Rapid Periphyton Survey 2014 Biocriteria Meeting Variability Study Results. Q Meeting March 26, 2015 Meghann Niesen

Transcription

1 Rapid Periphyton Survey 2014 Biocriteria Meeting Variability Study Results Q Meeting March 26, 2015 Meghann Niesen

2 Rapid Periphyton Survey (RPS) Measures extent and thickness of attached algae at 99 points in a 100m stretch of stream

3 Rapid Periphyton Survey Variability Study Objectives How repeatable is the RPS? Would samplers make the same RPS assessment related to Numeric Nutrient Criteria (NNC)? Study Design 18 samplers assessed the same 100m stretch Rock Springs Run, Orange County Staggered start point by 3 m to reduce trampling of algae Analysis focused on percent of points of algal ranks 4-6

4 Percent Nuisance Algae Coverage NNC threshold >25% coverage 14 Percent rank A B C D E F G H I J K L M N O P Q R Teams Excluding X values Including X (all 99)

5 40 Estimated vs X Number of points A B C D E F G H I J K L M N O P Q R Teams X Est

6 RPS Study Design Distribution of Teams Was there a difference in result between assessments at differing start points (0,3,6m) or between assessments in the morning and afternoon?

7 Staggered Start Point The group that started at the Zero meter mark had a higher average count of algae ranked 4-6, but sample size was lower. Groups starting at the Three and Six meter mark had an equal mean count of algae ranked 4-6. Algae

8 Morning vs Afternoon Groups collecting the RPS in the morning and afternoon had similar range and mean count of algae ranked 4-6. Algae

9 RPS Study Results Summary Good agreement among teams NNC threshold passed for all teams No evidence that trampling affected RPS percent coverage Coverage of periphyton in the stream was consistent. Groups preforming transects at 3m offsets still got similar results.

10 Linear Vegetation Survey 2014 Biocriteria Meeting Variability Study Results Q Meeting March 26, 2015 Larry Olney

11 Linear Vegetation Survey (LVS) Lists aquatic and wetland plants within wetted area of a 100m stretch of stream divided into 10 sections Two metrics summarize observations Percent of plant occurrences of FLEPPC taxa Weighted mean Coefficient of Conservatism (C of C) score

12 Linear Vegetation Survey (LVS) Variability Study Objectives How repeatable is the LVS? Would samplers make the same LVS assessment related to Numeric Nutrient Criteria (NNC) Study Design 18 samplers assessed the same 100m stretch Rock Springs Run, Orange County

13 LVS Results Summary LVS Weighted Mean C of C Score % FLEPPC Occurrence Number of Taxa Min Max Average Std Dev

14 Weighted Mean C of C Score Results C of C Score NNC Threshold > Teams NNC Evidentiary Threshold Achieved for All Teams

15 Percent FLEPPC Occurrence Results Percent FLEPPC Occurrences Teams NNC Threshold <25% NNC Evidentiary Threshold Achieved for All Teams

16 LVS Study Results Summary Good agreement among teams NNC thresholds pass for all teams Greater variability in % FLEPPC metric, mainly due to different total number of occurrences among teams Even wider variation in the total number of taxa identified, from a minimum of 8 to a high of 33. Possibly due in part to interpretation of plants present in the wetted area.

17 LVS Study Results Summary Commonly confused taxa Rhynchospora corniculata vs. inundata. R. corniculata was identified by 7 of the teams, while this same species was identified as R. inundata by 7 teams. It was not identified at all by two teams and was simply identified as Rhynchospora sp. by two teams. Schoenoplectus tabernaemontanis. This species was identified as Schoenoplectus validus, Schoenoplectus californicus, Schoenoplectus sp.,scirpus validus, and Scirpus sp. Note: Scirpus validus is the synonym and the old name. Polygonum punctatum vs. hydropiperoides. P. punctatum was identified by 6 teams while 3 teams identified it as P. hydropiperoides. One team identified it as Polygonum sp. while eight teams did not identify it at all.

18 LVI Experimental Dominance Assignment 2014 Biocriteria Meeting Study Results March 26, 2015 Ashley O Neal, Nia Wellendorf

19 Lake Vegetation Index (LVI) Four metrics % Native taxa % Sensitive taxa % FLEPPC taxa Coefficient of Conservatism (C of C, or CC) on dominant or co-dominant taxa Past studies have shown Dominant C of C to be the most variable metric

20 Study Objectives Use an alternative way of assigning dominance which is inclusive of all strata within the plant community; Compare LVI variability among teams between the traditional method of dominance assignment and the experimental method; Test a method of estimating the extent of submersed taxa; Determine what percent cover classes dominant or codominant taxa fall into; AND Determine consistency among teams in estimating percent cover.

21 Dominance Assignment Approaches Standard LVI: select one dominant or two codominant taxa for each lake section Experimental LVI: select one dominant or two codominant taxa for each strata of the plant community (if present) for each lake section Woody Emergent Floating Submersed

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23 Study Lakes Lake Hall, Leon County 8/13/14 7 Sampling Teams Lake Pickett, Seminole County 10/22/14 7 Sampling Teams Lake Buck, Seminole County 10/22/14 6 Sampling Teams

24 Lake Hall Hall LVI_STD LVI_EXP Range stdev Median Mean CV 9% 7% L V I S c o r e Two methods yielded same score Standard LVI had higher variability

25 Lake Hall example section dominance Section 9 Stratum BIO AEQA Leon Co. (*3) NED 1 NED 2 NWD Standard LVI Method Dominant/Codominant Standard LVI Method Dominant/Codominant Experimental LVI Method Woody Experimental LVI Method Woody Cabomba caroliniana Nymphaea odorata Cephalanthus occidentalis Brasenia schreberi Nymphaea odorata Cephalanthus occidentalis Cabomba caroliniana Nymphaea odorata Cephalanthus occidentalis Cabomba caroliniana Cephalanthus occidentalis Not assigned Cephalanthus occidentalis Not assigned Cephalanthus occidentalis Experimental LVI Method Emergent Experimental LVI Method Emergent Experimental LVI Method Floating Experimental LVI Method Floating Experimental LVI Method Submersed Experimental LVI Method Submersed Panicum hemitomon Nymphaea odorata Cabomba caroliniana Panicum hemitomon Polygonum hirsutum Nymphaea odorata Brasenia schreberi Cabomba caroliniana Panicum hemitomon Nymphaea odorata Brasenia schreberi Cabomba caroliniana Sacciolepis striata Nymphaea odorata Brasenia schreberi Cabomba caroliniana Panicum hemitomon Nymphaea odorata Cabomba caroliniana Panicum hemitomon Pontederia cordata Nymphaea odorata Brasenia schreberi Cabomba caroliniana Dominant selection difficult by standard method, but all high CC taxa. Some teams did not assign dominance. Greater agreement at each strata.

26 Lake Pickett Pickett LVI_STD LVI_EXP Range stdev Median Mean CV 5% 7% L V I S c o r e Standard LVI yielded higher score Standard LVI had lower variability

27 Lake Pickett example section dominance Section 5 Stratum BIO AEQA NED 2 SWD 1 Standard LVI Method Standard LVI Method Experimental LVI Method Experimental LVI Method Experimental LVI Method Experimental LVI Method Experimental LVI Method Experimental LVI Method Experimental LVI Method Experimental LVI Method Dominant/Codominant Dominant/Codominant Mayaca fluviatilis Mayaca fluviatilis Woody Taxodium sp. Taxodium sp. Woody Mayaca fluviatilis Taxodium sp. Mayaca fluviatilis Taxodium sp. Emergent Fuirena scirpoidea Fuirena scirpoidea Fuirena scirpoidea Fuirena scirpoidea Emergent Panicum Panicum hemitomon hemitomon Floating Nymphaea Nymphaea Nymphaea Nymphaea odorata odorata odorata odorata Floating Nuphar sp. Nuphar sp. Submersed Submersed Mayaca fluviatilis Mayaca fluviatilis Mayaca fluviatilis Mayaca fluviatilis Consistent dominance assignment and high CC for Standard LVI

28 Lake Buck Buck LVI_STD LVI_EXP Range Stdev Median Mean CV 9% 9% L V I S c o r e Standard LVI yielded higher score Two methods had same variability

29 Lake Buck example section dominance Section 1 Stratum BIO NED 1 NWD Pinellas South Standard LVI Method Dominant/C o-dominant Nitella Cyperus surinamensis Utricularia purpurea Utricularia purpurea (Walton) Utricularia purpurea South (Young) Not assigned Southwest Utricularia purpurea Standard LVI Method Dominant/C o-dominant Eichornia crassipes Eleocharis (Subm vivip) Eleocharis elongata Eleocharis elongata Experimental LVI Method Woody Myrica cerifera Acer rubrum Stratum Not present Taxodium sp. Ludwigia peruviana Ludwigia peruviana Ludwigia peruviana Experimental LVI Method Experimental LVI Method Experimental LVI Method Experimental LVI Method Experimental LVI Method Experimental LVI Method Experimental LVI Method Woody Emergent Emergent Oxycaryum cubense Cyperus surinamensis Oxycaryum cubense Panicum repens Oxycaryum cubense Oxycaryum cubense Oxycaryum cubense Oxycaryum cubense Floating Eichornia crassipes Eichornia crassipes Nuphar sp. Nuphar sp. Nuphar sp. Nuphar sp. Eichornia crassipes Floating Eichornia Nymphaea Eichornia crassipes odorata crassipes Submersed Nitella sp. Utricularia sp. Utricularia Utricularia Utricularia Utricularia Utricularia purpurea purpurea purpurea purpurea purpurea Submersed Eleocharis Eleocharis Nitella sp. Eleocharis (Subm vivip) elongata elongata Variability in both methods. Standard method yielded classic split between submersed and non-submersed dominants.

30 Commonly Confused Plants Oxycaryum cubense vs. Cyperus surinamensis Eleocharis elongata vs. Submersed viviparous species (some Eleocharis interstincta) Panicum hemitomon vs. Sacciolepis striata

31 Conclusion and Next Steps Strata-based dominance assignment reduces variability in some cases but not all Conduct additional analyses with Variability Study data Analyze data collected by ROCs in 2014 with standard and experimental dominance assignment We are not asking you to conduct this additional dominance data in 2015