British Columbia Vegetation and Climate History with Focus on 6 ka BP

British Columbia Holocene vegetation and climate is reconstructed from pollen records. A coastal Pinus contorta paleobiome developed after glacier retreat under cool and probably dry climate. Cool moist forests involving Picea, Abies, Tsuga spp., and Pinus followed until the early Holocene. Pseudotsuga menziesii arrived and spread in the south 10 000-9000 BP, and Picea sitchensis - Tsuga heterophylla forests developed in the north. T. heterophylla increased 7500-7000 BP, and Cupressaceae expanded 5000-4000 BP. Bogs began to develop and expland. Modern vegetation arose 4000-2000 BP. There were early Holocene grass and Artemisia communities at mid-elevations and pine stands at high elevations in southern interior B.C. Forests expanded downslope and lakes formed 8500-7000 BP. Modern forests arose 4500-4000 BP while lower and upper tree lines declined. In northern B.C. non-arboreal communities preceded middle Holocene Picea forests. Abies, Pinus and Picea mariana predominated at various sites after 4000 BP. At 6000 BP Tsuga heterophylla (south) and Picea sitchensis (north) dominated the coast and islands and Quercus garryana and Pseudotsuga on southeast Vancouver Island, but Thuja plicata was infrequent. Southern Interior Plateau vegetation at 6000 BP was more open than today at middle to lower elevations, whereas forests covered the Northern Interior Plateau. Picea forests occurred in northern B.C. Holocene climate phases were: 1) warm dry "xerothermic" ca. 9500-7000 BP, 2) warm moist "mesothermic" ca. 7000-4500 BP, 3) moderate and moist 4500-0 BP, with increasing moisture 8500-6000 BP and cooling (?increased moisture) 4500-3000 BP. B.Cs Hypsithermal had dry and wet stages; 6000 BP occurred in the warm and wet mesothermic stage.Cette reconstitution a été effectuée à partir des données polliniques. Un paléobiome à Pinus contorta s'est établi après le retrait des glaciers sous un climat frais et probablement sec. Des forêts de climat frais et humide à dominance de Picea, Abies, Tsuga spp. et Pinus ont suivi, jusqu'à l'Holocène inférieur. Pseudotsuga menziesii s'est ensuite répandu dans le sud de 10 000 à 9000 BP, tandis que les forêts à Picea sitchensis - Tsuga heterophylla se sont répandues dans le nord. T. heterophylla s'est accru de 7500 à 7000 BP et Cupressaceae s'est répandu de 5000 à 4000 BP. La végétation moderne s'est manifestée de 4000-2000 BP. Dans le sud de la partie intérieure, il y a eu des herbes et des communautés d'Artemisia aux altitudes moyennes et des peuplements de pins en haute altitude au début de l'Holocène. Les forêts modernes se sont formées de 4500 à 4000 BP, tandis que les limites des arbres déclinaient. Au nord, les communautés non arboréennes ont précédé les forêts de pins de l'Holocène moyen. Abies, Pinus et Picea mariana ont prédominé en différents sites après 4000 BP. À 6000 BP, Tsuga heterophylla (au sud) et Pinus sitchensis (au nord) ont dominé sur les côtes et les îles et Quercus garryana ainsi que Pseudotsuga, le sud-est de l'île de Vancouver. La végétation du sud du plateau intérieur à 6000 BP était plus ouverte que maintenant aux altitudes moyennes et basses, tandis que les forêts couvraient le nord du plateau intérieur. Les forêts de Picea occupaient le nord de la Colombie-Britannique. Les phases climatiques à l'Holocène sont les suivantes : 1) une phase chaude et sèche, dite xérothermique, vers 9500-7000 BP, 2) une phase chaude et humide dite mésothermique, vers 7000-4500 BP, 3) une phase tempérée et humide de 4500 à 0 BP, avec une humidité croissante de 8500 à 6000 BP et un refroidissement (et humidité croissante ?) de 4500-3000 BP. À l'hypsithermal, le climat était tantôt sec, tantôt humide.Ein Kùsten-Palâobiom mit Pinus contorta entwickelte sich nach dem Rùckzug des Gletschers wàhrend eines kalten und wohl trockenen Klimas. Darauf folgten kalte feuchte Wàlder mit Picea, Abies, Tsuga spp. und Pinus bis zum frùhen Holozân. Pseudotsuga menziesii breitete sich dann in Sùden von 10 000 bis 9000 v.u.Z. aus, und Picea sitchensis - Tsuga-Wàlder entwickelten sich im Norden. T. heterophylla nahm von 7500-7000 v.u.Z. zu, und Cupressaceae etablierte sich von 5000-4000 v.u.Z. Sùmpfe begannen zu entstehen und sich auszubreiten. Es gab im frùhen Holozân Gras- und Artemisia-Einheiten in mittleren Hôhen und Kiefer-Populationen in groBen Hôhen im sùdlichen lnnern von British Columbia. Moderne Wàlder entstanden zwischen 4500-4000 v.u.Z. wàhrend die untere und obère Baumgrenze zurùckgingen. In Nord-B.C gab es nichtbaumartige Einheinten vor den P/cea-Wâldem des mittleren Holozân. An verschiedenen Plàtzen dominierten Abies, Pinus und Picea mariana nach 4000 v.u.Z. Um 6000 v.u.Z. dominierten an der Kùste und auf den Insein Tsuga heterophylla (im Sùden) und Picea sitchensis (im Norden) und Quercus garryana und Pseudotsuga im Sùdosten der Insel Vancouver, aber Thuja plicata war selten. Die Vegetation im Sùden des inneren Plateaus um 6000 v.u.Z. war offener als heute in mittleren und niedrigen Hôhen, wàhrend Wàlder das nôrdliche innere Plateau bedeckten. P/cea-Wàlder gab es in Nord-B.C. Die Klimaphasen im Holozân waren: 1) eine warme trockene "xerothermische", Phase etwa 9500-7000 v.u.Z., 2) eine warme feuchte "meso-thermische" Phase etwa 7000-4500 v.u.Z., eine gemàBigte und feuchte Phase 4500-0 v.u.Z., mit zunehmender Feuchtigkeit von 8500-6000 v.u.Z. und Abkùhlung (und zunehmender Feuchtigkeit?) 4500-3000 v.u.Z

Pollen, Plant Macrofossils, and Insects from Fossil Woodrat (Neotoma Cinerea) Middens in British Columbia

Bushy-tailed woodrats (Neotoma cinerea) occur commonly in cliffs, rock talus, and caves in the open Pseudotsuga menziesii and Pinus ponderosa forests throughout interior British Columbia. Fossil N. cinerea middens from two sites in central British Columbia were radiocarbon dated and examined for pollen, plant macrofossils and insect remains. The Oregon Jack Creek site contains a midden that is dated 1150 ± 80 (WAT-1764) radiocarbon years ago. Pollen analyses reveal an abundance of Cupressaceae (Juniperus) and Pinus. Shrub and herb pollen types include Artemisia. Fabaceae, Poaceae, and Asteraceae. Juniperus scopulorum leaves, Pseudotsuga menziesii needles, Chenopodiaceae seeds. Rosa thorns and Artemisia leaflets are the main plant macrofossils. The remains of three beetle genera, Cryptophagus, Lathridius, and Enicmus represent insects that probably lived in the midden, eating decaying organic matter or moulds. Click beetle (Limonius) remains were probably brought into the midden from nearby soil or plant material. The Bull Canyon site contains a midden that dates to 700 ± 80 (WAT-1765) years BP. Pollen and plant macrofossil assemblages are similar to those at the Oregon Jack Creek site. Woodrat middens offer a new dimension in reconstructing Holocene paleoenvironments in the arid interior of British Columbia, in much the same way as they do in the southwest United States.Les rats à queue touffue s'observent souvent dans les escarpements, les talus rocheux et les cavernes dans les forêts ouvertes de Pseudotsuga menziesii et de Pinus ponderosa de l'intérieur de la Colombie-Britannique. Des amoncellements de matières fécales fossilisés de N. cinerea recueillis dans deux sites du centre de la Colombie-Britannique ont été datés au radio-carbone et analysés pour leur contenu en pollen, en macrofossiles de végétaux et en restes d'insectes. Le site d'Oregon Jack Creek renferme un amoncellement daté à 1150 ± 80 BP (WAT-1764). Les analyses polliniques ont révélé qu'il y avait abondance de Cupressaceae (Juniperus) et de Pinus. Les grains de pollen d'arbustes et d'herbacées comprennent Artemisia, Fabaceae. Poaceae et Asteraceae. Les principaux macrofossiles de végétaux étaient des feuilles de Juniperis scopulorum, des aiguilles de Pseudotsuga menziesii, des graines de Chenopodiaceae, des épines de Rosa et des folioles o"Artemisia. Les restes de trois genres de coléoptères (Cryptophagus, Lathridius et Enicmus) représentent les insectes qui vivaient probablement dans les amoncellements, se nourrissant de la matière organique en décomposition ou des moisissures. Les restes de Limonius proviennent probablement du sol environnant ou des végétaux. Le site de Bull Canyon renferme un amoncellement qui date de 700 ± 80 BP (WAT-1765). Les assemblages de pollen et de végétaux ressemblent à ceux du site d'Oregon Jack Creek. Les matières fécales du rat à queue touffue offrent de nouvelles possibilités de reconstitution des paléoenvironnements de l'Holocène de la région intérieure aride de la Colombie-Britannique, un peu comme c'est déjà le cas dans le sud des Etats-Unis.Ratten mit buschigem Schwanz (Neotoma cinerea) findet man oft in den Klippen, Schutthalden und Hôhlen in den offenen Pseudotsuga menziesii und Pinus ponderosa Wàldern im ganzen lnnern von British Columbia. Fosile N. cinerea Fâkalien von zwei Plâtzen in Zentral British Columbia wurden mit Radiokarbon datiert und auf Pollen, pflanzliche Makrofossile und lnsektenspuren untersucht. Der Platz Jack Creek in Oregon enthàlt einen Fakalienfund, der auf 1150 ± 80 (WAT-1764) Radiokarbonjahre v.u.Z. datiert wird. Die Pollenanalysen enthullen eine FuIIe von Cupressaceae (Juniperus) und Pinus. Buschund Graspollenarten schliessen Artemisia, Fabaceae, Poaceae und Asteraceae ein. Blatter von Juniperus scopulorum, Nadeln von Pseudotsuga menziesii, Samen von Chenopodiaceae, Dornen von Rosa und Blâttchen von Artemisia sind die hauptsâchlichen Pflanzenmakrofossile. Die Reste von drei Kaferarten, Cryptophagus, Lathridius und Enicmus reprâsentieren Insekten, die môglicherweise in den Fâkalien lebten und verwesendes organisches Material Oder Schimmel assen. Limonius-Reste wurden wahrscheinlich in die Fâkalien von nahegelegenem Erdreich Oder Pflanzenmaterial gebracht. Der Platz Bull Canyon enthàlt Fâkalien, die auf 700 ± 80 (WAT-1765) Jahre v.u.Z. datiert werden. Pollen- und makrofossile Pflanzenansammlungen sind denen des Jack Creek-Platzes von Oregon àhnlich. Fâkalien von Waldratten liefern eine neue Dimension bei der Rekonstruktion der Palàoumwelt im Holozàn im trockenen lnnern von British Columbia, ganz in derselben Weise, wie sie das schon im Sudwesten der Vereinigten Staaten tun

Geodesics on a supermanifold and projective equivalence of super connections

We investigate the concept of projective equivalence of connections in supergeometry. To this aim, we propose a definition for (super) geodesics on a supermanifold in which, as in the classical case, they are the projections of the integral curves of a vector field on the tangent bundle: the geodesic vector field associated with the connection. Our (super) geodesics possess the same properties as the in the classical case: there exists a unique (super) geodesic satisfying a given initial condition and when the connection is metric, our supergeodesics coincide with the trajectories of a free particle with unit mass. Moreover, using our definition, we are able to establish Weyl's characterization of projective equivalence in the super context: two torsion-free (super) connections define the same geodesics (up to reparametrizations) if and only if their difference tensor can be expressed by means of a (smooth, even, super) 1-form.Comment: 20 page

A palaeolimnological study of Tugulnuit Lake, British Columbia, Canada, with special emphasis on river influence as recorded by chironomids in the lake's sediment

Sediments from Tugulnuit Lake in the Okanagan Valley of British Columbia, Canada, were examined for chironomid assemblages. The chironomid stratigraphy obtained encompasses the last 4000 to 5000 years and suggests a warm and fairly stable climate typical for a temperate lake at low- to mid-elevation. This is indicated by the even distribution of warm-water taxa, such as Cladopelma, Dicrotendipes, Polypedilum, Pentaneurini, Stempellina, Stempellinella/Zavrelia and Pseudochironomus throughout the core. Very few cold-water taxa occurred in the sediments. However, stream inputs have had a major impact on Tugulnuit Lake. Sandy sediments and the appearance of Simuliidae and stream-inhabiting chironomid taxa (e.g., Brillia/Euryhapsis, Eukiefferiella/Tvetenia, Rheocricotopus) indicate that a stream intruded into the current lake's basin ca. 3800 yr Before Present (BP). Sediments deposited prior to, and after, the stream's intrusion show a distinctly different chironomid assemblage exhibiting chironomid taxa more typical for lentic habitats. This result indicates that chironomids can serve to detect past stream influences on lake environments. Thus, rheophilic chironomids preserved in lake cores provide a new alternative for reconstructing stream palaeoenvironmental record

On fine differentiability properties of horizons and applications to Riemannian geometry

We study fine differentiability properties of horizons. We show that the set of end points of generators of a n-dimensional horizon H (which is included in a (n+1)-dimensional space-time M) has vanishing n-dimensional Hausdorff measure. This is proved by showing that the set of end points of generators at which the horizon is differentiable has the same property. For 1\le k\le n+1 we show (using deep results of Alberti) that the set of points where the convex hull of the set of generators leaving the horizon has dimension k is ``almost a C^2 manifold of dimension n+1-k'': it can be covered, up to a set of vanishing (n+1-k)-dimensional Hausdorff measure, by a countable number of C^2 manifolds. We use our Lorentzian geometry results to derive information about the fine differentiability properties of the distance function and the structure of cut loci in Riemannian geometry.Comment: Latex2e, 13 pages in A4 forma

Breeding success of the great tit Parus major in relation to attributes of natural nest cavities in a primeval forest

An overlap in attributes of nest cavities used by Great Tit Parus major across Eurasia suggests similar nest site preferences within the geographical range, although the drivers of these preferences are unclear. To determine whether preferred cavities provide conditions enhancing successful reproduction, we investigated the breeding performance of Great Tits in relation to tree cavity characteristics using data collected during 2008–2011 in primeval conditions (Białowieża National Park, Poland). Here, tree cavities are diverse and superabundant but nesting birds are at risk from a variety of predators. According to expectations, nest losses were high (60 % of Great Tit nests failed), mostly due to predation (69 % of nest failures). The risk of nest failure varied with nest cavity attributes. Compared to successful nests, failures were situated higher above the ground and placed closer to the cavity entrance. Very deep cavities with narrow entrances and strong livings walls provided effective protection against larger predators (e.g., martens, woodpeckers), unable to enter the cavity or pull out the contents. Yet, such holes were no barrier for the smallest predators (e.g., Forest Dormouse Dryomys nitedula), which were able to enter any Great Tit nest cavity and destroyed most of the nests. Avoiding small predators would give a selective advantage to the birds, but this seems hardly possible to achieve. We conclude that tree cavities preferred by the tits show a combination of properties which are a compromise for avoiding predation (the strongest selective pressure) and providing the minimum requirements (sufficient nest illumination, microclimate, protection against nest soaking) for development and growth of young

Influence of surfactant on dynamics of photoinduced motions and light emission of a dye-doped deoxyribonucleic

Pure deoxyribonucleic acid (DNA) is known to be soluble in water only and exhibits poor temperature stability. In contrary, it is well known that the complex of DNA - with cetyltrimethyl ammonium (CTMA) is insoluble in water but soluble in alcohols and can be processed into very good optical quality thin films by solution casting or spin deposition. Despite the success of DNA-CTMA, there is still need for new cationic surfactants which would extend the range of available solvents for DNA complex. We test and present experimental results of influence of new surfactants replacing CTMA in the DNA complex and based on benzalkonium chloride (BA) and didecyldimethylammonium chloride (DDCA) on their optical properties. Particularly, we were interested in all optical switching and light generation in amplified spontaneous emission process in these materials

The dual role of LESION SIMULATING DISEASE 1 as a condition-dependent scaffold protein and transcription regulator

Since its discovery over two decades ago as an important cell death regulator in Arabidopsis thaliana, the role of LESION SIMULATING DISEASE 1 (LSD1) has been studied intensively within both biotic and abiotic stress responses as well as with respect to plant fitness regulation. However, its molecular mode of action remains enigmatic. Here, we demonstrate that nucleo-cytoplasmic LSD1 interacts with a broad range of other proteins that are engaged in various molecular pathways such as ubiquitination, methylation, cell cycle control, gametogenesis, embryo development and cell wall formation. The interaction of LSD1 with these partners is dependent on redox status, as oxidative stress significantly changes the quantity and types of LSD1-formed complexes. Furthermore, we show that LSD1 regulates the number and size of leaf mesophyll cells and affects plant vegetative growth. Importantly, we also reveal that in addition to its function as a scaffold protein, LSD1 acts as a transcriptional regulator. Taken together, our results demonstrate that LSD1 plays a dual role within the cell by acting as a condition-dependent scaffold protein and as a transcription regulator

Darboux-Box Variables and the Existence of a Complete Set of Lagrangians for Given n-Dimensional Newtonian Equations of Motion. The Isomorphism of n-Dimensional Newtonian Dynamical Systems

For given time-independent Newtonian system of equations of motion and given Poisson Brackets allowed by these equations, it is proven that locally a Lagrangian exists that gives these equations of motion as its regular Euler-Lagrange equations, and gives these Poisson Brackets in a regular process of obtaining the Hamiltonian and its Poisson Brackets. However, this Lagrangian may be using generalized position-velocity variables instead of the original position-velocity variables from the original equations of motion. Also, Darboux Box variables are introduced to prove that all Newtonian dynamical systems are locally isomorphic, meaning that locally there exists a one-to-one function relating the variables describing both systems that preserves equations of motion, Poisson Brackets, the Hamiltonian and, in a sense, also the Lagrangian