Shuffling leaf litter samples produces more accurate and precise snapshots of terrestrial arthropod community composition.
Understanding the accuracy of sampling techniques is critical to accurate interpretation of local and global ecological patterns. Over the past 20 yr, Winkler leaf litter extractors have become one of the most common techniques used to collect terrestrial arthropods. Although the original  description of this technique recommends the use of disturbance during extraction to increase extraction efficiency, most published studies do not follow this recommendation. Here we test experimentally how disturbing, or "shuffling" leaf litter during extraction affects collection  efficiency for four groups of arthropods: ants, micro-Hymenoptera, beetles, and spiders. Our results show that extraction efficiency for abundance and richness of ants is increased with disturbance. Disturbance also improves extraction efficiency for beetle abundance, but does not affect micro-Hymenoptera  and spider abundance or richness. Significantly, our results also demonstrate that shuffling litter can greatly reduce the variability of extraction efficiency between different sites. Because of this greater efficiency, we recommend use of the shuffling technique, when sampling leaf litter  via Winkler extractors to maximize the collection of ants and beetles, especially for studies that compare abundance and richness across multiple sites.
Department of Biology and the Keck Center for Behavioral Biology, North Carolina State University, Campus Box 7617, Raleigh, NC 27695-7617, USA. bsguenar@ncsu.edu
Benoit
B
Guénard
Andrea
A
Lucky
D000818:Animals; D001000:Ants / Q000502:physiology; D001181:Arthropods / Q000502:physiology*; D044822:Biodiversity; D001517:Coleoptera / Q000502:physiology; D004463:Ecology / Q000295:instrumentation / Q000379:methods*; D006927:Hymenoptera / Q000502:physiology; D009657:North Carolina; D018515:Plant Leaves; D012987:Soil; D013022:South Carolina; D013112:Spiders / Q000502:physiology
D012987:Soil