Native Habitat Inventory Final Report 2004 - St. Lucie County

The species-area relationship does not mean that only large areas should be valued or
protected. There are many instances where small areas can be of very high ecological
value and even without landscape scale connectivity should be protected. This is
especially true where there is a very rare species or a unique habitat (i.e., endemics).
Countywide Overview
Native Habitat Lost and Preserved 1992-2002
The County ESL Program goal is to increase the acreage of native habitat preserved as
well as preserve unique communities and species. As of 2002, there were 19,417 acres of
public conservation land within the County (St. Lucie County ESL020303 shapefile).
Some key protected areas are interspersed with areas under intensive development
pressure such as the coastal and island areas, the high ancient dunes along US 1, as well
as the St. Lucie River and its tributaries.
An indicator of development is the number of parcels per unit area. In the eastern third of
the county (roughly east of the western boundary of Port St. Lucie) there are 129,000
parcels. This is 98% of all of the parcels in the entire county. This suggests there is
intensive development of the entire eastern third of the county. A subset of this area, the
southeastern corner, as framed by the northern and western extents of Port St. Lucie,
contains 71% of the parcels (94,000) within less than 20% of the county. However,
within this portion of the county there are several large natural areas remaining (e.g.,
Savannas Reserve – nearly 500 acres and the series of conservation lands stretching south
from Bear Point – over 800 acres).
The western two-thirds is less developed. The land is used for intensive agriculture such
as cattle grazing and citrus groves. However, within this landscape are large patches
(>500 acres) of natural to semi-natural habitat, mainly in unimproved cattle pasture and
wetlands. These large areas are central elements to the proposed Florida ecological
greenway network (Florida 1999-2001) within the Treasure Coast region.
The intensive development pressure in the eastern third of the county accounts for most
of the 3,052 acres of natural areas lost between 1992 and 2002. Most of this was within
or immediately adjacent to urban areas, especially Port St. Lucie.
In addition to the direct loss of acres of native habitat there is increased fragmentation of
the remaining natural lands outside of public ownership. Only about half (52%) of the
natural lands left are greater than 100 acres in size. The small areas cost more per acre to
acquire and manage, often have a greater percentage of undesirable edge, fewer species, a
reduced likelihood of long-term persistence, and reduced management options due to
external constraints (e.g., fire and residential areas).
To calculate areas of native habitat lost and conserved between 1992 and 2002 two GIS
coverages were created. An approximate historic landcover of the county in 1992 was
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