Browsing by Subject "kertyminen"

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  • Herve, Sirpa; Paasivirta, Jaakko; Ahkola, Heidi; Heinonen, Pertti (Finnish Environment Institute, 2010)
    Reports of the Finnish Environment Institute 14/2010
  • Truchy, Amélie; Sarremejane, Romain; Muotka, Timo; Mykrä, Heikki; Angeler, David G.; Lehosmaa, Kaisa; Huusko, Ari; Johnson, Richard K.; Sponseller, Ryan A.; McKie, Brendan G. (Wiley, 2020)
    Global Change Biology 26 6 (2020)
    Ongoing climate change is increasing the occurrence and intensity of drought episodes worldwide, including in boreal regions not previously regarded as drought prone, and where the impacts of drought remain poorly understood. Ecological connectivity is one factor that might influence community structure and ecosystem functioning post-drought, by facilitating the recovery of sensitive species via dispersal at both local (e.g. a nearby habitat patch) and regional (from other systems within the same region) scales. In an outdoor mesocosm experiment, we investigated how impacts of drought on boreal stream ecosystems are altered by the spatial arrangement of local habitat patches within stream channels, and variation in ecological connectivity with a regional species pool. We measured basal ecosystem processes underlying carbon and nutrient cycling: (a) algal biomass accrual; (b) microbial respiration; and (c) decomposition of organic matter, and sampled communities of aquatic fungi and benthic invertebrates. An 8-day drought event had strong impacts on both community structure and ecosystem functioning, including algal accrual, leaf decomposition and microbial respiration, with many of these impacts persisting even after water levels had been restored for 3.5 weeks. Enhanced connectivity with the regional species pool and increased aggregation of habitat patches also affected multiple response variables, especially those associated with microbes, and in some cases reduced the effects of drought to a small extent. This indicates that spatial processes might play a role in the resilience of communities and ecosystem functioning, given enough time. These effects were however insufficient to facilitate significant recovery in algal growth before seasonal dieback began in autumn. The limited resilience of ecosystem functioning in our experiment suggests that even short-term droughts can have extended consequences for stream ecosystems in the world's vast boreal region, and especially on the ecosystem processes and services mediated by algal biofilms.
  • Nakari, Tarja; Pehkonen, Riitta; Nuutinen, Jari; Järvinen, Olli (Suomen ympäristökeskus, 2009)
    Suomen ympäristökeskuksen raportteja 18/2009
  • Nakari, Tarja; Pehkonen, Riitta; Nuutinen, Jari; Järvinen, Olli (Suomen ympäristökeskus, 2008)
    Suomen ympäristökeskuksen raportteja 16/2008
  • Porvari, Petri (Finnish Environment Institute, 2003)
    Monographs of the Boreal Environment Research 23
    Deposition, catchment runoff concentrations and fluxes, lake water concentrations of total mercury (TotHg) and methyl mercury (MeHg), and potential Hg methylation in different compartments of boreal ecosystem and TotHg concentrations of fish in boreal and tropical reservoirs were studied. The results provide new knowledge of behaviour and cycling of Hg for Hg pollution protection policy. Anthropogenic and natural Hg emissions have led to increased Hg deposition and further accumulation of Hg in soil. A decline of 50% in atmospheric TotHg deposition from the late 1980s to 2000 was observed in southern Finland. During the period of 1995–2000 TotHg and MeHg deposition remained unchanged in southern Finland. The vast storage of Hg in forest soil had a determining role as a source of TotHg and MeHg for forest drainage lakes. Only small variations in TotHg concentrations and output fluxes in runoff waters were detected among the catchments, but clearly the highest MeHg concentrations and output fluxes came from the pure peatland and the lowest from forested upland catchments. This indicates more effective MeHg production in peatlands than in uplands. Silvicultural treatment of a small spruce forest catchment increased significantly the runoff concentrations and export of TotHg and MeHg. The results indicated that clear cutting and soil treatment may significantly increase the mobility of TotHg and MeHg accumulated in forest soil and silvicultural treatment is thus an important factor for the total input of Hg and MeHg to boreal lakes. Flooding of forest soils (humus and peat) released TotHg and MeHg to water column and enhanced Hg methylation. Moreover, Hg methylation process was favoured by anoxic conditions. Flooding of soils on a large scale, i.e. when constructing man-made lakes (reservoirs) caused elevated fish Hg levels through enhanced Hg methylation. Hg accumulation as elevated TotHg concentrations in fish (especially predatory fish) was observed both in boreal (Ostrobothnia and Lapland, Finland) and tropical reservoirs (Amazonia, Brazil). In Brazil, the highest mercury levels were recorded in predatory fish, the intermediate levels in planktivorous and omnivorous fish and the lowest in herbivorous fish. In Finland, even 20 years after flooding, the TotHg concentrations of the predatory fish (northern pike, Esox lucius L.) in some of the reservoirs exceeded the upper limit for fish consumption and in Brazil, 6 years after flooding 92% of all predatory fish sampled exceeded the safety limit for Hg concentrations in fish. The observations from Finnish and Brazilian reservoirs showed that the duration of the phenomenon of Hg contamination of fish in reservoirs may last for 15–30 years. The Hg contamination succession in fish appears to be similar in boreal and tropical reservoirs. The results of this work distinctly indicate the determining role of catchment as a MeHg source to forest lakes. The effects of forestry practices on Hg export emphasise the need for more research on this issue. The long lasting Hg contamination in reservoirs regardless of climatological zone requires restrictions of predatory fish consumption especially where people utilise a large amounts of fish for food.
  • Fjäder, Päivi (Suomen ympäristökeskus, 2016)
    Suomen ympäristökeskuksen raportteja 43/2016
    Yhdyskuntalietteeseen pidättyy runsaasti orgaanista ainesta ja ravinteita, kuten fosforia, jota hyödyntämällä voitaisiin korvata kalliiden keinolannoitteiden käyttöä ja myös säästää rajallisia fosforivarantoja. Lietteen koostumus riippuu kuitenkin pitkälti jätevedenpuhdistamolle saapuvien jätevesien koostumuksesta. Puhdistamoita ei ole nykyisellään suunniteltu poistamaan jätevesistä muuta kuin lähinnä ravinteita ja kiintoainesta, minkä vuoksi erilaiset orgaaniset haitta-aineet voivat joko kulkeutua puhdistusprosessin läpi tai pidättyä lietteeseen. Yhdyskuntalietteistä onkin havaittu lukuisia erilaisia orgaanisia haitta-aineita kuten esim. erilaisia palonsuoja-aineita, pintakäsittelyaineita, muovin pehmentimiä sekä lääkeaineita. Ympäristöön päätyessään lietteen sisältämät yhdisteet voivat vaikuttaa niin maaperään, vesistöihin kuin eliöihin. Tämän tutkimuksen perusteella, eräiden orgaanisten haitta-aineiden on havaittu olevan pysyviä lietteen käsittelyketjussa ja voivan näin ollen aiheuttaa haittaa ympäristölle. Toistuvien lietelevitysten seurauksena tiettyjen pysyvien yhdisteiden, kuten PBDE-yhdisteiden, maaperäpitoisuudet voivat nousta. Osa PFAS-yhdisteistä (etenkin lyhytketjuiset) sekä lääkeaineista saattaa vesiliukoisempina puolestaan joko kertyä kasveihin tai huuhtoutua maaperästä edelleen pinta- tai pohjavesiin. PFAS- ja PBDE-yhdisteet kertyvät myös lieroihin, joista ne puolestaan voivat päätyä eteenpäin ravintoketjussa. Triklosaanin ja ftalaattien pitoisuudet olivat myös yhdyskuntalietettä sisältävissä lannoitevalmisteissa sekä maaperässä, jonne näitä tuotteita oli levitetty, melko korkeita. Antibakteerisena yhdisteenä käytetyn triklosaanin vaikutuksia maaperän mikrobistoon ei voida täysin sulkea pois. Sama pätee myös muihin maaperässä havaittuihin antibioottijäämiin, etenkin fluorokinololi antibiootteihin.
  • Руоппа, Марья; Хейнонен, Пертти (Институт окружающей среды Финляндии, 2006)
    Справочное издание по охране окружающей среды
    Данная публикация содержит описания важнейших биологических методов исследований, которые традиционно используются при проведении мониторинга и при изучении экологического состояния водоёмов. Кроме того, в публикации приведены гидробиологические и экотоксикологические стандартные методики, которые используются в исследованиях на международном уровне и в Финляндии. В публикации приведено описание: - Методов оценки качества воды и состояния водоёмов - Биологических тестов - Методов экотоксикологических исследований - Методов исследований аккумуляции веществ в организмах - Методов исследования биологической деструкции веществ - Методов отбора проб - Вопросов контроля качества Особенности водоохранных мероприятий на поверхностных водоёмах в Европе определены в многочисленных документах Европейского Союза. С точки зрения формирования и контроля качества воды важнейшим документом является Рамочная Директива ЕС по водной политике (2000/60/EY), которая вступила в силу в 2000 году. Директива содержит необходимую информацию для определения типов водоёмов, их классификации, а также и для выполнения мониторинга состояния водных объектов. Для определения экологического статуса водоёма разработан список водных гидробионтов (планктон, водные растения, бентос и рыбы). Реализация Директивы ЕС по водной политике предполагает использование международных стандартов ISO и CEN.