I am putting together a vegetation protocol for measuring plant communities and general habitat characteristics associated with known observations of a Sierra Nevada owl. My question is: how best can one capture patchy vegetation in 15-m radius circular plots (associated with foraging points)? Foraging habitat for this owl, while often at meadow edges, is quite variable (e.g. sometimes in very small drainages further in the forest, on dry upland logged areas, larger riparian non-meadow areas, etc.). Keeping in mind that vegetation within the plot is not homogeneous (the plot being often, but not always, half meadow and half forest) is there a statistically sound method for capturing vegetation, especially herbaceous? I would like the protocol to be user-friendly for non-botanist field crew. Because of this I would like to avoid visual cover estimation or any other subjective method of data collection. Would it be feasible to use a 10-cm square sub-quadrat and record presence/absence of individual species (or where botany skills falter, type: forb, grass, sedge) and average height class at each meter point on each of the four cardinal direction transects (= 60 points)?
Also, regarding the use of circular plots, is there a standard way to collect canopy closure measurements? I am using a GRS densiometer. Thank you very much.
