Minitraps: A simple, compact, low-cost, and reusable method for collecting soil nematodes

Soil organisms are a crucial part of the terrestrial biosphere and are essential for ecosystem functioning. A major part of soil and sediment ecosystems are nematodes worms, which can be used as a bioindicator of soil status. These worms represent one of the most numerous animal phyla on earth, filling all trophic levels in the soil food web. Overall nematode abundance is related to net ecosystem productivity, and regional variations in abundance provides insight into local patterns of soil fertility and functioning. Methods for extracting nematodes from soils have been established, but these can be cumbersome, or require specialist equipment or consumables, meaning they are not always suitable for the field or remote areas. We have built on previous methods to develop a simple, more compact, and zero-waste method of extracting nematodes, using basic equipment. We demonstrate this in a small collection of soils from deforested, native forest, and reforested sites. On a larger scale, this method can be used to reflect overall ecosystem function, indicating current soil status, and future success and proliferation of reforested sites.