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Effects of permafrost thaw on nitrogen availability and plant-soil interactions in a boreal Alaskan lowland: I - Percent Cover Data 2013

This dataset examines shifts in plant community structure along a lowland boreal permafrost thaw chronosequence. Data was collected in 2013 at the APEX Beta and forested study plots, located adjacent to the BNZ experimental forest. Percent cover data was collected for subcanopy vascular and nonvascualr vegetation in July 2013.

Effects of permafrost thaw on nitrogen availability and plant-soil interactions in a boreal Alaskan lowland: II - Nitrogen Data 2013

This dataset examines shifts in extractable soil pore water chemistry along a lowland boreal permafrost thaw chronosequence. Data was collected in 2013 at the APEX Beta and forested study plots, located adjacent to the BNZ experimental forest. Measured parameters include: dissolved inorganic N (DIN), dissolved organic N (DON), free amino acids, total dissolved N (TDN), soil temp. at 10 cm, seasonal ice depth, and volumetric soil moisture at 10 cm. Soil pore water samples and environmental variables were collected every three to four weeks from late June to late September, 2013 for a total of five sampling events.

Effects of permafrost thaw on nitrogen availability and plant-soil interactions in a boreal Alaskan lowland: III - Root Abundance 2013

This dataset examines shifts in rooting along a lowland boreal permafrost thaw chronosequence. Data was collected in 2013 at the APEX Beta and forested study plots, located adjacent to the BNZ experimental forest.

Effects of permafrost thaw on nitrogen availability and plant-soil interactions in a boreal Alaskan lowland: IV - Plant vs Nitrogen Data 2013

This dataset examines shifts in soil and plant characteristics, and extractable soil pore water chemistry along a lowland boreal permafrost thaw chronosequence. Data was collected in 2013 at the APEX Beta and forested study plots, located adjacent to the BNZ experimental forest. Data includes mean DIN, DON, free amino acids, and TDN from seasonal pore water measurements as well as aboveground vegetation C and N concentrations, and summertime, litterfall % N, and resorption efficiency for C. calyculata.

Effects of permafrost thaw on nitrogen availability and plant-soil interactions in a boreal Alaskan lowland: V - Isotape Data 2013

This dataset examines shifts in foliar del N 15 concentations for three plant species found across a lowland boreal permafrost thaw chronosequence. Data was collected in 2013 at the APEX Beta and forested study plots, located adjacent to the BNZ experimental forest.

Effects of permafrost thaw on nitrogen availability and plant-soil interactions in a boreal Alaskan lowland: VI - Soil Nitrogen Pools

This dataset examines shifts in soil N and extractable soil pore water chemistry along a lowland boreal permafrost thaw chronosequence. Data was collected in 2013 at the APEX Beta and forested study plots, located adjacent to the BNZ experimental forest. Measured parameters include: dissolved inorganic N, dissolved organic N, free amino acids, total dissolved N, C:N of soil material, soil bulk density, soil N concentration, soil C concentrations, volumetric soil moisture. Soil pore water samples were collected every three to four weeks from late June to late September, 2013 for a total of five sampling events, while soil cores were collected in late July 2013 for physical characterstics and soil C and N concentrations.

openOpenMar 2016View details →

Post-fire succession in 1994 Hajdukovich Creek Burn: measurements of root biomass, shoot biomass, total plant C content, total plant N content for aspen and spruce

This dataset contains measurements of root biomass, shoot biomass, total plant C, and total plant N of 10 aspen and 10 spruce saplings harvested in one severely burned and one lightly burned site in the 1994 Hajdukovich Creek burn.

openOpenMar 2020View details →

Post-fire Variability in Siberian Alder in Interior Alaska: Distribution Patterns, Nitrogen Fixation Rates, and Ecosystem Consequences IX - Plant Identifications 2015

This data set was collected as a part of Brian Houseman's MS Thesis, Post-fire Variability in Siberian Alder in Interior Alaska: Distribution Patterns, Nitrogen Fixation Rates, and Ecosystem Consequences (December 2017). Data include plant voucher collections that were collected on study plots in 2015. Data were collected on study plots established across two burn scars (2004 Boundary Fire and 1971 Wickersham Dome Fire) within the Yukon-Tanana Uplands ecoregion of interior Alaska.

openOpenDec 2020View details →

Measurement of Fuel load (organic biomass) Quantities of Organic Soils, Understory Plants and Trees at Sites within the Bonanza Creek LTER Regional Site Network in Interior Alaska, 2019

This dataset contains fuel load measurements for a subset of the BNZ LTER's RSN sites (n = 28). The data for each site separted by 16 fuel types (or plant functional types) including organic soil layers (fibric, mesic), vascular understory (evergreen shrub, short deciduous shrub, graminoid, forb, tall deciduous shrub, tree seedling/sapling, dead-downed wood), nonvascular understory (feather moss, Sphagnum moss, colonizer moss, lichen) and trees (evergreen tree, deciduous tree).

openCC0Dec 2020View details →

Long-term record of wetted area, substrate type, and plant features in Sycamore Creek, Arizona, USA (2010-2020)

The primary objective of this project is to understand how long-term climate variability and change influence the structure and function of desert streams via effects on hydrologic disturbance regimes. Climate and hydrology are intimately linked in arid landscapes; for this reason, desert streams are particularly well suited for both observing and understanding the consequences of climate variability and directional change. Researchers try to (1) determine how climate variability and change over multiple years influence stream biogeomorphic structure (i.e., prevalence and persistence of wetland and gravel-bed ecosystem states) via their influence on factors that control vegetation biomass, and (2) compare interannual variability in within-year successional patterns in ecosystem processes and community structure of primary producers and consumers of two contrasting reach types (wetland and gravel-bed stream reaches). This dataset was collected to understand changes of biota patch cover in different sites and reaches of Sycamore Creek and the transition of different algal and plant communities in post-flood succession.

openCC0Jul 2020View details →

Nitrogen cycling in accidental urban wetlands in the Salt River (central Arizona, USA): the effects of season, inundation and plants on denitrification (2013-2014)

This project sought to understand the spatial and temporal patterns and drivers of denitrification in nine accidental wetlands in the Salt River in Phoenix, AZ. Accidental urban wetlands are the result from human activities but are not designed nor managed for any specific purpose; thus, they are useful for examining the effects of both human and non-human drivers of ecosystem processes. For this study, we examined how seasonal monsoon and winter floods affected denitrification in different plant patch types at wetlands with different inundation regimes. Inundation regimes of the study wetlands are driven by storm drains that supply urban baseflow to the wetlands; however, the timing and frequency of discharges differ among storm drains resulting in different durations of inundation. Some storm drains provide enough baseflow that wetlands remain inundated year-round (perennially inundated) while others provide very little baseflow, so inundation is largely in response to rain events (ephemerally inundated). Intermittently inundated wetlands receive enough baseflow to remain inundated for part of the year. At each study wetland, we identified 2-4 dominant plant patch types, including one unvegetated patch. We took 2-4 soil samples from each patch type at each site in each season (pre-monsoon, post-monsoon and winter rainy seasons). We measured denitrification potential, soil organic matter, soil moisture, soil nitrate, soil texture, and water depth. In addition to soil characteristics, we also collected data on plant traits for each patch type. Plant functional traits provide one method to examine mechanistic links between plants and ecosystem processes. Measured plant traits were above- and belowground biomass, above- and belowground C:N ratios, and rooting depth.

Plant species percent cover data: Successional Dynamics on a Resampled Chronosequence

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. Past work at CDR and elsewhere has demonstrated an overriding influence of fire frequency in maintaining prairie openings and oak savanna at the prairie-forest border. Fire regimes harm some types of species while favoring others and drive light and nutrient dynamics, which in turn drive community functional attributes and diversity levels. Ultimately, fire frequency interacts with climate, N deposition, land use, and biotic invasion to determine the outcomes of tree-grass interactions and the dynamics of vegetation at ecotones such as the prairie-forest border in Minnesota. In 2006 each field was divided in half, and one half randomly chosen for periodic prescribed burning (a fire every other year). We anticipate that th

Plant aboveground biomass data: Long-Term Nitrogen Deposition: Population, Community, and Ecosystem Consequences

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.

openCC0Feb 2025View details →

Plant aboveground biomass data: Old-Field Chronosequence: Plant Productivity

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 1987 by lead investigators David Tilman and Johannes Knops. Past work at CDR and elsewhere has demonstrated an overriding influence of fire frequency in maintaining prairie openings and oak savanna at the prairie-forest border. Fire regimes harm some types of species while favoring others and drive light and nutrient dynamics, which in turn drive community functional attributes and diversity levels. Ultimately, fire frequency interacts with climate, N deposition, land use, and biotic invasion to determine the outcomes of tree-grass interactions and the dynamics of vegetation at ecotones such as the prairie-forest border in Minnesota. In 2006 each field was divided in half, and one half randomly chosen for periodic prescribed burning (a fire every other year). We anticipate that the burned half will continue succession to prairie grassland while the unburned half will become white pine stands if seed sources are nearby, or will otherwise undergo extremely slow succession to oaks.

Root biomass data: Biodiversity II: Effects of Plant Biodiversity on Population and Ecosystem Processes

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.

Plant aboveground biomass data: Biodiversity II: Effects of Plant Biodiversity on Population and Ecosystem Processes

openCC0Jan 2024View details →

Plant aboveground biomass data: BioCON : Biodiversity, Elevated CO2, and N Enrichment

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 affe

openCC0Mar 2024View details →

Plant aboveground biomass data: Natural Enemies, Plant Diversity and Plant Community Composition

The purpose of this experiment is to determine the influences of natural enemies, including plant pathogenic fungi and insect pests, influence plant community composition, productivity, and diversity over time. The experiment is being conducted in a subset of plots within the Big Biodiversity field, including monoculture, 2-species, 4-species, 8-species, 16-species, and 32-species plots. There are 5 different treatments: foliar fungicide, soil drench fungicide, foliar insecticide, the combination of all pesticides, and nontreated control. The pesticides are applied repeatedly throughout the growing season. Within the plots, community productivity, species composition, percent cover, and pest damage are being quantified over time.

openCC0Mar 2024View details →

Plant aboveground biomass data: The influence of natural enemies on plant community composition and productivity

The purpose of this experiment is to determine the influences of natural enemies, including plant pathogenic fungi and insect pests, influence plant community composition, productivity, and diversity over time. The experiment is being conducted in an old field that is burned every other year. Within the old field, there are 8 blocks, and within each block there are 6 treatments: foliar fungicide, soil drench fungicide, foliar insecticide, mammal exclosure, the combination of all enemy suppression tactics (pesticides and mammal exclosure), and a nontreated control. The pesticides are applied repeatedly throughout the growing season. Within the plots, community productivity, species composition, percent cover, and pest damage are being quantified over time.