patrickbdevaney/mia9 · Datasets at Hugging Face

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1 For reference, a table of all species common names and equivalent scientific names discussed throughout the
management plan is provided in Appendix A.
EEL Program, Management Plan, Part II – Pine Rockland (DRAFT) _____________________________________________________________________________________________________________________
Page 2
and small areas of the Big Cypress National Preserve in Collier and Monroe counties. This
chapter will focus on the pine rockland ecosystem in Miami-Dade County, where the ecosystem
has been almost entirely destroyed by agricultural, urban, and suburban development. Only
scattered, small parcels remain today. The pine rockland fragments that do remain have suffered
from impacts of forest fragmentation, fire suppression, exotic pest invasions, and other forms of
disturbance. Fragments that have been acquired by the EEL program must be managed to ensure
their long term viability.
1.2 Purpose
The purpose of this plan is to contribute to the preservation of the natural resources in pine
rockland sites owned and/or managed by EEL. To achieve this purpose, this management plan
provides:
• A brief description of the values and justification for conservation of pine rocklands
• A historical perspective of pine rockland presence in the landscape of the county
• Current conditions of the pine rockland habitat
• Main threats to the pine rockland habitat
• Perceived trends within the pine rockland habitat
• Management issues that are important to conservation of pine rocklands
• Guidelines for future public use
• Priorities for monitoring and research
This plan draws from other resources, including the Restoration Plan for Dade County’s Pine
Rockland Forests Following Hurricane Andrew (DERM 1995), the Miami-Dade County Habitat
Management Plan (Miami-Dade County Natural Areas Management Working Group 2004), and
the pine rockland chapter of the South Florida Multi-Species Recovery Plan (USFWS 2000).
Recommendations from these documents, as well as many other resources cited in the references
section, have been reviewed, and when relevant and acceptable, used in this management plan.
This chapter is intended not only to guide management of pine rocklands on EEL sites, but also
other pine rockland fragments in Miami-Dade County.
EEL Program, Management Plan, Part II – Pine Rockland (DRAFT) _____________________________________________________________________________________________________________________
Page 3
2.0 Historical Reference Conditions for the Pine Rockland Ecosystem
This section describes the historical condition of Miami-Dade County pine rocklands, as they
existed prior to major human disturbance. In considering conservation goals and alternatives, the
historical condition described is regarded as the baseline for the ecosystem. Utilizing these
conditions as a basis for weighing the importance of conservation efforts will aid in the
preservation of the valuable resources associated with pine rocklands in Miami-Dade County and
South Florida overall.
2.1 Original Pine Rockland Distribution in Miami-Dade County
Pine rockland in Miami-Dade County historically occurred on the Miami Rock Ridge. The
Miami Rock Ridge is an oolitic limestone formation that extends from north of downtown Miami
in a southwesterly arc to Mahogany Hammock in ENP, varying in width from four (4) to ten (10)
miles. In historic conditions, the ridge was at a higher elevation than the adjacent marshes of the
Everglades, with small wetland prairies dissecting the ridge into numerous, distinct islands
(Figure 1). This matrix of limestone and prairies allowed the Everglades to drain into Biscayne
Bay.
On the Miami-Rock Ridge, pine rockland was historically the dominant habitat. Of the 151,000
acres that the ridge historically occupied, almost all of the area was pine rockland. Only small
areas of the ridge were occupied by rockland hammock or other ecosystems.
2.2 Physiography
As discussed above, pine rocklands in Miami-Dade County occur on the Miami Rock Ridge.
This ridge varies in elevation between two (2) and 20 feet above sea level. Elevations are highest
in the Coconut Grove area and generally decline to the south (Craighead 1971). Other relevant
aspects of the physiography (geology, soils, and hydrology) of the pine rocklands are discussed
in the paragraphs below.
2.2.1 Geology
The geology and soils of Miami-Dade’s pine rocklands have a relatively simple structure and are
derived from recent geologic history. The surface rocks of the county, exposed in many
locations, are nearly all Miami Limestone, a formation produced in the most recent interglacial
period of the Pleistocene Epoch when sea level was about 25 feet above today’s level. The
interglacial period gradually ended about 100,000 years before present. The parent material
deposited during the interglacial time was grains of calcium carbonate, formed by two shallowmarine processes. Along the eastern edge of the county’s mainland where accumulations were
thicker, the material consisted of small (but visible) egg-shaped grains of calcium carbonate
called “ooids.” These oolitic deposits thinned westward, away from the deeper waters of the
Atlantic, where they intergraded with fine-grained (microscopic) calcium carbonate particles
deposited from marine algae and the shells of tiny animals called bryozoans in a calmer shallow
marine interglacial environment away from more turbulent coastal waters. (Lodge 2005)
The most recent glacial period (with the glacial maximum occurring approximately 20,000 years
ago), caused much lower sea levels that exposed the sediments. The oolites were initially sand-
EEL Program, Management Plan, Part II – Pine Rockland (DRAFT) _____________________________________________________________________________________________________________________
Page 4
EEL Program, Management Plan, Part II – Pine Rockland (DRAFT) _____________________________________________________________________________________________________________________
Page 5
like and subject to wind redistribution and dune formation. Percolation of rainwater gradually
solidified the grains by recrystallization into the soft rock we now recognize as Miami
Limestone. (Lodge 2005)
2.2.2 Soils
The presence of a limestone substrate is a major defining character of the pine rockland
ecosystem which differentiates it from other types of pine-dominated ecosystems in Florida.
Soils in pine rocklands, when present, are usually nutrient-poor sand or loam in a matrix of
exposed oolitic limestone. Soil type varies with geographic location on the Miami Rock Ridge.
There are two main soil types in Miami-Dade’s pine rocklands outside of ENP. The USDA
(1996) has mapped these as Cardsound Rock Outcrop Complex and Opalocka Rock Outcrop
Complex. Each of these soils, when present, typically occurs as thin layers over the oolitic
limestone substrate, with much of the limestone breaking the surface of the soil deposit.
Opalocka Rock Outcrop Complex soil occurs north of the Goulds region. Robertson (1955)
referred to the region covered by this soil as the northern Biscayne pinelands. This soil is a
highly permeable quartz sand, which is usually white to brown in color (USDA 1996) and
slightly basic (Craighead 1971, USFWS 2000). The amount and depth of the quartz sands varies
with latitude. To the north, where the Miami Rock Ridge formerly merged with the sandy
Atlantic Coastal Ridge, sands were probably very extensive and deep (examples are now
destroyed). On some more northerly pine rockland fragments that currently exist, such as the
Ludlam Pineland and Rockdale Pineland EEL sites, the sands can be several feet thick and have
areas with little or no exposed limestone. In contrast, pine rocklands further south, such as those
at Larry and Penny Thompson Park, have thinner deposits of sand, which cover less area.
Cardsound Rock Outcrop Complex soil occurs south of the Goulds Region. Robertson (1955)
referred to the region covered by these soils as the southern Biscayne pinelands. This silty loam

1 For reference, a table of all species common names and equivalent scientific names discussed throughout the

management plan is provided in Appendix A.

EEL Program, Management Plan, Part II – Pine Rockland (DRAFT) _____________________________________________________________________________________________________________________

Page 2

and small areas of the Big Cypress National Preserve in Collier and Monroe counties. This

chapter will focus on the pine rockland ecosystem in Miami-Dade County, where the ecosystem

has been almost entirely destroyed by agricultural, urban, and suburban development. Only

scattered, small parcels remain today. The pine rockland fragments that do remain have suffered

from impacts of forest fragmentation, fire suppression, exotic pest invasions, and other forms of

disturbance. Fragments that have been acquired by the EEL program must be managed to ensure

their long term viability.

1.2 Purpose

The purpose of this plan is to contribute to the preservation of the natural resources in pine

rockland sites owned and/or managed by EEL. To achieve this purpose, this management plan

provides:

• A brief description of the values and justification for conservation of pine rocklands

• A historical perspective of pine rockland presence in the landscape of the county

• Current conditions of the pine rockland habitat

• Main threats to the pine rockland habitat

• Perceived trends within the pine rockland habitat

• Management issues that are important to conservation of pine rocklands

• Guidelines for future public use

• Priorities for monitoring and research

This plan draws from other resources, including the Restoration Plan for Dade County’s Pine

Rockland Forests Following Hurricane Andrew (DERM 1995), the Miami-Dade County Habitat

Management Plan (Miami-Dade County Natural Areas Management Working Group 2004), and

the pine rockland chapter of the South Florida Multi-Species Recovery Plan (USFWS 2000).

Recommendations from these documents, as well as many other resources cited in the references

section, have been reviewed, and when relevant and acceptable, used in this management plan.

This chapter is intended not only to guide management of pine rocklands on EEL sites, but also

other pine rockland fragments in Miami-Dade County.

EEL Program, Management Plan, Part II – Pine Rockland (DRAFT) _____________________________________________________________________________________________________________________

Page 3

2.0 Historical Reference Conditions for the Pine Rockland Ecosystem

This section describes the historical condition of Miami-Dade County pine rocklands, as they

existed prior to major human disturbance. In considering conservation goals and alternatives, the

historical condition described is regarded as the baseline for the ecosystem. Utilizing these

conditions as a basis for weighing the importance of conservation efforts will aid in the

preservation of the valuable resources associated with pine rocklands in Miami-Dade County and

South Florida overall.

2.1 Original Pine Rockland Distribution in Miami-Dade County

Pine rockland in Miami-Dade County historically occurred on the Miami Rock Ridge. The

Miami Rock Ridge is an oolitic limestone formation that extends from north of downtown Miami

in a southwesterly arc to Mahogany Hammock in ENP, varying in width from four (4) to ten (10)

miles. In historic conditions, the ridge was at a higher elevation than the adjacent marshes of the

Everglades, with small wetland prairies dissecting the ridge into numerous, distinct islands

(Figure 1). This matrix of limestone and prairies allowed the Everglades to drain into Biscayne

Bay.

On the Miami-Rock Ridge, pine rockland was historically the dominant habitat. Of the 151,000

acres that the ridge historically occupied, almost all of the area was pine rockland. Only small

areas of the ridge were occupied by rockland hammock or other ecosystems.

2.2 Physiography

As discussed above, pine rocklands in Miami-Dade County occur on the Miami Rock Ridge.

This ridge varies in elevation between two (2) and 20 feet above sea level. Elevations are highest

in the Coconut Grove area and generally decline to the south (Craighead 1971). Other relevant

aspects of the physiography (geology, soils, and hydrology) of the pine rocklands are discussed

in the paragraphs below.

2.2.1 Geology

The geology and soils of Miami-Dade’s pine rocklands have a relatively simple structure and are

derived from recent geologic history. The surface rocks of the county, exposed in many

locations, are nearly all Miami Limestone, a formation produced in the most recent interglacial

period of the Pleistocene Epoch when sea level was about 25 feet above today’s level. The

interglacial period gradually ended about 100,000 years before present. The parent material

deposited during the interglacial time was grains of calcium carbonate, formed by two shallowmarine processes. Along the eastern edge of the county’s mainland where accumulations were

thicker, the material consisted of small (but visible) egg-shaped grains of calcium carbonate

called “ooids.” These oolitic deposits thinned westward, away from the deeper waters of the

Atlantic, where they intergraded with fine-grained (microscopic) calcium carbonate particles

deposited from marine algae and the shells of tiny animals called bryozoans in a calmer shallow

marine interglacial environment away from more turbulent coastal waters. (Lodge 2005)

The most recent glacial period (with the glacial maximum occurring approximately 20,000 years

ago), caused much lower sea levels that exposed the sediments. The oolites were initially sand-

EEL Program, Management Plan, Part II – Pine Rockland (DRAFT) _____________________________________________________________________________________________________________________

Page 4

EEL Program, Management Plan, Part II – Pine Rockland (DRAFT) _____________________________________________________________________________________________________________________

Page 5

like and subject to wind redistribution and dune formation. Percolation of rainwater gradually

solidified the grains by recrystallization into the soft rock we now recognize as Miami

Limestone. (Lodge 2005)

2.2.2 Soils

The presence of a limestone substrate is a major defining character of the pine rockland

ecosystem which differentiates it from other types of pine-dominated ecosystems in Florida.

Soils in pine rocklands, when present, are usually nutrient-poor sand or loam in a matrix of

exposed oolitic limestone. Soil type varies with geographic location on the Miami Rock Ridge.

There are two main soil types in Miami-Dade’s pine rocklands outside of ENP. The USDA

(1996) has mapped these as Cardsound Rock Outcrop Complex and Opalocka Rock Outcrop

Complex. Each of these soils, when present, typically occurs as thin layers over the oolitic

limestone substrate, with much of the limestone breaking the surface of the soil deposit.

Opalocka Rock Outcrop Complex soil occurs north of the Goulds region. Robertson (1955)

referred to the region covered by this soil as the northern Biscayne pinelands. This soil is a

highly permeable quartz sand, which is usually white to brown in color (USDA 1996) and

slightly basic (Craighead 1971, USFWS 2000). The amount and depth of the quartz sands varies

with latitude. To the north, where the Miami Rock Ridge formerly merged with the sandy

Atlantic Coastal Ridge, sands were probably very extensive and deep (examples are now

destroyed). On some more northerly pine rockland fragments that currently exist, such as the

Ludlam Pineland and Rockdale Pineland EEL sites, the sands can be several feet thick and have

areas with little or no exposed limestone. In contrast, pine rocklands further south, such as those

at Larry and Penny Thompson Park, have thinner deposits of sand, which cover less area.

Cardsound Rock Outcrop Complex soil occurs south of the Goulds Region. Robertson (1955)

referred to the region covered by these soils as the southern Biscayne pinelands. This silty loam