scholarly journals The relative roles of inheritance and long-term passive margin lithospheric evolution on the modern structure and tectonic activity in the southeastern United States

Geosphere ◽  
2018 ◽  
Vol 14 (4) ◽  
pp. 1385-1410 ◽  
Author(s):  
Lara S. Wagner ◽  
Karen M. Fischer ◽  
Robert Hawman ◽  
Emily Hopper ◽  
Dorran Howell
Keyword(s):  
United States ◽  
Southeastern United States ◽  
Passive Margin ◽  
Tectonic Activity ◽  
Lithospheric Evolution

scholarly journals Long-Term Timber Contracts in the Southeastern United States: Updating the Primer Valuation Framework

2020 ◽  
Vol 66 (6) ◽  
pp. 653-665
Author(s):  
Hector I Restrepo ◽  
Bin Mei ◽  
Bronson P Bullock
Keyword(s):  
United States ◽  
Interest Rates ◽  
Southeastern United States ◽  
Price Volatility ◽  
Forest Products ◽  
The United States ◽  
Raw Material ◽  
Conditional Volatility ◽  
Material Supply

Abstract Timberland ownership has drastically changed in the United States since the 1980s, driven by the divestitures of vertically integrated forest products companies. Having sold their timberland, forest products companies have exposed themselves more to the risk of raw material supply. To hedge against this risk, forest products companies usually use long-term timber contracts (LTTC). The objective of this article is to update the valuation framework for LTTCs proposed by Shaffer (1984) by including alternative option price models and refining the estimates of some key economic variables. In particular, conditional volatility from the generalized autoregressive conditional heteroscedasticity model and quasi-conditional volatility from rolling estimation windows, in addition to simple standard deviation, are used for the volatility estimates in the option pricing models. Contrary to the previous result by Shaffer (1984), our analysis suggests that LTTCs that were once profitable for forest products companies in the 1980s are no longer so under current market conditions. This is primarily because both timber price volatility and the risk-free interest rates have declined significantly. Thus, to be better off, forest products companies need to either lower the administration and management costs of those LTTCs or rely more on the open market for timber procurement. Study Implications: Forest products companies have traditionally relied on long-term timber contracts (LTTC) negotiated with forest landowners to mitigate the risk of raw material supply. The value of these LTTCs highly depends on the economic context. This research provides some insights into the valuation of LTTCs in the southeastern United States. Forest products companies can use this updated framework to aid their decisionmaking in timber procurement.

Histological Evidence that Microsclerotia Play a Significant Role in Disease Cycle of the Boxwood Blight Pathogen in Southeastern United States and Implications for Disease Mitigation

2012 ◽  
Vol 13 (1) ◽  
pp. 45 ◽  
Author(s):  
Sarah M. Weeda ◽  
Norman L. Dart
Keyword(s):  
United States ◽  
Significant Role ◽  
Potential Role ◽  
Histological Study ◽  
Southeastern United States ◽  
Host Tissue ◽  
Term Survival ◽  
Long Term Survival ◽  
Histological Evidence

Cylindrocladium pseudonaviculatum, the causal agent of box blight, has been shown to survive in soil for at least 5 years. The occurrence of microsclerotia in host tissue remains undocumented, making the mechanism for long term survival of this pathogen unclear. If the boxwood blight pathogen has indeed lost or never evolved the ability to produce microslerotia in tissues, one could infer that the pathogen is either less equipped for long term survival in soil than other Cylindrocladium species or the pathogen has evolved another mechanism to enable it to persist in soil. Based on these assumptions, we conducted a histological study to determine the potential role, if any, of microsclerotia in the lifecycle of C. pseudonaviculatum. Accepted for publication 17 February 2012. Published 3 April 2012.

A Long-Term, Consistent Land Cover History of the Southeastern United States

2018 ◽  
Vol 84 (9) ◽  
pp. 559-568 ◽  
Author(s):  
Matthew P. Dannenberg ◽  
Conghe Song ◽  
Christopher R. Hakkenberg
Keyword(s):  
United States ◽  
Land Cover ◽  
Southeastern United States ◽  
History Of

Loblolly pine outperforms slash pine in the southeastern United States – A long-term experimental comparison study

2019 ◽  
Vol 450 ◽  
pp. 117532 ◽  
Author(s):  
Dehai Zhao ◽  
Bronson P. Bullock ◽  
Cristian R. Montes ◽  
Mingliang Wang ◽  
Dale Greene ◽  
...  
Keyword(s):  
United States ◽  
Loblolly Pine ◽  
Southeastern United States ◽  
Slash Pine ◽  
Experimental Comparison ◽  
Comparison Study

A 12,000 Kyr Paleohydroclimate Record in the Southeastern, U.S.A based on Deuterium from Bat Guano

2021 ◽  
Author(s):  
Alexandra Tsalickis ◽  
Matthew Neal Waters ◽  
Joshua William Campbell
Keyword(s):  
United States ◽  
Human Impacts ◽  
Southeastern United States ◽  
Sediment Cores ◽  
Population Increase ◽  
Time Interval ◽  
Moisture Regimes ◽  
Climate Proxies ◽  
Bat Guano

Abstract The southeastern United States endures environmental change from human population increase, climate change, and land use alterations creating the need to understand baseline conditions and environmental patterns prior to human impacts. While paleoenvironmental data can be reconstructed from a variety of archives (e.g. lake sediments, tree rings, speleothems), some geographic areas contain fewer of such records. One archive capable of recording moisture regimes and other paleoenvironmental changes over millennia but has received little attention relative to other climate proxies, are bat guano deposits in cave systems. Bat guano deposits are found in many cave environments in the southeastern United States and can be used as an archive of paleoenvironmental data including precipitation, vegetation, and aspects associated with the ecology of bats. Here, we present a 12,000-year record of paleoenvironmental change based on δ2H stable isotopes in a guano core collected from Cave Springs Cave in Alabama, USA. Results suggest distinct shifts in moisture during the lower Holocene/upper Pleistocene (9,551 – 12,131 cal yr BP) (δ2H values -86.82 – -77.70) and during the middle Holocene (3,886 – 9,351 cal yr BP) (δ2H values -125.74 – -80.63), roughly coinciding with the Holocene Climatic Optimum (HCO) time interval (5,000 – 9,000 cal yr BP). During the last 4,000 years, conditions in the region shifted once again in the southeastern United States region. Climate inferences based on guano δ2H are consistent with the role of atmospheric moisture on regional vegetation changes suggested by previous pollen records obtained from lake sediment cores. This study suggests bat guano δ2H may be a reliable method to provide a long-term paleoclimate record.

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