Response of Early Life Stage Homarus americanus to Ocean Warming and Acidification: an Interpopulation Comparison

Anthropogenic carbon released into the atmosphere is driving rapid, concurrent increases in temperature and acidity across the world’s oceans, most prominently in northern latitudes. The geographic range of the iconic American lobster (Homarus americanus) spans a steep thermal gradient and one of the most rapidly warming oceanic environments. Understanding the interactive effects of ocean warming and acidification on this species’ most vulnerable early life stages is important to predict its response to climate change on a stage-specific and population level. This study compares the responses of lobster larvae from two sub-populations spanning New England’s north-south temperature gradient (southern New England and eastern Gulf of Maine) to the joint effects of elevated pCO2 and temperature. Using a full factorial experimental design, we subjected planktonic larval and post-larval stages to different combinations of ambient, end-century projected, and extreme pCO2 concentrations (400 ppm, 750 ppm, 1200 ppm), and ambient and projected end-century temperatures (16°C and 19°C). We measured larval growth (both linear and dry weight), oxygen consumption, and elemental composition. In addition, with postlarvae, we quantified swimming speed and feeding behavior. Our experiments suggested that elevated temperature has a larger influence over measured parameters than elevated pCO2 alone, resulting in faster development times of all larvae. However, responses in other measured parameters were location and stage-specific, suggesting that larvae from contrasting thermal regimes respond differently to elevated pCO2 and temperature. Larvae from southern New England were more responsive to temperature than pCO2 stress, resulting in a longer carapace and greater dry, carbon and nitrogen weights in stage II when reared at elevated temperature. Larvae from eastern Gulf of Maine, however, more often showed no treatment effects, grew to longer carapace lengths, had greater elemental and dry weights and exhibited higher rates of oxygen consumption than southern New England larvae, despite starting at the same elemental weight and carapace length at stage I. In addition, this study also investigated the interactive effects of ocean warming and acidification on the gene expression response of the planktonic postlarval lobster from southern New England. Using a full factorial experimental design, lobsters were raised in ambient and elevated pCO2 concentrations (400ppm, 1200 ppm) and temperatures (16°C and 19°C). When temperature alone was elevated (19°C), larvae downregulated genes related to cuticle development; when pCO2 alone was elevated (1200 ppm), larvae upregulated chitinase as well as genes related to stress response and immune function. The joint effects of end-century stressors (19°C, 1200ppm) resulted in the upregulation of those same genes, as well as cellulase, and the downregulation of calcified cuticle proteins, and a greater upregulation in genes tied to immune response and functioning. These first results of the impact of varying conditions on larval lobster gene expression suggest the existence of compensatory mechanisms in response to stressors resulting from a rapidly changing environment

Determining basis for pit size variation in Myrmeleon immaculatus between two lakeshores of Northern Michigan.

Behavioral EcologyEnvironmental factors influencing pit-building behavior of the antlion Myrmeleon immaculatus are fairly well studied. The purpose of this study was to identify and differentiate environmental, genetic, and possible organizational or early learning factors influencing different behavioral phenotypes of two populations at Douglas Lake and Sturgeon Bay in northern Michigan, USA. We collected 60 antlions from each site and measured pit diameters in a common garden design. We distinguished treatments by feeding frequency, site, and day for a total of 22 days under a controlled laboratory setting with a regular disturbance regime. Sturgeon Bay antlions built larger pits that Douglas Lake antlions, animals that were subjected to a higher feeding frequency built smaller pits than a lower feeding frequency, and no apparent trend was gleaned from the day effect due to a presumed temperature effect. As a follow-up experiment we measured the effects of temperature on pit-building using light-bulb warming stations on 64 of our animals. Antlion pits that were given supplemental heat grew at a faster rate than controls. We also compared weight and pit diameters of at least 15 animals from seven sites between Sturgeon Bay and Pine Point. No significant difference was found between any site or lakeshore, though our data suggested that the original Sturgeon Bay study site displayed a larger pit size than any other site. These results indicate that genetic effects on these animals are unlikely, due to the close proximity of all populations. We suggest that organizational or early learning effects are significant determinants of pit-building behavior in this species.http://deepblue.lib.umich.edu/bitstream/2027.42/101736/1/Niemisto_Maura_2013.pd

WheelieKing Trainer Project Report

In this report we will detail the design and implementation process of the WheelieKing Trainer project, a device that helps people learn how to do wheelies on a bicycle by preventing backward falls. Formal project requirements are specified, followed by the ideation and iteration process to meet those requirements. The components and methods used to create the device are described in detail. The results of the development process and usage test results of the device are included. Appendices at the end of this report include references, supporting analyses, and project management and timeline details

Instantaneous Effects of Sediment Resuspension on Inorganic and Organic Benthic Nutrient Fluxes at a Shallow Water Coastal Site in the Gulf of Finland, Baltic Sea

Climate change is leading to harsher resuspension events in shallow coastal environments influencing benthic nutrient fluxes. However, we lack information on the quantitative connection between these fluxes and the physical forces. Two identical experiments that were carried out both in May and August provided novel knowledge on the instantaneous effects of resuspension with known intensity on the benthic dissolved inorganic (phosphate: DIP, ammonium: NH4+, nitrite+nitrate: NOx, silicate, DSi) and organic nutrient (phosphorus: DOP, nitrogen: DON, carbon: DOC) fluxes in the shallow soft bottoms of the archipelago of Gulf of Finland (GoF), Baltic Sea. Resuspension treatments, as 2 times the critical shear stress, induced effluxes of one to two orders of magnitude higher than the diffusive fluxes from the studied oxic bottoms. The presence of oxygen resulted in newly formed iron oxyhydroxides and the subsequent precipitation/adsorption of the redox-dependent nutrients (DIP, DSi, organic nutrients) affecting their fluxes. Resuspension-induced NH4+ and NOx fluxes were associated with the organic content of sediments showing the highest values at the organic rich sites. NH4+ showed the strongest responses to resuspension treatments in August, but NOx at the time of high oxygen concentrations in near-bottom water in May. Foreseen increases in the frequency and intensity of resuspension events due to climate change will most likely enhance the internal nutrient loading of the studied coastal areas. The fluxes presented here, connected to known current velocities, can be utilized in modeling work and to assess and predict the internal nutrient loading following climate change.Peer reviewe

Approximating optimal control problems governed by variational inequalities

It is proposed an approximating method for optimal control problems governed by elliptic variational inequalities. Some applications and numerical examples are treated

Biobutanol as a Potential Sustainable Biofuel - Assessment of Lignocellulosic and Waste-based Feedstocks

This paper introduces the production process of an alternative transportation biofuel, biobutanol. European legislation concerning biofuels and their sustainability criteria are also briefly described. The need to develop methods to ensure more sustainable and efficient biofuel production processes is recommended. In addition, the assessment method to evaluate the sustainability of biofuels is considered and sustainability assessment of selected feedstocks for biobutanol production is performed. The benefits and potential of using lignocellulosic and waste materials as feedstocks in the biobutanol production process are also discussed. Sustainability assessment in this paper includes cultivation, harvest/collection and upstream processing (pretreatment) of feedstocks, comparing four main biomass sources: food crops, non-food crops, food industry by-product and wood-based biomass. It can be concluded that the highest sustainable potential in Finland is when biobutanol production is integrated into pulp & paper mills

Production of genetically improved silver birch plantations in southern and central Sweden

Investing in planting genetically unproved silver birch (Betula pendula Roth) in Swedish plantations requires understanding how birch stands will develop over their entire rotation. Previous studies have indicated relatively low production of birch compared to Norway spruce (Picea abies (L.) Karst.) and Scots pine (Pinus sylvestris L.). This could result from using unrepresentative basic data, collected from unimproved, naturally-regenerated birch (Betula spp.) growing on inventory plots often located in coniferous stands. The objective of this study was to develop a basal area development function of improved silver birch and evaluate production over a full rotation period. We used data from 52 experiments including planted silver birch of different genetic breeding levels in southern and central Sweden. The experimental plots were established on fertile forest sites and on former agricultural lands, and were managed with different numbers of thinnings and basal area removal regimes. The model best describing total stand basal area development was a dynamic equation derived from the Korf base model. The analysis of the realized gain trial for birch showed a good stability of the early calculated relative differences in basal area between tested genotypes over time. Thus, the relative difference in basal area might be with cautious used as representation of the realized genetic gain. On average forest sites in southern Sweden, improved and planted silver birch could produce between 6-10.5 m(3) ha(-1) year(-1), while on fertile agriculture land the average productivity might be higher, especially with material coming from the improvement program. The performed analysis provided a first step toward predicting the effects of genetic improvement on total volume production and profitability of silver birch. However, more experiments arc needed to set up the relative differences between different improved material

Factors behind the variability of phosphorus accumulation in Finnish lakes

Phosphorus retention (TPacc) is one of the major water quality regulators in lakes. The current study aimed at ascertaining the specific lake characteristics regulating TPacc. Moreover, we were interested whether NAO (North Atlantic Oscillation), a proxy of climatic forcing, can explain variability in TPacc, additionally to that ascribed to lake characteristics. Sediment cores were obtained from 21 Finnish lakes, subject to radiometric dating and measurements of TP concentrations. Principal components (PCs) were generated using lake characteristics that are usually included into the modelling of TPacc (e.g. lake area, lake depth, catchment area, P inflow) but also the parameters that the classical models usually missed (e.g. anoxic factor). We used significant principal components (PCs), specific combinations of lake characteristics and monthly NAO values as predictors of TPacc. Lake characteristics explained the bulk of TPacc variability. The most influential factors (positive drivers) behind TPacc included PC1 (representing mainly deep lakes), PC2 (small lakes with high levels of anoxia and water column stability), PC3 (productive lakes with large catchment area and short water residence time), PC4 (lakes with high water column stability, low anoxic factor and relatively high sediment focusing) and PC5 (lakes with high levels of P inflow, anoxia and long water residence time). Additionally, we found a potential negative effect of NAO in October on the annual TPacc. This NAO was significantly positively related to temperatures in surface and near-bottom water layer (also their difference) in autumn, suggesting the possible implications for the internal P dynamics. Increased mineralization of organic matter is the most likely explanation for the reduced TPacc associated with NAO-driven water temperature increase. The analysis presented here contributes to the knowledge of the factors controlling P retention. Moreover, this spatially and temporally comprehensive sediment data can potentially be a valuable source for modelling climate change implications.Peer reviewe

Individual tree basal area increment models suitable for different stand structures in Finland

Forest growth models employed in Fennoscandia have been generally targeted at rotation forestry (RF) stands, relying on age as a key predictor. Uneven aged, irregular stands, such as the ones managed with continuous cover forestry, are becoming of increasingly common. New models suited for all kind of management approaches (i.e., age-independent) have been developed in Fennoscandia. Although the ongoing climate change is projected to strongly affect tree growth in boreal regions, climatic variables included in current models are usually restricted to temperature sum averages with simple links. The objectives of our research were: 1) fitting a new age independent empirical tree basal area increment model (B2023) with inclusion of additional climatic variables for the main Nordic tree species (Norway spruce, Scots pine, and birches); 2) using independent data to validate both the new model and other two age-independent published empirical models (P2013, P2021); and 3) investigating the sensitivity of growth predictions of all the empirical models to climate change. Our results showed that the new model B2023 was as accurate as P2013 when independently validated. Both models performed well in different forest structures and management alternatives (namely rotation forestry, continuous cover forestry, two-storied stands, and old-growth natural forests), although with few differences, and on average slightly better than P2021. At plot level, the new model B2023 showed slight underprediction for the overstorey pine layer in continuous cover forestry and two-storied stands. The predicted climate change scenarios increased simulated growth in all models, although P2021 showed very high values for spruce. We failed to include additional climatic variables than temperature sum in B2023, thus not improving much its accuracy under historical data, nor its sensitivity to future climate. Concluding, the individual tree models here presented can be applied to a wide range of forest structures and managements in Fennoscandia. For long-term simulation scenarios, different approaches to improve the climate sensitivity of empirical, individual tree model should be explored