https://www.fs.fed.us/rm/pubs/rmrs_gtr074.pdf

Sampling surface and subsurface particle-size distributions in wadable gravel- and cobble-bed streams for analyses in sediment transport, hydraulics, and streambed monitoring

The forest vegetation of the northern Colorado Front Range was studied using a combination of gradient analysis and classification methods. A graphical model of forest composition based on elevation and topographic-moisture gradients was constructed using 305 0.1 ha samples. To derive the topographic moisture gradient, stands were stratified into eight 200 m elevation belts, and then ordinated by correspondence analysis using understory (<1 m) data. Each of the resultant gradients was scaled against a standard site moisture scalar derived from incident solar radiation and topographic position. Except for krummholz sites, the vegetation defined gradients fit the moisture scalar closely. Once scaled, these gradients were stacked vertically, sandwich-style, to create the graphical representation shown in Figure 5.

Forest vegetation of the Colorado Front Range

/pdf/vegetation-ecology-theory-methods-and-applications-with-4cd9vjdu4a.pdf

Vegetation ecology: theory, methods and applications with reference to Fennoscandia

To document environmental impact predictions for land development, as required by United States government regulatory agencies, vegetation studies are conducted using a variety of methods. Density measurement (stem counts) is one method that is frequently used. However, density measurement of shrub and herbaceous vegetation is time-consuming and costly. As an alternative, the Braun-Blanquet cover-abundance scale was used to analyze vegetation in several ecological studies. Results from one of these studies show that the Braun-Blanquet method requires only one third to one fifth the field time required for the density method. Furthermore, cover-abundance ratings are better suited than density values to elucidate graphically species-environment relationships. For extensive surveys this method provides sufficiently accurate baseline data to allow environmental impact assessment as required by regulatory agencies.

Application of the Braun-Blanquet cover-abundance scale for vegetation analysis in land development studies

Changes in the vascular plant floras of England and Scotland between 1930–1960 and 1987–1988: The BSBI Monitoring Scheme

The properties offour sampling models, random and its derivative stratified random sampling, systematic and its derivative stratified systematic unaligned sampling, are examined empirically with special reference to the context of vegetation survey. Some interesting behaviour patterns emerge in relation to (i) relative accuracy at high and low sample intensity, (ii) variability of estimation, (iii) performance with units of different shape and fragmentation, and (iv) stabilization across sample intensity. Stratified sampling techniques are found to exhibit greater overall comparative accuracy then either random or systematic sampling, though their general behavioural properties mirror those of the parent strategy in other respects. Finally, the different spatial properties of the models are briefly discussed.

P. F. M. Smartt

Papers

Sampling for vegetation survey: some aspects of the behaviour of unrestricted, restricted, and stratified techniques