Airborne electromagnetic and magnetic survey of parts of the Upper Peninsula of Michigan and Northern Wisconsin

1981 ◽  
Author(s):  
◽  
William D. Heran
Keyword(s):  
Magnetic Survey ◽  
Upper Peninsula ◽  
Airborne Electromagnetic ◽  
Upper Peninsula Of Michigan

scholarly journals Press-Pulse Odocoileus Virginianus Herbivory in Relict Tsuga Canadensis Stands in the Western Upper Peninsula of Michigan, USA

Forests ◽  
2019 ◽  
Vol 10 (6) ◽  
pp. 496
Author(s):  
Grace L. Parikh ◽  
Christopher R. Webster
Keyword(s):  
Odocoileus Virginianus ◽  
Polar Vortex ◽  
Tsuga Canadensis ◽  
Forest Community ◽  
Population Declines ◽  
Upper Peninsula ◽  
Deer Population ◽  
High Severity ◽  
Substantial Decline ◽  
Upper Peninsula Of Michigan

Ungulate herbivory occurring within a forest plant community’s natural range of variation may help maintain species diversity. However, acute or chronically elevated levels of herbivory can produce dramatic changes in forest communities. For example, chronically high levels of herbivory by white-tailed deer (Odocoileus virginianus Zimmerman) in regions of historically low abundance at northern latitudes have dramatically altered forest community composition. In eastern hemlock (Tsuga canadensis L. Carrière) stands where deer aggregate during winter, high deer use has been associated with a shift towards deciduous species (i.e., maples [Acer spp.]) dominating the regeneration layer. Especially harsh winters can lead to deer population declines, which could facilitate regeneration of species that have been suppressed by browsing, such as hemlock. To enhance our understanding of how fluctuations in herbivory influence regeneration dynamics, we surveyed regeneration and deer use in 15 relict hemlock stands in the western Upper Peninsula of Michigan in 2007 and again in 2015. With the exception of small seedlings (0.04–0.24 m height), primarily maples whose abundance increased significantly (p < 0.05), we observed widespread significant declines (p < 0.05) in the abundance of medium (0.25 ≤ 1.4 m height) and large regeneration (>1.4 m tall ≤ 4 cm diameter at breast height) over the study period. Midway through our study period, the region experienced a high severity winter (i.e., “polar vortex”) which resulted in a substantial decline in the white-tailed deer population. Given the dominance of maples and dearth of hemlock in the seedling layer, the decline in the deer population may fail to forestall or possibly hasten the trend towards maple dominance of the regeneration layer as these stands recover from pulses of acute herbivory associated with high-severity winters and the press of chronically high herbivory that precedes them.

Catastrophic disturbance in the presettlement forests of the Upper Peninsula of Michigan

1999 ◽  
Vol 29 (1) ◽  
pp. 106-114 ◽  
Author(s):  
Quanfa Zhang ◽  
Kurt S Pregitzer ◽  
David D Reed
Keyword(s):  
Forest Cover ◽  
Vegetation Type ◽  
Natural Disturbance ◽  
Growth Stages ◽  
Mosaic Landscape ◽  
Upper Peninsula ◽  
Rotation Periods ◽  
General Land Office ◽  
Ecological Unit ◽  
Upper Peninsula Of Michigan

The General Land Office (GLO) survey notes (1840-1856) were used to examine the interaction among natural disturbance, vegetation type, and topography in the presettlement forests of the Luce District, an ecological unit of approximately 902 000 ha in the Upper Peninsula of Michigan, U.S.A. The surveyors recorded 104 fire and 126 windthrow incidences covering 3.1 and 2.8% of the total length of the surveyed lines, respectively. The rotation periods over the entire landscape were 480 years for fire and 541 years for windthrow, but these varied with vegetation type and topographic position. Fire occurred more frequently on southerly aspects and at elevations where pinelands were concentrated. The density of windthrow events increased with elevation and slope, with the highest occurrence on westerly aspects. Based on the estimated rotation periods, we calculated that 7.5, 24.4, and 68.1% of the presettlement forest were in the stand initiation, stem exclusion, and old forest (including both understory reinitiation and old growth) stages, respectively. Pinelands and mixed conifers were the major components in both the stand initiation (34.5 and 31.1%) and the stem exclusion stage (20.9 and 39.8%), while mixed conifers (39.3%) and northern hardwoods (34.7%) were the major old-forest cover types. The diverse mosaic of various successional stages generated by natural disturbance suggests a "shifting-mosaic" landscape in this region.

Significance of Organic Detritus in the Diet of Larval Lampreys in the Great Lakes Basin

1994 ◽  
Vol 51 (11) ◽  
pp. 2380-2387 ◽  
Author(s):  
Trent M. Sutton ◽  
Stephen H. Bowen
Keyword(s):  
Great Lakes ◽  
Feeding Rate ◽  
Assimilation Efficiency ◽  
Dry Mass ◽  
Great Lakes Basin ◽  
Organic Detritus ◽  
Upper Peninsula ◽  
Sea Lampreys ◽  
Gut Fullness ◽  
Upper Peninsula Of Michigan

Larval sea lamprey (Petromyzon marinus) and northern brook lamprey (Ichthyomyzon fossor) were collected monthly from three streams in the Upper Peninsula of Michigan from May 1992 through May 1993 and larval sea lampreys were collected during summer months from sites throughout the Great Lakes basin. Organic detritus made up most of the diet ash-free-dry-mass (AFDM) throughout the year, averaging 97.79%, with algae (2.12%) and bacteria (0.09%) making up the remainder of the diet AFDM. Assimilation efficiency for AFDM averaged 72% during warmer months and 53% during cooler months (annual mean = 61%). Gut fullness (amount of AFDM in the anterior one-tenth of the intestine) was low (mean = 0.10 mg diet AFDM∙g−1 ammocoete). There were no significant differences in these measures between ammocoetes collected from the Upper Peninsula and those collected throughout the Great Lakes basin. From a laboratory-determined relationship between gut fullness and feeding rate, feeding rate in the field was estimated to be extremely slow, ranging from 4.2 to 5.5 mg diet AFDM∙g−1 ammocoete∙d−1. These observations indicate that larval lampreys efficiently utilize a diet of organic detritus during warmer months when stream temperatures and food quality are more favorable for feeding, digestion, and growth.

scholarly journals Radiocarbon “Wiggles” in Great Lakes Wood at About 10,000 to 12,000 BP

Radiocarbon ◽  
2007 ◽  
Vol 49 (2) ◽  
pp. 855-864 ◽  
Author(s):  
Steven W Leavitt ◽  
Irina P Panyushkina ◽  
Todd Lange ◽  
Li Cheng ◽  
Allan F Schneider ◽  
...  
Keyword(s):  
Great Lakes ◽  
Younger Dryas ◽  
Great Lakes Region ◽  
Chemical Pretreatment ◽  
Upper Peninsula ◽  
White Mountains ◽  
East Central ◽  
Subfossil Wood ◽  
Upper Peninsula Of Michigan ◽  
Source Of Error

High-resolution radiocarbon calibration for the last 14,000 cal yr has been developed in large part using European oaks and pines. Recent subfossil wood collections from the Great Lakes region provide an opportunity to measure 14C activity in decadal series of rings in North America prior to the White Mountains bristlecone record. We developed decadal 14C series from wood at the classic Two Creeks site (∼11,850 BP) in east-central Wisconsin, the Liverpool East site (∼10,250 BP) in northwestern Indiana, and the Gribben Basin site (∼10,000 BP) in the Upper Peninsula of Michigan. Initial AMS dates on holocellulose produced younger-than-expected ages for most Two Creeks subsamples and for a few samples from the other sites, prompting a systematic comparison of chemical pretreatment using 2 samples from each site, and employing holocellulose, AAA-treated holocellulose, alpha-cellulose, and AAA-treated whole wood. The testing could not definitively reveal the source of error in the original analyses, but the “best” original ages together with new AAA-treated holocellulose and α-cellulose ages were visually fitted to the IntCal04 calibration curve at ages of 13,760–13,530 cal BP for the Two Creeks wood, 12,100–12,020 cal BP for Liverpool East, and 11,300–11,170 cal BP for Gribben Basin. The Liverpool East age falls squarely within the Younger Dryas (YD) period, whereas the Gribben Basin age appears to postdate the YD by ∼300 yr, although high scatter in the decadal Gribben Basin results could accommodate an older age nearer the end of the YD.

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