Lifetime antipsychotic medication and cognitive performance in schizophrenia at age 43 years in a general population birth cohort

This naturalistic study analysed the association between cumulative lifetime antipsychotic dose and cognition in schizophrenia after an average of 16.5 years of illness. Sixty participants with schizophrenia and 191 controls from the Northern Finland Birth Cohort 1966 were assessed at age 43 years with a neurocognitive test battery. Cumulative lifetime antipsychotic dose-years were collected from medical records and interviews. The association between antipsychotic dose-years and a cognitive composite score based on principal component analysis was analysed using linear regression. Higher lifetime antipsychotic dose-years were significantly associated with poorer cognitive composite score, when adjusted for gender, onset age and lifetime hospital treatment days. The effects of typical and atypical antipsychotics did not differ. This is the first report of an association between cumulative lifetime antipsychotic dose and global cognition in midlife schizophrenia. Based on these data, higher lifetime antipsychotic dose-years may be associated with poorer cognitive performance at age 43 years. Potential biases related to the naturalistic design may partly explain the results; nonetheless, it is possible that large antipsychotic doses harm cognition in schizophrenia in the long-term.Peer reviewe

Managing erosion, sediment transport and water quality in drained peatland catchments

Abstract Peatland drainage changes catchment conditions and increases the transport of suspended solids (SS) and nutrients. New knowledge and management methods are needed to reduce SS loading from these areas. This thesis examines sediment delivery and erosion processes in a number of peatland drainage areas and catchments in order to determine the effects of drainage on sediment and erosion dynamics and mechanics. Results from studies performed in peat mining, peatland forestry and disturbed headwater catchments in Finland are presented and potential sediment load management methods are discussed for drainage areas and headwater brooks. Particular attention is devoted to erosion of organic peat, sediment transport and methods to reduce the impacts of peatland drainage in boreal headwaters. This thesis consists of six articles. The first and second papers focus on the erosion and sediment transport processes at peat harvesting and peatland forestry drainage networks. The results indicate that in-channel processes are important in drained peatland, since the drainage network often constitutes temporary inter-storm storage for eroding and transporting material. Sediment properties determine the bed sediment erosion sensitivity, as fluffy organic peat sediment consolidates over time. As flashiness and peak runoff control sediment entrainment and transport from drained peatland areas, water quality management should include peak runoff management. The third, fourth and fifth papers studies use and application of peak runoff control (PRC) method to the peat harvesting and peatland forestry conditions for water protection. Results indicate that effective water quality management in drained peatland areas can be achieved using this method. Installation of the PRC structures is a useful and cost-effective way of storing storm runoff waters temporarily in the ditch system and providing a retention time for eroded sediment to settle to the ditch bed and drainage network. The main effect of the PRC is on SS and SS-bound nutrients. The sixth paper is concentrated to test new restoration structure to be used in degraded headwater brooks. The results show that addition of woody restoration structures to the channel is effective and simple sediment management methods in headwater areas. New information provided in this thesis on sediment erosion and transport processes in drained peatland areas can help to improve water quality control in these areas. In-channel processes are important for both peatland uses, since the drainage network often constitutes temporary inter-storm storage for eroding and transporting material. Therefore, controlling these processes is a key to effective water quality management, which can be achieved using the PRC method in drainage areas or by utilisation of natural fluvial processes in natural channels downstream

Hydrology under change: long-term annual and seasonal changes in small agricultural catchments in Norway

Abstract In agricultural catchments, hydrological processes are highly linked to particle and nutrient loss and can lead to a degradation of the ecological status of the water. Global warming and land use changes influence the hydrological regime. This effect is especially strong in cold regions. In this study, we used long-term hydrological monitoring data (22–26 years) from small agricultural catchments in Norway. We applied a Mann–Kendall trend and wavelet coherence analysis to detect annual and seasonal changes and to evaluate the coupling between runoff, climate, and water sources. The trend analysis showed a significant increase in the annual and seasonal mean air temperature. In all sites, hydrological changes were more difficult to detect. Discharge increased in autumn and winter, but this trend did not hold for all catchments. We found a strong coherence between discharge and precipitation, between discharge and snow water equivalent and discharge and soil water storage capacity. We detected different hydrological regimes of rain and snow-dominated catchments. The catchments responded differently to changes due to their location and inherent characteristics. Our results highlight the importance of studying local annual and seasonal changes in hydrological regimes to understand the effect of climate and the importance for site-specific management plans

Recent and future hydrological trends of aapa mires across the boreal climate gradient

Abstract Aapa mires are boreal peatland complexes comprised of wet, typically patterned fens in the center and Sphagnum bog vegetation at the margins. Their distribution is controlled by climate and local catchment hydrology. The daily discharge of twelve aapa mires across the boreal zone was explored for 1961–2099, with the CPIsnow model using observational weather data and projections based on climate models (CMIP5) and emission scenarios (RCP4.5 and RCP8.5). Mire hydrology was assessed for climate-zonal differences, seasonal patterns, and longer-term trends. The results indicated past and future changes in hydrology, particularly related to the duration and magnitude of snow cover and the timing of snowmelt. Increasing winter discharge and decreasing spring discharge were detected in recent past in the southern sites, and these trends were indicated to continue in the future throughout the study area. By the end of the 21st century, the typical seasonality of discharge is indicated to weaken throughout the study area and to largely disappear in the south boreal catchments. In the northernmost sites, a mismatch between past trends and future projections of spring discharge was discovered, indicating complexity and uncertainty of snow process modeling. The hydrological changes indicated in this study, together with direct impacts of increasing temperatures, threaten aapa mires, affecting biodiversity and greenhouse gas balance. In changing climate, special attention should be paid to winter conditions and snow, essential for the hydrological cycle in the north but under-explored in mire hydrology studies

Predicting iron transport in boreal agriculture-dominated catchments under a changing climate

Abstract Increases in iron (Fe) concentration have been reported in boreal regions in recent decades, raising concerns about the fate of ecosystems along water courses. In this study, the SWAT (Soil and Water Assessment Tool) model was applied to the river Mustijoki catchment in southern Finland to determine the current state of Fe transport and to evaluate possible effects of ongoing environmental change in this agriculture-dominated catchment. The model was calibrated using five-year discharge, suspended solids, and Fe data, and validated with a three-year dataset of the same parameters. Further, the model was run with spatially downscaled and bias-corrected climate change scenario data to the year 2100 obtained using five different global climate models. The results were divided into 20-year time steps (2020–2039, 2040–2059, 2060–2079, 2080–2099) and compared against a reference modeling period (1997–2016). With present catchment characteristics of the river Mustijoki, Fe transport was shown to be related to soil erosion and suspended solids transport, driven by hydrological conditions. Arable fields, especially with steeper slopes, were identified as the most likely source of Fe loading. Climate change-induced alterations in riverine Fe transport were simulated as concentrations and as annual mass fluxes. High Fe transport season is already shifting from spring snowmelt events to autumn and winter, and this change is likely to increase in coming decades. Based on modeling results, annual peak concentration in the River Mustijoki was projected to decrease by up to 32% (from 6.2 mg L⁻¹ to 4.2 mg L⁻¹ in scenarios RCP4.5 and RCP8.5) in the coming 20-year period, while lowest winter concentration was projected to increase by 126% (from 1.5 mg L⁻¹ in the reference period (1997–2016) to 3.5 mg L⁻¹ in 2080–2099 in scenario RCP8.5. To compensate for these changes in Fe transport dynamics, water protection and land use management planning must be improved

Understanding variability in root zone storage capacity in boreal regions

Abstract The root zone storage capacity (Sr) of vegetation is an important parameter in the hydrological behaviour of a catchment. Traditionally, Sr is derived from soil and vegetation data. However, more recently a new method has been developed that uses climate data to estimate Sr based on the assumption that vegetation adapts its root zone storage capacity to overcome dry periods. This method also enables one to take into account temporal variability of derived Sr values resulting from changes in climate or land cover. The current study applies this new method in 64 catchments in Finland to investigate the reasons for variability in Sr in boreal regions. Relations were assessed between climate-derived Sr values and climate variables (precipitation-potential evaporation rate, mean annual temperature, max snow water equivalent, snow-off date), detailed vegetation characteristics (leaf cover, tree length, root biomass), and vegetation types. The results show that in particular the phase difference between snow-off date and onset of potential evaporation has a large influence on the derived Sr values. Further to this it is found that (non-)coincidence of snow melt and potential evaporation could cause a division between catchments with a high and a low Sr value. It is concluded that the climate-derived root zone storage capacity leads to plausible Sr values in boreal areas and that, apart from climate variables, catchment vegetation characteristics can also be directly linked to the derived Sr values. As the climate-derived Sr enables incorporating climatic and vegetation conditions in a hydrological parameter, it could be beneficial to assess the effects of changing climate and environmental conditions in boreal regions

Changing snow conditions and vegetation patterns:impact on boreal flow conditions

Abstract Recent climate projections and studies indicate drastic changes in snow cover extent, properties and timing in boreal areas. Snow cover duration is expected to decrease in Finland and more frequent warm spells and rain-on-snow events will lead to more variable snowpack. Snowmelt acts as a major input to northern hydrology affecting soil moisture conditions, recharging groundwater and sustaining flow during the winter and early summer. Simultaneous to changing climate and snow conditions the vegetation patterns are evolving due to natural and/or anthropogenic processes. Vegetation, snow properties and the physical catchment structure together with climate conditions determine the hydrological response of the catchments. However, their co-evolution, interconnections and impact on hydrology are still not completely understood. In this study, existing long (over 30 year) and spatially well represented monitoring time series from meteorology and hydrology monitored at dozens of headwater catchments in Finland are combined with multi-source data. We utilize latest calculation methods, high resolution digital elevation model and remote sensed vegetation inventory data sets. The objective is to evaluate the impact of changing environmental factors on snow cover and consequently on boreal headwater flow conditions. The evaluation will be done by determining relevant streamflow signatures for different catchments and analysing their relationships and sensitivity to catchment structure and changes in vegetation and snow cover. The results are needed for deeper understanding of the future hydrological behaviour of the boreal catchments which is necessary information for future decision making in water resources management and sustainable bioeconomy in boreal region

A new evolutionary time series model for streamflow forecasting in boreal lake-river systems

Abstract Genetic programming (GP) is an evolutionary regression method that has received considerable interest to model hydro-environmental phenomena recently. Considering the sparseness of hydro-meteorological stations on northern areas, this study investigates the benefits and downfalls of univariate streamflow modeling at high latitudes using GP and seasonal autoregressive integrated moving average (SARIMA). Furthermore, a new evolutionary time series model, called GP-SARIMA, is introduced to enhance streamflow forecasting accuracy at long-term horizons in a lake-river system. The paper includes testing the new model for one-step-ahead forecasts of daily mean, weekly mean, and monthly mean streamflow in the headwaters of the Oulujoki River, Finland. The results showed that a combination of correlogram and average mutual information (AMI) analysis might yield in the selection of the optimum lags that are needed to be used as the predictors of streamflow models. With Nash-Sutcliffe efficiency values of more than 99%, both GP and SARIMA models exhibited good performance for daily streamflow prediction. However, they were not able to precisely model the intramonthly snow water equivalent in the long-term forecast. The proposed ensemble model, which integrates the best GP and SARIMA models with the most efficient predictor, may eliminate one-fourth of root mean squared errors of standalone models. The GP-SARIMA also showed up to three times improvement in the accuracy of the standalone models based on the Nash-Sutcliff efficiency measure

Recent results from an ecohydrological study of forest species in drained tropical peatlands

Abstract Ecohydrological studies in tropical peatland have mostly focused on a small number of non-native commercial species. However, studies of native species are urgently needed as they are considered to be a possible solution in the restoration of millions of hectares of degraded tropical peatlands. We investigated peatland species on Padang Island, Indonesia, to assess their responses to changing environmental factors, particularly the high fluctuation of the water table due to intensive peatland draining. We monitored the sap-flux velocity and radial growth of six trees (four native and one non-native peatland species) in high temporal resolution using sap-flux meters and dendrometers up to seven months. Monitoring also included hydrological and micrometeorological parameters. We found that sap-flux velocity in the monitored species was mainly controlled by air vapor pressure deficits, photosynthetic active radiation, and to some extent, by wind speed and water-table depth. We also observed a species-specific correlation between daily sap-flux velocity and daily radial growth. Non-native Acacia crassicarpa had up to twice the radial growth of native species. This growth of non-native species was significantly higher at a shallow water-table depth, while native species did not show the same relationship. The interaction between water-table depth, sap-flux velocity, and radial growth in daily timescale was not straightforward, presumably because of the complex carbon-allocation mechanism in trees

Stable water isotopes as an indicator of surface water intrusion in shallow aquifer wells:a cold climate perspective

Abstract Groundwater in shallow aquifers is commonly used for community water supply in cold climates. Shallow groundwaters are inherently susceptible to contamination from land-use and surface water intrusion threatening drinking water usage. We used a large-scale snapshot data set of stable water isotopes from shallow glaciofluvial aquifers used for drinking water supply in Northern Finland to assess surface water intrusion risks and recharge conditions. This data set was supplemented by long-term stable water isotope precipitation data, Geographic Information System proximity analysis and multivariate statistics. The isotope analysis suggest that a warm season contributes about 60% to the total annual precipitation in the region. This is reflected in the aquifers isotopic composition as it represents an approximately equal mixture of warm and cold season precipitation. Groundwater isotope data normalized to precipitation inputs by line-conditioned excess (lc-excess) was used to flag the water supply wells impacted by surface water intrusions. The proximity analysis showed some of the wells may be affected by intrusions from gravel pit ponds, lakes and peatland drainage. On the larger scale, the wells in coastal areas were more likely to have evaporated water (intrusion) compared to inland regions of Northern Finland due to lower water availability and the presence of man-made structures. This application of stable water isotopes with lc-excess is a useful approach not only for recharge studies but also within water management for supply well surface water contamination risk assessment