Transects should capture the seaward edge of marsh vegetation , the transition zones where elevation or vegetation change occurs , and continue through into the upper areas of the marsh . These upper areas may also include the approximate Mean Higher High Water ( MHHW ) line , different elevations , upper elevation , and different regions within the site . It is recommended to use around 25-50 plots measuring 1 meter squared ( 1 m2 ). Permanent plots are preferred , as they reduce sampling time once they established and capture changes to the site over time . Care should be taken when walking across the same areas over time to prevent damage to the monitoring site . Walking within the permanent plot areas should always be avoided unless using removable boardwalks to avoid damaging the site .
If there are unique vegetation zones ( i . e ., low marsh , high marsh ) it may be valuable to use a stratified random design ( with strata being the vegetation and / or elevation zones ) with randomization occurring within each stratum . For example , if there are two zones of relatively equal size and 6 quadrats total , three would be placed at randomly determined locations ( along the transect ) within each zone . If zones are substantially different in width , it may be worth distributing the sample plots proportionally .
Guidelines for estimating Percent Cover of Biomass
Identify all plant species found in the quadrat . Materials needed for this task include meter sticks , PVC quadrat , clipboards , and data collection sheets . For each species , estimate and record the total percent cover by category . Table 8 below provides an outline of the NCVS vegetation categories ( 1-9 ) as developed by Peet et al . ( 1998 ). The same coverage categories should be used to identify and record the cover of live oyster , live mussels , and wrack .
Table 8 : Vegetative cover catagories from the North Carolina Vegetative Survey ( Peet et . al ., 1998 )
106
NATURE-BASED SOLUTIONS MANUAL FOR KIAWAH ISLAND