Here, we use a unique long-term data set on total organic carbon (TOC) fluxes, its climatic drivers and effects of land management from a large boreal watershed in northern Finland. TOC and runoff have been monitored at several sites in the Simojoki watershed (3160 km(2) ) since the early 1960s. Annual TOC fluxes have increased significantly together with increased inter-annual variability. Acid deposition in the area has been low and has not significantly influenced losses of TOC. Forest management, including ditching and clear felling, had a minor influence on TOC fluxes - seasonal and long-term patterns in TOC were controlled primarily by changes in soil frost, seasonal precipitation, drought, and runoff. Deeper soil frost led to lower spring TOC concentrations in the river. Summer TOC concentrations were positively correlated with precipitation and soil moisture not temperature. There is some indication that drought conditions led to elevated TOC concentrations and fluxes in subsequent years (1998-2000). A sensitivity analysis of the INCA-C model results showed the importance of landscape position, land-use type, and soil temperature as controls of modeled TOC concentrations. Model predictions were not sensitive to forest management. Our results are contradictory to some earlier plot-scale and small catchment studies that have shown more profound forest management impacts on TOC fluxes. This shows the importance of scale when assessing the mechanisms controlling TOC fluxes and concentrations. The results highlight the value of long-term multiple data sets to better understand ecosystem response to land management, climate change and extremes in northern ecosystems.
Arctic moistening will affect the circumpolar forested riparian ecosystems. Upward trends observed for precipitation in high latitudes illustrate that the moistening may be underway to influence the woody biomass production near the inland waters, lakes and streams with effects on carbon pools and fluxes. Although the flooding and waterlogging tolerance of seedlings has been investigated, our understanding of responses in mature trees is still limited. Here we employ tree-ring d13 C and width data from a subarctic riparian setting in Lapland, where artificially high lake level (HLL) has already altered the ecophysiological and growth responses of riparian Pinus sylvestris trees to external drivers under conditions simulating moister environment. Prior to the HLL event, the carbon assimilation rate was primarily limited by irradiance as reflected in the d13 C data and the radial growth of south-facing riparian trees remained increased in comparison to shaded upland trees. By contrast, the riparian trees were not similarly benefited during the HLL period when reduced assimilation depleted the riparian in comparison to upland d13 C despite of increased irradiance. As a result, the radial growth of riparian trees was markedly reduced over the HLL event while the upland trees benefited from increased irradiance and summer time warming. Although the production of biomass at high latitudes is commonly considered temperature-limited, our results highlight the increasing role of Arctic moistening to limit the growth when increased precipitation (cloudiness) reduces the incoming solar radiation in general and when the riparian habitat becomes increasingly waterlogged in particular. The effects of high-latitude warming to induce higher biomass productivity may be restricted by negative feedbacks.
Climate change is expected to lead to higher precipitation amounts and intensities causing an increase of the risk for flooding and combined sewer overflows in urban areas. To cope with these changes, water managers are requesting practical tools that can facilitate adaptive planning. This study was carried out to investigate how recent developments in downscaling techniques can be used to assess the effects of adaptive measures. A combined spatial-temporal downscaling methodology using the Statistical DownScaling Model-Decision Centric (SDSM-DC) and the Generalized Extreme Value distribution was applied to project future precipitation in the city of Bergen, Norway. A raingarden was considered a potential adaptive measure, and its performance was assessed using the RECARGA simulation tool. The benefits and limitations of using the proposed method have been demonstrated and compared to current design practices in Norway. Large differences in the raingarden's performance with respect to percentage overflow and lag-time reduction were found for varying projections. This highlights the need for working with a range of possible futures. Further, it was found that Ksat was the determining factor for peak-flow reduction and that different values of Ksat had different benefits. Engineering flexible solutions by combining measures holding different characteristics will induce robust adaptation.
Understanding the interaction between the response of a complex ecosystem to climate change and the protection of vulnerable wildlife species is essential for conservation efforts. In the Northwest Territories (Canada), the recent movement of the Mackenzie wood bison herd (Bison bison athabascae) out of their designated territory has been postulated as a response to the loss of essential habitat following regional lake expansion. We show that the proportion of this landscape occupied by water doubled since 1986 and the timing of lake expansion corresponds to bison movements out of the Mackenzie Bison Sanctuary. Historical reconstructions using proxy data in dated sediment cores show that the scale of recent lake expansion is unmatched over at least the last several hundred years. We conclude that recent lake expansion represents a fundamental alteration of the structure and function of this ecosystem and its use by Mackenzie wood bison, in response to climate change.
Cites: Proc Natl Acad Sci U S A. 2015 Sep 22;112(38):11789-94 PMID 26351688
Cites: Can J Vet Res. 1993 Oct;57(4):231-5 PMID 8269360
Cites: Proc Natl Acad Sci U S A. 2007 Jul 24;104(30):12395-7 PMID 17606917
CIER was founded in 1994 by a small group of First Nation leaders from across Canada who recognized the need for Aboriginal peoples to have the capacity to solve environmental problems affecting their lands and resources.
This article provides examples of adverse health effects, including weather-related injury, food insecurity, mental health issues, and water infrastructure damage, and the responses to these effects that are currently being applied in two Northwest Alaska communities.
In Northwest Alaska, warming is resulting in a broad range of unusual weather and environmental conditions, including delayed freeze-up, earlier breakup, storm surge, coastal erosion, and thawing permafrost. These are just some of the climate impacts that are driving concerns about weather-related injury, the spread of disease, mental health issues, infrastructure damage, and food and water security. Local leaders are challenged to identify appropriate adaptation strategies to address climate impacts and related health effects. IMPLEMENTATION PROCESS: The tribal health system is combining local observations, traditional knowledge, and western science to perform community-specific climate change health impact assessments. Local leaders are applying this information to develop adaptation responses.
The Alaska Native Tribal Health Consortium will describe relationships between climate impacts and health effects and provide examples of community-scaled adaptation actions currently being applied in Northwest Alaska.
Climate change is increasing vulnerability to injury, disease, mental stress, food insecurity, and water insecurity. Northwest communities are applying adaptation approaches that are both specific and appropriate.
The health impact assessment process is effective in raising awareness, encouraging discussion, engaging partners, and implementing adaptation planning. With community-specific information, local leaders are applying health protective adaptation measures.
Cites: Am J Public Health. 2008 Nov;98(11):2072-818382002
Cites: Int J Circumpolar Health. 2011 Jun;70(3):266-7321703129
Cites: Int J Public Health. 2010 Apr;55(2):85-9619941059
Climate change is increasingly recognized as one of the greatest threats to human health of the 21st century, with consequences that mental health professionals are also likely to face. While physical health impacts have been increasingly emphasized in literature and practice, recent scholarly literature indicates that climate change and related weather events and environmental changes can profoundly impact psychological well-being and mental health through both direct and indirect pathways, particularly among those with pre-existing vulnerabilities or those living in ecologically sensitive areas. Although knowledge is still limited about the connections between climate change and mental health, evidence is indicating that impacts may be felt at both the individual and community levels, with mental health outcomes ranging from psychological distress, depression and anxiety, to increased addictions and suicide rates. Drawing on examples from diverse geographical areas, this article highlights some climate-sensitive impacts that may be encountered by mental health professionals. We then suggest potential avenues for public mental health in light of current and projected changes, in order to stimulate thought, debate, and action.
More than a decade after the 1997 Red River Flood, vulnerability to future flooding exists due to a lack of risk communication. This study identifies risk communication gaps and discusses the creation of strategies to enhance information-sharing, bottom-up activity and partnership development. The objectives were achieved using mixed methods, including interviews, a floodplain-wide survey, and a decision-makers' risk management workshop. The results highlight a number of external pressures exerted by regional floodplain policies and procedures that restrict risk communication and affect social vulnerability in the rural floodplain. The failures of a top-down approach to floodplain management have impacted on communities' abilities to address floodplain risks, have amplified local risks, and have decreased community cooperation in floodplain management initiatives since the 1997 'Flood of the Century'. Recommended policies promote the establishment of community standards to compensate for gaps in risk communication and the development of partnerships between floodplain communities.