Swedish Forests in the Bioeconomy: Stories from the National Forest Program

Abstract

The concept of a bioeconomy has been placed central in formation of a Swedish National Forest Program (NFP). Drawing on Hajer’s conceptual framework of storylines, we present a discourse analysis of the working group reports underlying the establishment of the NFP strategy. We ask what stories about Swedish forests come to dominate the NFP process, how well they reflect the commitment of balancing economic, social and environmental interests, and what role the concept of a bioeconomy, has on the formation of these stories. Storylines of Swedish forests in the bioeconomy unite wider European discourses on the bioeconomy and climate change with historical Swedish forest policy discourses, revitalizing a discourse coalition comprising the state and the industry. Particular to the Swedish discourse is the strong emphasis on creating consensus around a single story of the forest-based bioeconomy.     

An efficient technique for pre-selecting low-redshift damped Lyα systems

The number of z ∼ 1 damped Lyα systems (DLAs, log  N (H  i ) ≥ 20.3) per unit redshift is approximately 0.1, making them relatively rare objects. Large, blind QSO surveys for low-redshift DLAs are therefore an expensive prospect for space-borne ultraviolet telescopes. Increasing the efficiency of these surveys by pre-selecting DLA candidates based on the equivalent widths (EWs) of metal absorption lines has previously been a successful strategy. However, the success rate of DLA identification is still only ∼35 per cent when simple EW cut-offs are applied, the majority of systems having 19.0 < log  N (H  i ) < 20.3. Here, we propose a new way to pre-select DLA candidates. Our technique requires high-to-moderate-resolution spectroscopy of the Mg  ii λ2796 transition, which is easily accessible from the ground for 0.2 ≲ z ≲ 2.4. We define the D -index, the ratio of the line equivalent width to velocity spread, and measure this quantity for 19 DLAs and eight sub-DLAs in archival spectra obtained with echelle spectrographs. For the majority of absorbers, there is a clear distinction between the D -index of DLAs compared with sub-DLAs (Kolmogorov–Smirnov probability = 0.8 per cent). Based on this pilot data sample, we find that the D -index can select DLAs with a success rate of up to 90 per cent, an increase in selection efficiency by a factor of 2.5 compared with a simple EW cut. We test the applicability of the D -index at lower resolution and find that it remains a good discriminant of DLAs for full width at half-maximum (FWHM) ≲ 1.5 Å. However, the recommended D -index cut-off between DLAs and sub-DLAs decreases with poorer resolution and we tabulate the appropriate D -index values that should be used with spectra of different resolutions.     

Design of a tri-axial thrust anemometer for measurement of atmospheric turbulence over water

The BIO Mark 8 thrust anemometer measures the drag of the wind on a perforated table tennis ball mounted on a vertical beam. The tri-axial displacement of the beam is sensed by eddy current proximity sensors. This anemometer has a flat frequency response from 0 to 10 Hz and can measure wind from 0 to 28 m s⁻¹ at temperature from − 19 to + 28°C. It is designed for remote operation for extended periods of time such as on stable towers at sea.     

Terrestrial and Submerged Aquatic Vegetation Mapping in Fire Island National Seashore Using High Spatial Resolution Remote Sensing Data

The vegetation communities and spatial patterns on the Fire Island National Seashore are dynamic as the result of interactions with driving forces such as sand deposition, storm-driven over wash, salt spray, surface water, as well as with human disturbances. We used high spatial resolution QuickBird-2 satellite remote sensing data to map both terrestrial and submerged aquatic vegetation communities of the National Seashore. We adopted a stratified classification and unsupervised classification approach for mapping terrestrial vegetation types. Our classification scheme included detailed terrestrial vegetation types identified by previous vegetation mapping efforts of the National Park Service and three generalized categories of high-density seagrass, low-density seagrass coverages, and unvegetated bottom to map the submerged aquatic vegetation habitats. We used underwater videography, GPS-guided field reference photography, and bathymetric data to support remote sensing image classification and information extraction. This study achieved approximately 82% and 75% overall classification accuracy for the terrestrial and submnerged aquatic vegetations, respectively, and provided an updated vegetation inventory and change analysis for the Northeast Coastal and Barrier Network of the National Park Service.     

Comparison of dissolved and particulate arsenic distributions in shallow aquifers of Chakdaha, India, and Araihazar, Bangladesh

Background  

The origin of the spatial variability of dissolved As concentrations in shallow aquifers of the Bengal Basin remains poorly understood. To address this, we compare here transects of simultaneously-collected groundwater and aquifer solids perpendicular to the banks of the Hooghly River in Chakdaha, India, and the Old Brahmaputra River in Araihazar, Bangladesh.     

Study of the post-flare loops on 29 July 1973

Bright and dark curvilinear structures observed between the two major chromospheric ribbons during the flare of 29 July 1973 on films from the Big Bear Solar Observatory are interpreted as a typical system of coronal loops joining the inner boundaries of the separating flare ribbons. These observations, made through a 0.25 Å H filter, only show small segments of the loops having Doppler shifts within approximately ± 22 km s^–1 relative to the filter passband centered at H, H -0.5 Å or H +0.5 Å. However, from our knowledge of the typical behavior of such loop systems observed at the limb in H and at 5303 Å, it has been possible to reconstruct an appoximate model of the probable development of the loops of the 29 July flare as they would have been viewed at the limb relative to the position of a prominence which began to erupt a few minutes before the start of the flare. It is seen that the loops ascended through the space previously occupied by the filament. On the assumption that H fine structures parallel the magnetic field, we can conclude that a dramatic reorientation of the direction of the magnetic field in the corona occurred early in the flare, subsequent to the start of the eruption of the filament and prior to the time that the H loops ascended through the space previously occupied by the filament.     

A dipole field model for axisymmetric alfvén waves with finite ionosphere conductivities

An axisymmetric model for approximate solution of the magnetospheric Alfvén wave problem at latitudes above the plasmapause is proposed, in which a realistic dipole geometry is combined with finite anisotropic ionosphere conductivities, thus bringing together various ideas of previous authors. It is confirmed that the axisymmetric toroidal and poloidal modes interact via the ionospheric Hall effect, and an approximate method of solution is suggested using previously derived closed solutions of the uncoupled wave equations.A solution for zero Hall conductivity is obtained, which consists of sets of independent shell oscillations, regardless of the magnitude of the Pedersen conductivity. One set reduces to the classical solutions for infinite Pedersen conductivity, while another predicts a new set of harmonics of a quarter-wave fundamental, with longer eigenperiods than the classical solutions for a given L-shell.     

Strike-slip fault bridge fluid pumping mechanism: insights from field-based palaeostress analysis and numerical modelling

We present a finite-element study of stress perturbation in evolving compressive and extensional strike-slip fault bridges. The results are compared with a fracture study of a compressive bridge at St Donats, UK. Horizontally interbedded calcareous mudstone and bioclastic calcilutite at St Donats have a distinct vertical permeability anisotropy. This sedimentary sequence behaves as a set of horizontal aquifers. The fluid flow in these aquifers is sensitive to mean stress gradients. Paleostress analysis of field fracture data, verified by finite-element modelling, indicates a rotation of σ₁ towards parallelism with boundary faults inside the growing compressive bridge. Boundary faults and bridge faults recorded numerous fluid flow events. The modelled mean stress pattern shows a regional maximum within the bridge and local maxima/minima pairs at boundary fault tips.Finite-element modelling of an extensional bridge indicates that σ₃ rotates towards parallelism with boundary faults. The mean stress pattern is similar to the pattern in compressive bridge but with maxima and minima locations interchanged. The stress patterns are reestablished by each stress build-up preceding the rupturation of the boundary faults throughout the development stages of strike-slip fault bridges. Mean stress gradients developed pre-failure control the fluid flow in fractures of the strike-slip fault system at and after the end of each stress build-up and the fluid flow in boundary faults post-failure. Fracture reactivation and new fracture generation within an evolving bridge is a process consisting of multiple successive events that retain the storage capacity of the bridge. Rupture and sealing of the main bounding-faults is a step-wise process that opens and closes fluid conduits between areas with different pressures.     

新形势下林区的就业机会与渠道

我国实施“天然林保护工程”以来,林区人民积极转产分流,寻找新的就业门路和生计,为走出困境、改善生活做出了不懈的努力。为了进一步开阔视野,拓展思路,借鉴他国的经验,我们选刊了“国际森林趋势组织”的几篇关于寻找新的林区就业渠道和森林环境服务市场开发方面的研究文章,以期对我国的林业改革与建设有所启示。(注:这些文章已经“森林趋势组织”的执行主管Mivhael Jenkins先生同意译成中文在本刊刊登,本刊作了部分删节和改动。原文及参考文献请参阅森林趋势组织的网页:http://www. forest-trends. org)     

Late Quaternary Upper Mississippi River alluvial episodes and their significance to the Lower Mississippi River system

The period in the Upper Mississippi Valley (UMV) from about 25 000 years B.P. until the time of strong human influence on the landscape beginning about 150–200 years ago can be characterized by three distinctly different alluvial episodes. The first episode is dominated by the direct and indirect effects of Late Wisconsin glacial ice in the basin headwaters. This period, which lasted until about 14 000 years B.P., was generally a time of progressive valley aggradation by a braided river system transporting large quantities of bedload sediment. An island braided system evolved during the second episode, which extended from about 14 000 to 9000 years B.P. The second episode is associated with major environmental changes of deglaciation when occurrences of major floods and sustained flows of low sediment concentration from drainage of proglacial lakes produced major downcutting. By the time of the beginning of the third episode about 9000 years B.P., most vegetation communities had established their approximate average Holocene locations. The change of climate and establishment of good vegetation cover caused upland landscapes of the UMV to become relatively stable during the Holocene in comparison to their relative instability during the Late Wisconsin. However, Holocene remobilization of Late Wisconsin age sediment stored in tributary valleys resulted in a return to long-term upper Mississippi River aggradation. The dominance of Holocene deposition over transportation reflects the abundance of sandy bedload sediment introduced from tributaries and the situation that energy conditions for floods and the hydraulic gradient of the upper Mississippi River are much less for the Holocene than they were for the Late Wisconsin and deglaciation periods.Outburst floods from glacial lakes appear to have been common in the UMV during the Late Wisconsin and especially during deglaciation. Magnitudes for the Late Wisconsin floods are generally poorly understood, but an estimate of 10 000–15 000 m³ s⁻¹ was determined for one of the largest events in the northern UMV based on heights of paleo-foreset beds in a flood unit deposited in the Savanna Terrace. For comparison, the great flood of 1993 on the upper Mississippi River was about 12 000 m³ s⁻¹ at Keokuk, Iowa, near the Des Moines River confluence where it represented the 500-year event in relation to modem flood series. Exceptionally large outburst floods derived from the rapid drainage of pro-glacial Lake Michigan and adjacent smaller proglacial lakes between about 16 000 and 15 500 years B.P. are a likely cause of the final diversion of the Mississippi River through the Bell City-Oran Gap at the upstream end of the Lower Mississippi Valley (LMV). The largest outburst flood from northern extremities of the UMV appears to have occurred between about 11700 and 10 800 years B.P. when the southern outlet of Lake Agassiz was incised. Based on the probable maximum capacity of the Agassiz flood channel 600 km downstream near the junction of the Wisconsin and Mississippi Rivers, the Agassiz flood discharge apparently did not exceed 30 000 m³ s⁻¹. However, if the Agassiz flood channel here is expanded to include an incised component, then the flood discharge maximum could have been as large as 100,000 to 125 000 m³ s⁻¹. The larger flood is presently viewed as unlikely, however, because field evidence suggests that the incised component of the cross-section probably developed after the main Agassiz flood event. Nevertheless, the large Agassiz flood between about 11 700 and 10 800 years B.P. produced major erosional downcutting and removal of Late Wisconsin sediment in the UMV. This flood also appears to be mainly responsible for the final diversion of the Mississippi River through Thebes Gap in extreme southwestern Illinois and the formation of the Charleston alluvial fan at the head of the LMV.After about 9000 years B.P. prairie-forest ecotones with associated steep seasonal climatic boundaries were established across the northern and southern regions of the UMV. The general presence of these steep climatically sensitive boundaries throughout the Holocene, in concert with the natural tendency for grasslands to be especially sensitive to climatic change, may partially explain why widespread synchroneity of Holocene alluvial episodes is recognized across the upper Mississippi River and Missouri River drainage systems. Comparison of estimated beginning ages of Holocene flood episodes and alluvial chronologies for upper Mississippi River and Missouri River systems with beginning ages for LMV meander belts and delta lobes shows a relatively strong correlation. At present, dating controls are not sufficiently adequate and confidence intervals associated with the identified ages representing system changes are too large to establish firm causal connections. Although the limitations of the existing data are numerous, the implicit causal connections suggested from existing information suggest that further exploration would be beneficial to improving the understanding of how upper valley hydrological and geomorphic events are influencing hydrological and geomorphic activity in the LMV. Since nearly 80% of the Mississippi River drainage system lies upstream of the confluence of the Mississippi and Ohio Rivers, there is a strong basis for supporting the idea that UMV fluvial activity should be having a strong influence on LMV fluvial activity. If this assertion is correct, then the traditional assignment of strong to dominant control by eustatic sea level variations for explaining channel avulsions, delta lobes, and meander belts in the LMV needs re-examination. A stronger role for upper valley fluvial activity as a factor influencing lower valley fluvial activity does not disregard the role of eustatic sea level, tectonic processes or other factors. Rather, upper valley fluvial episodes or specific events such as extreme floods may commonly serve as a “triggering mechanism” that causes a threshold of instability to be exceeded in a system that was poised for change due to sea level rise, tectonic uplift, or other environmental factors. In other situations, the upper valley fluvial activity may exert a more dominant control over many LMV fluvial processes and landforms as frequently was the case during times of glacial climatic conditions.