The original ground beetle sampling design accommodated 40 pitfall traps deployed within 10 plot locations (4 traps per plot; 10 plots per site) from 2013-01-01 to 2017-12-31. Due to budget limitations, beginning in 2018 the sampling design was altered to eliminate one trap cup from each plot, resulting in reduced sampling per bout (3 traps per plot; 10 plots per site).
The change in sampling effort reduced the number of samples generated during a bout; requiring a reduced budget for analytical costs to analyze samples (for species composition). All NEON terrestrial sites sample 10 plot locations within the landscape. Before 2018, up to 40 samples could be expected per sampling bout; one sample per pitfall trap. After 2018, up to 30 samples could be expected per sampling bout.
This change to 30 traps per site per bout affects the following data products at all terrestrial sites from collections occurring after 2018-01-01.
- Ground beetles sampled from pitfall traps (DP1.10022.001)
- Impact of this change on data values: Up to 40 field sampling records will be available for affected sites during this time frame. Current sampling regime yields up to 30 field sampling records.
- Ground beetle sequences DNA barcode (DP1.10020.001)
- Impact of this change on data values: Because there were more samples (and thus species) collected from the field during this time frame, a greater diversity of individuals were available for DNA sequencing during this time. This change did not impact the quantity of individuals sent for DNA barcoding.
The reduced quantity of sampling (starting in 2018), is under evaluation and consideration by the Ground Beetle Technical Working Group. Pending their evaluation, alternate design options may be implemented to produce data that adequately address the needs of the suite of beetle data products. Please use the data portal contact form for further inquiries; select DP1.10022.001 in the Data Product dropdown list.