The effect of collector size on forest litter-fall collection and analysis

Litter fall is commonly collected for a variety of ecological studies. This study was designed to test the effect of collectorsize on the precision of forest litter-fall estimates and on the time involved in laboratory sample sorting. Collectors varied insize from 0.010 to 0.933 m2 and were physically nested, the smaller units within larger units. Ten of these collectorcombinations were randomly placed on a 1-ha plot in a Douglas-fir/western hemlock (Pseudotsuga men:iesii ( Mirb.)Franco/Tsuga heterophvlla (Raf.) Sang.) stand in H. J. Andrews Experimental Forest. Collections were made monthly andrecords were kept of the time required to sort the litter into needles, epiphytes, and miscellaneous categories. Based on adefinition of precision as ± 10% of the mean, 90% of the time, results indicate (i) that the cost of obtaining precise estimatesof needle fall decreases with decreasing collector size to 0.010 m2, (ii) that collectors of any size can be used to obtain estimatesof total litter fall if the number of collectors required to obtain precise results is determined, and ( iii) that precise estimatesof epiphyte biomass require large numbers of samplers and are not cost effective.