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>>Project ID:: DRY9402


>>Date Submitted (MM/DD/YY):: 04/15/94 

>>Descriptive title (3 lines max.):: Gap dynamics for barrier 
island shrub thickets (Myrica cerifera)

>>Responsible PIs:: Don Young

>>Student(s)/ technician(s):: Ed Crawford, Dave Martin 

>>LTER core topic(s) (Y or N)::

>>>>Primary Productivity:: 

>>>>Trophic Structure::

>>>>Organic Matter::

>>>>Nutrient Movements::

>>>>Disturbance:: Y

>>>>Other (specify):: Community structure

>>Study site description:: All field sampling will be focused on 
the natural gaps that occur in Myrica thickets on the northern 
portion of Hog Island.  

>>Expected project duration (number of growing seasons):: 1

>>Sampling (put Y after all that apply)::

>>>>Harvest::

>>>>Coring::

>>>>Pumping::

>>>>Topographic Survey:: Y

>>>>Trapping:: 

>>>>Collecting:: Y

>>>>Aerial/remote sensing::  

>>>>Other (specify):: Soil samples will be collected to determine 
the composition and density of the seed bank.

>>Method/location of sample/voucher/core preservation:: no 
samples will be archived

>>Keywords (separated by commas):: Gaps, Myrica cerifera, shrub 
thicket, seedbank, disturbance, senescence

>>Study purpose and goals:: The purpose of this study is to 
quantify natural shrub thicket gaps to better elucidate 
successional processes on barrier islands.  Specific questions to 
be answered include: Do gap formation and gap characteristics 
vary with position and thicket age on Hog Island?  Do the gap 
colonizing community characteristics vary among mid-island gaps, 
bay side gaps, and the adjacent intact thickets?  Do edaphic 
characteristics vary between the mid-island and bay side gaps? 
The results will elucidate the importance of gaps for 
accelerating successional processes in communities with dense, 
low diversity seral stages.  Further, the results will contribute 
to the understanding of successional processes that occur in 
maritime communities.

>>Experimental/ sampling/ collecting methods::  After gaps have 
been located, specific global coordinates will be recorded with 
the Magellan GPS.  Gap position will be overlaid on a vegetation 
map of the island.  Gap characteristics, including size, 
location, cause, and colonizing species will be determined.  To 
assess gap seed banks, soil samples will be collected from each 
gap, returned to VCU, placed in a glasshouse, and emergent 
seedlings identified.  Similarly, potential seed banks will be 
determined for soil samples collected from beneath intact 
thickets.  Spatial variations in soil N, organic matter, bulk 
density and pH will also be determined for the gaps and adjacent 
thickets.

>>Impact of sampling on site integrity:: None.  This study is 
limited to naturally occurring gaps. 

>>Other information::