Are they two seeds in a pod? Comparing seed rain recovery in grasslands using artificial grass carpets versus sticky traps

Abstract Premise Seed dispersal is a critical process for plant community assembly; however, natural rates of seed arrival are rarely quantified compared with other assembly mechanisms, especially in herbaceous communities. Methods Here we compare the utility of artificial grass carpet squares (“artificial grass”) for capturing seed rain with classic “sticky trap” methods. We placed paired sticky traps and artificial grass squares in two grassland ecosystems, added known numbers of seeds of multiple species to each trap, and recovered seeds at one‐week, one‐month, and two‐month intervals. Results We found that both trap types lost seeds through time at similar rates, but each trap type had advantages and disadvantages. Overall, sticky traps retained more seeds and measured primary dispersal, but recovering seeds was difficult and hindered by debris stuck to the traps. Alternatively, artificial grass traps measured effective dispersal as more seeds were lost through time to secondary dispersal and granivory, but recovered seeds could be handled easily and retained for long‐term storage and germination. Discussion We encourage the broad adoption of seed rain studies to improve links between theoretical and empirical community ecology. Both sticky traps and artificial grass traps are useful in measuring seed rain in grasslands but vary in the types of information they provide.