scholarly journals Westward Expansion by Juniperus virginiana of the Eastern United States and Intersection with Western Juniperus Species in a Novel Assemblage

Forests ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 101
Author(s):  
Brice B. Hanberry

Eastern redcedar (Juniperus virginiana L.) is increasing in density in the eastern United States and expanding in range to the west, while western Juniperus species also are increasing and expanding, creating the potential for a novel assemblage. I estimated range expansion and intersection by comparing recent USDA Forest Service Forest Inventory and Analysis surveys (mean year = 2009) to the oldest available surveys (mean year = 1981), with adjustments for sampling changes, and predicted climate envelopes during the following year ranges: 1500–1599, 1800–1849, 1850–1899, 1900–1949, and 1960–1989. During approximately 28 years, eastern redcedar range expanded by about 54 million ha (based on ≥0.5% of total stems ≥12.7 cm in diameter in ecological subsections). Combined range of western species of juniper did not expand. Range intersection of eastern redcedar and western Juniperus species totaled 200,000 km2 and increased by 31,600 km2 over time, representing a novel assemblage of eastern and western species. Predicted ranges during the other time intervals were 94% to 98% of predicted area during 1960–1989, suggesting major climate conditions have been suitable for centuries. The southern western Juniperus species and Rocky Mountain juniper (Juniperus scopulorum Sarg.) have the greatest potential for intersection with eastern redcedar, whereas eastern redcedar may have concluded westward expansion.

PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0242003
Author(s):  
David Ward

The expansion of woody plants into grasslands and old fields is often ascribed to fire suppression and heavy grazing, especially by domestic livestock. However, it is also recognized that nutrient availability and interspecific competition with grasses and other woody plants play a role in certain habitats. I examined potential factors causing range- and niche expansion by the eastern redcedar Juniperus virginiana, the most widespread conifer in the eastern United States, in multifactorial experiments in a greenhouse. Historical records suggest that the eastern redcedar is a pioneer forest species, and may be replaced as the forest increases in tree density due to shading. Another possible factor that affects its distribution may be nutrient availability, which is higher in old fields and other disturbed lands than in undisturbed habitats. In its historic range, eastern redcedars are particularly abundant on limestone outcrops, often termed ‘cedar barrens’. However, the higher abundance on limestone could be due to reduced interspecific competition rather than a preference for high pH substrates. I manipulated shade, fertilization, lime, and interspecific competition with a common dominant tree, the post oak Quercus stellata. In a separate experiment, I manipulated fire and grass competition. I measured growth rates (height and diameter) and above- and belowground biomass at the end of both experiments. I also measured total non-structural carbohydrates and nitrogen in these plants. Shade was the most important factor limiting the growth rates and biomass of eastern redcedars. I also found that there were significant declines in nitrogen and non-structural carbohydrates when shaded. These results are consistent with the notion that the eastern redcedar is a pioneer forest species, and that shade is the reason that these redcedars are replaced by other tree species. In the second experiment, I found that a single fire had a negative effect on young trees. There was no significant effect of competition with grass, perhaps because the competitive effect was shading by grasses and not nutrient depletion. Overall, the effects of shade were far more apparent than the effects of fire.


1969 ◽  
Vol 280 (2) ◽  
pp. 57-62 ◽  
Author(s):  
Gerald W. Hazard ◽  
Robert N. Ganz ◽  
Robert W. Nevin ◽  
Alan H. Nauss ◽  
Ever Curtis ◽  
...  

2019 ◽  
Vol 64 (2) ◽  
pp. 137-147
Author(s):  
Susan Will-Wolf ◽  
Sarah Jovan

AbstractLichen element (N, S, metals) indicators of local air pollution load (a widely used technique) are recommended for five predefined regions covering central and southern parts of the eastern United States. The final recommendations integrate the advice of regional lichenologists, information from regional floras, and species abundance data from a United States Forest Service Forest Inventory and Analysis Program (FIA) lichen database for 11 of the 21 covered eastern states. Recommended species were frequent in their region, easy for nonspecialists to distinguish in the field after training, and easy to handle using clean protocols. Regression models of species abundance in FIA plots from five southeastern states vs. climate, air pollution (both from a regional lichen response model) and type of nearby landcover (from the National Land Cover Database) identified species’ environmental limitations. Punctelia rudecta is recommended for cooler forested uplands of all regions, with three Physcia species combined and Punctelia missouriensis for isolated woodlands or urban areas of three regions. Parmotrema hypotropum and P. hypoleucinum combined (weak environmental limitation) or P. perforatum. and P. subrigidum combined (limited in more polluted areas) are recommended for warmer Coastal Plains in two regions each. Additional species are recommended for single regions. Each species must be quantitatively evaluated in each region, to demonstrate indication reliability in practice and to calculate element data conversions between species for region-wide bioindication.


Author(s):  
J T Vogt ◽  
B D Allen ◽  
D Paulsen ◽  
R T Trout Fryxell

Abstract Haemaphysalis longicornis Neumann, Asian longhorned tick, was collected in Madison County, Kentucky, United States as part of an ongoing collaborative-tick surveillance project. This is the first collection of this invasive tick that includes ancillary data on habitat and landscape features derived from the USDA Forest Service, Forest Inventory and Analysis program.


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