Recent trends in the chemistry of major northern rivers signal widespread Arctic change

Nature Geoscience, Год журнала: 2023, Номер 16(9), С. 789 - 796

Опубликована: Авг. 21, 2023

Язык: Английский

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Reviewing peatland forestry: Implications and mitigation measures for freshwater ecosystem browning

Forest Ecology and Management, Год журнала: 2023, Номер 531, С. 120776 - 120776

Опубликована: Янв. 13, 2023

Freshwaters of the boreal and temperate regions have experienced increased browning during last decades. Browning, or brownification, is mostly driven by organic carbon (OC) iron concentrations. It can cause detrimental changes in aquatic ecosystems through effects on chemistry, physics ecology. Additionally, impact greenhouse gas emissions, increase costs drinking water treatment weaken recreational value bodies. All these impacts call for means to mitigate excess export humic matter ecosystems. Browning has often been associated with decreased atmospheric sulphur deposition climate change-induced alterations temperature, vegetation hydrological regime catchments. Lately, it attributed land use, especially drainage peatlands forestry purposes afforestation. In this review, we evaluate peatland operations OC leaching assess possible mitigation measures. We reveal that traditional, even-aged forest management clear felling, site preparation ditch cleaning creates hot spots moments carbon-rich runoff due fluctuations hydrology, peat decomposition exposure. Simultaneously, most current protection measures are either ineffective ambiguous retaining OC, a dissolved form. Hence, practices prevent future reduce connectivity essential negative quality impacts. conclude systemic change would be needed formation loading leaching. More research needed, but seems transition towards more natural diverse abundantly applied continuous cover forestry, mixed improved catchment retention restoration could result fewer undesirable Protecting biodiversity counteracting requires integration updated into policies guidelines, as green shift bioeconomy will create an increasing demand sustainable use forests.

Язык: Английский

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Phytoplankton response to whole lake inorganic N fertilization along a gradient in dissolved organic carbon

Ecology, Год журнала: 2017, Номер 98(4), С. 982 - 994

Опубликована: Фев. 1, 2017

Abstract Global change has increased inorganic nitrogen (N) and dissolved organic carbon ( DOC ; i.e., “browning”) inputs to northern hemisphere boreal lakes. However, we do not know how phytoplankton in nutrient poor lake ecosystems of different concentration respond N availability. Here, monitored changes production, biomass community composition response whole fertilization six unproductive Swedish lakes divided into three pairs (control, enriched) at levels (low, medium, high), with one reference year (2011) 2 impact yr (2012, 2013). We found that production decreased before fertilization. Further, also differed respect , a dominance non‐flagellated autotrophs low towards an increasing flagellated concentration. The all lakes, but did affect composition. the net declined implying is critical order infer responses fertilization, system switches from being primarily limited becoming increasingly light In conclusion, our results show browning will reduce influence composition, whereas loadings deposition, forestry or other land use enhance production. Together, any landscape enhances availability increase biomass, positive effects be much weaker even neutralized browner as caused by limitation.

Язык: Английский

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Global changes may be promoting a rise in select cyanobacteria in nutrient‐poor northern lakes

Global Change Biology, Год журнала: 2020, Номер 26(9), С. 4966 - 4987

Опубликована: Май 23, 2020

Abstract The interacting effects of global changes—including increased temperature, altered precipitation, reduced acidification and dissolved organic matter loads to lakes—are anticipated create favourable environmental conditions for cyanobacteria in northern lakes. However, responses these changes are complex, if not contradictory. We hypothesized that absolute relative biovolumes (both total specific genera) increasing Swedish nutrient‐poor lakes increases associated with changes. tested hypotheses using data from 28 over 16 years (1998–2013). Increases biovolume were identified 21% the study sites, primarily southeastern region Sweden, composed mostly three genera: Merismopedia , Chroococcus Dolichospermum . Taxon‐specific related different stressors; is, surface water temperature favoured higher low pH high nitrogen phosphorus ratios, whereas recovery was statistically In addition, enhanced as potential determinants suppression promotion. Our findings highlight genera benefit ability predict risk prevalence requires consideration condition a lake sensitivities within lake. Regional patterns may emerge due spatial autocorrelations among history, rates direction change niche space occupied by cyanobacteria.

Язык: Английский

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Increases in organic carbon and nitrogen concentrations in boreal forested catchments — Changes driven by climate and deposition

The Science of The Total Environment, Год журнала: 2021, Номер 780, С. 146627 - 146627

Опубликована: Март 20, 2021

Brownification, caused by increasing dissolved organic carbon (DOC) concentrations is a threat to aquatic ecosystems over large areas in Europe. The of DOC northern boreal streams and lakes have attracted considerable attention with proposed important drivers such as climate, deposition land-use, complex interactions between them. Changes total N (TON) received less attention, even though nitrogen losses are highly related each other. We used long-term (1990–2019) monitoring records 12 small data-rich headwater forested catchments gradient climate deposition. found that (TOC) were significantly almost all study catchments. mean air temperature change sulphate had strong, significant correlation TOC change-%. Both explained, alone, more than 65% the concentrations, and, together, up 83% variation. Sulphur has already decreased low levels, our results indicate its importance driver leaching but still clearly detected, while impact warming will be pronounced future. A positive was drainage-% increases TON, suggesting also land management. TON trends tightly connected changes TOC, not directly linked decreasing S

Язык: Английский

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