay cover. Based on these findings, we derived new status class boundaries for the PIT index in clay rivers. Clay rivers are suggested to be assessed in only two status classes, i.e., “good or better” or “moderate or worse”, respectively. The good/moderate status class boundary for the PIT index was shown to increase with increasing catchment clay cover.publishedVersio

Do benthic algae provide important information over and above that provided by macrophytes and phytoplankton in lake status assessment? – Results from a case study in Norway

To test if phytobenthic algae provide additional important information to macrophytes and phytoplankton for lake monitoring, we sampled two large lakes in Norway. In each lake, we analyzed water chemistry and phytoplankton above the deepest site, recorded macrophytes and non-diatom phytobenthic algae at 20 sites around the shoreline and estimated site-specific nutrient input from land cover. Since no ready-to-use phytobenthos index exists for lakes in Norway, we tested the PIT index developed for rivers, commonly perceived signs of disturbance such as high algal cover, and taxon richness as well as similarity patterns. Both lakes were nutrient poor, but had potential local nutrient inputs (villages, agriculture). In neither of the lakes did phytobenthos indicate a worse overall ecological status than macrophytes and phytoplankton. Our data therefore, did not suggest that it would be useful to add phytobenthos into surveillance monitoring of lakes in Norway. There was a loose correlation between macrophyte and phytobenthic site-specific taxon richness and similarities. This means that macrophytes and phytobenthos do indeed give partly redundant information. High algal cover was found at sites with both high and low phosphorus input. Using algal cover as indicator of site-specific nutrient input is therefore overly simplistic. Urban and cultivated areas were associated with a more eutrophic PIT. This indicates that the PIT, despite being developed for lotic waters, may be used to detect site specific nutrient input in lakes.publishedVersio

How Characean algae take up needed and excrete unwanted ions – An overview explaining how insights from electrophysiology are useful to understand the ecology of aquatic macrophytes

Characean algae have been a model plant for electrophysiology for many decades, due to the large size of the internodal cells and their robust recovery from invasive manipulation. The information gained from them has provided a template for understanding the electrophysiology of many plant groups. The relative ability to take up or export ions, including nutrients and toxins, can be part of the explanation as to why certain macrophytes occur preferably in nutrient-rich or oligotrophic habitats, why some macrophytes can grow in brackish water or only in freshwater, or why growth is limited to a particular range of pH. The electrical characteristics of the macrophyte’s cells play a determining factor in these transport properties, yet electrophysiological results are seldom cited in ecological publications, perhaps due to difficulties of communication between fields with different research approaches and terminology. We here present main electrophysiological findings on the transport of ions in and out of cells, in a way that is more accessible to ecologists. We examine the mechanism by which Characean algae generate the electrical voltage difference across their membrane, its effect on the transport of ions, and the mechanisms by which ions can be moved against the gradients that determine passive movements. Finally, we use the example of salinity tolerance to show what we learn about the evolution of salt tolerance in plants by using electrophysiological techniques.publishedVersio

Overvåking av krypsiv – resultater 2014-2023

Prosjektleder: Susanne C. SchneiderTi år med overvåkning av krypsiv ved 9 stasjoner i Tovdalselva, Otra, Mandalselva og Sira-Kvina vassdraget avdekket få konsistente trender i dekningsgrad og plantelengde av krypsiv. Vi kan konkludere med at: (1) Noen steder er det normalt med mye krypsiv. (2) Mange steder har krypsivet nådd en slags balanse mellom vekst og tilbakegang. (3) Det er usannsynlig at «tette skyer» med påvekstalger kan forhindre massevekst av krypsiv. (4) Det kan ikke utelukkes at tette krypsivbestander påvirker diversiteten av andre vannplanter negativt.Krypsiv på Sørlandet (KPS)publishedVersio

Økologisk tilstand i Norddalselva i Vanylven kommune i 2021/2022

Prosjektleder: Jonas PerssonDet ble i 2021/2022 gjennomført biologiske og vannkjemiske undersøkelser i Norddalselva i Møre. Hensikten var å vurdere økologisk tilstand og graden av eutrofipåvirkning, og hvorvidt reguleringen av vassdraget har bidratt til redusert økologisk tilstand. Middelkonsentrasjonene av næringssalter (Tot-P og Tot-N) var lave og viste svært god tilstand ved alle stasjoner. Begroingsalgene viste svært god økologisk tilstand ved samtlige stasjoner med tanke på eutrofiering (PIT-indeksen). Andelen næringskrevende arter var lav, og det ble ikke observert unormalt høy dekningsgrad ved noen av stasjonene. Resultatene fra bunndyrsundersøkelsene viste overlag god tilstand med hensyn til organisk forurensing/eutrofiering (ASPT-indeksen). Dette tyder på lite forurensing av lett nedbrytbart organisk stoff og gode oksygenforhold. Ved stasjon NK4 viste ASPT-indeksen moderat økologisk tilstand, men med en indeks-verdi veldig nær grensen til god tilstand og resultatene er basert på bare én prøvetaking. Den samlede økologiske tilstanden for biologien er god ved NK1, NK2 og NK3, samt moderat ved NK4. Samlet sett fremstår den økologiske tilstanden i Norddalselva som god med hensyn til eutrofiering (næringssaltforurensing) og organisk belastning, med små avvik fra naturtilstanden. Vi finner få tegn på at redusert vannføring som følge av reguleringen har økt konsentrasjonen av forurensing eller næringsstoffer i den grad at det har hatt tydelige negative konsekvenser for begroing eller bunndyr i elva.Tussa Energi ASpublishedVersio

Nuisance growth of Juncus bulbosus: the roles of genetics and environmental drivers tested in a large-scale survey

1. Invasive species can transform aquatic ecosystems, and the nuisance growth of the freshwater macrophyte Juncus bulbosus has become a problem in many lakes and rivers in northern Europe. It affects biodiversity strongly and conflicts with human uses, not least compromising the generation of hydroelectricity. The causes of the proliferation of these massive stands of J. bulbosus are not finally resolved, however. 2. In this study, a wide range of catchment, lake and sediment parameters (n = 34) were assessed for 139 lakes in Southern Norway, with the aim of explaining the presence or absence of J. bulbosus and to assess potential drivers behind its prolific growth. 3. Juncus bulbosus was more often present in lakes with lower pH and phosphate concentrations, and a higher element ratio of dissolved inorganic nitrogen (DIN) to total phosphorus (DIN : TotP). 4. Despite the many parameters measured across substantial environmental gradients, none explained nuisance growth. Genetic screening (amplified fragment length polymorphism fingerprinting) of plants from a subset of lakes and additional river sites also showed no genetic differences between the various growth forms. A macrophyte trophic index, however, suggested that the most problematic growth occurred in the most oligotrophic lakes. 5. The lack of consistent patterns may reflect either factors not assessed in our survey, or that the current extension of stands represents a gradual cumulative response over time, not characterised effectively in our snapshot survey. Nevertheless, we can now exclude some putative causes of nuisance growth, including in particular genetics and N‐deposition.acceptedVersio

PERKEMBANGAN SENI PERTUNJUKAN LONGSER DI KABUPATEN BANDUNG TAHUN 1975-2002: suatu tinjauan tentang peranan ateng japar sebagai seniman longser

Skripsi ini berjudul “Perkembangan Seni Pertunjukan Longser di Kabupaten Bandung Tahun 1975-2002: Suatu Tinjauan Tentang Peranan Ateng Japar Sebagai Seniman Longser”. Penelitian ini bertolak dari kekhawatiran peneliti terhadap seni pertunjukan Longser yang hampir punah. Untuk itu diperlukan upaya mempertahankan seni tradisi tersebut agar tetap bertahan di tengah kehidupan masyarakat modern saat ini. Rumusan masalah dalam penelitian ini diantaranya: Pertama, Bagaimana latar belakang seni pertunjukan Longser sejak dipimpin oleh Ateng Japar? Kedua, Bagaimana peranan Ateng Japar dalam mengembangkan seni pertunjukan Longser Pancawarna (1975-2002)? Ketiga, Faktor-faktor apa saja yang dapat menghambat perkembangan seni pertunjukan Longser? Keempat, Bagaimana upaya pemerintah Kabupaten Bandung dan masyarakat dalam melestarikan seni pertunjukan Longser pasca meninggalnya Ateng Japar? Dalam penyusunan skripsi ini, peneliti menggunakan metode historis, yang terdiri dari empat langkah yaitu heuristik, kritik, interpretasi, dan historiografi. Berdasarkan hasil penelitian, dapat dijelaskan bahwa Longser merupakan seni teater rakyat yang hidup di daerah Priangan, khususnya Kabupaten Bandung. Longser seringkali disebut sebagai seni sandiwara rakyat yang banyak menampilkan tarian-tarian berpasangan dan memberikan kesempatan kepada para penonton untuk menari bersama dengan penarinya. Salah satu tokoh seniman dalam seni Longser yang terkenal ialah Ateng Japar. Pada tahun 1939 Ateng Japar mendirikan kelompok Longser yang diberi nama Pancawarna. Awalnya kelompok ini melakukan pertunjukannya dengan cara mengamen, namun memasuki tahun 1970an terjadi peralihan tempat pertunjukan menjadi ke dalam gedung kesenian. Selain itu di tahun yang sama (1970an) kelompok Longser Ateng Japar menjadi satu-satunya kelompok yang masih aktif melakukan pertunjukan di wilayah Bandung. Hal ini dikarenakan pada saat itu hanya kelompok Longser Ateng Japar yang digemari oleh masyarakat Bandung. Pada tahun 2002 sang seniman (Ateng Japar) diberitakan wafat dan hal ini berdampak pada perkembangan Longser yang semakin meredup. Eksistensi Longser semakin diperparah ketika sebagian masyarakatnya terutama dari kalangan generasi muda masih banyak yang belum mengetahui tentang Longser. Adapun salah satu upaya yang dilakukan oleh pemerintah Kabupaten Bandung untuk melestarikan seni pertunjukan Longser adalah dengan cara melakukan kegiatan sosialisasi Longser kepada siswa-siswa dengan cara berkunjung ke sekolah-sekolah. Hal ini ditujukan untuk memperkenalkan kembali Longser, agar generasi muda dapat mempertahankan eksistensi Longser sebagai kesenian tradisional yang tumbuh dan berkembang di Kabupaten Bandung, Jawa Barat. ---------- This scientific work entitled "The Development of Performing Arts in Bandung Regency Longser Year 1975-2002: An Overview of the Role Ateng Japar For Artists Longser". This study is based on the fears of the researcher of the performing arts Longser endangered, it is necessary for maintaining the tradition of art in order to stay afloat amid the life of today's modern society. Formulation of the problem are taken in this research are: First, What is the background of performing arts led by Ateng Longser since Japar? Secondly, How Japar Ateng role in developing the performing arts Longser Pancawarna (1975-2002)? Third, any factors which may inhibit the development of performing arts Longser? Fourth, how the government's efforts Bandung District and the community in preserving the performing arts after the death Longser Ateng Japar? In preparing this paper, the researcher uses historical method, which consists of four steps that heuristics, criticism, interpretation, and historiography. Based on the results, it can be explained that Longser is the art of theater folk who live in the area Priangan, especially Bandung regency. Longser often referred to as a theatrical art displays many folk dances in pairs and provide an opportunity for the audience to dance along with the dancers. One of the figures in the artist's famous art Longser is Ateng Japar. In 1939 Ateng Japar establish Longser group named Pancawarna. Initially this group did show by way of singing, but entered the 1970s there was a shift in the venue into an art gallery. Also in the same year (1970) Japar Ateng Longser group be the only group that still actively performing in Bandung. This is because at that time only Ateng Japar Longser group that favored by the people of Bandung. In 2002 the artist (Ateng Japar) reported the death and this affects the development Longser increasingly dim. Existence Longser aggravated when most people especially among the younger generation there are many who do not know about Longser. As one of the efforts undertaken by the government to preserve the Bandung District Longser performing arts is to conduct socialization activities Longser to students by means visiting schools. It is intended to reintroduce Longser, so that younger generations can maintain the existence Longser as a traditional art that grows and develops in Bandung regency, West Java

Gjenvekst av krypsiv etter tiltak, og effekter av kalking på krypsiv i Otra ved Rysstad – oppdatert status 2022

Prosjektleder: Susanne C. SchneiderOtra ved Rysstad har i lang tid hatt utfordringer med massevekst av krypsiv. Mekanisk fjerning av krypsiv i utvalgte områder der plantene er til særlig sjenanse for fiske og bading blir sett på som det mest praktiske tiltaket, men det er ukjent hvor raskt krypsivet kommer tilbake etter tiltak. I tillegg er Otra ved Rysstad blitt kalket siden april 2021, og det er blitt uttrykt bekymring for at kalkingen kan føre til ytterlige vekst av krypsiv. Kartlegging av krypsiv i august 2022, det vil si cirka to år etter at krypsiv ble fjernet i et utvalgt område og ett år og 4 mnd. etter at kalkingen startet, viser at (1) to år etter tiltaket var krypsivbiomassen tilbake på omtrent samme nivå som før; og (2) kalkingen har hittil ikke hatt målbar effekt på dekningsgrad eller plantelengde av krypsiv, men førte til en markant økning i forekomst av flotgras, tjønnaks og tusenblad i Rysstadbassenget.Krypsiv på SørlandetpublishedVersio

Annual changes in aquatic plant photosynthesis in the regulated river Otra and the effect of plant removal

Prosjektleder: Benoît O.L. DemarsMass development of submerged aquatic plants is often seen as nuisance for human activities. The present study used novel methods to estimate the changes in ecosystem photosynthesis (mostly Juncus bulbosus), through an annual cycle, under varying dissolved gas supersaturation events in the Rysstad basin, Otra River. The methods and results from this study may help us to understand the dynamics between supersaturation, J. bulbosus and fish health, and guide management decisions on aquatic plant removal.Krypsivprosjektet på Sørlandet (KPS). Sekretariat: Fylkesmannen i Agder, MiljøvernavdelingenpublishedVersio