DOI: 10.5061/dryad.2547d7x1n
title: Ground beetle trophic interactions alter available nitrogen in forest soil

description: It is generally held that microbes exert primary control over nitrogen
 availability in temperate forests. Yet the role of soil and
 litter-dwelling invertebrates to provide additional control via the
 breakdown of organic matter is an area of current exploration. Through
 trophic interactions within soil food webs, predators may indirectly
 affect prey with cascading effects on litter breakdown and nitrogen
 availability. The importance of these interactions, however, may be
 context-dependent, varying with the stage of forest development and
 associated decomposer species composition given that young and old forests
 have vast differences in nitrogen availability, vegetation litter, soil
 properties, and invertebrate functional groups. We examined ground beetle
 control over soil nitrogen and soil properties using a 68-day mesocosm
 experiment that manipulated trophic structure (omnivore + predator
 beetles, predator beetles, and no beetles) in a young and old forest stand
 in the northeastern United States. In the young forest, net nitrogen
 mineralization decreased under predator + omnivore and the bulk soil C:N
 ratio in the old forest. However, we found no response in either forest
 context to the predator only treatment. Our study demonstrates the
 potential for ground beetles to strongly impact nitrogen availability and
 soil properties in forest ecosystems. Therefore, animal trophic
 interactions and their contexts must be included in our paradigm of
 nutrient cycles in temperate forests.
description: # Ground beetle trophic interactions alter available nitrogen in forest
 soil
 [https://doi.org/10.5061/dryad.2547d7x1n](https://doi.org/10.5061/dryad.2547d7x1n) ## Description of the data and file structure We collected soil data in June and Sept 2022 at Yale-Myers Forest for "Ground beetle trophic interactions alter available nitrogen in forest soil" including Nitrogen Mineralization, pH, Water Holding Capacity, Total Nitrogen, and Total Carbon. ### Files and variables #### File: Cascade\_PlotInfo.csv **Description:** Plot info including plot number, block, treatment applied to plots, forest and significant dates ##### Variables * Plot: (individual cage 1-30) * Treatment (PT, HT, C): Ground beetle treatments (PT- predator only), (HT- predator and omnivore), (C-control no beetles) * Block: (treatments were grouped into blocks) * Forest: (Old or Young forest site) * Initial_Stock: (date of stocking cages with beetles) * Second_Stock: (date of stocking cages with beetles) * Final_Soil_Sample: (date of soil sample) * Notes: any notes taken during sample #### File: rawdata.csv **Description:** data separated into June and Sept sample periods ##### Variables * Plot: (1-30) * Nmin_June: Net Nitrogen Mineralization (ug N g-1 day-1) * Nnit_June: Nitrite Mineralization (ug N g-1 day-1) * Nam_June: Ammonium Mineralization (ug N g-1 day-1) * Nmin_Sept: Net Nitrogen Mineralization (ug N g-1 day-1) * Nnit_Sept: Nitrite Mineralization (ug N g-1 day-1) * Nam_Sept: Ammonium Mineralization (ug N g-1 day-1) * pH_June: Soil pH * pH_Sept: Soil pH * WHC_June: Water Holding Capacity (Average % soil moist at 100% WHC) * WHC_Sept: Water Holding Capacity (Average % soil moist at 100% WHC) * Temp_Sept: In-situ soil temp (C) * TN_June: Total Percent Organic Nitrogen * TC_June: Total Percent Organic Carbon * TN_Sept: Total Percent Organic Nitrogen * TC_Sept: Total Percent Organic Carbon #### File: Season.csv **Description:** Data transformed into long format. ##### Variables * Plot: (1-30) * Season: (June or Sept) * Nmin: Net Nitrogen Mineralization (ug N g-1 day-1) * Nnit: Nitrite Mineralization (ug N g-1 day-1) * Nam: Ammonium Mineralization (ug N g-1 day-1) * pH: Soil pH * WHC: Water Holding Capacity (Average % soil moist at 100% WHC) * TN: Total Percent Organic Nitrogen * TC: Total Percent Organic Carbon ## Code/software csv files are easily accessible ## Access information Other publicly accessible locations of the data: * [https://github.com/janeyl/beetle-trophic-cascade](https://github.com/janeyl/beetle-trophic-cascade)