Finnish Lake Survey: The Role of Catchment Attributes in Determining Nitrogen, Phosphorus, and Organic Carbon Concentrations

This study is based on a Finnish lake survey conducted in 1995, a dataset of 874 statistically selected lakes from the national lake register. The dataset was divided into subgroups to evaluate lake water-catchment relationships in different geographical regions and in lakes of different size. In the three southernmost regions, the coefficients of determination in multiple regression equations varied between 0.40 and 0.53 for total nitrogen (TN) and between 0.37 and 0.53 for total phosphorus (TP); the best interpreters were agricultural land and water area in the catchment. In the two northernmost regions, TN concentrations in lake water were best predicted by the proportion of peatlands in the catchment, the catchment slope, and TP concentrations by lake elevation and latitude. Coefficients of determination in multiple regression equations in these northern regions varied between 0.39 and 0.67 for TN and between 0.41 and 0.52 for TP. For all the subsets formed, the best coefficients of determination explaining TN, TP, and total organic carbon (TOC) were obtained for a subset of large lakes (>10 km²), in which 72–83% of the variation was explained. This was probably due to large heterogeneous catchments of these lakes.     

Nuclear contamination sources in surface air of Finnish Lapland in 1965–2011 studied by means of 137Cs, 90Sr,and total beta activity

Environmental Science and Pollution Research - Radionuclides 137Cs and 90Sr and total beta activity were determined from air filters collected in Rovaniemi (Finnish Lapland) in 1965–2011....     

Changes in Lumbriculus variegatus metabolites under hypoxic exposure to benzo(a)pyrene,chlorpyrifos and pentachlorophenol: Consequences on biotransformation

The regulation of endogenous metabolites is still not fully understood in aquatic invertebrates exposed concurrently to toxicants and hypoxia. Despite the prevalence of hypoxia in the aquatic environment, toxicity estimations seldom account for multiple stressors thereby differing from natural conditions. In this study, we examined the influence of hypoxia (<30% O₂) on contaminant uptake and the composition of intracellular metabolites in Lumbriculus variegatus exposed to benzo(a)pyrene (B(a)P, 3 μg L⁻¹), chlorpyrifos (CPF, 100 μg L⁻¹) or pentachlorophenol (PCP, 100 μg L⁻¹). Tissue extracts of worms were analyzed for 123 metabolites by gas chromatography–mass spectrometry and metabolite levels were then related to treatments and exposure time. Hypoxia markedly increased the accumulation of B(a)P and CPF, which underlines the significance of oxygen in chemical uptake. The oxygen effect on PCP uptake was less pronounced. Succinate and glycerol-3-phosphate increased significantly (p < 0.0001) following hypoxic treatment, whereas sugars, cysteine, and cholesterol were effectively repressed. The buildup of succinate coupled with the corresponding decline in intracellular 2-oxo- and 2-hydroxy glutaric acid is indicative of an active hypoxia inducible factor mechanism. Glutamate, and TCA cycle intermediates (fumarate, and malate) were disturbed and evident in their marked suppression in worms exposed concurrently to hypoxia and PCP. Clearly, hypoxia was the dominant stressor for individuals exposed to B(a)P or CPF, but to a lesser extent upon PCP treatment. And since oxygen deprivation promotes the accumulation of different toxicants, there may be consequences on species composition of metabolites in natural conditions.     

Static yields and quality issues: Is the agri-environment program the primary driver?

The Finnish agri-environmental program (AEP) has been in operation for 20 years with >90 % farmer commitment. This study aimed to establish whether reduced nitrogen (N) and phosphorus (P) use has impacted spring cereal yields and quality based on comprehensive follow-up studies and long-term experiments. We found that the gap between genetic yield potential and attained yield has increased after the AEP was imposed. However, many contemporary changes in agricultural practices, driven by changes in prices and farm subsidies, also including the AEP, were likely reasons, together with reduced N, but not phosphorus use. Such overall changes in crop management coincided with stagnation or decline in yields and adverse changes in quality, but yield-removed N increased and residual N decreased. Further studies are needed to assess whether all the changes are environmentally, economically, and socially sustainable, and acceptable, in the long run. The concept of sustainable intensification is worth considering as a means to develop northern European agricultural systems to combine environmental benefits with productivity.

Electronic supplementary material

The online version of this article (doi:10.1007/s13280-015-0637-9) contains supplementary material, which is available to authorized users.     

Comparison of static and mineralogical ARD prediction methods in the Nordic environment

Acid rock drainage (ARD) is a major problem related to the management of mining wastes, especially concerning deposits containing sulphide minerals. Commonly used tests for ARD prediction include acid–base accounting (ABA) tests and the net acid generation (NAG) test. Since drainage quality largely depends on the ratio and quality of acid-producing and neutralising minerals, mineralogical calculations could also be used for ARD prediction. In this study, several Finnish waste rock sites were investigated and the performance of different static ARD test methods was evaluated and compared. At the target mine sites, pyrrhotite was the main mineral contributing to acid production (AP). Silicate minerals were the main contributors to the neutralisation potential (NP) at 60% of the investigated mine sites. Since silicate minerals appear to have a significant role in ARD generation at Finnish mine waste sites, the behaviour of these minerals should be more thoroughly investigated, especially in relation to the acid produced by pyrrhotite oxidation. In general, the NP of silicate minerals appears to be underestimated by laboratory measurements. For example, in the NAG test, the slower-reacting NP-contributing minerals might require a longer time to react than is specified in the currently used method. The results suggest that ARD prediction based on SEM mineralogical calculations is at least as accurate as the commonly used static laboratory methods.     

Managing Biodiversity in a Forestry Environment

In forest management and other land-use planning, ecological, social, and economical demands often conflict. Forest planning in particular has been biased towards maximizing economic output while disregarding the ecological effects of forestry practices. In this paper we present an approach for taking biological diversity into account in strategic forest management planning. We used the Analytic Hierarchy Process (AHP) method for resource allocation and priority setting. We carried out a case study, whereby a set of management strategies was evaluated in order to identify the strategy which best fulfills the requirement of maintaining biological diversity while at the same time yielding a reasonable income from timber production. We discuss applicability of the approach in solving different forest management and conservation planning problems, as well as in assessment of ecological impacts.     

Geographical variability in the bioenergetic characteristics of Monoporeia/Pontoporeia spp. populations from the northern Baltic Sea,and their potential contribution to benthic nitrogen mineralization

The physiological condition, determined as the ammonia excretion rate (V NH ₄ ⁺ ), total lipid level and lipid class composition, of two deposit-feeding benthic amphipods, Monoporeia (=Pontoporeia) affinis and Pontoporeia femorata, was studied from 12 opensea stations in the northern Baltic Sea between 24 May and 11 June 1993. The M. affinis populations can be geographically grouped according to their physiological condition: (1) eastern Gulf of Finland, with moderate lipid level (mean 24.4% of dry wt) and high V NH ₄ ⁺ (45.2 mol NH ₄ ⁺ g^-1 dry wt d^-1); (2) Bothnian Sea, wigh high lipid level (34.5%) and low V NH ₄ ⁺ (24.6 mol NH ₄ ⁺ g^-1 dry wt d^-1); and (3) Bothnian Bay, with low lipid level (15.2%) and high V NH ₄ ⁺ (44.3 mol NH ₄ ⁺ dry wt d^-1). A similar pattern could be observed also in the level of triacylglycerols and the neutral-to-polar lipid ratio. P. femorata, the dominating species in the western Gulf of Finland, showed variable station-specific excretion rates (22.3 to 43.0 mol NH ₄ ⁺ g^-1 dry wt d^-1) and lipid levels (23.4 to 30.4%). The spatial variability in the weight-specific V NH ₄ ⁺ of M. affinis could not be explained by the differences in the size of individuals, lipid level or lipid class composition; this emphasizes the significance of the effects of spatially differing nutritional conditions, which manifest themselves as different modes of metabolic energy production and different intensities of energy storage. In addition, the potential contribution of the amphipod populations to benthic nitrogen mineralization was estimated; in May to June, the NH ₄ ⁺ release of different populations ranged from 12 to 237 mol NH ₄ ⁺ m^-2d^-1. In general, populations with high abundance and/or biomass release the greatest amounts of NH ₄ ⁺ , but the values are modified by the physiological condition of the individuals.