Scorpionid Resting Trace from The Lower Permian of Southern New Mexico,USA

We describe an arthropod body impression associated with arthropod trackways of the ichnogenus Stiaria from the Lower Permian (upper Wolfcampian) Robledo Mountains Formation (Hueco Group) in the Prehistoric Trackways National Monument of southern New Mexico. The probable producer of these traces was a scorpion, and we name the likely scorpionid resting trace Alacranichnus braddyi, new ichnogenus and ichnospecies. There are no prior reports of scorpionid body impressions from terrestrial settings in the fossil record.     

Effects of western juniper (Juniperus occidentalis) control on ecosystem nitrogen stocks in central Oregon,USA

控制西美圆柏数量对美国俄勒冈州中部生态系统氮储量的影响 在美国俄勒冈州,控制西美圆柏(Juniperus occidentalis)的数量是一种公认的牧场管理措施,该做法 有助于恢复蒿草草原(sagebrush steppe)生境,该生境对野生动物和家畜都十分重要。然而,尽管控制木本 植物数量会对当地的流域管理和区域性氮库造成重要影响,但砍伐西美圆柏对生态系统中氮元素的影响问题尚未得到很好的解决。本文定量研究了两个相邻流域生态系统中的氮储量,其中一个流域经过处理(流域内的大部分圆柏已被清除掉),而另一个流域未处理(圆柏未被清除)。在圆柏被移除13年后,我们测定了两个流域里圆柏树林、灌木丛、草丛和枯枝落叶层的地上氮储量,以及两个流域中两个土层(0–25和25–50 cm)内的地下氮储量(根系和土壤氮储量)。研究结果表明,未处理流域的地上氮储量是处理流域 的6.9倍,因为未处理流域的地上生物量要大得多。然而,由于砍伐圆柏导致林下植被的根系生物量增加,所以处理流域的根系氮储量是未处理流域的3.1倍。0–25和25–50 cm土层氮储量没有受到圆柏砍伐的影响。总体而言,生态系统总氮储量在处理流域(9536 kg N ha⁻¹)和未处理流域(9456 kg N ha⁻¹)之间并没有显著差异。在两个流域里,生态系统中最大的氮积累量(至少95%的生态系统总氮量)均存在于地下(0–25 cm深的土壤以及根系)。这项研究证明,清除圆柏并不会显著影响生态系统的储氮能力。     

Historical dendroarchaeology of two log structures in the Valles Caldera National Preserve,New Mexico,USA

We used dendroarchaeological techniques to determine the year of construction of two historic structures in the Valles Caldera National Preserve of New Mexico, USA. Historical documents date some structures in the headquarters area of the Preserve, but the Commissary Cabin and Salt Barn were lacking conclusive construction dates. Both structures were originally thought to have been built by the Otero family who bought the property in 1899. We found that the structures were built from two tree species, white fir (Abies concolor (Gordon) Lindl. ex Hildebr.) and Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), surprising given that ponderosa pines are also found in great numbers in the adjacent forest. Tree rings from 20 logs were confidently crossdated both graphically and statistically and provided cutting dates of trees in both structures of 1940 and 1941 when compared against the Fenton Lake reference chronology (Commissary Cabin: r = 0.69, t = 15.54, p < 0.0001, n = 263 years; Salt Barn: r = 0.77, t = 11.7, p < 0.0001, n = 232 years). By combining the cutting date years and terminal ring attributes, we suggest that both structures were built in the spring or early summer of 1941 using freshly cut logs and logs that had been cut the previous spring (1940, before or during the growing season) and stockpiled. The cutting dates of 1940 and 1941 indicate that these buildings were constructed during the Franklin Bond (1939–1945) era and associated with the transition from sheep ranching to more modern cattle grazing. These new dates provide a more distinct understanding of the cultural resources at the Valles Caldera National Preserve and provide interpretative staff with more accurate information that can be given to the public.     

Estimation of Successful Breeding Pairs for Wolves in the Northern Rocky Mountains,USA

Abstract: Under the Endangered Species Act, documenting recovery and federally mandated population levels of wolves (Canis lupus) in the Northern Rocky Mountains (NRM) requires monitoring wolf packs that successfully recruit young. United States Fish and Wildlife Service regulations define successful breeding pairs as packs estimated to contain an adult male and female, accompanied by ≥2 pups on 31 December of a given year. Monitoring successful breeding pairs will become more difficult following proposed delisting of NRM wolves; alternatives to historically intensive methods, appropriate to the different ecological and regulatory context following delisting, are required. Because pack size is easier to monitor than pack composition, we estimated probability a pack would contain a successful breeding pair based on its size for wolf populations inhabiting 6 areas in the NRM. We also evaluated the extent to which differences in demography of wolves and levels of human-caused mortality among the areas influenced the probability of packs of different sizes would contain successful breeding pairs. Probability curves differed among analysis areas, depending primarily on levels of human-caused mortality, secondarily on annual population growth rate, and little on annual population density. Probabilities that packs contained successful breeding pairs were more uniformly distributed across pack sizes in areas with low levels of human mortality and stable populations. Large packs in areas with high levels of human-caused mortality and high annual growth rates had relatively high probabilities of containing breeding pairs whereas those for small packs were relatively low. Our approach can be used by managers to estimate number of successful breeding pairs in a population where number of packs and their sizes are known. Following delisting of NRM wolves, human-caused mortality is likely to increase, resulting in more small packs with low probabilities of containing breeding pairs. Differing contributions of packs to wolf population growth based on their size suggests monitoring successful breeding pairs will provide more accurate insights into population dynamics of wolves than will monitoring number of packs or individuals only.     

A new species of the enigmatic archosauromorph Doswellia from the Upper Triassic Bluewater Creek Formation,New Mexico,USA

Abstract: Doswellia sixmilensis is a new species of the doswelliid archosauromorph genus Doswellia named for an incomplete skeleton from the Upper Triassic Bluewater Creek Formation of the Chinle Group in west‐central New Mexico, USA. D. sixmilensis differs from D. kaltenbachi Weems, the type and only other known species of Doswellia, in its larger size, higher tooth count and greater heterodonty, possession of keels on the cervical centra and the presence of discrete knobs or spikes on some osteoderms. The holotype of D. sixmilensis is the fourth occurrence of Doswellia and only the second occurrence of a Doswellia skull, which includes the previously unknown premaxilla and maxilla (and therefore the best dentition) and has the best‐preserved cervical vertebrae. Although it adds to our knowledge of the anatomy of Doswellia, this new information does not alter previous concepts of the phylogenetic relationships of the doswelliid genera, largely because they are so poorly known anatomically. The genus Doswellia is known from the Newark Supergroup in Virginia, and the Chinle Group in Texas, New Mexico and Utah, in strata of Otischalkian–Adamanian age. The type locality of D. sixmilensis is c. 43 m stratigraphically below a bed from which U‐Pb dating of detrital zircons yields a maximum depositional age of c. 220 Ma, so this is a reasonable approximate numerical age for D. sixmilensis.     

Spatial patterns and vegetation–site relationships of the presettlement forests in western New York, USA

Aim The purposes of this study were to develop a Geographic Information System and spatial analytical methodology to reconstruct and represent the presettlement vegetation in a spatially continuous manner over large areas and to investigate vegetation–site relationships before widespread changes of the vegetation had taken place. Location The study area was the Holland Land Company Purchase in western New York, a 14,400 km² area extending across the physiographic provinces of the Erie–Ontario Lowlands and the Appalachian Uplands. Methods Bearing‐tree records from the Holland Land Company township surveys of western New York in c. 1800 were collected and analysed. The geostatistical method of indicator kriging was used to map spatially continuous representations of individual tree species. Rule‐based and statistically clustered approaches were used to analyse and classify the reconstructed tree species distributions in order to obtain the vegetation association distribution. Contingency table analysis was conducted to quantify species relationships with soil conditions. Results The presettlement vegetation at both the tree species and the vegetation association levels were easier to interpret and visually more effective as a spatially continuous representation than as a discontinuous distribution of symbols. The results for tree species were probability occurrences of species distribution, showing spatial patterns that were not apparent in discrete maps of points or in summary tables of species frequencies. Analysis of the 8792 bearing trees suggested the dominance of American beech (Fagus grandifolia) and sugar maple (Acer saccharum) in the forest composition 200 years ago. Both soil drainage and texture were important site determinants of the vegetation in western New York. The rule‐based and statistically clustered approaches had the advantage of summarizing vegetation compositional patterns in a single image, thus avoiding the need to delineate manually and subjectively the location of boundaries between adjacent vegetation associations. Main conclusions The study offers more insights into the spatial pattern of presettlement forests in western New York than do prior studies. The spatially continuous representation could also enable the comparison of vegetation distribution from data sources that have different sampling schemes, for example the comparison of presettlement vegetation from the presettlement land survey records with current vegetation from modern forest inventories. The results are of value, providing a useful benchmark against which to examine vegetation change and the impacts of human land use.     

Influences of 20th‐century warming at the upper tree line contingent on local‐scale interactions: evidence from a latitudinal gradient in the Rocky Mountains,USA

Aims Twentieth‐century climate, the spatial pattern of tree establishment and positive feedback influence upper tree line ecotones. Here, I investigate how these factors interact to gain a more holistic understanding of how broad‐scale abiotic and local‐scale site conditions regulate tree establishment within upper tree line ecotones. Location A latitudinal gradient (c. 35–45° N) in the US Rocky Mountains. Study sites (n= 22) were located in the Bighorn (BH), Medicine Bow (MB), Front Range (FR) and Sangre de Cristo (SDC) mountain ranges. Methods Dendroecological techniques were used to reconstruct tree establishment dates that were compared with 20th‐century climate data using correlation and regime shift analyses. Spatial patterns of tree establishment were analysed by Ripley's K and used to determine local‐scale interactions capable of ameliorating broad‐scale climate inputs through positive feedback. Results Significant correlations (P < 0.01) between tree establishment and climate were confined to the FR, where a positive correlation was found with summer (June–August) and cool season (November–April) temperature range (T_max?T_min). These trees were almost exclusively situated in a random spatial pattern. Similar patterns exist in the BH, yet their establishment was contingent on the availability of local shelter in the lee of boulders. Trees in the MB and SDC were primarily clustered in space and had no significant correlations with climate. Considerable lag times exist between regime shift changes in climate towards more favourable growing conditions and corresponding shifts in tree establishment in all mountain ranges except the FR, where synchronous shifts occurred in the early 1950s. Main conclusions These results suggest that the influence of broad‐scale climate on upper tree line dynamics is contingent on the local‐scale spatial patterns of tree establishment and related influences of positive feedback. This research has important implications for understanding how vegetation communities will respond to global climate change.     

Variation in the Late Triassic Canjilon quarry (Upper Chinle Group, New Mexico) phytosaur skulls: a case for sexual dimorphism

The Canjilon quarry, located in north-central New Mexico near Ghost Ranch, contains a death assemblage of phytosaurs located stratigraphically high within the Petrified Forest Formation of the Chinle Group (Revueltian = early-mid Norian). The site has yielded numerous fossils ofPseudopalatus-grade phytosaurs, including at least 10 skulls collected from the locality byCharles Camp in 1928 and 1933 and another collected more recently byAlex Downs, curator of paleontology at Ghost Ranch. A re-examination of these skulls reveals two morphotypes that differ only in the relative lengths and relative robustness of their premaxillae. In these two morphotypes, the premaxillae define the shape and length of the rostral crest, the dimensions of which are independent of skull size. In one morphotype, the premaxillae are long, thin bones that lead to an abrupt, volcano-like narial crest. In the second morphotype, the premaxillae are of approximately the same length, but expand dorsoventrally halfway along their lengths, creating a longer and more robust crest. The most probable explanation of these two variants in rostral crest morphology in a Single, catastrophic death assemblage is thatPseudopalatus-grade phytosaurs are sexually dimorphic. Thus, the larger, more robust crest of the first morphotype is probably a display feature, most likely of the male animal. The more gracile snout änderest characterize the female morph. In the sample of phytosaurs examined, there are three individuals of the more robust (male) morphotype, five individuals of the gracile (female) morphotype, and three individuals (2 adult, 1 juvenile) that cannot be assigned to either morphotype because the skulls are too damaged to make an aecurate assessment. This is the first clear evidence of sexual dimorphism in phytosaurs, and has important implications for phytosaur species-level taxonomy, as well as for understanding aspects of their paleobiology (e.g., population dynamics).     

Oxygen minimum zone and internal waves as potential controls on location and growth of Waulsortian mounds (Mississippian, Sacramento Mountains, New Mexico)

Summary Lower Mississippian Waulsortian mounds in the Sacramento Mountains grew on a south-dipping homoclinal ramp at depths ranging from approximately 110 to 250 m, a setting in which nutrient sources and pathways are poorly understood in ancient carbonate depositional systems. Lithologic, biotic, and chemical data suggest that the mounds grew in an area on the ramp within a dysoxic oxygen minimum zone (OMZ) resulting from the concentration of organic matter below a thermocline. The abundance of organic matter there, perhaps a consequence of upwelling, enhanced the productivity of the major sediment contributors to the mounds—sponges, pelmatozoans, bryozoans, and heterotrophic carbonate-producing microbes. The siting and growth of individual mounds within the OMZ is best explained by two factors. One is the positive low-relief intra-ramp topography on and around which the mounds grew. The other is that nutrient supply for carbonate producing microbes was concentrated at the sites of mounds growth by internal waves on the pycnocline coincident with the thermocline. The internal waves mixed the nutrient-rich water of the OMZ with the better-oxygenated adjacent water mass, stirred the substrate and resuspended organic matter so that it was more available for the primarily suspension-feeding macrofauna both above and below the pycnocline, and generated local vertical mixing. Because of initial intra-ramp topography and subsequently increased relief as the mounds grew, internal waves focused and localized these processes, thus enhancing carbonate production at individual mound sites in a positive feed-back loop.     

The Lepidoptera of White Sands National Monument, Otero County, New Mexico, USA 3. A new species of Aleptina Dyar, 1902 (Lepidoptera, Noctuidae, Amphipyrinae, Psaphidini)

In 2006 the US National Park Service initiated a long-term study of the Lepidoptera at White Sands National Monument, Otero County, New Mexico. Aleptina arenariasp. n., described here, was discovered in 2008, the second year of the study. The adult moths and male and female genitalia are illustrated.     

Factors influencing in vitro infectivity and growth of Rickettsia peacockii (Rickettsiales: Rickettsiaceae), an endosymbiont of the Rocky Mountain wood tick, Dermacentor andersoni (Acari, Ixodidae)

Rickettsia peacockii, a spotted fever group rickettsia, is a transovarially transmitted endosymbiont of Rocky Mountain wood ticks, Dermacentor andersoni. This rickettsia, formerly known as the East Side Agent and restricted to female ticks, was detected in a chronically infected embryonic cell line, DAE100, from D. andersoni. We examined infectivity, ability to induce cytopathic effect (CPE) and host cell specificity of R. peacockii using cultured arthropod and mammalian cells. Aposymbiotic DAE100 cells were obtained using oxytetracycline or incubation at 37 degrees C. Uninfected DAE100 sublines grew faster than the parent line, indicating R. peacockii regulation of host cell growth. Nevertheless, DAE100 cellular defenses exerted partial control over R. peacockii growth. Rickettsiae existed free in the cytosol of DAE100 cells or within autophagolysosomes. Exocytosed rickettsiae accumulated in the medium and were occasionally contained within host membranes. R. peacockii multiplied in other cell lines from the hard ticks D. andersoni, Dermacentor albipictus, Ixodes scapularis, and Ixodes ricinus; the soft tick Carios capensis; and the lepidopteran Trichoplusia ni. Lines from the tick Amblyomma americanum, the mosquito Aedes albopictus, and two mammalian cell lines were non-permissive to R. peacockii. High cell densities facilitated rickettsial spread within permissive cell cultures, and an inoculum of one infected to nine uninfected cells resulted in the greatest yield of infected tick cells. Cell-free R. peacockii also were infectious for tick cells and centrifugation onto cell layers enhanced infectivity approximately 100-fold. The ability of R. peacockii to cause mild CPE suggests that its pathogenicity is not completely muted. An analysis of R. peacockii-cell interactions in comparison to pathogenic rickettsiae will provide insights into host cell colonization mechanisms.     

Classification and ordination of plant communities along an altitudinal gradient on the Presidential Range,New Hampshire,USA

An analysis of vegetation along an altitudinal gradient on the Presidential Range, New Hampshire, USA, using the Braun–Blanquet approach followed by multivariate data analysis is presented. Twelve main plant communities have been distinguished. Floristic information is presented in twelve tables and one appendix. The relationships of the communities to complex environmental gradients are analyzed using Correspondence Analysis. Floristic composition and community structure are controlled primarily by the altitudinal gradient (temperature, precipitation), and by mesotopographic conditions (snow accumulation, exposure and cryoturbation, slope position, and soil moisture).     

The Lepidoptera of White Sands National Monument, Otero County, New Mexico, USA 2. Rediscovery and description of Sparkia immacula (Grote, 1883) (Noctuidae, Noctuinae, Hadenini)

In 2006 the U.S. National Park Service initiated a long term study of the Lepidoptera at White Sands National Monument, Otero County, New Mexico. Sparkia immacula (Grote, 1883), previously known only from historical specimens collected in Arizona and New Mexico, was discovered in the Monument in 2007 during the second year of the study. The adult moths and male and female genitalia are illustrated for the first time.     

Characterization of 13 microsatellite loci for the deep-sea coral, Lophelia pertusa (Linnaeus 1758), from the western North Atlantic Ocean and Gulf of Mexico

A suite of 13 polymorphic tri- and tetranucleotide microsatellite loci were isolated from the ahermatypic deep-sea coral, Lophelia pertusa. Among 51 individuals collected from three disjunct oceanic regions, allelic diversity ranged from six to 38 alleles and averaged 9.1 alleles per locus. Observed heterozygosity ranged from 9.1 to 96.8% and averaged 62.3% in the Gulf of Mexico population. For some loci, amplification success varied among collections, suggesting regional variation in priming site sequences. Four loci showed departures from Hardy-Weinberg equilibrium in certain collections which may reflect nonrandom mating.     

Biogeochemical controls on aluminum chemistry in the O horizon of a red spruce (Picea rubens Sarg.) stand in central Maine,USA

This study examined the biotic and abiotic processes controlling solution chemistry and cycling of aluminum (Al) in the organic horizons of a northern coniferous forest ecosystem. A mass balance budget indicated that aboveground inputs of Al to the O horizon averaged 0.9 kg ha^–1 1 yr^–1, with major inputs accounted for by litterfall (69%), followed by precipitation (21%), and net canopy throughfall plus stemflow (10%). Estimated leaching losses of Al from the O horizon averaged 2.1 kg Al ha^-1 yr1. We hypothesize that the difference between measured Al inputs and outputs can be accounted for by Al release from weathering of soil minerals admixed into the O horizon. Variations in O horizon solution Al chemistry were influenced by a number of factors, including pH, Al equilibria with different solid-phase organic exchange sites, and Al complexation with humic ligands in soil solution.     

Fertilizer impacts on the understorey of a regenerating Mountain Ash (Eucalyptus regnans F. Muell.) forest,Victoria

Abstract We examined the effects of adding fertilizers on nutrient concentrations in foliage, and on species composition and density of the understorey in a 10 year old Mountain Ash (Eucalyptus regnans F. Muell.) forest. Nutrient concentrations in foliage of three woody understorey species (Acacia dealbata, Pomaderris aspera and Olearia argophylla) showed no significant response to the addition of phosphorus and nitrogen either alone, in combination or combined with other nutrients. The phosphorus concentration in foliage and stems of two herbaceous species (Australina pusilla and Urtica incisa) was significantly increased by applying phosphorus. The addition of fertilizers had no significant effect on species composition and density of the understorey.     

The invertebrate fauna of epiphyte mats in the canopy of northern rata (Myrtaceae: Metrosideros robusta A. Cunn.) on the West Coast of the South Island,New Zealand

Abstract

The range of microhabitats and microclimatic conditions provided by epiphytes has been linked to the high diversity of invertebrates in many forest canopies worldwide, but comparably little is known about the invertebrate fauna in this habitat in New Zealand. This study compiled an inventory of the invertebrate fauna of epiphyte mats in the canopy of northern rata (Myrtaceae: Metrosideros robusta A. Cunn.) at two study sites on the West Coast of the South Island. A total of 242 069 invertebrate specimens was collected over one year, representing 4 phyla, 9 classes and more than 160 families, 225 genera and 446 species. At least 10 new species and 3 new genera were identified, while 5 species were recorded outside their known geographical range. Epiphyte mats provided habitat for an invertebrate fauna, highly diverse and abundant both taxonomically and functionally, dominated in terms of abundance by Acari, Collembola and Hymenoptera (largely ants), and in terms of feeding guilds by epiphyte grazers and ants. As the first inventory of this taxonomic depth and breadth compiled for New Zealand forest epiphyte habitats, this study provides important baseline data for the conservation of biodiversity in New Zealand's indigenous forests.