A Vegetational Transect along California’s Pacific Crest Trail

 

Authors:  Rob York, Jennifer McElhaney, and John Battles

                   UC Berkeley- Environmental Science, Policy, and Management

 

Project Description:  The California portion of the Pacific Crest Trail provides a unique opportunity for observing vegetational change along a contiguous transect of over 1,700 miles!  The vegetation along the trail is influenced by the geology associated with eight different mountain ranges, as well as by changing factors of climate, elevation, latitude, and disturbance.  During the summer of 2002, researchers will “thru-hike” the entire California section of the trail while collecting data on the composition and structure of different vegetation types.  The results will help us quantify the proportions of high elevation land that are covered by different vegetation types, with implications for wildland management and quantifying carbon cycling. 

 

 

Methods:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

            PCT trail                      D = Length of trail transecting the vegetation type

                                                     => Minimum Mapping Unit (500 meters)

            GPS waypoint 

                                                 d_i = distance (m) between type boundary and first plot

            Plot location                      = Random number between 0 and ½*MMU

        

           Stand type polygon    d_i+1 = d_i + ½*MMU

                                     

   x = distance of plot from trail (perpendicular to trail)

                                                      = Random number between 0 and ½*MMU

 

Plot Parameters

1. Vegetation type (sensu Calfornia Native Plant Society)
2. Disturbance agents influencing structure
3. Successional status
1. Time since last disturbance
2. Sere
4. Prism Plot
1. Species, dbh, and status (live/dead) of each “in” tree
5. Height of dominant canopy layer, and any understory or intermediate layer.
6. Age of representative tree
7. Tally of < 5cm dbh trees within fixed radius 1/300 hectare plot