Miller N.G.,Biological Survey |
Robinson S.C.,New York University
Rhodora | Year: 2015
The bryoflora of Martha's Vineyard and Nomans Land has received little organized study. However, these islands of 100 mi2 and 1 mi2, respectively, seven miles south of Cape Cod, are of considerable bryological interest. They are part of the Atlantic Coastal Plain and are located near the northern, largely submerged end of this physiographic province, which extends southward along the entire eastern coast of the United States. Late Pleistocene glaciers reached as far south as the Vineyard area, leaving behind massive deposits of terminal moraine and associated outwash that remained above sea level as islands when the sea transgressed landward at end of the Ice Age. The maritime climate of Martha's Vineyard and Nomans Land is characterized by moderate temperatures throughout the year, and the islands lack large seasonal temperature variation typical of more continental regions. Thus, on the basis of these and other circumstances the bryoflora of the Vineyard and Nomans Land was expected to consist of an interesting mixture of southern and northern species, some of which potentially are at their range limits. Four visits to Martha's Vineyard and one visit to Nomans Land resulted in 480 collections documenting 168 taxa (1 hornwort, 43 liverworts, and 124 mosses). Of these, 15 (11 1iverworts, and four mosses) are new records for Massachusetts. A list of the taxa found and brief descriptions of collecting sites are presented in two appendices. © Copyright 2015 by the New England Botanical Club.
Karig D.E.,Cornell University |
Miller N.G.,Biological Survey
Quaternary Research (United States) | Year: 2013
Areal mapping of the middle Wisconsin varved clay site along Sixmile Creek near Ithaca, New York, has revealed a much more widespread and varied array of sediments than previously thought. Lacustrine clays, some varved, are interbedded with sands and gravels interpreted as sub-aqueous fan deposits, and both are overlain by a deformation till. Nine radiocarbon dates indicate a 34-37 14C ka BP age for the lacustrine sediment, with the deformation till less than a few thousand years younger. Beneath this sequence is a deposit dated at ±42 14C ka BP. Both strata represent a tundra climate with a mean July temperature of about 10°C. The Sixmile Creek deformation till must correlate with the 35 14C ka BP till along the Genesee River, 125km to the NW, and defines a Cherrytree stade glacial advance into the Appalachian Plateau, much further south than what has generally been accepted. Such an advance would require drainage from a proglacial lake in the western Ontario basin to flow westward instead of northeastward. The Sixmile strata suggest a colder than accepted middle Wisconsin stage. Recent data indicate that this stage is one of progressive cooling, with large climatic fluctuations. © 2013 University of Washington.
Miller N.G.,Biological Survey |
Griggs C.B.,Cornell University
Canadian Journal of Earth Sciences | Year: 2012
Tree macrofossils dating from the middle to end (about 1000 years, ca. 12 600-11 600 cal years BP) of the Younger Dryas chronozone were found in an organic deposit on the southwest side of the Mohawk River, near its junction with the Hudson River in Cohoes, New York, USA. The fossils included substantial wood fragments, associated plant remains, and pollen, which indicate a forest of white spruce (Picea glauca), balsam fir (Abies balsamea), and tamarack (Larix laricina). The presence of white, rather than black (P. mariana) or red (P. rubens) spruce in the Younger Dryas was probably due to a riparian-type environment, confirmed by its location and American beaver tooth marks on some of the wood fragments. The clusters of wood radiocarbon dates indicate periodic changes in erosion and deposition at the site. One possible but very short decline (temperature reversal?) may be indicated by tree-ring growth, but in general, the ring widths of the trees and their growth responses suggest variable but slowly improving conditions over time, possibly from warming temperatures, before the end of the Younger Dryas.
Miller N.G.,Biological Survey |
Hastings R.I.,Royal Alberta Museum
Bryologist | Year: 2013
Summarized are results of field studies of small, cushion-forming species of Grimmia in high altitude mountain areas of New York State, Vermont, New Hampshire, and Maine, and of associated research with herbarium specimens from these regions. We here report eight species. Grimmia anodon is added to the flora of the Northeast, and new records and clarifications are presented for G. donniana, G. incurva, G. longirostris, G. milleri, G. sessitana, and G. trichophylla. Collections of these species came from rock types of varying composition (calcareous to acidic), sometimes different vegetation, and varying altitudinal ranges. In spite of these advancements in knowledge, Grimmia of the northeastern United States remains incompletely understood, taxonomically and ecologically. Copyright © 2013 by The American Bryological and Lichenological Society, Inc.
Published in the journal PLOS ONE, the University of Adelaide research, in partnership with the Department of Environment, Water and Natural Resources (DEWNR) and the Terrestrial Ecosystem Research Network, highlights six biodiversity hotspots. They are western Kangaroo Island, southern Mount Lofty Ranges, Anangu Pitjantjatjara Yankunytjatjara lands, southern Flinders Ranges, southern Eyre Peninsula and the Lower South East. The researchers used detailed biological data collected over time, including from the State's Biological Survey and the State Herbarium, and a suite of sophisticated metrics to identify biodiverse regions and the potential threats to their conservation. "We also looked at the extent to which the vegetation of each site was likely to change under future climates," says lead author Dr Greg Guerin. "We concluded that all of the state's ecosystems are expected to be impacted but the southern Flinders Ranges location is expected to be the most sensitive of these regions to climate change. "All of the 'hotspots', however, are subject to serious conservation issues, such as habitat fragmentation, weed invasion and altered fire regimes." The study found that the southern Mount Lofty Ranges region contained a high proportion of unique species and had high overall diversity but it has been subjected to the highest levels of disturbance since European settlement. The western side of Kangaroo Island has perhaps the most significant plant biodiversity in South Australia, but was rated as less vulnerable due to higher reservation levels and lower incidences of weed species. DEWNR's principal Ecologist Dr Dan Rogers says "This study has contributed to our understanding of South Australia's native biodiversity, particularly in relation to the relative impacts of climate change" "By improving our understanding of potential ecosystem change under future climates, we are able to better inform the management of native biodiversity that reflects these climate-induced changes." Co-author Professor Andrew Lowe, Chair of Plant Conservation Biology at the University of Adelaide, says: "Importantly, this study measures biodiversity at ecosystem rather than individual species level, and it uses numerical methods which can now be repeated and updated to meet future conservation management requirements. "Now we have a tool in place that can contribute to how we assess South Australia's biodiversity." Explore further: Major changes needed to protect Australia's species and ecosystems More information: Greg R. Guerin et al. Identifying Centres of Plant Biodiversity in South Australia, PLOS ONE (2016). DOI: 10.1371/journal.pone.0144779