Investigators:	Ken G. Rice Frank J. Mazzotti Leonard G. Pearlstine
		Additional Project Information at:	--

Project Topic: Landscape Patterns

Start Date: 10/1/2001
End Date: 12/31/2003 (Projected)

Off-road vehicle (ORV) use in Big Cypress National Preserve (BICY) has impacted wildlife populations and habitats through modifications to water flow patterns (direction and velocity) and water quality, soil displacement and compaction, direct vegetation damage, disturbance to foraging individuals, and, ultimately, overall suitability of habitats for wildlife (NPS 2000).  Further, evidence exists that hydrological variables addressed in Comprehensive Everglades Restoration Plan (CERP) such as water depth and duration have a role in determining the extent of ORV impacts.  For example, the wetter conditions in the 1990’s (NPS 2000) led to increased impacts of ORV’s to BICY habitats through soil displacement (Duever et al. 1981).  Over 25 T&E species and numerous other indicator species monitored through performance measures in CERP occur in BICY.  While efforts are completed or are underway to map ORV use (NPS 1991), the direct impacts on wildlife species have not been addressed.  Also, incorporating existing information on vegetation, ORV use, and wildlife habitats into a comprehensive GIS tool for management and restoration uses has not been accomplished.  Measures of hydrological restoration success cannot be apportioned without information associating ORV impact with wildlife populations in BICY.  Understanding these impacts and their association with CERP has been identified as a high priority information need for Everglades restoration.

An extensive network of ORV trails exists at BICY.  The extent to which this network influences the volume, timing, and distribution of surface water flows is not understood nor are the impacts to wildlife populations.  This information is critical to predicting restoration outcomes, evaluating restoration success, and management of wildlife populations in BICY. 

Objectives

• Develop GIS tools that synthesize existing information on vegetation, ORV use, hydrology, and selected species habitats for use in evaluating restoration and management success.
• Examine the impacts of ORV use on the biodiversity of wildlife populations in BICY through field studies of selected wildlife groups.
• Using the spatial databases above, identify wildlife habitats and areas sensitive to ORV use and hydrological restoration, identify potential areas of concern, and analyze spatial patterns of habitat, biodiversity, and ORV use.

Information Needs and Uses

• This research directly addresses CESI (EP3, LP5) and CERP (3007-7, 3050-10) tasks.  These tasks require information assessing the landscape and population level impacts of ORV use on wildlife species and their habitats.


• This project has been cited as a high priority research information need for the Southwest Florida Feasibility Study.


• This information contributes to several science information needs of CESI (SI1, SI2, SI3) and CERP/RECOVER (3070-1, 3070-4, 3070-6): to enter historical scientific data and provide access to the public and agencies; to develop and maintain a database that contains biological and physical data for access by the public and agencies; and, to organize existing ecological data for the southern Everglades into GIS.

Project Description

Purpose and Goals

ORV impacts to habitats through displacement of soil (Duever et al. 1986a), direct damage to vegetation, and spread of invasive species (NPS 2000) are readily visible and effects on highly studied species such as the Florida panther have been noted (Janis and Clark 1999).  However, subtler habitat effects due to increased water flow rates and, thus, shorter hydroperiods and depths on suites of wildlife species have not been examined except at the local level (Duever et al. 1981, Duever et al. 1986b, NPS 2000).  Studies have shown that ORV ruts and airboat trails can accelerate water flow.  Further, habitat alteration through changes to water quality via suspension of soil particles certainly can effect aquatic fauna populations.  Measures of biodiversity have long been used to examine the effects of altered habitat quality on wildlife populations.  New quantitative methods allow us to not only estimate diversity through measures of species richness but to obtain estimates of variability and habitat occupancy rates of various species assemblages.  We propose to: gather existing information on vegetation, hydrology, ORV use, and wildlife habitat use into a GIS database, use this database to stratify habitats by ORV use and hydrological factors, estimate species richness and occupancy in the stratified habitats, and incorporate this new information into a comprehensive GIS assessment of actual and potential impacts.

Objectives

• Develop GIS tools that synthesize existing information on vegetation, ORV use, hydrology, and selected species habitats for use in evaluating restoration and management success. 


• Examine the impacts of ORV use on the biodiversity of wildlife populations in BICY through field studies of selected wildlife groups. 


• Using the spatial databases above, identify wildlife habitats and areas sensitive to ORV use and hydrological restoration, identify areas of concern, and analyze spatial patterns of habitat, biodiversity, and ORV use.

Urgency or Timelines

The timeliness of this project is on target for the completion of the Southwest Florida Feasibility Study environmental studies components scheduled for FY2004.

The relevance of this project to CERP and CESI tasks and information needs is through direct completion of tasks identified in ecological processes, indicator species, and landscape patterns, processes, and modeling in CESI and CERP tasks 3007-7 and 3050-10, through development and monitoring of restoration performance measures defined in the ridge and slough and rocky glades/marl prairie conceptual models, and as a high priority information need for the Southwest Florida Feasibility Study.

Synopsis of Research Methods

GIS Development.-- Appropriate GIS layers will be identified, located, and incorporated into a GIS. These layers will include but are not limited to:  vegetation (University of Georgia coverage, Welch et al. 1999;  GAP), ORV use (NPS 1991), hydrology (Everglades National Park, SFWMD), and wildlife habitat use (a minimum of known habitat associations; GAP). Ground-truthing at selected and random GPS locations will be conducted to assess the reliability of the associated GIS layers.

Task 2. Biodiversity.-- After consultation with appropriate BICY management personnel and examination of new criteria from the Southwest Florida Feasibility Study, we will select 1 or more of the following species assemblages which include indicator, threatened, and endangered species for study: 

• Amphibians.
• Other aquatic fauna.
• Alligators and other reptiles.
• Birds.
• Insects.
• Other groups defined through the consultation process.

The number of groups studied will be dependent on feasibility of sampling various groups in concert and other factors. We will use the GIS developed in Task 1 to stratify habitats by the various data layers and sample accordingly.

Estimating variation in species richness through time and among different locations is one means of tracking the status of amphibians as a group, and may be more effective than focusing on abundance measures of individual species, which have been shown in most studies to lack statistical power. We will use species richness estimates to detect differences in the amphibian assemblage among plots, habitats, and seasons.

In the past the main hindrance to making valid inferences about variation in species richness has been the inability to count all species present in an area during a survey. Weather conditions, the behavior of different species, cryptic coloration, and observer skill are just some factors affecting detection. Invariably some species will be missed, thus biasing the estimates (Boulinier et al. 1998). However, methods are now available which account for variation in detection probabilities and which estimate not only species richness, variation as well (Nichols and Conroy 1996). These methods have been extended to estimate several important vital rates in animal communities that bear on amphibian status, e.g., rates of local species extinction, turnover, and colonization (Nichols et al. 1998a). They have been used to test hypotheses concerning factors affecting temporal (Boulinier et al. 1998) and spatial variation (Nichols et al. 1998b.) in species richness as well. This approach can also be extended to estimate the proportion of habitat occupied by species (J.D. Nichols pers. comm.).

Further, statistical methods have been developed to estimate not only the number of species inhabiting an area (species richness) but to estimate the proportion of a habitat that is occupied by a given species. The motivation for considering these estimators involves an effort to develop reasonable estimation methods that are logistically feasible over relatively large spatial scales with moderate levels of field effort (J.D. Nichols, unpub. data). With respect to level of resolution and effort, the approach is intended to fit between methods for estimating species richness (these methods generally require the least field effort) and methods for estimating abundance of particular species (these methods generally require more effort). The approach yields species-specific estimates of the proportion of sample units (e.g., habitats, regions) that are occupied by the species, rather than abundance (J.D. Nichols, unpub. data). While this method requires less effort that estimation of population size, it explicitly deals with the issue of detectability and does not rely on the assumption that nondetection is equivalent to absence

Task 3. Analysis of spatial patterns.--State-of-the-art spatial statistics will be used to analyze the data obtained from Tasks 1 and 2. We will identify areas of special concern, habitat/species groups that will need to be monitored during the CERP process, and provide a framework for answering management and restoration questions regarding ORV use such as least impact pathways between BICY entry points and recreational use areas.

The ability to redefine and combine different layers of spatially referenced data in the GIS environment allows for analysis and visualization of the spatial relations between ORV activities (for example density of trails) and ecological characteristics such as species richness, habitat quality, and vulnerability. Least cost path analysis can be used to identify routes of minimal impact to ecological resources as well as areas of high ecological sensitivity. Another advantage of using GIS is the ability to visualize the spatial relations of the data layers for presentation to decision-makers and stakeholders.

Application of Information

The results of this project will be used during management of BICY habitats and ORV use, during the Southwest Florida Feasibility Study, and during implementation and monitoring of various projects identified in CERP.

Information Products

• In addition to a technical report, products from Task 1 will include a supporting GIS data base with the aforementioned data layers from BICY. These products will form the basis for the analyses to be performed in Tasks 2 and 3.


• A new data layer for the GIS developed in Task 1 will be constructed and incorporated into the comprehensive GIS. This Task also will provide the first monitoring point for the species identified in restoration performance measures.


• A final comprehensive GIS database and assessment.

Data & Models

All GIS data layers and output will be maintained at the USGS-BRD, Florida Caribbean Science Center, Restoration Ecology Branch, University of Florida Field Station in Fort Lauderdale, Florida and at the University of Florida Research and Education Center in Fort Lauderdale, Florida. All data requests should be forwarded to Kenneth G. Rice (954-577-6305 or ken_g_rice@usgs.gov).

Literature Cited and Related References

Boulinier, T., J. D. Nichols, J. E. Hines, J. R. Sauer, C. H. Flather, and K. H. Pollock. 1998. Higher temporal variability of forest breeding bird communities in fragmented landscapes. Proc. Nat. Acad. Sci. USA 95:7497‑7501.

Duever, M.J., J.E. Carlson, and L.A. Riopelle. 1981. Off-road vehicles and their impacts in the Big Cypress National Preserve. National Audubon Society, Ecosystem Research Unit.

Duever, M.J., L.A. Riopelle, and J.M. McCollom. 1986a. Long term recovery of experimental off-road vehicle impacts and abandoned old trails in the Big Cypress National Preserve. National Audubon Society, Ecosystem Research Unit.

Duever, M.J., J.E. Carlson, J.F. Meeder, L.C. Duever, L.H. Gunderson, L. Riopelle, T.R. Alexander, R.L. Meyers, and D.P. Spangler. 1986b. The Big Cypress National Preserve. National Audubon Society, Ecosystem Research Unit.

Janis, M.W. and J.D. Clark. 1999. Final report to the Big Cypress National Preserve, National Park Service: the effects of recreational deer and hog hunting on the behavior of the Florida Panther. University of Tennessee, Knoxville, Tennessee.

National Park Service. 1991. General management plan and final environmental impact statement: Big Cypress National Preserve, Florida. Volume 1. Big Cypress National Preserve. Ochopee, Florida.

National Park Service. 2000. Final recreational Off-road vehicle management plan Supplemental Environmental Impact Statement. USNPS, Big Cypress National Preserve. Ochopee, Florida. 603pp.

Nichols, J.D., J.R. Sauer, K.H. Pollock, and J.B. Hestbeck. 1992. Estimating transition probabilities for stage-based population projection matrices using capture-recapture data. Ecology 73:306-312.

Nichols, J. D., and M. J. Conroy. 1996. Estimation of species richness. Pp. 226‑234 in Measuring and Monitoring Biodiversity. Standard Methods for Mammals. Wilson, D.E.,F. R. Cole, J. D. Nichols, R. Rudran, and M. S. Foster (eds). Smithsonian Institution Press, Washington, D.C.

Nichols, J. D., T. Boulinier, J. E. Hines, K. H. Pollock, and J. R. Sauer. 1998a. Estimating rates of local species extinction, colonization, and turnover in animal communities. Ecol. Applic. 8:1213‑1225.

Nichols, J. D., T. Boulinier, J. E. Hines, K. H. Pollock, and J. R. Sauer. 1998b. Inference methods for spatial variation in species richness and community composition when not all species are detected. Conserv. Biol.12:1390‑1398.

Rexstad, E., and K. P. Burnham. 1991. User's guide for interactive program CAPTURE. Abundance estimation of closed animal populations. Colorado State University, Fort Collins, Colorado.

Welch, R., M. Madden, and R.F. Doren. Mapping the Everglades. Photogrammetric Engineering and Remote Sensing. 65(2):166-170.