Conditioning sulfidic mine waste for growth of Agrostis capillaris—impact on solution chemistry

Contamination of the environment due to mining and mineral processing is an urgent problem worldwide. It is often desirable to establish a grass cover on old mine waste since it significantly decreases the production of leachates. To obtain sustainable growth, it is often necessary to improve several properties of the waste such as water-holding capacity, nutrient status, and toxicity. This can be done by addition of organic materials such as wood residues, e.g., compost. In this study, we focus on the solution chemistry of the leachates when a substrate containing historic sulfidic mine waste mixed with 30 % (volume) bark compost is overgrown by Agrostis capillaris. The pot experiments also included other growth-promoting additives (alkaline material, mycorrhiza, and metabolizable carbon) to examine whether a more sustainable growth could be obtained. Significant changes in the plant growth and in the leachates composition were observed during 8 weeks of growth. It was concluded that in this time span, the growth of A. capillaris did not affect the composition of the leachates from the pots. Instead, the composition of the leachates was determined by interactions between the bark compost and the mine waste. Best growth of A. capillaris was obtained when alkaline material and mycorrhiza or metabolizable carbon was added to the substrate.     

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.     

自然保护区、恢复力和动态景观

在这个日益被人类活动所改变的世界里,保护生物多样性对于维持有恢复力的生态系统和确保生态系统产品的可持续流动以及对社会的服务是至关重要的.但是,现有的自然保护区和国家公园不大可能结合生态系统的长期和大尺度的动态.因此,保护策略必须包括大面积的人类利用经营的土地.为了能使生态系统在大规模的自然和人为干扰之后得以重组,以生态存储形式出现的空间恢复力是必备的前提.生态存储包括那些能使生态系统得以重组的物种、相互作用和结构,它的组成部分可能出现在干扰斑块中,也可能出现在周围的景观中.现有的静态自然保护区应该由动态自然保护区加以补充,例如生态休闲地和动态演替保护区,这些都是在景观尺度上模拟自然干扰状况,进行生态系统经营的组成部分.     

Solid waste treatment within the framework of life-cycle assessment

Traditionally, treatment of solid waste has been given limited attention in connection with life-cycle assessments (LCAs). Often, only the amounts of solid wastes have been noted. This is unsatisfactory since treatment of solid waste, e.g. by landfilling or incineration, is an operation, requiring inputs and producing outputs, which should be described in the inventory of an LCA, in parallel to other operations. However, there are difficulties in describing emissions from solid waste treatments and there is a need for development of such methods. In this paper an approach for describing emissions from incineration and landfilling is outlined. Methodological questions concerning the time-frame and allocation principles are discussed. Methods for estimating potential emissions from landfilling of municipal solid waste and industrial wastes are suggested. The methods are used for calculating potential emissions from landfilling of some typical wastes. These emissions are compared with the emissions from other stages in the life cycle for some materials and wastes. it is shown that the potential emissions from landfilling are, for some products, of importance for the final results. Hence, if emissions from landfilling are neglected, or underestimated, results and conclusions in an LCA may be misleading.     

Relationships between ecological variables and four organochlorine pollutants in an artic glaucous gull (Larus hyperboreus) population

The Arctic has become a sink for organochlorine contaminants (OCs) from lower latitudes, and relatively high levels have been found in different biota. Recent studies of the glaucous gull, Larus hyperboreus, a top predator in the arctic food web, have documented that high blood residues of various OCs are related to lower reproductive performance and reduced adult survival. Here we provide additional evidence that OCs are having ecological effects in the glaucous gull population at Bear Island in the Norwegian Arctic, and compare the effects of the four major OCs found in the glaucous gulls: HCB, oxychlordane, DDE and PCBs, which made up >95% of measured OCs. Firstly; it has previously been shown that gulls with high levels of PCBs in their blood spent more time away from the nest site during incubation than gulls with low levels. Here we reanalyzed the data and found that PCBs (P<0.02) and oxychlordane (P<0.05) were positive and significantly related to time away from the nest site, while DDE and HCB were not related to this trait. Secondly, among females which bred in an area where fish dominated the diet, and thus had high flight costs during feeding, early chick growth was negatively related to maternal levels of all four OCs, especially HCB and DDE (P<0.01). On the contrary, among females breeding in an area where the diet was dominated by eggs and young from nearby seabird colonies, and thus feeding costs were low, there were no effects of OC levels on early chick growth. This indicates that additional stress may be fundamental in causing reproductive effects of OCs in this population. Finally, during three breeding seasons we examined the probability of adults returning to the breeding grounds in the subsequent season, as a function of blood concentration of the four OCs. Overall, return rate from one year to the next was negatively related to blood residues of oxychlordane (P=0.02), but not significantly related to the other three compounds. Further support for the importance of oxychlordane was that a 60% drop in the blood levels between 1997 and 2000 led to a significant increase in return rate between these two years.     

Reserves, resilience and dynamic landscapes

In a world increasingly modified by human activities, the conservation of biodiversity is essential as insurance to maintain resilient ecosystems and ensure a sustainable flow of ecosystem goods and services to society. However, existing reserves and national parks are unlikely to incorporate the long-term and large-scale dynamics of ecosystems. Hence, conservation strategies have to actively incorporate the large areas of land that are managed for human use. For ecosystems to reorganize after large-scale natural and human-induced disturbances, spatial resilience in the form of ecological memory is a prerequisite. The ecological memory is composed of the species, interactions and structures that make ecosystem reorganization possible, and its components may be found within disturbed patches as well in the surrounding landscape. Present static reserves should be complemented with dynamic reserves, such as ecological fallows and dynamic successional reserves, that are part of ecosystem management mimicking natural disturbance regimes at the landscape level.     

Impact of ozone and reduced water supply on the biomass accumulation of Norway spruce saplings

Norway spruce saplings [Picea abies (L.) Karst.] were exposed during four growing seasons to two different ozone treatments in open-top chambers: charcoal filtered air (CF), and non-filtered air with extra ozone (NF+, 1.4xambient concentrations). Within each ozone treatment the saplings were either kept well watered or treated with a 7-8 week period with reduced water supply each growing season. The total biomass of the trees was measured in April and September during each of the last three growing seasons. NF+ significantly reduced the total biomass accumulation of Norway spruce saplings during the fourth growing season. No interaction between ozone and reduced water supply could be detected. The magnitude of the ozone impact after 4 years of exposure was an 8% reduction of the total plant biomass and a 1.5% reduction of the RGR. The reduced water supply reduced the total biomass 29% and the RGR 12%.     

A one year study of the seasonal variations of sDDT and PCB levels in fish from heated and unheated areas near a nuclear power plant

An investigation of the influence of excess heat discharge from a nuclear power plant on the residual levels of the sDOT and PCB in roach and perch has been made during a period of one year. A seasonal variation of the residual concentrations was observed, with the highest levels during spring and early summer and lower more stable levels in the autumn. Significantly higher levels of the sDDT and PCB was observed in perch from the cooling water recipient as compared to values in perch from the intake area. No significant differences could however be verified for roach. The result stress the importance that, in a monitoring program, a sampling period with stable ecological conditions is selected.     

Quantifying spatial patterns of landscapes

In this paper we discuss information theoretical landscape indices based on data from digitized maps in grid format: measures based on Shannon's entropy, e.g. the measures of diversity and contagion; and measures based on conditional entropy, e.g. a new index which can be seen as an alternative to the measure of contagion that does not have the disadvantage of being highly correlated to the measure of diversity. We also introduce a measurement on how much information is contained in a coarse-scale map about a fine-scale map.