biogeochemical processes
| Abstract | |
|---|---|
| Jianwu Tang, Ned Fetcher, Michael L Moody, 2019 Litter decomposition from 2014 reciprocal transplant garden Toolik Lake, Coldfoot, and Sagwon, Alaska 2016. 10.6073/pasta/12e95d63a6c0be0124c69487182b1750 |
Data on litter decomposition of Eriophorum vaginatum leaves collected at Toolik Lake, Coldfoot, and Sagwon and distributed to all three sites. Litter bags from the three populations were deployed at CF (8/26/15), TL (8/24/16) and SG (8/25/16) sites approximately 40 meter away from the main transplant gardens (east of CF, east of TL and west of SG) into 5 blocks with 4 intended harvests at each plots. |
| Jianwu Tang, Ned Fetcher, Michael L Moody, 2019 Absorbed soil nutrients on ion exchange membranes in the reciprocal transplant gardens at Toolik Lake, Coldfoot, and Sagwon in 2016. 10.6073/pasta/86225c3c1a98be0780d092f8b8bf9943 |
Transplant gardens at Toolik Lake and Sagwon were established in 2014. At each location, 60 tussocks each from ecotypes of Eriophorum vaginatum from Coldfoot (CF, 67°15′32″N, 150°10′12″W), Toolik Lake (TL, 68°37′44″N, 149°35′0″W), and Sagwon (SG, 69°25′26″N, 148°42′49″W) were transplanted. At the reciprocal transplant gardens, ion exchange membranes were used to measure nutrient availability over two time periods: Early season (June) and mid season (July). Membranes were deployed in the field for either 20 or 21 days, depending on travel constraints. |
| Abstract | |
|---|---|
| Edward Rastetter, 2020 Model output, drivers and parameters for Ecosystem Recovery from Disturbance is Constrained by N Cycle Openness, Vegetation-Soil N Distribution, Form of N Losses, and the Balance Between Vegetation and Soil-Microbial Processes . 10.6073/pasta/24624a295f418f36ae90c99ab49bca07 |
Files used to generate the data for figures in: Rastetter, EB, Kling, GW, Shaver, GR, Crump, BC, Gough, L. Ecosystem Recovery from Disturbance Is Constrained by N Cycle Openness, Vegetation-Soil N Distribution, Form of N Losses, and the Balance between Vegetation and Soil-Microbial Processes. Ecosystems (2020). https://doi.org/10.1007/s10021-020-00542-3. |
| Edward Rastetter, Bonnie Kwiatkowski, 2020 Model executable, output, drivers and parameters for modeling organism acclimation to changing availability of and requirements for substitutable and interdependent resources. 10.6073/pasta/314852535992295685284214cc0ae78b |
Files used to generate the data for figures in: Rastetter, EB, Kwiatkowski, BL. An approach to modeling resource optimization for substitutable and interdependent resources. Ecological Modelling (2020). https://doi.org/10.1016/j.ecolmodel.2020.109033. This paper presents a hierarchical approach to modeling organism acclimation to changing availability of and requirements for substitutable and interdependent resources. Substitutable resources are resources that fill the same metabolic or stoichiometric need of the organism. |
| Edward Rastetter, Kevin Griffin, Bonnie Kwiatkowski, George Kling, 2022 Model Simulations of The Effects of Shifts in High-frequency Weather Variability (With a Long-term Trend) on Carbon Loss from Land to the Atmosphere, Toolik Lake, Alaska, 2022-2122. 10.6073/pasta/83775003d8ef8978bf43d5c801f2a9a9 |
Climate change is increasing extreme weather events, but effects on high-frequency weather variability and the resultant impacts on ecosystem function are poorly understood. We assessed ecosystem responses of arctic tundra to changes in day-to-day weather variability using a biogeochemical model and stochastic simulations of daily temperature, precipitation, and light. Changes in weather variability altered ecosystem carbon, nitrogen, and phosphorus stocks and cycling rates. |
| Abstract | |
|---|---|
| Mark Harmon, 2002 Long-term Carbon and Nitrogen, and Phosphorus Dynamics of Leaf and Fine Root Litter project (LIDET-Long-term Intersite Decomposition Experiment Team) data for the ARC, Arctic LTER. 1990 to 2000.. 10.6073/pasta/96ee7de35954a3763ab4c244bad0c6f0 |
This file is from the Long-term Carbon and Nitrogen, and Phosphorus Dynamics of Leaf and Fine Root Litter project (LIDET-Long-term Intersite Decomposition Experiment Team). This file contains only the Arctic LTER data. In particular the mass looses over the ten year study. Three types of fine roots (graminoid, hardwood, and conifer), six types of leaf litter (which ranged in lignin/nitrogen ratio from 5 to 75), and wooden dowels were used for litter incubations over a ten year period. |
| Abstract | |
|---|---|
| Amanda Koltz, 2018 Effects of experimentally altered wolf spider densities and warming on soil microarthropods, litter decomposition, litter N, and soil nutrients near Toolik Field Station, AK in summer 2012 . 10.6073/pasta/d1fb3658f397c837b1ac49c42c2bdff7 |
Predators can disproportionately impact the structure and function of ecosystems relative to their biomass. These effects may be exacerbated under warming in ecosystems like the Arctic, where the number and diversity of predators are low and small shifts in community interactions can alter carbon cycle feedbacks. Here we show that warming alters the effects of wolf spiders, a dominant tundra predator, on belowground litter decomposition and nutrient dynamics. |
| Abstract | |
|---|---|
| Edward Rastetter, Bonnie Kwiatkowski, David Kicklighter, Audrey Baker Potkin, Helene Genet, Jesse Nippert, Kim O'Keefe, Steven Perakis, Stephen Porder, Sarah Roley, Roger Ruess, Jonathan Thomson, William Wieder, Kevin Wilcox, Ruth Yanai, 2022 Steady state carbon, nitrogen, phosphorus, and water budgets for twelve mature ecosystems ranging from prairie to forest and from the arctic to the tropics. 10.6073/pasta/b737b5f0855aa7afeda68764e77aec2a |
We use the Multiple Element Limitation (MEL) model to examine the responses of twelve ecosystems - from the arctic to the tropics and from grasslands to forests - to elevated carbon dioxide (CO2), warming, and 20% decreases or increases in annual precipitation. |
| Edward Rastetter, Bonnie Kwiatkowski, David Kicklighter, Audrey Baker Potkin, Helene Genet, Jesse Nippert, Kim O'Keefe, Steven Perakis, Stephen Porder, Sarah Roley, Roger Ruess, Jonathan Thomson, William Wieder, Kevin Wilcox, Ruth Yanai, 2022 Ecosystem responses to changes in climate and carbon dioxide in twelve mature ecosystems ranging from prairie to forest and from the arctic to the tropics. 10.6073/pasta/7ca56dfbe6c9bedf5126e9ff7e66f28d |
We use the Multiple Element Limitation (MEL) model to examine the responses of twelve ecosystems - from the arctic to the tropics and from grasslands to forests - to elevated carbon dioxide (CO2), warming, and 20% decreases or increases in annual precipitation. |
| Edward Rastetter, Kevin Griffin, Laura Gough, Jennie McLaren, Natalie Boelman, 2021 Modeling the effect of explicit vs implicit representaton of grazing on ecosystem carbon and nitrogen cycling in response to elevated carbon dioxide and warming in arctic tussock tundra, Alaska - Dataset B. 10.6073/pasta/5f95c98e963409a447322b205bbc7f62 |
We use a simple model of coupled carbon and nitrogen cycles in terrestrial ecosystems to examine how explicitly representing grazers versus having grazer effects implicitly aggregated in with other biogeochemical processes in the model alters predicted responses to elevated carbon dioxide and warming. The aggregated approach can affect model predictions because grazer-mediated processes can respond differently to changes in climate from the processes with which they are typically aggregated. |
| Edward Rastetter, Kevin Griffin, Laura Gough, Jennie McLaren, Natalie Boelman, 2021 Modeling the effect of explicit vs implicit representaton of grazing on ecosystem carbon and nitrogen cycling in response to elevated carbon dioxide and warming in arctic tussock tundra, Alaska - Dataset A. 10.6073/pasta/e8f2890db0a7a64a76580cadb47b472c |
We use a simple model of coupled carbon and nitrogen cycles in terrestrial ecosystems to examine how explicitly representing grazers versus having grazer effects implicitly aggregated in with other biogeochemical processes in the model alters predicted responses to elevated carbon dioxide and warming. The aggregated approach can affect model predictions because grazer-mediated processes can respond differently to changes in climate from the processes with which they are typically aggregated. |
| Edward Rastetter, Kevin Griffin, Bonnie Kwiatkowski, George Kling, 2022 Model Simulations of The Effects of Shifts in High-frequency Weather Variability (No Long-term Weather Trend) Control Carbon Loss from Land to the Atmosphere, Toolik Lake, Alaska, 2022-2122. 10.6073/pasta/a946904960bb11f44915b80fb4fc5981 |
Climate change is increasing extreme weather events, but effects on high-frequency weather variability and the resultant impacts on ecosystem function are poorly understood. We assessed ecosystem responses of arctic tundra to changes in day-to-day weather variability using a biogeochemical model and stochastic simulations of daily temperature, precipitation, and light. Changes in weather variability altered ecosystem carbon, nitrogen, and phosphorus stocks and cycling rates. |
| Abstract | |
|---|---|
| Jennie DeMarco, Michelle Mack, 2013 Mass, C, N, and lignin from litter decomposed across a shrub gradient and with snow manipulations near Toolik Field Station between 2003 and 2009.. 10.6073/pasta/badba3735996e3de4cd02ee4bd1cfd5c |
In arctic tundra near Toolik Lake, Alaska, we incubated a common substrate in a snow addition experiment to test whether snow accumulation around arctic deciduous shrubs altered the environment enough to increase litter decomposition rates. We compared the influence of litter quality on the rate of litter and N loss by decomposing litter from four different plant functional types in a common site. We used aboveground net primary production values and estimated k values from our decomposition experiments to calculate community-weighted mass loss for each site. |
| Jennie DeMarco, Michelle Mack, 2009 Net nitrogen mineralization from shrub gradient and snow manipulations, near Toolik field station, collect in the summer of 2006 and winter of 2006-2007. 10.6073/pasta/d63fe4fe5d2725aaa8732f1ae6548028 |
In arctic tundra, near Toolik Lake, Alaska, we quantified net N-mineralization rates under ambient and manipulated snow treatments at three different plant communities that varied in abundance and height of deciduous shrubs. |
| Gaius Shaver, 2006 Nitrogen mineralization was determined on Arctic LTERToolik and Sag River tussock tundra using the buried bag method, Toolik Field Station, Alaska, Arctic LTER 1989-2013.. 10.6073/pasta/79e01a508bb9021e265eec2a8201b2f9 |
Nitrogen mineralization was determined on LTER and Sag River tussock tundra using the buried bag method. Yearly bags have been deployed every August since 1990. |
