scholarly journals Importance of woodland patches as hibernacula for gartersnakes in a prairie river floodplain of central Nebraska

2021 ◽  
pp. 71-87
Author(s):  
Anthony Bridger ◽  
Keith Geluso
Keyword(s):  
Great Plains ◽  
Environmental Changes ◽  
Populus Deltoides ◽  
River System ◽  
Thamnophis Sirtalis ◽  
Platte River ◽  
European Settlement ◽  
Large Trees ◽  
Floodplain Habitats ◽  
Capture Rates

Gartersnakes are common inhabitants along prairie rivers in the Great Plains, but little information is known about hibernacula among diverse floodplain habitats. We radio-tracked Common Gartersnakes (Thamnophis sirtalis) and Plains Gartersnakes (Thamnophis radix) to hibernacula on islands in a braided river system subject to frequent environmental changes along the Platte River in central Nebraska. We further examined capture rates of gartersnakes in floodplain woodland patches from June to November to examine seasonal use of this habitat. In early and mid-September, movements of snakes with transmitters were in grasslands. From late September to mid-October, the farthest movements were documented, and snakes moved from grasslands into woodland patches. From late October to January, movements were minimal in and around hibernacula in wooded or formerly wooded habitats. Capture rates of gartersnakes in woodland trapping arrays also increased in October and November, further demonstrating woodland use during times when snakes travel to and reside at hibernacula. Although grasslands comprised most of the prairie islands at the study area, observations suggested that the limited woodlands on these islands are important for gartersnakes prior to and during hibernation along the Platte River in central Nebraska. Areas with large trees, such as Plains Cottonwoods (Populus deltoides), appeared to provide overwintering sites. In central Nebraska, riparian woodlands continue to be cleared to enhance habitat for endangered and threatened species such as Whooping Cranes (Grus americana), but some of these islands originally contained trees prior to European settlement. Conservation of at least some woodland habitats appears important for overwintering gartersnakes in central Nebraska.

An Assessment of Environmental Changes in Three Lakes from King's County (Nova Scotia, Canada) Using Diatom-Based Paleolimnological Techniques

2008 ◽  
Vol 43 (2-3) ◽  
pp. 85-98 ◽  
Author(s):  
Joshua R. Thienpont ◽  
Brian K. Ginn ◽  
Brian F. Cumming ◽  
John P. Smol
Keyword(s):  
Nova Scotia ◽  
Environmental Changes ◽  
Sediment Cores ◽  
Lake Management ◽  
River System ◽  
210Pb Dating ◽  
Hydroelectric Power ◽  
Diatom Assemblages ◽  
Shoreline Development ◽  
Before And After

Abstract Paleolimnological approaches using sedimentary diatom assemblages were used to assess water quality changes over the last approximately 200 years in three lakes from King's County, Nova Scotia. In particular, the role of recent shoreline development in accelerating eutrophication in these systems was assessed. Sediment cores collected from each lake were analyzed for their diatom assemblages at approximately 5-year intervals, as determined by 210Pb dating. Analyses showed that each system has changed, but tracked different ecosystem changes. Tupper and George lakes recorded shifts, which are likely primarily related to climatic warming, with diatom assemblages changing from a preindustrial dominance by Aulacoseira spp. to present-day dominance by Cyclotella stelligera. In addition to the recent climatic-related changes, further diatom changes in the Tupper Lake core between approximately 1820 and 1970 were coincident with watershed disturbances (farming, forestry, and construction of hydroelectric power infrastructure). Black River Lake has recorded an increase in diatom-inferred total phosphorus since about 1950, likely due to impoundment of the Black River system for hydroelectric generation and subsequent changes in land runoff. Before-and-after (i.e., top-bottom) sediment analyses of six other lakes from King's County provided further evidence that the region is being influenced by climatic change (decreases in Aulacoseira spp., increases in planktonic diatom taxa), as well as showing other environmental stressors (e.g., acidification). However, we recorded no marked increase in diatom-inferred nutrient levels coincident with shoreline cottage development in any of the nine study lakes. Paleolimnological studies such as these allow lake managers to place the current limnological conditions into a long-term context, and thereby provide important background data for effective lake management.

scholarly journals The Impact of the Nocturnal Transition on the Lifetime and Evolution of Supercell Thunderstorms in the Great Plains

2018 ◽  
Vol 33 (4) ◽  
pp. 1045-1061 ◽  
Author(s):  
Matthew E. Gropp ◽  
Casey E. Davenport
Keyword(s):  
Thermodynamic Parameters ◽  
Great Plains ◽  
Environmental Changes ◽  
Kinematic Parameters ◽  
Storm Evolution ◽  
Composite Parameter ◽  
Convective Inhibition ◽  
Supercell Thunderstorms ◽  
Parameter Values ◽  
The Impact

Abstract Predicting the evolution of supercell thunderstorms during and after the evening transition is a known challenge due to an incomplete understanding of how these events evolve in response to associated environmental changes. To quantify the connection between storm evolution and environmental changes during the nocturnal transition, 157 initially isolated Great Plains supercell thunderstorms occurring between 2005 and 2016 are examined. Each supercell is categorized as either maintained, dissipating, growing upscale, or merging. Changes in the inflow environment are quantified using hourly RUC and RAP model proximity soundings between 1 h prior to local sunset time and 5 h postsunset. Using these soundings, numerous thermodynamic and kinematic parameters are derived, and distributions of these parameter values are statistically compared among the evolution categories. It was found that each evolution classification existed in a unique set of kinematic and thermodynamic parameters; this distinction was most evident when comparing maintained and dissipation categories. In particular, storm-relative helicity, most unstable convective inhibition (MUCIN), and associated composite parameters were best able to distinguish supercell evolution. Notably, maintained supercells were characterized by significant increases in storm-relative helicity and comparatively smaller increases in the magnitude of MUCIN during the nocturnal transition; together, these parameters promote a sustained and robust rotating updraft. A convective inhibition–scaled supercell composite parameter is proposed to further assist in predicting supercell maintenance during the nocturnal transition.

scholarly journals Holocene Evolution of the Outer Lake of Hwajinpo Lagoon On the Eastern Coast of Korea; Environmental Changes with Holocene Sea-Level Fluctuation of the East Sea (Sea of Japan)

Radiocarbon ◽  
2004 ◽  
Vol 46 (2) ◽  
pp. 797-808 ◽  
Author(s):  
Jong-Gwon Yum ◽  
Kang-Min Yu ◽  
Keiji Takemura ◽  
Toshiro Naruse ◽  
Akihisa Kitamura ◽  
...  
Keyword(s):  
Sea Level ◽  
Environmental Changes ◽  
River System ◽  
Eastern Coast ◽  
Estuarine System ◽  
Level Fluctuation ◽  
Radiocarbon Dates ◽  
Sedimentary Environments ◽  
Sea Level Fluctuation ◽  
Low Sulfur Content

The evolution of the outer lake of Hwajinpo Lagoon in Korea has been reconstructed using environmental proxies (lithologic, geochemical, and fossil data) with a chronology established using 7 accelerator mass spectrometry (AMS) radiocarbon dates. Grain size, water content, and X-ray analyses from the core of outer coastal lakes (HJ99) were used to reconstruct sedimentary environments by using total organic carbon, C/N, S, and C/S chemical proxies. Assemblages of mollusc remains also provided paleoenvironmental information. The environmental changes of the outer lake of Hwajinpo Lagoon can be divided into 6 depositional phases. The basin of the Hwajinpo was exposed and underwent a weathering process before the Holocene period. The muddy sand layer on the weathered bedrock indicated an estuarine system about 6000 BP. The laminated layer implies that the lagoonal system was anoxic between about 5500–2800 BP. The marl layer implies a relatively oxic lagoonal condition with mollusc presence about 2500 B P. The layer of very low sulfur content indicates a freshwater lake system isolated by a sand barrier about 1700 BP. Beginning about 1000 B P, the river system deposits progress progradation on the marl layer. Two erosional landforms could be related with a high standing sea level span during Holocene. These high-stands are dated at 5700 BP and 2200 BP and are supposed to have formed erosional landforms of about 1.6 amsl and 0.8 amsl, respectively. Environmental changes of the outer lake of Hwajinpo Lagoon are considered due mainly to the lake- and sea-level fluctuation during Holocene.

Environmental history since 11,000 14c yr b.p. of the northeastern Pampas, Argentina, from alluvial sequences of the Luján River

2004 ◽  
Vol 62 (2) ◽  
pp. 146-161 ◽  
Author(s):  
Aldo R. Prieto ◽  
Adriana M. Blasi ◽  
Claudio G. De Francesco ◽  
Celina Fernández
Keyword(s):  
Shallow Water ◽  
Environmental History ◽  
Environmental Changes ◽  
Water Bodies ◽  
Pollen Record ◽  
Groundwater Levels ◽  
European Settlement ◽  
Subaerial Exposure ◽  
Dry Conditions ◽  
Detailed Record

Sedimentological, malacological, and pollen analyses from 14C-dated alluvial sections from the Luján River provide a detailed record of environmental changes during the Holocene in the northeastern Pampas of Argentina. From 11,200 to 9000 14C yr B.P., both sedimentary and biological components suggest that the depositional environment was eutrophic, alkaline, and freshwater to brackish shallow water bodies without significant water circulation. During this time, bioclastic sedimentation was dominant and the shallow water bodies reached maximum development as the climate became more humid, suggesting an increase in precipitation. Short-term fluctuations in climate during the last stage of this interval may have been sufficient to initiate changes in the water bodies, as reduction of the volume alternated with periods of flooding. The beginning of the evolution of shallow swamps in the wide floodplain or huge wetlands was contemporaneous with a sea level lower than the present one. From 9000 and 7000 14C yr B.P., mesotrophic, alkaline, brackish, probably anoxic swamps existed. Between 7000 and 3000 14C yr B.P., anoxic calcareous swamps were formed, with subaerial exposure and development of the Puesto Berrondo Soil (3500–2900 14C yr B.P.). A trend to a reduction of water bodies is recorded from 9000 to ca. 3000 14C yr B.P., with a significant reduction after ca. 7000 14C yr B.P. A shift to subhumid–dry climate after 7000 14C yr B.P. appears to be the main cause. During this time, an additional external forcing toward higher groundwater levels was caused by Holocene marine transgression causing changes in the water bodies levels. The climate became drier during the late Holocene (ca. 3000 yr B.P.), when clastic sedimentation increased, under subhumid–dry conditions. Flood events increased in frequency during this time. From ca. A.D. 1790 to present, the pollen record reflects widespread disturbance of the vegetation during the European settlement.

Ecology of the Honey possum, Tarsipes rostratus, in Scott National Park, Western Australia

2007 ◽  
Vol 29 (1) ◽  
pp. 25 ◽  
Author(s):  
S.D. Bradshaw ◽  
R.D. Phillips ◽  
S. Tomlinson ◽  
R. J. Holley ◽  
S. Jennings ◽  
...  
Keyword(s):  
Plant Species ◽  
Western Australia ◽  
National Park ◽  
Environmental Changes ◽  
Phytophthora Cinnamomi ◽  
Late Summer ◽  
Food Sources ◽  
Burnt Areas ◽  
Honey Possum ◽  
Capture Rates

The Honey possum, Tarsipes rostratus, is an obligate nectarivore, known to feed on plant species from only three Families in south-western Western Australia: Myrtaceae, Proteaceae and Epacridaceae. These plants can be adversely affected by fire, decreased rainfall or groundwater levels and the pathogen Phytophthora cinnamomi. We investigated the ecology of T. rostratus in terms of: (i) how the population fluctuated in response to rainfall and fire over a 20-year period and (ii) changes in diet and movements during a period of decreased food availability in late summer. Mean capture rates were significantly positively correlated with mean flowering rates of Banksia ilicifolia over a 20-year period. Winter capture rates were also significantly positively correlated with both annual and winter rainfall two years prior to trapping in recently burnt areas, but not in long unburnt� areas. Capture rates were significantly higher in unburnt Banksia woodland during winter but densities there have declined since 1996, associated with the death of many Banksia ilicifolia trees from persistent Phytophthora infection. Notwithstanding this decline, winter capture rates in the unburnt areas were still approximately double those in the burnt areas 6 years after the last fire. Short-term capture rates were negatively correlated with barometric pressure, showing that movement and foraging is stimulated by the passage of low pressure frontal weather systems. Despite the paucity of known food sources flowering in late summer and autumn, there was no evidence of T. rostratus using plant species from other than the three above-noted Families. Utilisation areas in summer were also no larger than those previously recorded across all seasons in Scott National Park. Some individuals, however, moved extensive distances to locate spatially restricted food sources. The conservatism of their diet and the sensitivity of the population to changes in rainfall and fire history indicate that T. rostratus populations are particularly vulnerable to some of the environmental changes now occurring in south-western Australia.

scholarly journals A 1200-year history of environmental changes in Bay Jimmy area, coastal Louisiana, USA

The Holocene ◽  
2019 ◽  
Vol 30 (2) ◽  
pp. 201-209 ◽  
Author(s):  
Lawrence M Kiage
Keyword(s):  
Environmental Changes ◽  
Forest Disturbance ◽  
Climatic Conditions ◽  
Ice Age ◽  
Pollen Record ◽  
Ambrosia Pollen ◽  
Paleoenvironmental Changes ◽  
European Settlement ◽  
Red Mangrove ◽  
Coastal Louisiana

Paleoecological studies from the northern Gulf of Mexico (GOM) have mostly aimed at understanding long-term paleoenvironmental changes. Only a few studies have been performed in the southern United States focusing on paleoenvironmental changes during the common era. This study investigated paleoenvironmental changes in coastal Louisiana over the past 1200 years by utilizing proxy data, including loss-on-ignition (LOI) and pollen from a sediment core collected from a wetland in Bay Jimmy. The results indicate that the marsh in the study area was formed at ca. AD 1090 and has been primarily shaped by prevailing climatic conditions, including rare extreme events. At least four major hurricanes impacted the site over the 1200 years, including two that made landfall in recent times. The findings show that coastal Louisiana was warm and dry during the ‘Medieval Warm Period’ (ca. AD 950–1250). The environment after AD 1090 contained scattered Pinus and Juglans vegetation communities that were later succeeded by a closed forest that included Quercus and Morus. Red mangrove ( Rhizophora) was established in the vicinity of Bay Jimmy until shortly after cal AD 1450 and 1640. The pollen record indicates that the ‘Little Ice Age’ period (AD 1550–1850) was cold and dry, characterized by a more open vegetation community. There is evidence of forest disturbance that is marked by a rise in Ambrosia pollen in the 1700s, coinciding with the time of European settlement in North America. The presence of Ambrosia and Cheno/Am pollen throughout the record suggests that anthropogenic influence has been part of the fabric of the southern Louisiana landscapes throughout the 1200 years.

Climatic Implications of the Late Quaternary Alluvial Record of a Small Drainage Basin in the Central Great Plains

1994 ◽  
Vol 41 (3) ◽  
pp. 298-305 ◽  
Author(s):  
Alan F. Arbogast ◽  
William C. Johnson
Keyword(s):  
Great Plains ◽  
Drainage Basin ◽  
Late Quaternary ◽  
Soil Formation ◽  
River System ◽  
Early Holocene ◽  
The Past ◽  
Kansas River ◽  
Dakota Sandstone ◽  
Sand And Gravel

AbstractFour late-Quaternary alluvial fills and terraces are recognized in Wolf Creek basin, a small (163 km2) drainage in the Kansas River system of the central Great Plains. Two terraces were created during the late Pleistocene: the T-4 is a fill-top terrace underlain by sand and gravel fill (Fill I), and the T-3 is a strath terrace cut on the Cretaceous Dakota Sandstone. Both Fill II (early Holocene) and Fill III (late Holocene) are exposed beneath the T-2, a Holocene fill-top terrace. The T-1 complex, consisting of one cut and three fill-top terraces, is underlain by Fills III and IV. A poorly developed floodplain (T-0) has formed within the past 1000 yr. As valleys in Wolf Creek basin filled during the early Holocene, an interval of soil formation occurred about 6800 yr B.P. Early Holocene fill has been found only in the basin's upper reaches, indicating that extensive erosion during the middle Holocene removed most early-Holocene fill from the middle and lower reaches of the basin. Valley filling between 5000 and 1000 yr B.P. was interrupted by soil formation about 1800, 1500, and 1200 yr B.P. As much as 6 m of entrenchment has occurred in the past 1000 yr. Holocene events in Wolf Creek basin correlate well with those in other localities in the central Great Plains, indicating that widespread changes in climate, along with adjustments driven by complex response, influenced fluvial activity.

scholarly journals Supplemental Material: Ancestral trans–North American Bell River system recorded in late Oligocene to early Miocene sediments in the Labrador Sea and Canadian Great Plains

2021 ◽  
Author(s):  
Julia I. Corradino ◽  
Alex Pullen
Keyword(s):  
Great Plains ◽  
North American ◽  
River System ◽  
Early Miocene ◽  
Labrador Sea ◽  
Late Oligocene ◽  
Nd Isotope ◽  
Isotope Data ◽  
Marine Bivalves

S1: U-Pb data from the Saglek Basin Rut H-11 well and Canadian Great Plains samples; S2: Sr and Nd isotope data for marine bivalves in Saglek Basin Rut H-11 well.

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