Based on Discriminant Analysis to Investigate Habitat Characteristics of Uca formosensis in Hsiang-Shan Wetland

Uca formosensis is an endemic fiddler crab in Taiwan. Hsiang-Shan
Wetland is one of the few habitats left for Uca formosensis. Construction
of wastewater treatment station in the wetland between Sanhsingkung
river and Dachuang river may deteriorate habitats for Uca formosensis in
that area. Soil sampling were taken with 100 meter intervals by grid, and
particle size distribution, electrical conductivity and pH of saturated soil
water, oxidation-reduction potential, heavy metal concentration, total
organic content, total nitrogen, bulk density, porosity, in-situ bulk density
and water content were measured in the laboratory. Soil penetration were
measured in situ. Percentage of vegetation coverage were measured by
aerial photograph. Average submerged time were measured by in-situ
investigation and tidal records. Four types of habitats were classified by
discriminant analysis.
We found Uca formosensis live in the upper intertidal zone with a
mean submerged time of 5.1%. Vegetation coverage percentage on the
ground is less than 1.4%. Soil contains 40.4% of clay and 15.8% of sand.
Penetration force is 41.6N/cm2. Discriminant analysis shows that there
are 10.9 ha., 2.9 ha., 18.1 ha., 8.2 ha. classified for bare area, herbaceous
plant area, mangrove area and Uca formosensis habitat, respectively.