Hi Amy, Ahh, thanks for clarifying your approach. :-) As you are using circular plots (and, it seems, a form of distance sampling), you might consider adapting the "trapping web" design to your needs. Trapping webs are often used for capture-recapture studies. The web design uses spokes radiating out from the center of the circle. Samples are then taken at specific intervals along the spokes. This approach yields several subsets of samples that are equidistant from the center (i.e. rings of samples, like pearls on a necklace). The following paper describes the design as applied to capture-recapture studies, along with statistical analysis.
Anderson, D.R., K.P. Burnham, G.C. White, and D.L. Otis. 1983. Density estimation of small-mammal populations using a trapping web and distance sampling methods. Ecology 64:674-680. The above is an early paper on the topic. The authors have written several related papers, including one that compares the web design to grid designs (Parmenter et al. 2003. Ecological Monographs 73:1-26). All the best, Mike > Date: Sat, 2 Jun 2007 11:57:37 -0700 > From: Amy Williams <[EMAIL PROTECTED]> > Subject: Re: Sampling vegetation for wildlife habitat purposes > > Thank you all for your many insightful responses. Perhaps I can > clarify a > little bit. The research is already designed to gather plot-level > information on vegetation physiognomy (canopy height and density, > DBH, tree > condition, percent of plot that is meadow, forest, bare ground, > downed wood, > etc.), as well as soil attributes and hydrology. In addition, I did > intend > to use the 10-cm square sub-quadrats to represent single points to > gather > presence/absence of either species or type (sedge, forb, grass), > and average > height. Is there a systematic way to place a large number of these > in a 15-m > square circular plot, besides limiting them to orthogonal cross- > transects? I > will make sure to consult the texts recommended to me; maybe I will > find my > answers there. > > Again, thank you for the help!
