MAERC at Buck Island Ranch
300 Buck Island Ranch Road Lake Placid, Florida 33852 USA
Phone: 863-699-0242 FAX: 863-699-2217 send e-mail

Evaluation of the Effectiveness of Wetland Restoration on a Florida Cattle Ranch

MacArthur Agro-ecology Research Center (MAERC)

Objectives | Restoration Sites | Plant Communities | Bayhead Restoration | Grazing Impacts | Soil Carbon Study | Research Projects Home | MAERC Home 

Background

USDA Wetland Reserve Program.  The US Department of Agriculture (USDA) Natural Resources Conservation Service (NRCS) Wetlands Reserve Program (WRP) is a voluntary program offering landowners the opportunity to protect, restore, and enhance wetlands on their property.  The USDA provides technical and financial support to help landowners with their wetland restoration efforts.  The NRCS goal is to achieve the greatest wetland functions and values, along with optimum wildlife habitat.  

History of WRP sites at MAERC.  MAERC staff took the initiative to meet with NRCS staff in 1999 to explore options to apply for WRP site(s) at the Ranch. Many cattle ranchers regionally are signing up for easement programs, such as WRP, to complement their agricultural operations. After consultation with the MacArthur Foundation, which owns the Ranch, MAERC submitted three potential sites to NRCS for consideration in 2000. In a regionally competitive ranking process, two sites on the Ranch, the east marsh and the south-west marsh, encompassing a total of approximately 750 acres, were approved for the WRP under the permanent easement option. The MacArthur Foundation entered into negotiations with USDA for a conservation easement in perpetuity on these sites and the easements were established in 2002.  Plans for the restoration will be developed by the fall of 2004 and implementation of the restoration plan will occur in winter/spring 2005.

Evaluation of the restoration.  One limitation of USDA-NRCS conservation easement programs is lack of adequate resources to monitor the success or conservation or restoration programs.  Our interest in establishing WRP sites at MAERC was twofold:  1) initiate a research and monitoring program to evaluate the effectiveness of the restoration in terms of the explicitly stated goals of the WRP program, and 2) demonstrate the viability of such easements to other ranchers in the region and provide them with information of the land management and economic consequences of such an easement.  Seed funded to start the research and monitoring program was obtained through a generous gift from the John D. and Catherine T. MacArthur Foundation to Archbold Biological Station. 

Objectives

1. restore and protect aquatic and associated upland habitats

2. enhance biological diversity

3. increase carbon storage

4. improve water quality

5. and assess impacts on sustainable economic performance of the Ranch

Research and Monitoring Approach

Restoration sites  Top

The WRP sites are on two locations at Buck Island Ranch: one in the East Marsh North, and one in the West 770 pasture.  The East Marsh site consists of a mosaic of native and semi-native communities including: depressional sawgrass and other herbaceous marshes, wet prairies, upland savanna, hardwood hammock, calcareous wetland ecotones, and a willow swamp.  The West 770 site consists of a mixture of wet prairie and bahia grass communities with a few scattered swamp trees.  This site was historically mostly a bayhead swamp community, but the swamp trees were removed at various stages during the period from 1940-1980.

A wet prairie area of the East Marsh WRP site at MAERC.

Hydrologic Conditions

We have installed 19 instrumented ground water well at various location inside and adjacent to the two WRP sites at MAERC to collect baseline data on hydrologic conditions prior to and after implementation of the wetland restoration plans.  The wells are 10 feet deep and are instrumented with small data logging pressure transducers for monitoring ground water levels.

Wetland Plant Communities  Top

Objectives:

 1.  Characterize the the current plant community or associations based on groundcover dominance, in the two wetland reserve program sites.

Existing vegetation maps of MAERC are not at a fine enough level of detail of mapping or delineation of plant communities to be sufficient as baseline data for documentation of subtle changes in dominance of various herbaceous species at specific locations.  We will create detailed plant community level digital vegetation map of the current conditions in each of the two wetland reserve sites.  Community boundaries will be entered in ArcView as polygon shapefiles.  The resulting combined map will serve as baseline qualitative spatially explicit data, as well as providing the basis for designing a vegetation sampling system stratified to more intensively sample the plant communities most likely to show change as a result of hydrologic restoration.

 2.  Design a vegetation sampling procedure to provide quantitative vegetation cover data for the plant communities associated with the hydrologic zones most likely to experience hydrological/vegetation change as a result of wetland restoration activities.

Plant communities will be sampled with a stratified sampling design with base sampling units of one square meter plots spaced along linear transects.  Linear transects of from 50 to 100 meters in length will be established with sample plots at equally spaced distances (5 to 10 meters apart) along each transect.  The current proposal for stratification of the transects is detailed in Table 1.   Small grazing exclosures of 10m x 10m will be established around one randomly selected sampling plot along most of the transects.  An exception is the areas of remnant bay stands in West 770 marsh, which will be divided into a grazed and a grazing exclosure section, and a transect of 5 plots to be placed in each section of each of the two stands.

 Table 1:  Initial proposal for stratification of vegetation sampling. 

 3.  Locate and permanently mark vegetation sampling transects, and conduct initial vegetation sampling of the sampling units. 

The endpoints and midpoint of each transect will be determined, and the locations marked with 6 foot angled aluminum stakes and recorded by GPS. Each aluminum stake will have a metal tag with its plot number riveted to the stake.  Within each one meter square sample plot, the estimated percent coverage will be determined for bare ground and each vascular plant taxon, identified to the level of species and variety. 

4.  Enter the vegetation sampling data in relational database format and link to GPS locations of transects and plots sampled.  

All vegetation cover from the sample plots will be transferred into normalized tables in a relational database system using Microsoft Access 2000.   Environmental parameter data collected will also be computerized in this format.  All sampling data will be linked to tables giving the GPS locations of transects sampled.  All sampling data, GPS locations, ArcView shapefiles, and a summary report will be provided in digital format.

Restoring Bayhead Swamp Communities  Top

Bayhead swamps are a form a seepage swamp, which are forested wetlands characterized by saturated soils rather than periodic inundation.  Many of these systems have been drained and converted to agricultural uses.  Many of the classic bayhead or baygall swamps formed where groundwater seeped along the fringe of the Lake Wales ridge in south-central Florida.  Most of these swamps were cleared and converted to grow high value agricultural crops, such as caladiums and gladiolas, on the rich muck soils formed under these swamps.  Wildlife species that use these swampls include Florida panther (Puma concolor), bald eagle (Haliaeetus leucocepahlus), wood stock (Myteria americana), Florida black bear (Ursus americanus floridanus), squirrel tree from (Hyla squirrella), and many other wetland species.

Estimates of wetland loss rates are not refined enough for meaningful estimates of the loss of bayhead swamp. One estimate is that 38% of forested wetland present at the time of European colonization remains in Florida.  Most wetland restoration projects in Florida have been aimed at restoring marsh wetlands and significant resoration of forested wetlands has only occurred in the past 15-20 years.  It it too early to evaluate how successful these restoration projects will be.

Historical aerial photos reveal that much of the West Marsh WRP site at MAERC was formerly bayhead swamp.  A remnant of the original swamp remains on the neighboring property to the west of the site, and there are a few scattered bay trees at limited number of locations within the WRP site.  Any true attempt at restoration of this site needs to include an attempt to reestablish or expand existing bayhead communities within the site.  

Bayhead restoration will proceed along several lines of approach:

1)  Fence areas containing remnant bayhead trees to suppress fire and prevent cattle browsing on the bay trees.  

Although bay trees can withstand some degree of fire and grazing, intense amount of either inhibit regeneration of the trees, and we expect the trees will increase in abundance when fire and grazing are excluded.  The fencing will be imposed as a paired experimental treatment that will include fenced and unfenced plots in two different locations (blocks) where there are an adequate number of bay trees to serve as a base for expansion.  The plant communities in these paired plots will be evaluated as part of the the wetland plant community assessment described above.  

2)  Plant selected bayhead tree species in fenced plots that will be protected from fire and grazing.

In addition to encouraging natural expansion of bayhead from existing remnant trees, we also propose to plant selected tree species, such as sweetbay (Magnolia virginiana), swamp bay (Persea palstris), red bay (Persea borbonia), and red maple (Acer rubrum).  Survivorship and growth of the planted trees will be monitored along with associated changes in the entire plant community in the planted areas.

Evaluating Impacts of Cattle Grazing on Restored Sites  Top

USDA-NRCS staff are eager for more information on using grazing as a management tool in restored wetland plant communities.  Cattle is viewed as an agricultural use with potentially negative impact on restored wetland sites, but with proper management of winter (dry season) cattle may actually help control invasion of woody and shrub species and may also enhance plant species diversity.  More information is need on the effects of cattle on these systems.  We propose to evaluate the effects of cattle by placing grazing exclosures around sampling points on the permanent transects that will be established to monitor changes in the plant community at the sites.  Plant communities inside and outside the exclosures will be assessed over time to evaluate the small scale effects of grazing. on the plant community.  Fenced exclosures around bay trees may also provide insight to the effects of cattle on tree establishment and regeneration.

Cows grazing in an isolated wetland in an improved pasture at MAERC.

Soil Carbon Study Top

Conversion of bayhead swamp to wet prairie at the West 770 March site involved a shift in the plant community from bayhead trees, which have a C-3 photosynthetic pathway, to C-4 grasses.  The carbon in the tissues of these plants differ in its isotopic composition, with C-3 plants being more depleted  in ¹³C relative to C-4 plants which are more enriched in ¹³C.  We are using the different isotopic composition of these dominant plants to examine how shifts in the plant community and alteration of landscape hydrology has influenced soil C turnover and composition.  We plan to do other studies on these sites to evaluate the influence of hydrologic restoration on soil C storage.   

Funding Sources

Home | Top | Index