Hello ECOLOG, First time poster, I’m a 6th year PhD student studying forest productivity in high-elevation red spruce ecosystems. One of the questions I’m asking with my research project is how total litterfall varies along a gradient of atmospheric pollution. I have 7 study sites in these forests and in each site I have 8 litter traps (laundry baskets) to collect litter. I’ve collected samples at roughly monthly intervals since decomposition is pretty low at these sites. Once returned to lab, I sort the litter samples into 6 categories: foliage and coarse woody debris for red spruce, other conifers, and all deciduous trees. Here’s the issue: since red spruce and hemlock co-occur at my sites I have samples that are very time-consuming to sort since the needle size of these two species is basically identical. After days and weeks of mind-numbing sorting, I still have many samples left to go through and I’m already behind on my defense.
After talking with my advisor, he suggested subsampling my litter to cut down on time. Basically, sieve out my total sample for various sizes, collect a few subsamples from each size class (a handful of needles for example), weigh each subsample, sort these subsamples into the 6 categories and weigh each. This will give me a percentage of say, red spruce needles for that particular size class, and then if I weigh the entire sample, I should have a reasonable estimate of each pool. My question for anyone who has had similar issues is whether this is a good method of measuring litterfall, given the inherent variability of this important component of NPP. If there are other methods or particular papers that come to mind, I welcome any and all suggestions (trying to count down the days to my defense). Thanks everyone! Kenny Smith West Virginia University, Department of Biology
