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HomeMy WebLinkAboutBack-Up DocumentsTrail Map Area Map Rickenbacker Causeway Virginia Key CoastI Hammock Interpretive TmiI Key Biscayne Ocean Agar Acknowledgements Manuel A. Diaz Tomas Regalado Johnny L. Winton Angel Gonzalez Joe Sanchez Arthur E. Teele, Jr. Carlos A. Gimenez Mayor Chairman Vice -Chairman Commissioner Commissioner Commissioner City Manager The City of Miami would like to thank Juan Femandez (Park Naturalist, City of Miami Parks and Recreation Department), Mabel Fentress Miller (Environmental Education Specialist), and Carlos Rivero for their efforts in developing this guidebook. Zanthoxylum coriaceum Biscayne Prickly Ash All drawings by Carlos Acosta City of Miami (arks and 7 creat on (Department Virginia 9Cey Coastal 9-lammock 9nkrprelive frail guidebook Introduction The island of Virginia Key lies between the Atlantic Ocean and Biscayne Bay. It is easy to get sand in your shoes exploring this sedimentary barrier island. The sandy overburden rests on an old coral reef which was alive approximately 100,000 years ago when the water was 25 to 30 feet higher than today. Soldier Key, the first of the true Florida Keys, is where the coral rock of this ancient reef meets the surface. Over time, as the water receded due to the buildup of ice in the Polar Regions, the reef became overladen with sand brought by longshore currents from the north. The elevation of the island gradually increases approximately three to four feet from sea -level to the beach dune. Further inland, the coastal hammock rises approximately six to seven feet above sea level. Changes in plant and animal communities are a result of changes in elevation. These changes are apparent in the different ecological systems (ecosystems) found within Virginia Key. Dense seagrass beds comprised of turtle grass (Thalassia testudinum), manatee grass (Syringodium filiforme), and shoal grass (Halodule wrightii) can be found within wading distance of the low energy beach adjacent to the coastal dune and beach. These benthic ecosystems typically begin ten to fifteen feet waterward of the mean high water line. These dense seagrass beds contain a relatively high diversity of fish, sponges, invertebrates, and algae. Furthermore, sea turtles, manatees, and dolphins have been observed feeding within this area on many occasions. The dune and beach community adjacent to the land -water interface possesses several threatened and endangered plant species, comprises a significant amount of this type of community within Miami -Dade County, and is an essential sea turtle nesting beach. In addition to the ecologically significant dune system, this area also has an interesting mangrove area lining a tidal creek that runs parallel to the beach between the hammock and beach area. This mangrove community consists primarily of red (Rhizophora mangle), black (Avicennia germinans), white (Languncularia racemosa) mangroves, and buttonwood (Conocarpus erectus). In addition to their ecological value, the dune system and mangroves help protect the hammock from the detrimental effects of storms. The plant community in this coastal hammock is composed almost exclusively of native upland species including Spanish Stopper (Eugenia foetida), Simpson Stopper (Myrcianthes fragrans), Strangler Fig (Ficus aurea), Cocoplum (Chrysobalanus icaco), Pigeon Plum (Coccoloba diversifolia), Mastic (Mastichodendron foetidissimum), Indigo Berry (Randia aculeata), Wild Coffee (Psychotria nervosa), Wild Lime (Zanthoxylum fagara), Florida Privet (Foresteria segregate), Seven-year Apple (Cassia clusiifolia), Torchwood (Amyris elemifera), and Biscayne Prickly Ash (Zanthoxylum coriaceum), which is a State endangered plant listed by the Florida Department of Agriculture & Consumer Services. Areas previously dominated by exotic species have been plotted and reforested Indigoberry Randia aculeata This plant has fragrant flowers and white berries. Historically, it has been used to make cooking tools and fishing rods in the Netherland Antilles (Aruba, Bonaire, and Curacao). Darling Plum Reynosia septentrionalis The Darling Plum has leathery evergreen leaves and pointed olive - sized fruit. The fruit is dark -purple and very sweet. The wood is very hard and can be used for making cabinets. Silver Palm Coccothrinax argentata This is a rare tree with fan -shaped leaves and silver underleaf. The Silver Palm is a perfect little tree for your home landscape since it requires very little water and no additional fertilizer. Dildoe Cactus Cereus pentagonus Also known as the Barbed -Wire Cactus, this plant is listed as a threatened species by the State of Florida. The flowers of this cactus are light green and are followed by red, oblong edible fruits. Station 10 As a pioneer plant, the Indigoberry sets the scene for succession and eventually the development of a mature hammock. Ecological succession is the gradual change in the types of species in an area. Pioneer species are extremely important because they can inhabit an area when nothing else is growing there and help to recruit species. The Indigoberry has morphological adaptations like small leaves and spines that make it resistant to drought and sun. This adaptation allows it to grow in disturbed areas or areas with full exposure to sun light. As a result, the microclimate of these areas changes with the decreased sun light and increased humidity. These species are eventually replaced by others until a climax community is formed. Railroad Vine Ipomea pes-caprae with native plant material, most of which was propagated from on -site sources. This area now contains a well -established population of native plants that includes threatened and endangered species. As a result of the ecological restoration, this area provides vital resources for wildlife species. Migrating songbirds that travel down the Atlantic coast flyway use the coastal hammock for food and shelter including many rare migrants like the pine siskin (Carduelis pinus), Tennessee warbler (Vermivora peregrina), Swainson's thrush (Catharus ustulatus), and indigo bunting (Passerina cyanea). In addition, the piping plover uses the adjacent beaches as wintering grounds. Furthermore, many of the animal species that occur in the hammock are listed as endangered by the State of Florida. The City of Miami Parks and Recreation Department has brought back a site worthy of aesthetic appreciation, scientific study, and environmental education through its diligent ecological restoration effort. This project began shortly after Hurricane Andrew ravaged the landscape in August 1992. The restoration began with the removal of invasive exotic plant species throughout the 15-acre hammock. Initially, these species dominated 70% of the hammock area. Currently, they can be found in less than 5% of the total hammock area. During the exotic removal process, many ecologically important species have been discovered including some that are listed as threatened or endangered. Realizing that this site is a rare ecological and educational treasure within Miami - Dade County, the City has made it accessible to the local community by creating an interpretive nature trail. In lieu of taking a passive role in providing access, the City of Miami Parks and Recreation Department wanted to provide more than just entertainment. This is an opportunity to educate the community on the importance of preserving and protecting our natural areas. In addition, the interpretive trail should help to inspire members of the community to promote the planting of native species in their homes, work areas, and other green spaces. There is no better place to get acquainted with the dynamics of the maritime world of tropical and sub -tropical life in South Florida than by following the nature trail in Miami's Virginia Key Park. Gulf Fritillary Agraulis vanillae Station 1 The seeds of the Sabal Palm, Florida's state tree, seek secure and productive areas for its development and reproduction. The specimen in this station has found the perfect spot next to other native plants in the transitional area between the hammock and the coastline. This transitional area was created to demonstrate the effectiveness and attractiveness of landscaping with native plants. Although this community was artificially created, in time, more native species will fill in the spaces through the natural distribution of seeds from the other areas of the hammock. Native species like the Sea Grape, Gumbo Limbo, Wild Lime, and Black - bead are thriving in this area as a result of the ecological restoration and conservation effort. As long as exotic invasive plants are not allowed to grow in this area, the native species will continue to grow and develop a true coastal hammock community. This station provides an ideal location to observe the panorama of areas ranging from recreational to reforested, from coastal hammock to coastal dune. Sabal Palm Sabal palmetto Biscayne Prickly Ash Zanthoxylum coriaceum This tree was historically referred to as the "toothache tree" since its leaves numb the gums. The black seeds of this plant are attractive to birds and its leaves are aromatic when crushed. Wild Lantana Lantana involucrata This species is an unusually good attractant of birds, butterflies, and bees. This plant releases an aromatic odor when its leaves are crushed or broken. This plant is toxic and should not be eaten. Mastic Mastichodendron foetidissimum The Mastic often tends to be the tallest tree in a mature hammock with heights reaching upwards of 80 feet. The yellow fruits of this tree are eaten by raccoons and squirrels. Marlberry Ardisia escallonioides The Marlberry grows best in areas with lots of sun light which makes it an ideal pioneer species. This species is especially attractive to insects due to the sweet smell of its flowers. Station 9 The shade of the robust Mastic and Sea Grape trees and the empty spaces left by the removal of exotics create a striking contrast in light that is perfect for the reintroduction of the Biscayne Prickly Ash. The Prickly Ash populations in South Florida have been significantly reduced in recent history and have caused this species to be listed as Endangered by the State of Florida. When the restoration project began in 1996, there was only one known specimen within the hammock. Today, there are more than 40 specimens protected and conserved. In addition, a native plant nursery has been developed to grow the seeds collected from the hammock plants in a controlled environment for their reintroduction. Beach Sunflower Helianthus debilis Sabal Palm Sabal palmetto The Sabal Palm is protected by law as the Florida state tree. Historically, the Native Americans used this tree to thatch Chickees, make rope, and fortify their canal walls. Wild Lime Zanthoxylum fagara The Wild Lime is a member of the citrus family. In the Florida Keys, this tree is a host plant to the endangered Schaus Swallowtail Butterfly. Gumbo Limbo Bursera simarouba The Gumbo Limbo is also known as the "tourist tree" for its reddish peeling bark that resembles a typical sun burn. This tree is used throughout the Caribbean and Central America as a "living fence". Black -bead Pithecollobium guadalupense The Black -bead is listed as threatened by the State of Florida Department of Agriculture. The shiny, black seeds of this plant are housed within a spiral -shaped legume. Station 2 We can conserve our beaches and coastlines by protecting the Sea Oats of the coastal dune. The brave Sea Oat defends the dune by providing stability against the destructive forces of the winds and waves. The Sea Oat develops a complex root structure that fortifies the existing sand dune and traps additional sand blown in by winds. These are known as primary dunes since they are closest to the water. On some islands, you may find additional, larger secondary dunes that have developed as a result of the protection provided by the primary sand dunes. For many years, developers have removed or leveled the sand dunes to construct homes and hotels on the beach. This practice is now discouraged and in some places prohibited due to the increased coastal erosion that occurs. Sea Oats With one look towards the horizon you will notice the blue ocean inviting you to discover the abundance of treasures hiding under the waves. Among these treasures you will find seagrass beds of Turtle grass, Manatee grass, and Shoal grass. The seagrass beds form an important ecosystem acting as a nursery for juvenile fish and supporting animal species including barracudas, sharks, sea turtles, mollusks, crustaceans, and marine mammals like manatees and dolphins. Although the dolphins do not feed directly on or in the seagrass beds, their favorite prey species can be found migrating through the different areas looking for food. The dolphins catch these fish in the channels or open areas between the seagrass beds as they move from one bed to another. Spanish Stopper Eugenia foetida In this capacity, the Spanish Stopper is a pioneer species establishing itself before any of the other hammock species. The name "stopper" refers to its historical use as a treatment for diarrhea. Bahama Nightshade Solanum bahamense This species was named after the Bahamas where it was first discovered. The fruits are not edible and could be considered poisonous since relatives of this plant contain compounds like atropine and nicotine. Simpson Stopper Myrcianthes fragans The Simpson Stopper is a small tree that has small, aromatic leaves hence the scientific name "fragans". It produces small, white flowers with orange berries that are consumed by birds. Blolly Guapira discolor This shrub or small tree becomes established during the early successional stages of the coastal hammock providing significant ecological value. In addition, its bright red fruits are appealing to birds. Station 8 The Spanish Stoppers in this area have survived the effects of storms and other disturbances leaving a great number of descendants. These trees are well established and have distributed themselves evenly within this small area. Thus, a healthy community of understory plants will fill in to form the diversity a healthy hammock requires. This spacing is a result of competition, where individual trees compete for the same limited resources as those around them. In this case, the competition is intraspecific (within the same species). Interspecies competition refers to competition between members of different species. There are different ways that plants compete with one another. Some just grow faster overshadowing its competitors while others release toxic chemicals (allelopathy) into the soil to keep others from growing. Competition is an important part of the ecology of natural systems. Nutrients that were once trapped in the soil have been absorbed by the different plants in the community. Those species that can produce more with limited resources will be the winners of this marathon. Wild Coffee Psychotria nervosa Sea Oats Uniola paniculata The Sea Oat, a species that is protected by law, stabilizes the coastal dunes by extending its complex root system keeping sand from being blown away by the wind and carried away by the waves. Bay Cedar Suriana maritima Another member of the dune community, the Bay Cedar is a very decorative plant that has been successfully reintroduced as a result of the reforestation effort. Beach Inkberry Scaevola plumieri Listed as "Threatened" by the State of Florida, the Beach Inkberry has been reintroduced on Virginia Key through the germination of seeds collected from the only specimen encountered in 1996. Bottlenose Dolphins Tursiops truncatis Bottlenose dolphins can be seen in the seagrass beds just 40 feet from shore. The healthy seagrass communities provide an abundance of feeding opportunities for this agile predator. Station 3 This plant community, devastated by Hurricane Andrew in 1992, was once inaccessible and full of undesirable plants. Plants like the Brazilian Pepper, Australian Pine, and Lather Leaf have taken advantage of the disorder caused by the disturbance and began taking control of the area preventing native plants from growing. In 2002 the view is significantly different thanks to the restoration effort conducted by the City of Miami Parks and Recreation Department The goal of this project was to conserve and protect the native plant species that live on Virginia Key. Due to this effort, the native plant communities have thrived and established a stable system that has positively influenced the growth of associated animal populations. Bayleaf Capertree Capparis flexuosa Sea Grape Coccoloba uvifera The large, wide leaves of the Sea Grape make it one of the easiest trees to identify in the coasldl hammock. The small, spherical fruits of this tree are edible and are commonly used to make jelly. Poisonwood Metopium toxiferum The presence of this species is indicative of a maturing hammock. The Poisonwood is often succeeded by mature hammock species like the Strangler Fig and the Mastic. It is also found in the understory of the pine rocklands. Saw Palmetto Serenoa repens The Saw Palmetto is a major understory plant providing food and shelter to a variety of animals including opossums, raccoons, birds, and insects. This plant is fire- resistant and quickly regenerates after a fire. Virginia Creeper Parthenocissus quinquefolia This plant is often confused with Poison Ivy since they both are related vines, however, the Virginia Creeper has 5 leaflets instead of 3. The fruits of both vines are consumed by birds and squirrels. Station 7 The tiny rays of light that make it through the canopy of the Sea Grape grace the green leaves of the endeared Saw Palmetto. The Saw Palmetto has served humanity in many ways from its use in artisan crafts to medical applications (for example, extracts from this plant have been known to reduce the benign enlargement of the prostate). The successful development of the Saw Palmetto is dependant upon the periodic occurrence of fire in the community. The Saw Palmetto relies on periodic fires to re -energize the soil by returning nutrients trapped in the living tissues of other plants. Natural fires help return organic matter to the ground where insects and bacteria break it down into nutrients. These nutrients are now available to the variety of fire-resistant plants like the Saw Palmetto. Florida Trema Trema michantha The contribution of the Sea Grape to this community is invaluable. Although some species must be forced to give up their organic content, the Sea Grape willingly returns organic matter by continuously dropping leaves on the hammock floor. The dry leaves donated by this tree maintain the microclimate of this community cool and humid by thoroughly covering the soil. In addition, the decomposition of the leaves releases organic matter and raises the nutrient content of the soil. Wild Coffee Psychotria nervosa Wild Coffee is an important understory shrub of the coastal hammock. This plant is easily identified by its glossy, spear -shaped leaves and red fruits. Northern Cardinal Cardinalis cardinalis The northern cardinal is a beautiful red bird with an orange beak and a black mask. They are usually found foraging for food on the ground, eatings grasses, fruits, and insects like spiders, snails, and slugs. Pigeon Plum Coccoloba diversifolia In 1997, there was only one specimen of Pigeon Plum in the area. Since then, seeds have been collected from other parks and distributed here to help reintroduce this species on Virginia Key. Osprey Pandion haliaetus The osprey hunts by soaring over the water looking to make a meal of an unsuspecting fish. The osprey dives feet first, grabs the fish with its claws, and carries it to its nest. Station 4 Although this area has been impacted by storms, the members of the mangrove community have found a refuge where they can "wait out" the inclement weather and reorganize themselves into their typical order. Here you can see the four mangrove species together in a community that is in sharp contrast to their common community structure. Usually, these species distribute themselves in certain zones based on the amount of salt in the environment. The Red Mangrove is usually found closest to or in the water. You can easily identify the Red Mangrove by its characteristic prop roots that extend from the trunk into the water and the long, cigar -shaped propagules that hang from its branches. The prop roots of the Red Mangrove keep salt from entering the vascular system of the tree. The Black Mangrove is found further inland than the Red Mangrove. This species can be identified by its pneumatophores or exposed roots that stick up out the ground and help it "breathe". The Black Mangrove excretes salt onto the surface of its leaves. Further inland, the White Mangrove thrives in drier soils with minimal exposure to salt water. The White Mangrove can tolerate this environment since it excretes salt through two small glands at the base of its leaves. Although not as salt -tolerant as the other mangroves, the Buttonwood is the most competitive of the four being able to thrive in upland environments where the hammock species dominate. Strangler Fig Ficus aurea This species is often seen growing on other trees initially as a vine with hanging roots. Over time, the vine becomes a tree and outcompetes its "host" by overshadowing it or cutting off the flow of nutrients. White Stopper Eugenia axilaris This species, also known as the stink bush, has a foul, skunk -like smell that eminates from its leaves when the wind blows. However, the leaves of this species have been used medicinally to treat diarrhea. Snowberry Chiococca alba The beautiful white berries of this plant are easy to identify and contain two small seeds that resemble coffee beans. This species requires direct sunlight and will die if other species overshadow it. Torchwood Amyris elemifera Historically, the branches of this tree were used to make torches hence its name. More importantly, however, this species is the primary food source of the endangered Schaus swallowtail butterfly. Station 6 This station provides a clear example of the importance of robust and hearty trees in a mature hammock. Since these trees were strong enough to survive Hurricane Andrew in 1992, they were able to protect their area from the invasion of exotic plants that occurred after the hurricane. While other areas were overrun with Brazilian Pepper, Lather Leaf, and Australian Pine, this area was maintained relatively clear of exotics due to the presence of the Strangler Figs. Other species that are usually found within a maturing coastal hammock include the Snowberry, White Stopper, Spanish Stopper, Torchwood, and Prickly Ash. The Snowberry is a beautiful plant with white berries that contain two small seeds that resemble coffee beans. The White Stopper is another species found in the coastal hammock. This species is also known as the"Stink Bush" due to the foul odor that surrounds it when the breeze blows through its leaves. Coco Plum Chrysobalanus icaco Red Mangrove Rhizophora mangle This species is usually found closest to or in the water. You can easily identify the Red Mangrove by the prop roots extending from the trunk into the water and the long, cigar - shaped propagules hanging from its branches. White Mangrove Laguncularia racemosa The White Mangrove thrives in drier soils and can usually be found landward of the Black Mangrove. Historically, the bark of the White Mangrove was once used as a remedy to treat dysentery. Black Mangrove Avicennia germinans The Black Mangrove is found further inland from the Red Mangrove. This species can be identified by the pneumatophores (exposed roots) that stick up out of the ground and help it "breathe". Buttonwood Conocarpus erectus Sometimes referred to as the "false mangrove", the Buttonwood grows landward of the White Mangrove. This species was once used to create charcoal by the early settlers in the late 1800s. Station 5 The organization of plants within their natural communities, the colorful tones of their canopies and their constant struggle for light form an exceptional scene that invites you to explore and enjoy. Here we can observe the effect of the exotic plant invasion on the development of the Spanish Stopper populations. Exotic plants like the Brazilian Pepper and Lather Leaf once covered the area at the entrance of the hammock. These plants would not let the seeds of the Spanish Stopper germinate and grow due to the absence of light underneath the exotic plants. The removal of the exotics has opened the way for the development of the new generation of Spanish Stoppers. Coontie Zamia pumila The new stoppers will fill in the spaces left by the exotics and extend the hammock area. This process will continue until the hammock reaches the tidal creek and coastal dune to the east. The Spanish Stoppers will continue to dominate the developing hammock community until larger species like the Strangler Fig and Mastic are introduced. These species will eventually outcompete and overshadow the Spanish Stoppers limiting their growth. Brazilian Pepper Schinus terebinthefolius Originally introduced as an ornamental plant, the Brazilian Pepper (also known as the Florida Holly) infests an area and forms dense thickets eliminating the native plant community. Australian Pine Casuarina equisetifolia Brought from Australia as a wind breaker, the needle -shaped leaves of the Australian Pine litter the ground in thick layers preventing the growth of native plants. Lather Leaf Colubrina asiatica Lather Leaf aggressively invades coastal areas and smothers native vegetation until there is nothing left. The seeds of this species float in seawater and are distributed by ocean currents and storms. Burma Reed Neyaudia reynaudiana This species outcompetes the native understory plants and forms a thick monotypic stand. This species presents a significant threat to the rare native plants of the Dade County pine rocklands.