Complete record of Furongian polymerid trilobites and agnostoids of Scandinavia – a biostratigraphical scheme

Terfelt, F., Ahlberg, P. & Eriksson, M.E. 2011: Complete record of Furongian polymerid trilobites and agnostoids of Scandinavia – a biostratigraphical scheme. Lethaia, Vol. 44, pp. 8–14. So far, 112 polymerid trilobite species/subspecies and 13 agnostoid species/subspecies have been recorded from the Furongian (upper Cambrian) of Scandinavia. For the first time, their zonal occurrences are summarized in a biostratigraphical scheme serving as a practical synopsis for students of this interval in time. Ninety‐six of the recorded polymerid trilobite species/subspecies belong to the family Olenidae whereas the remaining 16 are distributed across eight other families. Levels of increased speciation and low diversity (including stratigraphical range gaps) are conspicuous and these may be correlated with recorded physical and chemical anomalies. □Agnostoids, biostratigraphy, Cambrian, Furongian, polymerids, Scandinavia, trilobites.     

Post‐Soviet farmland abandonment,forest recovery,and carbon sequestration in western Ukraine

Land use is a critical factor in the global carbon cycle, but land‐use effects on carbon fluxes are poorly understood in many regions. One such region is Eastern Europe and the former Soviet Union, where land‐use intensity decreased substantially after the collapse of socialism, and farmland abandonment and forest expansion have been widespread. Our goal was to examine how land‐use trends affected net carbon fluxes in western Ukraine (57 000 km²) and to assess the region's future carbon sequestration potential. Using satellite‐based forest disturbance and farmland abandonment rates from 1988 to 2007, historic forest resource statistics, and a carbon bookkeeping model, we reconstructed carbon fluxes from land use in the 20th century and assessed potential future carbon fluxes until 2100 for a range of forest expansion and logging scenarios. Our results suggested that the low‐point in forest cover occurred in the 1920s. Forest expansion between 1930 and 1970 turned the region from a carbon source to a sink, despite intensive logging during socialism. The collapse of the Soviet Union created a vast, but currently largely untapped carbon sequestration potential (up to～150 Tg C in our study region). Future forest expansion will likely maintain or even increase the region's current sink strength of 1.48 Tg C yr^?1. This may offer substantial opportunities for offsetting industrial carbon emissions and for rural development in regions with otherwise diminishing income opportunities. Throughout Eastern Europe and the former Soviet Union, millions of hectares of farmland were abandoned after the collapse of socialism; thus similar reforestation opportunities may exist in other parts of this region.     

A partial revision of Gyptis (Gyptini,Ophiodrominae, Hesionidae,Aciculata, Annelida), with descriptions of a new tribe,a new genus and five new species

Phylogenetic analyses of molecular data (COI, 16SrDNA, 18SrDNA, and 28SrDNA) show that the hesionid genus Gyptis Marion & Bobretzky in Marion, 1874, and the tribe Gyptini Pleijel, 1998, are nonmonophyletic as currently delineated. We introduce the new tribe Amphidurini and the new genus Neogyptis to accommodate these new findings. Amphidurini is sister to Gyptini and Ophiodromini and includes Amphiduros Hartman, 1959, Amphiduropsis, Pleijel, 2001, Neogyptis gen. nov. , and, possibly, Parahesione Pettibone, 1956. Morphologically, Amphidurini can be separated from Gyptini by the distally, rather than subdistally, inserted ventral cirri, and Neogyptis by the combination of this feature, the presence of a median antenna, and a distal ring with papillae on the proboscis. We redescribe and transfer the four species Gyptis crypta Pleijel, 1993, Gyptis mediterranea Pleijel, 1993, Gyptis plurisetis Hilbig, 1992, and Gyptis rosea (Malm, 1874) from Gyptis to Neogyptis gen. nov. , and describe five new species from shallow waters in Belize, Hong Kong, off Vladivostok, and deep‐sea hydrothermal vents in the Lau Basin off Fiji.     

The Optimal Oxygen Equilibrium Curve: A Comparison Between Environmental Hypoxia and Anemia

SYNOPSIS. Internal hypoxia in vertebrates occurs during anemia,when blood oxygen (0₂) carrying capacity is reduced, or duringexposure to environmental hypoxia. In non-altitude adapted vertebrates,exposure to environmental hypoxia results in a change in bloodO₂ affinity which, in some cases is beneficial to tissue O₂delivery. In contrast, the elevation in blood O₂ carrying capacityobserved in almost all vertebrates is always beneficial to tissueO₂ delivery (assuming no large changes in blood viscosity) andmay be more important than changes in blood O₂ affinity in maintainingtissue O₂ delivery. Experimental anemia in vertebrates results in a decrease inblood O₂ affinity which is always beneficial to tissue O₂ delivery.The reduction in affinity is brought about by an increase inthe organic phosphate to hemoglobin ratio (NTP:Hb) within thered cell. In fish NTP:Hb decreases during environmental hypoxiabut increases during anemia indicating that NTP regulation isquite different between these treatments despite the similarityof these treatments at the tissue level.     

Benthic insects in Swedish lake-outlet streams: patterns in species richness and assemblage structure

1. We studied how species richness of three hierarchical insect species groups, namely all benthic, lotic and filtering taxa, were related to a number of environmental variables in a data set from fifteen Swedish lake outlets. 2. In partial least-squares analyses, we found that size-related factors (stream width, discharge) and velocity-related factors (current velocity, substratum particle size) were positively associated, and productivity-related factors (chlorophyll a, seston energy, conductivity) negatively associated, with the species richness of the three groups. 3. The weak and negative relationship of richness with productivity largely negated theoretical predictions, whereas the species-environment results corroborated earlier findings from running water systems. 4. The most important factors associated with the species composition of the lake outlets studied included pH, lake area, discharge, channel width and detritus. 5. Of the filter feeders, most species of blackflies (Diptera: Simuliidae) showed a negative relationship with pH. 6. A nested subset analysis demonstrated that species-poor sites did not have a subset of species found at more species-rich sites in any of the three hierarchical groups.     

Factors Influencing the Growth and Division of Pea Mesophyll Protoplasts

High yields of viable protoplasts were produced from pea leaves provided that only leaves of the same age were used in each preparation. The conditions under which the pea plants were grown and the age of the plants were also important. The protoplasts were cultured in a medium supplemented with 1 mg/1 2iP and 1 mg/1 2,4-D. They were able to regenerate cell walls within two days. After 5 days cell divisions were apparent and sustained divisions led to callus formation. Special emphasis has been given in this paper to the choice of leaf material for protoplast isolation.