http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
Landscape development and dynamics of woody vegetation in a subtropical savanna parkland, 1941-1990
xiii, 92 leaves : illustrations, maps ; 28 cm.
A study was undertaken in southern Texas to (1) evaluate two
remote sensing techniques (ground-penetrating radar [GPR] and
electromagnetic induction [EMI] as tools for detection of
diagnostic subsurface features, (2) assess the uses of EMI
for mapping subsoil heterogeneity, (3) document spatial
changes in woody landscape elements form 1941 to 1990 and
determine soil properties that might explain variation in
plant community dynamics, and (4) compare development and
dynamics of landscape vegetation components for the Mesquite
Brushiand Preserve (NMP) with the La Copita Research Area
(LCRA). GPR was not effective in delineating differences in
soils and correlations between EMI readings and soil
properties were low or non-significant. Even so, results
suggest EMI can be useful for general research, survey and
exploration applications. Landscape elements classified as
woodlands and groves increased in area (1.0 and 1.30/o/y from
Upslope migration of woodland margins was dynamic in some
areas but static in others. 'Soil properties were comparable
across woodland-savanna boundaries. However, differences in
soil conductivity along transacts spanning static and dynamic
boundaries suggest edaphic factors may account for
differences in boundary behavior. Expansion of landscape
elements classified as groves was variable and it is proposed
that patterns of grove expansion are a function of (a) the
size and shape of coarse-textured inclusion which occur in an
otherwise continuous argillic horizon and (b) time of
habitation of these inclusion by woody plants. A net
increase in areal cover in vegetation classified as woodlands
(37 vs. 38%) and groves (128 vs. 5%) on the LRCA and the
MBP. Densities of landscape elements classified as small
shrub clusters and individual shrubs were more variable on
the MBP than on the LCRA, and no consistent trends were
observed. Grove size increased on the LCRA (362 M2 in 1941
to 825 M2 in 1990), and did not change on the MBP. The MBP
appears to be farther along the process of succession from
grassland to woodland than the LCRA. This may reflect site
specific differences in historical grazing practices or in
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