greatest mean leaf area with 3.5 leaves/m2 occurred in areas with 26-50% herbaceous
understory vegetative cover.


Abiotic Data


 Sunlight Transmittance

 Figure 6.30 shows the distribution of rooted vines throughout the entire range of
sunlight transmittance. However, most rooted vines occur when sunlight transmittance is
less than 50%. This also appears true for vine biomass, with the greatest concentration of
vine biomass occurring in the range of 5-50% sunlight transmittance. This does not
include vine biomass that may have already reached the canopy which may be a higher
light environment.


 Water Depth

 Figure 6.31 illustrates that no distinct pattern relating rooted vines and vine
biomass to water depth were apparent. The only vine found rooted in any level of
standing water was the herbaceous vine Mikania scandens.


 Soil Characteristics

 Soils data from the square meter quadrats from the intensive sites were used to
 explore what conditions support vine growth. Soil moisture, bulk density, percent
 organic matter, pH, and plant available nutrients were determined from soil cores taken
 within each square meter quadrat. Some threshold levels and trends are apparent. Table
 6.12 provides a summary of soil moisture (%), dry bulk density (g/cm3), and soil organic
 matter (%), which have been averaged for quadrats without rooted vines, with rooted
 herbaceous vines, and with rooted woody vines.

 Figure 6.32 shows the soil moisture conditions where vines occur. There is no
 apparent significant difference between soil moisture ranges of areas not hosting or
 hosting vines. Additionally, herbaceous vines and woody vines show great similarity in
 ranges of acceptable soil moisture. There is little intra-site variability where vines are
 and are not rooted, yet there is great inter-site variability in soil moisture ranges. Figure
 6.33 depicts similar trends for rooted vines and dry soil bulk density (g/cm3), and Figure
 6.34 shows the presence of rooted vines according to soil organic matter content (%).
 Neither soil bulk density nor soil organic matter levels seem to restrict the presence of
 rooted herbaceous or woody vines. Figure 6.35 provides the equation for the relationship
 between soil moisture (%), dry bulk density (g/cm3), and organic matter content (%),
 explaining 78.3% of the soil cores sampled.


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