U.S. Department of the Interior U.S. Fish and Wildlife Service Coefficients of Conservatism Values and the Floristic Quality Index for the Vascular Plants of South Florida Coefficients of Conservatism Values and the Floristic Quality Index for the Vascular Plants of South Florida Steve Mortellaro1, Mike Barry 2, George Gann3, John Zahina4, Sally Channon5, Charles Hilsenbeck6, Douglas Scofield7, George Wilder8 and Gerould Wilhelm9 1U. S. Fish and Wildlife Service, 1339 20th Street, Vero Beach FL 32960 2U. S. Fish and Wildlife Service, Naples, FL (Formerly) 2Institute for Regional Conservation, 22601 S.W. 152 Ave., Miami, FL 33170 (Currently) 3Institute for Regional Conservation, 22601 S.W. 152 Ave., Miami, FL 33170 4 South Florida Water Management District, 3301 Gun Club Road, West Palm Beach, FL 5Palm Beach County Department of Environmental Resources Management, 2300 North Jog Rd, 4th Floor, West Palm Beach, FL 33411 6 17516 Birchwood Drive, Boca Raton, FL 33487 7University of California, Los Angeles, 1509 Life Sciences, Box 951786, Los Angeles, CA 90095-1786 8Naples Botanical Garden, 4820 Bayshore Drive, Naples, FL 34112 9Conservation Design Forum, Inc., 375 W. First Street, Elmhurst, IL 60126 January 2009 South Florida Ecological Services Field Office Vero Beach, Florida Table of Contents ABSTRACT.................................................................................................................................... 1 Introduction..................................................................................................................................... 1 Methods........................................................................................................................................... 3 Defining the region................................................................................................................... 3 Species list................................................................................................................................ 3 Ranking Criteria ....................................................................................................................... 5 Assignment of C Values........................................................................................................... 7 Peer Review of C Values ......................................................................................................... 7 Final C Values.......................................................................................................................... 8 Floristic Quality Index .................................................................................................................... 8 Mean Coefficient of Conservatism .......................................................................................... 8 Floristic Quality Index ............................................................................................................. 9 Results and Discussion ................................................................................................................... 9 Acknowledgements....................................................................................................................... 11 References..................................................................................................................................... 12 Appendix A................................................................................................................................. A-1 Appendix B ................................................................................................................................. B-1 Appendix C ................................................................................................................................. C-1 Appendix D................................................................................................................................. D-1 Figures Figure 1. Phytogeographic regions of Florida. .............................................................................. 4 Figure 2. Distribution of coefficient of conservatism designations for ranked plant taxa in south Florida. ................................................................................................................. 9 Tables Table 1. Coefficient of Conservatism guilds ................................................................................. 6 Table 2. Coefficient of Conservatism ranking criteria................................................................... 6 The use of trade, product, or firm names in this publication is for descriptive purposes only and does not imply endorsement by the U.S. Government. The findings and conclusions in this article are those of the author(s) and do not necessarily represent the views of the U.S. Fish and Wildlife Service. ABSTRACT Since pre-European settlement, major alterations to the native landscape have been made, due largely to urban and agricultural developments. In south Florida, these activities have caused extensive degradation to native plant communities leaving remnant native lands. Therefore, the floristic quality of these native lands is changing and a tool to assess their quality is needed. Assignment of coefficient of conservatism (C) values (ranging from 0 to10) to each native plant within south Florida, allows for the use of the Floristic Quality Index (FQI), a powerful tool to assess the quality of natural or remnant native plant communities. The coefficient of conservatism concept is based on two factors: 1) plants have varying degrees of fidelity to specific habitats and their quality, and 2) plants have varying tolerances to disturbances and respond in varying degrees. The establishment of C values and the use of the FQI eliminate subjectivity and provide a standardized method to evaluate the floristic condition of a site, allows for comparisons between different sites and monitoring of sites over time. Non-native plants are not assigned conservatism coefficients values because they did not evolve in the native landscape. In south Florida (Keys excluded), there are approximately 2,230 plants, 64% (1,437) are considered native and 36% (793) considered non-native. Of the 1,437 plants examined, only 94 remain unranked. Approximately 33% of plants ranked fell into ruderal categories (0 – 4), while 67 % fell into obligate to natural areas (5-10). Once a thorough inventory of a site has been completed a mean C value and FQI can be calculated. Key Words: coefficient of conservatism, C values, Floristic Quality Index, Floristic Quality Assessment, habitat restoration, floristic inventory, south Florida. Introduction Rapidly increasing land development and extensive agricultural operations pose significant challenges to the survivability and sustainability of Florida’s native ecosystems. Since pre- European settlement, the native landscape has undergone extensive modifications due to agricultural and urban developments. Activities such as land clearing, drainage (digging of ditches and canals, channelization of rivers and streams), water mining for urban and agricultural consumption, filling of wetlands, and pollution from urban and farming actives have resulted in extreme ecological degradation. The introduction of exotic plants and suppression of natural fires or prescribed burning during inappropriate times of the season have also contributed to major changes in the native landscape. The dewatered landscape, filled wetlands, polluted estuaries, and diminution of base flow in streams has contributed to the reduction in the native biodiversity of the state. The assessment of natural, restored, and created habitats is one of the most important tasks facing ecologists. Natural plant community descriptions have historically focused on plant communities (associations) or plant species with word descriptors used to convey quality. Terminology consists of words such as degraded, good, poor, high, low, etc. These descriptors are vague and rely on such factors as the observer’s perception, understanding of pre-settlement habitats, ecological knowledge and level of experience with the flora, and personal biases. One 1 observer’s assessment of poor quality may be another’s good. Therefore, a tool is desirable for assessing quality of a plant community in an objective and repeatable way that can be used to make meaningful comparisons between sites. A numerical index describing floristic quality of area based on species conservatism or “nativeness” ratings of individual species was articulated by Wilhelm (1977) and refined by Swink and Wilhelm (1979, 1994) and Wilhelm and Ladd (1988). The “nativeness” or species conservatism is expressed as a coefficient of conservatism (C) value and is the basic metric in the Floristic Quality Index (FQI). The concept around species conservatism is organized around the idea that the presence of a species involves a certain level of confidence in the observer as to where the plant is likely to grow; ranging from a highly intact remnant native ecosystem to highly degraded man-made land. Most native plants are confined to remnant native landscapes and a few function as “camp followers” which admix with exotics to occupy areas severely damaged by contemporary cultural practices. The FQI is designed to reduce subjectivity, produce an objective standard to judge the quality of plant communities in a repeatable fashion. The principal concept of the FQI is that a natural plant community’s quality can