GLKN Miscellaneous Inventories |
Assessing the impacts of European earthworm invasions in beech-maple hardwood and aspen-fir boreal forests of the western Great Lakes region |
Cindy M. Hale and George E. Host |
In the Great Lakes region, little data exist on the distribution of exotic earthworm species or their relative impacts to soil structure and plant communities in forest types other than those dominated by sugar maple. Our objective was to document the earthworm populations in relation to their proximity to human development (e.g., campgrounds, boat landings, roads) in beech-maple dominated forests in Pictured Rocks National Lakeshore, Michigan, and aspen-fir forests in Voyageurs National Park, Minnesota, and to assess earthworm population relationships with soil characteristics and plant communities. Five earthworm species were commonly found in both forest types in three species assemblages also seen in other forests across the Great Lakes region. Total earthworm biomass supported by beech-maple forests was nearly half that reported in sugar maple dominated forests, and the total earthworm biomass supported by aspen-fir forests was half that of the beech-maple forests. Distances to human development were poor predictors of earthworm biomass and species assemblage in general, but were correlated with the presence of Lumbricus terrestris. Earthworm richness and biomass were negatively associated with thickness of the Olitter and Oe horizons and positively associated with A horizon thickness. Increasing plant richness and changes in plant composition associated with earthworms in the beech-maple forests are likely related to stand conditions that simultaneously affect plant and earthworm populations rather than an earthworm effect. Comparisons to earthworm-free stands were not possible and are needed to further explore any potential causal relationships between earthworm and understory plant populations. Project Status: Complete Final Report |
NPLichen: A Database of Lichens in the U. S. National Parks |
James P. Bennett and Clifford M. Wetmore |
This report describes the history of the development of NPLichen, a database of lichens of the U. S. National Parks, followed by a description of the steps taken to upgrade the database. Since beginning this project in 1992, we have increased coverage by adding more parks, species, and references. The new version is now available as a live database on the internet. A summary of statistics on each park is provided, as well as a discussion of potential errors in the data. Finally, disclaimers on the use of the data are provided, and suggestions for updates and recommendations for future work. Project Status: Complete |
Mussel (Bivalvia: Unionidae) Survey of the Mississippi National River and Recreation Area Corridor, 2000-01 |
Dan Kelner and Mike Davis |
During 2000 and 2001, we sampled 152 sites for mussels along the entire Mississippi National River and Recreation Area (MNRRA) Corridor which encompasses a 72-mile stretch of the Upper Mississippi River (UMR) (138 sites), a four-mile reach of the lower Minnesota River (MNR) near its confluence with the UMR (14 sites), and the lower Rum River (RR) near its confluence with the UMR (one site). The UMR stretch extends from approximately 20 miles north of the Twin Cities, through the Twin Cities, to just below Hastings, Minnesota. Five pools or reaches were surveyed and include from upstream to downstream: Coon Rapids Pool; St. Anthony Falls Pool; and Pools 1, 2, and Upper Pool 3. Sample methods were consistent throughout the study and consisted of timed searches and hand collection of mussels while wading, snorkeling, and diving. Quantitative samples were also collected and mussel bed boundaries mapped at five sites within the UMR. Over 12,000 live mussels representing 28 species were collected with an additional 12 species collected as empty shells. The mussel fauna of UMR Pools 1-3 appears to be recovering since its reported decimation by pollution during the first half of the 1900s. This survey provided clear evidence of recent and ongoing recruitment, and many of the individuals collected were less than 10 years old. Several state listed species were collected including two listed as endangered in Minnesota, rock pocketbook (Arcidens confragosus) and wartyback (Quadrula nodulata). Recolonization is probably due to improved water quality conditions over the past 15-20 years. Furthermore, mussels are expanding their range above St. Anthony Falls (historically a faunal barrier to upstream dispersal) as fish now circumnavigate the two navigation locks. A total of 16 live species were collected from the St. Anthony Falls Pool including 10 species previously not reported there. Zebra mussels were absent above Lock and Dam 1 and very scarce from UMR Pool 2 and Upper Pool 3 and the lower MNR. These UMR pools differ from those downstream (Pool 4 and below) where zebra mussels are extremely abundant and are decimating the native mussel communities. Ironically, this reach of the Mississippi River between the Twin Cities and Hastings, MN, once nearly a dead zone, may now be one of the last big river mussel refuges in the Midwestern United States. Project Status: Complete |
Paleontological Resource Inventory and Monitoring, Great Lakes Inventory and Monitoring Network |
ReBecca K. Hunt, Jason P. Kenworthy, and Vincent L. Santucci |
Paleontological resources (fossils) are any remains of past life preserved in a geologic context. Paleontological resources are non-renewable resources found in more than 190 National Park Service units. Despite the abundance and diversity of these resources throughout the NPS, few parks have adequate baseline paleontological resource data. The NPS National Inventory and Monitoring Program and the NPS Geologic Resources Division have developed various strategies to provide parks with the baseline paleontological resource data necessary for appropriate management of these resources. This report is a summary of paleontological resources of the parks served by the Great Lakes Network (GLKN). The summary was compiled through extensive literature review and interviews with park staff and professional geologists and paleontologists. Preliminary paleontological resource management recommendations are also included for each park. The Great Lakes Network parks lie within two adjacent physiographic provinces within the north-central portion of the United States: the Superior Upland Province, which is the southern portion of the Canadian Shield, and the Eastern Lake section of the Central Lowland Province. All but three of the parks in this network are directly associated with either Lake Michigan or Lake Superior. The GLKN parks share a common geologic history of continental rifting, volcanism and glaciation. Some of the oldest rocks in the GLKN extend back to the Archaen Eon, approximately 2.7 billion years ago. Rocks from the Archean and Proterozoic Eons (both “Precambrian”) known from this network were primarily igneous, marine, and shallow lacustrine deposits. The remains of ancient organisms were presumably preserved in these marine and lacustrine sediments; however, most life forms from this age were simple creatures lacking easily fossilized hard parts. These units were also subjected to folding and metamorphism over their long history. The forces associated with uplift and glaciation, along with great spans of geologic time, contributed to the alteration or destruction of fossils contained within these “Precambrian” sedimentary rocks. Fossils are far better known within the Great Lakes region from younger sedimentary rocks of the Paleozoic Era (542-251 million years old) and Pleistocene Epoch (approximately 11,477 years - 1.8 million years old). These fossil remains consist typically of invertebrate and trace fossils from early to mid-Paleozoic rocks. The fossilized remains of mammals, fish and mollusks along with wood, pollen, and spores preserved in the deposits of Pleistocene to Holocene epochs occur in several of the parks. Many of the parks’ fossil resources wash in from other locations and can vary in age. These resources are often the easy target for “beachcombing” and can be a resource management issue. Collectively the paleontological resources of the Great Lakes Network parks are somewhat rare and isolated but represent opposite ends of the geologic time scale. Further paleontological resource inventories will serve to expand this ever-widening base of paleontological knowledge represented throughout the National Park Service. Although more than 190 parks have already been identified as containing paleontological resources, much of what is to be known about the history of life on earth remains to be discovered. This report provides baseline paleontological resource data to National Park Service administration and resource management staff. The report contains information regarding the location of non-renewable paleontological resources within NPS units. It is not intended for distribution to the general public.Project Status: Completed |
