Each Cedar Creek research project is assigned an “experiment number”, such as “e001”. The data from each research project is indexed under that project’s experiment number. Cedar Creek research is grouped into two categories. Core LTER Data is data generated though research funded by LTER and is provided in accordance with the LTER Network Data Access Policy. Other Cedar Creek data is generated through many different funding sources, We strive to provide access to data from research not funded through LTER using the same LTER policy guidelines, but due to the historical nature of much of this data, we cannot guarantee these data are complete. All data may be searched for by experiment number, core area of research, keyword, and/or investigator. Use of data must be in accordance with the conditions agreed to in the Cedar Creek Ecosystem Science Reserve Data Access Policy.
Signature data is data which best represents the goals and research carried out at Cedar Creek. To view all of Cedar Creek's Core datasets, use the Search Box above.
The purpose of this experiment is to measure how adding nitrogen over a long time will affect the number of species, the type of species present, the amount of annual growth, and the change from year to year in the growth of each species in a plant community which is also relieved of grazing by large and small mammals. The experiment is being conducted within fields (A, B, C, and D) which were initially low in soil nutrients. There are 8 different levels of nitrogen addition with other nutrients added to ensure that nitrogen remains the limiting nutrient, and a control which receives no nutrients. There are 6 replicates of the 9 treatments in fields A, B, and C and 5 replicates in field D. The treatments were randomly assigned to the plots. In fields A, B, and C the plots are in 6 by 9 grids and are 4 by 4 meters in size with 1 meter aisles between plots. In field D the plots are 1.5 by 4 meters and are placed in a 3 by 17 grid. The plots are enclosed by a fence to keep out mammalian herbivores. Gophers are trapped and removed as they appear. Nitrogenfertilizer (NH4NO3) is applied twice per year, once in early May and once in late June. This experiment was begun in 1982 by David Tilman.
Compiled Arthropod Data: | Descriptions of Data Fields | TAB | JMP | EXCEL
Compiled Biomass and Soil Data: | Descriptions of Data Fields | TAB | JMP | EXCEL
The purpose of this experiment is to measure how initially disturbing an area and adding nitrogen over a long time will affect the number of species, the type of species present, the amount of annual growth, and the change from year to year in the growth of each species in a plant community which is also relieved of grazing by large and small mammals. This experiment is conducted within fields (A, B, and C) which were initially low in soil nutrients. The ground was disturbed by thoroughly disking the area prior to establishment of the experiment. There are 8 different levels of nitrogen addition with other nutrients added to ensure that nitrogen remains the limiting nutrient, and a control which receives no nutrients. Nitrogen fertilizer (NH4NO3) is applied twice per year, once in early May and once in late June. There are six replicates of each treatment per field. The treatments were randomly assigned to plots of size 4 by 4 meters. The plots are in 6 plot by 9 plot grids with 1 meter aisles between plots. The plot grids are enclosed by a fence to keep out mammalian herbivores. Gophers are trapped and removed as they appear. In the spring of 1992, subexperiments E097 and E098 were established. E097 is in fields A and C where randomly selected plots within each treatment no longer receive fertilizer. E098 is in field B where randomly selected plots within each treatment are burned. Note that the design of E002 is similar to E001 except E002 was thoroughly disked prior to establishment.
Compiled Ecosystem Responses to Chronic N Deposition: | Descriptions of Data Fields | TAB | JMP | EXCEL
The purpose of this experiment, begun in 1983 by Johannes Knops, is to determine what effect different fire frequencies have on grassland vegetation. This experiment is being conducted in field B. There are 4 different burn treatments:
1. plots burned every year
2. plots burned every other year
3. controls which are not burned
4. plots burned every fourth year
There are 6 replicates of each treatment which were randomly assigned to the 24 plots. Plots are 8 by 8 meters and are placed in a 3 by 8 grid with 2 meter walkways. Plots are marked with colored rebar at each corner.
Compiled Effect of fire frequency on prairie: | Descriptions of Data Fields | TAB | JMP | EXCEL
The purpose of this observational study is to describe the dynamics of ecosystem succession. The change in the number, type, and amount of plant and grazing animal species is monitored in more than 20 fields. These fields were previously cultivated, but then abandoned from agriculture at various times in the past. The fields were left undisturbed for plants to develop from seeds within the soil or brought into the fields by wind or animals. Permanent transects have been established in these abandoned fields for purposes of sampling in a consistent location from year to year. Permanent plots along these transects have been used to sample soil nutrients, (in particular, nitrogen) abundance of vegetation, species composition and herbivore populations. The sampling occurs approximately every 6 years. In the initial survey, 100 quadrats of size 1 by 0.5 m were sampled per field in 23 different fields. Abandoned fields included in E014 are 4, 5, 10, 21, 24, 26, 27, 28, 32, 35, 39, 40, 41, 44, 45, 47, 53, 70, 72, 76, 77. Fields 22(B), 29(A), and 69(C) were originally included in E014 but used for other purposes shortly after the start of the study. This experiment was established in 1983 and 1989 by principal investigators Johannes Knops and David Tilman.
Compiled Grasshopper Data: | Descriptions of Data Fields | TAB | JMP | EXCEL
Compiled Percent Cover and Related variables: | Descriptions of Data Fields | TAB | JMP
The goal of this research is to study the change in plant growth and species distribution during succession. Annual plant growth above ground is annually sampled in more than 20 fields from 4 permanently marked 3m x 4m plots in each field. These fields were previously cultivated, but then abandoned from agriculture at various times in the past. The fields were left undisturbed for plants to develop from seeds within the soil or brought into the fields by wind or animals. The fields included in this study are 4, 5, 10, 24, 26, 28, 35, 39, 41, 45, 53, 70, 72, 77 and the Lawrence strip that was abandoned in 1988. This experiment was started in 1988 by lead investigators David Tilman and Johannes Knops.
Compiled Biomass and Soil Data: | Descriptions of Data Fields | TAB | JMP | EXCEL
Biodiversity II (E120) is designed to determine how the number of plant species affects the dynamics of ecological processes at the population, community, and ecosystem levels. By experimentally manipulating the number of species and the kinds of species, the amount of plant growth and the change from year to year, that result can be examined. Plots are large (9m x 9m actively maintained) and well-replicated, allowing responses of plant pathogens, insect herbivores, seed predators, soil parameters, invasive plant species and other variables to also be studied. Plots were seeded in May 1994 to have 1, 2, 4, 8, or 16 species, with roughly 30 replicates of each diversity level. The species composition of each plot was chosen by random draw from a pool of 18 grassland perennials that included four warm-season (C4) grasses, four cool-season (C3) grasses, four legumes, four non-legume forbs, and two woody species. All species occur in monoculture allowing comparison of responses of each species in monoculture to combinations of these same species. The experiment was established in 1994 by the lead investigators David Tilman, Peter Reich, Johannes Knops, and David Wedin. Experiment 120 is similar to Experiment 123, but it uses larger plots to provide a large capacity for long-term subexperiments.
Compiled Arthropod Data: | Descriptions of Data Fields | TAB | JMP | EXCEL
Compiled Biomass and Soil Data: | Descriptions of Data Fields | TAB | JMP | EXCEL
Compiled Plant Cover Data: | Descriptions of Data Fields | TAB | JMP | EXCEL
The goal of this study was to examine the population of insects in prairies and savannahs. Most of the prairies had developed after being abandoned from agriculture, but none of the savannahs had been cultivated. The history of burning varied between sites. Insects were sampled via sweep-net sampling, pitfalls and ant plates throughout the growing season in each of 49 grassland fields and savannahs. In total, 89,596 individuals of 1,167 species were captured and enumerated. Body size was measured for a subset of grasshoppers collected. The study was conducted in 1992 by the lead investigators: John Haarstad, Evan Siemann, and David Tilman.
Abundance and Body size of Insects Collected
This study examines the effects of long-term prescribed burning treatments on vegetation structure and composition, productivity, and nutrient cycling in upland oak savanna and woodland vegetation. The basis for the study is an ongoing, experimental prescribed burning program begun in 1964 at Cedar Creek, and a similar program operating since 1962 on the adjacent Helen Allison Savanna property (owned by The Nature Conservancy). These prescribed burning programs are designed to subject upland oak communities (and some old fields) to different burn frequencies and patterns of burning, with the ultimate objectives of 1) restoring and maintaining the historically important savanna and open woodland vegetation, and 2) providing information about the effects of different burning patterns on vegetation structure and composition. This study addresses the latter of these two purposes and expands on it by also investigating possible influences of fire on resource availability (nutrients, water, and light) and net primary productivity. This study represents a continuation and expansion of experiments 015 and 094.
BioCON (Biodiversity, CO2, and Nitrogen) is an ecological experiment started in 1997 at the University of Minnesota's Cedar Creek Ecosystem Science Reserve. BioCON's goal is to explore the ways in which plant communities will respond to three environmental changes that are known to be occurring on a global scale: increasing nitrogen deposition, increasing atmospheric CO2, and decreasing biodiversity.
Why Biodiversity, CO2, and Nitrogen?
While there are many uncertainties in global change biology, there are also some well documented facts. Some of these are:
1. The amount of carbon dioxide (CO2) in the atmosphere is rising. Since the industrial revolution, the CO2 concentration in the atmosphere has increased from approximately 275 parts per million (ppm) to about 378 ppm today. This has been largely the result of fossil fuel burning. It is expected that CO2 levels will continue to rise, and that by the year 2050 these levels will be approximately 550 ppm. CO2 is the raw material for photosynthesis and is known to affect plant growth and development.
2. The amount of nitrogen moving through terrestrial ecosystems has increased in the recent past. While natural "background" levels of nitrogen fixation have remained constant, human additions to the system through fertilizer production and fossil fuel use have increased dramatically. Nitrogen is a key nutrient for plant growth and plays a critical role in plant community structure and composition in many environments.
3. Biodiversity levels are falling. While the research and data are not as complete as they are for CO2 and nitrogen, data indicate that the number of species globally, is being reduced. Perhaps more important for ecosystem function, diversity levels on local to regional scales have fallen due to land use change, biotic invasion and many other drivers.
While much is known about how each of these factors affects ecosystem functioning, many questions remain. There is also little data on how these issues affect each other, and what emergent qualities may arise when systems are exposed to these changes simultaneously. BioCON seeks to address these issues with this multi-year study at Cedar Creek Ecosytem Science Preserve.
LTER Site Profiles
LTER Climate / Hydrology Database
EcoTrends Project
LNO MetaCat
Remote Sensing Archive
