National Park Service

South Florida/Caribbean I&M Network (SFCN)

Invasive/Exotic Plants Monitoring

Karum Tree, a new exotic plant to Biscayne National Park
Karum Tree, a new exotic plant to Biscayne National Park.

Resource Briefs, Brochures, Reports, and Data

Protocols

The EPMT Digital Aerial Sketch-mapping Standard Operating Procedure is currently under development.

Links to Parks and Partners

Report a sighting of an exotic invasive plant in a SFCN park unit and win a prize!

Importance/Issues

Invasive/exotic plants are one of the most serious threats to maintaining ecosystem integrity in the South Florida and Caribbean parks. Once established, invasive exotic plant species can affect park natural resources and visitor satisfaction by altering the natural landscape, reducing habitat for native plants and animals, and increasing demand on park resources for trail maintenance and exotic plant eradication efforts. Detecting new species with the potential to become invasive, while they are still in small controllable populations, is important to the cost-effective management of this problem. Tracking established populations of known invasive species across the landscape is important for effective control strategy planning and implementation.

Monitoring Objectives

  • Detect newly emerging invasive plant species in the National Parks of South Florida along the most likely routes, or corridors, for infestations, e.g. trails, roadways, waterways, campgrounds, and boat launches.
  • Determine the status and trends of known problematic invasive exotic plants extent and distribution.

Overview of Approach

The strategy for monitoring invasive-exotic plants is to discover whether existing invasive plants are increasing in extent, and whether new invasives are establishing themselves in and around SFCN parks and includes:

Early Detection of Invasive Exotic Plants: Corridors of Invasiveness Monitoring

Approach

The South Florida/Caribbean Network (SFCN), in collaboration with the Florida and Caribbean Exotic Plant Management Team (EPMT), has created an early detection and rapid response plan to manage exotic and invasive plants. A pilot study for the Corridors of Invasiveness Protocol was conducted in 2009 in Big Cypress National Preserve, Biscayne National Park, and Everglades National Park. The formal South Florida\Caribbean Network Early Detection Protocol for Invasive Exotic Plants: Corridors of Invasiveness Protocol has been completed and is currently out for final review.

The basic approach to the Surveillance & Rapid Response Corridors of Invasiveness protocol is to conduct exotic plant surveys by scanning corridors, i.e., main roads, trails, canals, campgrounds, and boat launches within the National Parks of South Florida for exotic plant species. Surveys are conducted by an experienced SFCN botanist along with the assistance of a Florida and Caribbean EPMT member. When exotic species are found, data is collected and in the case of small infestations, the surveyors may eradicate the population of exotics by either applying an herbicide to the infestation, or by pulling them out of the ground by the roots. Larger infestations are reported immediately to park botanists, resource managers, and to the South Florida and Caribbean Exotic Plant Management Team. The data collected is also uploaded to the Early Detection and Distribution Mapping System website (EDDmaps Mapping Project), a web based mapping system that documents the location and distribution of invasive species around the world.

Status and Trends

The third year of field work on this vital sign was completed in 2013 in the southern region of BICY. A total of 307 km (191 miles) were surveyed, with a total of 65 exotic species encountered within the survey field of view area. Of these 65 species, seven (~11%) were new records of exotics found in the park. The new species are Crested Floating Heart (Nymphoides cristata), Grass Leaved Eulophia (Eulophia graminea), Bamboo (Bambusa vulgaris), Aloe (Aloe vera), Sago Palm (Cycas revoluta), Sprenger's Asparagus-Fern (Asparagus aethiopius), and Senegal Date Palm (Phoenix reclinata). There were a total of 311 infestations observed within the survey area. The total area surveyed taking into account the field of view estimate was 2,647,740 m2 (654 acres). The total area infested within the field of view survey was 25,358 m2 (6.3 acres); about 1% of the total area surveyed. This year, the SFCN spent 183 person hours in the field working on this vital sign.

Field work in the western region of EVER will commence in spring of 2014, and a summary report for the findings for that year will be started.

2013 Exotic Species Survey for Big Cypress National Preserve

Photos of Plants Found During 2013 Survey

Grass-leaved Eulophia

Grass-leaved Eulophia (Eulophia graminea). One of the new species found during the 2013 survey. This ground orchid was found in a pile of mulch at the edge of Eleven mile road. Mulch within the park should be monitored to prevent the spread of this species.

Sago Palm

Sago Palm (Cycas revoluta). One of the new species found during the 2013 surveys. This was most likely planted as an ornamental cycad at the entrance of Deep Lake.

Crested Floating Heart

Crested Floating Heart (Nymphoides cristata). One of the new species found during the 2013 surveys. This exotic species is on the spread and is usually found in canals and strands.

Common Bamboo

Common Bamboo (Bambusa vulgaris). One of the new species found during the 2013 surveys. This was most likely planted as an ornamental and was found on an old home site.

Cogon grass

Cogon grass (Imperata cylindrica). An exotic species of concern due to its invasive tendencies that may spread to drier prairie habitats if not contained. It is usually found along road shoulders.

Hydrilla

Hydrilla (Hydrilla verticillata). An exotic submerged aquatic that forms a monoculture in canals. This infestation was found in the canal at the intersection of Birdon Road and Wagonwheel Road.

Java Plum

Java Plum (Syzygium cumini). An exotic tree from the Indo-Malaysian region found in disturbed hammocks throughout the park.

Indian Laurel

Indian Laurel (Ficus microcarpa) is a hemi-epiphyte that starts out as an epiphyte growing in the crown of palm trees or rocks, and then forms a root system that eventually becomes the trunk of the tree. As this species grows it may eventually kill the host tree.

Sisal hemp

Sisal hemp (Agave sisalana) is a species of concern due its potential invasive nature. This infestation of 30-50 individuals was found along Loop Road in the vicinity of Golightly's.

Queen Palm

Queen Palm (Syagrus romanzoffiana) is a species of concern given its unknown invasive qualities. A few individuals of this species were found in the forests along Wagonwheel Road between Birdon Road and Highway 29.

2012 Exotic Species Survey for Everglades National Park

2011 Exotic Species Survey for Biscayne National Park

Official field work on this vital sign was initiated in 2011 in Biscayne National Park. A total of 35.71 miles were surveyed and 32 species of exotic plants found. Of these species, three were new to the park. The new species were the Karum Tree (Pongamia pinnata), Bo Tree (Ficus religiosa), and the Java Plum (Syzygium cumini). All three species were treated. A summary report was produced for the 2011 Biscayne National Park surveys but is still under the review process.

Photos of Plants Found During Survey

Australian Pine

Australian Pine (Casuarina equisetifolia) are native to Australia. Large trees can be seen scattered throughout south Florida. These photos were taken on the south side of Mowry canal in Biscayne National Park, where there are numerous young individuals along the berm.

Australian Pine

The stems of the Australian Pine (Casuarina equisetifolia) appear needle-like with the actual leaves being reduced to a ring of yellowish bands around the stems. This tree is allelopathic, which means the fallen stems from the tree release chemicals into the ground, prohibiting other species of plants from germinating.

Leatherleaf

Leatherleaf (Colubrina asiatica) is a common exotic vine. The vine produces numerious dry capsules containing three or four seeds each.

Leatherleaf

This picture shows the invasive nature of this vine, Leatherleaf (Colubrina asiatica). It is capable of forming impenetrable thickets such as this infestation on Adams key.

Bo Tree

Bo Tree (Ficus religiosa) is an exotic species new to Biscayne National Park. It is native to India and southeast Asia. It has fleshy fruits that are dispersed by birds. During the pilot study of 2009, one small sapling was found, treated, and was found resprouting again in the 2011 survey, where it was treated again.

Karum Tree

Karum Tree (Pongamia pinnata) is an exotic tree new to Biscayne National Park. Native to Asia, it contains small clusters of lavender pea flowers and one-seeded legumes. Numerous individuals can be found along the main park road to Convoy Point. They can be readily identified by the shiny compound leaves with five to seven leaflets.

Burma Reed

Burma Reed (Neyraudia reynaudiana) is an invasive exotic grass native to the Old World. Large infestations can be found in disturbed habitats.

Beach Naupaka

Beach Naupaka (Scaevola sericea) is an invasive exotic shrub common to the coastal regions of Biscayne National Park. Native to the Indian and Pacific Ocean regions, this species can be identified from the native Inkberry (Scaevola plumieri) by having larger leaves, white fruits and a more aggressive habit.

Beach Naupaka

Beach Naupaka (Scaevola sericea) is an aggressive exotic shrub that has formed large colonies at the ends of canals such as Military and Mowry.

Brazillian Pepper

Brazilian Pepper (Schinus terebinthifolius) is a native to tropical America. This species is one of Florida's most aggressive exotic colonizers and can displace the native flora, forming monocultures. It produces many small red fruits that are dispersed by birds. Brazilian Pepper is related to poisonwood and poison ivy, and the sap can cause dermatitis to those that are sensitive to poison ivy.

Java plum

Java plum (Szygium cumini) is a native to the Indo-Malayan region. It has dark purple fleshy, edible fruits that are dispersed by birds. Only one small tree was found during the survey and was cut down and treated.

Portia tree

Portia tree (Thespesia populnea) is an exotic tree. Native to the Old and New World tropics, it is identified by its heart-shaped (cordate) leaves, showy yellow flowers and 5-merous capsular fruits. Each capsule contains up to five seeds.

Extent and Distribution of Known Invasive Species

Approach

Figure 1. Digital area sketch map results for 2012-2013 exotic plant census.
Figure 1. Digital area sketch map results for 2012-2013 exotic plant census.

Two methods are utilized by the Florida and Caribbean Exotic Plant Management Team (EPMT) with assistance from parks and partners for assessing the extent and distribution of invasive plant species in south Florida and U.S. Virgin Island parks: 1) Digital Aerial Sketch Mapping (DASM) and 2) complete surveys.

Digital Aerial Sketch Mapping

Digital Aerial Sketch Mapping (DASM) was developed in the 1990's by the USDA Forest Service for the aerial detection and mapping of forest pests and pathogens. In 2005, the National Park Service (NPS) and the South Florida Water Management District (SFWMD) conducted an accurate and cost effective pilot project utilizing DASM technology for the mapping of invasive plant species in the 4 million-acre Everglades Protection Area.. Using an aircraft, observers sketch invasive plant distribution on touch-sensitive computer displays showing the aircraft's GPS position against a background of moving digital aerial photos and background data. The initial mapping which occurs quickly is then better mapped to the infestation boundaries using aerial imagery during post-processing. This method is operational for the Everglades Cooperative Invasive Species Management Area in Big Cypress National Preserve (BICY) and Everglades National Park (EVER) every 2 years. The species of current focus are Australian pine (Casuarina spp.), Brazilian pepper (Schinus terebinthifolius), Melaleuca (Melaleuca quinquenervia), and old world climbing fern (Lygodium spp.). Summaries and data files are periodically posted on the Everglades Cooperative Invasive Species Management Area website.

SFCN data management staff and the NRCA ecologist collaborated with the Exotic Plant Management Team (EPMT) and the South Florida Water Management District to test a new approach for exotic plant monitoring. The results of this coordinated effort are being evaluated, but appear promising. The current procedure of digital area sketch mapping (DASM) produces a map of the entire Everglades Cooperative Invasive Species Management Area (ECISMA) every two years. The map is a census of the four highest priority invasive plant species in the Everglades. SFCN organized and hosted a discussion among exotic plant managers from the ECISMA on 5/18/2013 to analyze the strengths and weaknesses of the DASM and to consider possible options for altering the current method for exotic plant mapping. The strengths of the current approach include:

  • Presence-absence detection of large canopy-level infestations and a rough estimate of the acreages infested.
  • The resulting DASM map is very useful for planning management strategies.
  • DASM helps each land manager tell the story of their area and is great for communicating the scale of the challenge and justifying funding requests for exotic control.
  • DASM is useful for identifying areas of invasive species expansion in remote areas that land managers typically do not visit.
  • Observing areas where large infestations of exotics are absent and documenting continuing absence is useful, because it save managers time.

During the discussion ECISMA land managers identified some challenges of the current approach:

  • The inability to collect invasive understory and herbaceous plants.
  • Land Managers would prefer even shorter time intervals (than current 2 year interval) for monitoring in areas under active management.
  • There is also a desire to develop capacity to detect change over time. There is uncertainty (and some skepticism) that DASM, as currently conducted, cannot detect small changes (10-20%).
Figure 2. Digital area sketch map results for 2012-2013 exotic plant census.
Figure 2. Digital area sketch map results for 2012-2013 exotic plant census.

As a result the group decided to pursue the development of a statistically designed, sample based approach for long term monitoring of exotic plant species across the landscape. The design would provide for a greater ability to detect small changes in invasive plant abundance and cover over time. The design selected is an expansion of the landscape monitoring design used in the Comprehensive Everglades Restoration Program (CERP). The strengths and weakness of different alternatives for landscape-scale monitoring have been carefully considered in the CERP process, and are thoroughly documented in Philippi (2007). The primary advantages of using this design for exotic plant species monitoring include:

  • Design ensures that statistically valid sampling can occur across multiple spatial scales to ensure that the landscape conditions can be quantified, and that estimates of infestation in unobserved locations are valid within a known range of certainty.
  • Design provides the ability to interact exotic monitoring with other monitoring (particularly vegetation community and landscape pattern monitoring). This provides a better opportunity to differentiate among causes of exotic species spread.
  • Flight time to support designed monitoring is less than flight time required to conduct DASM census. This allows managers to use helicopters to conduct more detailed and frequent mapping in treatment areas.

The results of what was learned this year, 2013, will be summarized and delivered to land managers, restoration practitioners, and natural resource managers in the coming months of 2014. Preliminary results indicate that the use of a statistically designed monitoring will allow monitoring funds to be used more effectively to support the near term and long-term goals of land managers. Also, although both NPS-EPMT and SFCN would like to develop a more formal protocol, SFCN needs to postpone this until other SFCN protocols are finalized although revision of their working SOP may be possible.

Complete Surveys

For the islands in Biscayne National Park (BISC), Buck Island Reef National Monument (BUIS), and Dry Tortugas National Park (DRTO), when an invasive species control effort is conducted, the EPMT specialist and contractors do a complete survey of the islands involved, noting all invasive species.

Acres treated are entered by National Park Service staff and contractors into the Alien Plant Control and Management (APCAM) database.

Report Exotic Plants

We need your help in locating the hard to find invasive exotic plants within the South Florida and Caribbean Network (SFCN). It is cost prohibitive for park resource management staff and Exotic Plant Management Team (EPMT) members to do extensive field sampling, which is why your participation is equally important even if your research plots contain NO exotic plants. Please fill out an exotic plant report even if you do not observe exotic plants because it is imperative to future studies in exotic plant management.

Win a prize just for participating! Annually, an exotic plant reporter who fills out an exotic plant report for SFCN park service units will be randomly chosen to win a personal GPS system. Please help by reporting both the presence and absence of exotic plants in your park.

Exotic Plant Field Guides (Brochures)

Last Updated: December 30, 2016 Contact Webmaster