In explaining the purpose of a research effort, several
levels of focus can be distinguished.  The first is goals, or
objectives, which describe components or responses of interest. 
For example, my first goal (I.) is to examine spatial patterns of
hurricane damage.  Each goal may lend itself to a more specific
question to be answered.  This question focuses the interest
within the broader goal.  For example, within the goal of
examining spatial patterns of damage I will specifically answer
the question "How do the spatial patterns of damage vary with
different measures of hurricane severity?" (I.A.).  When a
component or response is better known, we may be able to predict
a response or relationship, i.e. form a hypothesis to be tested. 
As is the case with I.C.1, "Hurricane damage is more highly
correlated to abiotic environmental factors than to biotic
factors."  Goals may be viewed as exploratory and may lead to
specific questions to be answered.  Hypotheses are statements,
and therefore are testable, applying some statistical test for
significance.

  I.  Examining the spatial patterns of hurricane damage and the
      factors that influence these patterns.

      A.  How do the spatial patterns of damage vary with
          different measures of hurricane severity?

      B.  What is the gap size of hurricane disturbance?

      C.  What are the relative roles of abiotic environmental
          factors (topography, substrate features, and
          disturbance history) and biotic factors (stem density,
          basal area, and community structure) in influencing
          patterns of disturbance?

          1.  Hypothesis 1 - Hurricane damage is more highly
              correlated to abiotic environmental factors than to
              biotic factors.


 II.  Exploring the vegetative community response to gradients of
      hurricane damage.


III.  Assessing the success of gradients of light and soil
      moisture in predicting rates of biomass accumulation.

      A.  Are maximum energy profits found in the middle of
          abiotic gradients?


 IV.  Analyzing the dynamics of recovery of the canopy structure
      and the factors that influence this process.
     
      A.  What is the role of community dynamics in influencing
          structure in the recovering canopy?

          1.   Hypothesis 2 - Recovering forests have
               significantly different canopy structures when
               dominated by recruitment (early successional
               species) as opposed to dominated by regrowth
               (surviving late successional species). 

              a.  Maximum canopy height is significantly more
                  variable in regrowing forest sites than in
                  those dominated by recruitment of early
                  successional species.

              b.  Percent cover increases in each successive
                  lower canopy interval in a regrowing forest.
                  Maximum cover occurs at the lowest canopy
                  interval - herb (0-1 m), through the first
                  three years of recovery.

              c.  By the third year after disturbance, forest
                  sites dominated by recruitment have maximum
                  cover at an intermediate canopy layer,
                  therefore any lower layers have less vegetative
                  cover.  


      B.  What is the role of topographic position in influencing
          structure in the recovering canopy?

          1.  Hypothesis 3 - Canopy structure is significantly
              different between sheltered valleys and exposed
              ridges.

              a.  Independent of the recovery vector, valley
                  sites have significantly lower percent cover in
                  the lowest two canopy layers: shrub (1-4 m) and
                  herb (0-1 m) than ridge sites.

              b.  The difference between the lowest canopy layers
                  is significantly greater in valley sites than
                  in ridge sites when comparing regrowth to
                  recruitment.  That is, the shading effect of
                  the canopy in a recruiting site is amplified in
                  valleys.

  V. Developing a spatially explicit landscape simulation model
     of hurricane disturbance and recovery that incorporates the
     above concepts.

     A. What would be the implications of recovery that follows
        the four phase Bohrmann and Likens model?

     B. What is the impact of the assumption that recovery time
        is less that the return time for hurricane disturbance as
        opposed to the assumption that the forest is in a
        constant state of recovery?

     C. What might be the result of changing the hurricane        
        disturbance regime?

Return to the Table of Contents