I. Data Set Descriptors A. Title: Hongyu Guo. 2013. Mechanisms mediating plant distributions across estuarine landscapes in a low-latitude tidal estuary. Georgia Coastal Ecosystems LTER Data Catalog (data set PLT-GCET-1309; http://gce-lter.marsci.uga.edu/public/app/dataset_details.asp?accession=PLT-GCET-1309) B. Accession Number: PLT-GCET-1309 C. Description 1. Originator(s): Name: Hongyu Guo Address: Department of Biology and Biochemistry 369 Science and Research Bldg 2 Houston, Texas 77204-5001 Country: USA Email: greatuniverse@hotmail.com 2. Abstract: Understanding of how plant communities are organized and will respond to global changes requires an understanding of how plant species respond to multiple environmental gradients. We examined the mechanisms mediating the distribution patterns of tidal marsh plants along an estuarine gradient in Georgia using a combination of field transplant experiments and monitoring. Our results could not be fully explained by the “competition-to-stress hypothesis” (the current paradigm explaining plant distributions across estuarine landscapes). This hypothesis states that the upstream limits of plant distributions are determined by competition, and the downstream limits by abiotic stress. We found that competition was generally strong in freshwater and brackish marshes, and that conditions in brackish and salt marshes were stressful to freshwater marsh plants, results consistent with the competition-to-stress hypothesis. Four other aspects of our results, however, were not explained by the competition-to-stress hypothesis. First, several halophytes found the freshwater habitat stressful, and performed best (in the absence of competition) in brackish or salt marshes. Second, the upstream distribution of one species was determined by the combination of both abiotic and biotic (competition) factors. Third, marsh productivity (estimated by standing biomass) was a better predictor of relative biotic interaction intensity (RII) than was salinity or flooding, suggesting that productivity is a better indicator of plant stress than salinity or flooding gradients. Fourth, facilitation played a role in mediating the distribution patterns of some plants. Our results illustrate that even apparently simple abiotic gradients can encompass surprisingly complex processes mediating plant distributions. 3. Study Type: Graduate Thesis Study 4. Study Themes: Plant Ecology, Population Ecology 5. LTER Core Areas: Other Site Research 6. Georeferences: geographic coordinates as data columns 7. Submission Date: Sep 01, 2013 D. Keywords: Altamaha River, biotic interaction, competition, estuaries, flooding, physical gradient, Plant Monitoring, salinity, tidal marsh, transplant experiments, zonation II. Research Origin Descriptors A. Overall Project Description 1. Project Title: Georgia Coastal Ecosystems LTER Project 2. Principal Investigators: Name: Merryl Alber Address: Dept. of Marine Sciences University of Georgia Athens, Georgia 30602-3636 Country: USA Email: malber@uga.edu 3. Funding Period: May 01, 2006 to Jan 01, 2013 4. Objectives: To understand the mechanisms by which variation in the quality, source and amount of both fresh and salt water create temporal and spatial variability in estuarine habitats and processes, in order to predict directional changes that will occur in response to long-term shifts in estuarine salinity patterns 5. Abstract: The Georgia Coastal Ecosystems (GCE) LTER program, located on the central Georgia coast, was established in 2000. The study domain encompasses three adjacent sounds (Altamaha, Doboy, Sapelo) and includes upland (mainland, barrier islands, marsh hammocks), intertidal (fresh, brackish and salt marsh) and submerged (river, estuary, continental shelf) habitats. Patterns and processes in this complex landscape vary spatially within and between sites, and temporally on multiple scales (tidal, diurnal, seasonal, and interannual). Overlain on this spatial and temporal variation are long-term trends caused by climate change, sea level rise, and human alterations of the landscape. These long-term trends are likely to manifest in many ways, including changes in water quality, river discharge, runoff and tidal inundation patterns throughout the estuarine landscape. The overarching goal of the GCE program is to understand the mechanisms by which variation in the quality, source and amount of both fresh and salt water create temporal and spatial variability in estuarine habitats and processes, in order to predict directional changes that will occur in response to long-term shifts in estuarine salinity patterns. The objectives of the current funding cycle are 1) to continue to document long-term patterns of environmental forcing to the coastal zone, 2) to link environmental forcing to observed spatial and temporal patterns of biogeochemical processes, primary production, community dynamics, decomposition and disturbance, 3) to investigate the underlying mechanisms by which environmental gradients along the longitudinal (freshwater-saltwater) and 4) lateral (upland-subtidal) axes of estuaries drive ecosystem change, and 5) to explore the relative importance of larval transport and the conditions of the adult environment in determining community and genetic structure across both the longitudinal and vertical gradients of the estuary. To meet these objectives, we utilize a suite of approaches including long-term monitoring of abiotic drivers and ecosystem responses; manipulative and natural experiments designed to enable us to examine the importance of key ecosystem drivers; and modeling. 6. Funding Source: NSF OCE 0620959 B. Sub-project Description 1. Site Description a. Geographic Location: GCE1 -- Eulonia, Georgia, USA GCE2 -- Four Mile Island, Georgia, USA GCE3 -- North Sapelo, Sapelo Island, Georgia, USA GCE4 -- Meridian, Georgia, USA GCE5 -- Folly River, Georgia, USA GCE6 -- Dean Creek, Sapelo Island, Georgia, USA GCE7 -- Carrs Island, Georgia, USA GCE9 -- Rockdedundy Island, Georgia, USA GCE10 -- Hunt Camp, Sapelo Island, Georgia, USA EPA7 -- EPA7 EPA8 -- EPA8 MSA -- MSA Coordinates: GCE1 -- NW: 081 25 42.53 W, 31 32 48.30 N NE: 081 24 38.64 W, 31 32 48.30 N SE: 081 24 38.64 W, 31 32 02.27 N SW: 081 25 42.53 W, 31 32 02.27 N GCE2 -- NW: 081 19 08.26 W, 31 33 09.19 N NE: 081 17 34.24 W, 31 33 09.19 N SE: 081 17 34.24 W, 31 32 00.97 N SW: 081 19 08.26 W, 31 32 00.97 N GCE3 -- NW: 081 13 59.70 W, 31 32 48.72 N NE: 081 11 44.38 W, 31 32 48.72 N SE: 081 11 44.38 W, 31 30 54.68 N SW: 081 13 59.70 W, 31 30 54.68 N GCE4 -- NW: 081 22 14.71 W, 31 27 48.72 N NE: 081 21 26.12 W, 31 27 48.72 N SE: 081 21 26.12 W, 31 26 54.31 N SW: 081 22 14.71 W, 31 26 54.31 N GCE5 -- NW: 081 21 15.89 W, 31 26 33.14 N NE: 081 19 37.92 W, 31 26 33.14 N SE: 081 19 37.92 W, 31 25 03.50 N SW: 081 21 15.89 W, 31 25 03.50 N GCE6 -- NW: 081 17 58.28 W, 31 23 38.66 N NE: 081 15 51.76 W, 31 23 38.66 N SE: 081 15 51.76 W, 31 22 15.61 N SW: 081 17 58.28 W, 31 22 15.61 N GCE7 -- NW: 081 29 36.59 W, 31 20 55.59 N NE: 081 28 33.24 W, 31 20 55.59 N SE: 081 28 33.24 W, 31 20 03.71 N SW: 081 29 36.59 W, 31 20 03.71 N GCE9 -- NW: 081 20 48.23 W, 31 21 29.31 N NE: 081 19 35.38 W, 31 21 29.31 N SE: 081 19 35.38 W, 31 20 21.02 N SW: 081 20 48.23 W, 31 20 21.02 N GCE10 -- NW: 081 17 43.82 W, 31 29 49.29 N NE: 081 15 32.07 W, 31 29 49.29 N SE: 081 15 32.07 W, 31 27 44.35 N SW: 081 17 43.82 W, 31 27 44.35 N EPA7 -- 081 28 46.4 W, 31 20 14.2 N EPA8 -- 081 24 33.1 W, 31 18 28.5 N MSA -- 081 24 07.1 W, 31 18 15.1 N b. Physiographic Region: GCE1 -- Lower coastal plain GCE2 -- Barrier island GCE3 -- Barrier island GCE4 -- Lower coastal plain GCE5 -- Barrier island GCE6 -- Barrier island GCE7 -- Lower coastal plain GCE9 -- Barrier island GCE10 -- Barrier island EPA7 -- Estuary and tidal marsh EPA8 -- Estuary and tidal marsh MSA -- Estuary and tidal marsh c. Landform Components: GCE1 -- Intertidal salt marsh bordering maritime forest GCE2 -- Intertidal salt marsh GCE3 -- Intertidal salt marsh, mud flat, and maritime forest GCE4 -- Intertidal salt marsh bordering maritime forest GCE5 -- Intertidal salt marsh GCE6 -- Intertidal salt marsh, sand beach, maritime forest GCE7 -- Freshwater tidal marsh, devegetated fields GCE9 -- Intertidal salt marsh GCE10 -- Intertidal salt marsh bordering maritime forest EPA7 -- Intertidal marsh bordering sounds, tidal channels and creeks EPA8 -- Intertidal marsh bordering sounds, tidal channels and creeks MSA -- Intertidal marsh bordering sounds, tidal channels and creeks d. Hydrographic Characteristics: GCE1 -- Site contains the upper reaches of the Sapelo River, and is subject to 2-3m semi-diurnal tides GCE2 -- Site contains the Sapelo River and associated tidal creeks, and is subject to 2-3m semi-diurnal tides GCE3 -- Site includes Sapelo Sound and portions of Blackbeard Creek, and is subject to 2-3m semi-diurnal tides GCE4 -- Site includes Hudson Creek and is subject to 2-3m semi-diurnal tides GCE5 -- Site contains the Folly River and borders Doboy Sound, and is subject to 2-3m semi-diurnal tides GCE6 -- Site contains Dean Creek and borders Doboy Sound, and is subject to 2-3m semi-diurnal tides GCE7 -- Site contains Hammersmith Creek and borders the South Champney River, and is subject to 2-3m semi-diurnal tides GCE9 -- Site contains Crooked Creek and borders the Little Mud River, and is subject to 2-3m semi-diurnal tides GCE10 -- Site borders the Mud River and contains tidal creeks and the upper reach of the Duplin River, and is subject to 2-3m semi-diurnal tides EPA7 -- Site encompasses the Altamaha River estuary and nearby tidal creeks, and is subject to 2-3.4m semi-diurnal tides. High freshwater input from the Altamaha River, one of the largest rivers in the Southeastern United States. EPA8 -- Site encompasses the Altamaha River estuary and nearby tidal creeks, and is subject to 2-3.4m semi-diurnal tides. High freshwater input from the Altamaha River, one of the largest rivers in the Southeastern United States. MSA -- Site encompasses the Altamaha River estuary and nearby tidal creeks, and is subject to 2-3.4m semi-diurnal tides. High freshwater input from the Altamaha River, one of the largest rivers in the Southeastern United States. e. Topographic Attributes: GCE1 -- Flat, with elevations ranging from 0-3m above mean low tide GCE2 -- Flat, with elevations ranging from 0-3m above mean low tide GCE3 -- Flat, with elevations ranging from 0-3m above mean low tide GCE4 -- Flat, with elevations ranging from 0-3m above mean low tide GCE5 -- Flat, with elevations ranging from 0-3m above mean low tide GCE6 -- Flat, with elevations ranging from 0-3m above mean low tide GCE7 -- Flat, with elevations ranging from 0-3m above mean low tide GCE9 -- Flat, with elevations ranging from 0-3m above mean low tide GCE10 -- Flat, with elevations ranging from 0-3m above mean low tide EPA7 -- Flat, with elevations ranging from 0-3.4m above mean low tide EPA8 -- Flat, with elevations ranging from 0-3.4m above mean low tide MSA -- Flat, with elevations ranging from 0-3.4m above mean low tide f. Geology, Lithology and Soils: GCE1 -- unspecified GCE2 -- unspecified GCE3 -- unspecified GCE4 -- unspecified GCE5 -- unspecified GCE6 -- unspecified GCE7 -- unspecified GCE9 -- unspecified GCE10 -- unspecified EPA7 -- unspecified EPA8 -- unspecified MSA -- unspecified g. Vegetation Communities: GCE1 -- Vegetation is 3/4 Juncus and 1/4 Spartina alterniflora, and upland area is heavily forested. GCE2 -- Spartina alterniflora all tall or medium. GCE3 -- Short and tall Spartina alterniflora, very small amounts of Juncus. GCE4 -- Vegetation is 1/4 Juncus, 3/4 medium and tall Spartina alterniflora. GCE5 -- Dominated by short and medium Spartina alterniflora, with areas of taller S. alterniflora near several small creeks. GCE6 -- Vegetation is mostly short and tall Spartina alterniflora, with small amounts of Juncus and Borrichia. GCE7 -- dominated by Zizaniopsis GCE9 -- Low marsh is tall Spartina alterniflora, high marsh has a small amount of medium Spartina alterniflora and lots of Juncus. Some hammocks with upland vegetation. GCE10 -- Vegetation mostly tall and medium Spartina alterniflora, with some Juncus present. Upland heavily forested. EPA7 -- unspecified EPA8 -- unspecified MSA -- unspecified h. History of Land Use and Disturbance: GCE1 -- Oct 01, 2000: Permanent plots were established in two nominal marsh zones based on marsh structure -- creek zone and high marsh -- and eight plots were randomly located in each zone and marked with stakes. Oct 01, 2001: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. No significant disturbance was observed, and no plots were replaced. Oct 16, 2002: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack (some have no shoots): C4, C5, C6, C7, C8. The following creekbank plots are on creekbank areas that are collapsing: C5, C6, C8. No disturbance by animal activity was observed and no plots were replaced. Oct 18, 2003: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following creekbank plots are on creekbank areas that are collapsing: C5, C6, C7 and C8. No disturbance by wrack or wildlife activity was observed, and no plots were replaced. Oct 25, 2004: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were lost due to creekbank erosion, catastrophic wrack disturbance, or catastrophic wildlife activity: C7, C8. No disturbance by wrack or wildlife activity was observed, and no plots were replaced. Oct 21, 2005: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were lost due to creekbank erosion, catastrophic wrack disturbance, or catastrophic wildlife activity: C5, C6. The following plots are on creekbank areas that are collapsing: C18. No disturbance by wrack or wildlife activity was observed, and no plots were replaced. Oct 16, 2006: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were lost due to creekbank erosion, catastrophic wrack disturbance, or catastrophic wildlife activity: C2, C16. No disturbance by wrack or wildlife activity was observed, and no plots were replaced. Oct 22, 2007: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were lost due to creekbank erosion, catastrophic wrack disturbance, or catastrophic wildlife activity: C3, C15. The following plots were disturbed by wrack or wildlife activity: C17, C18, C25. The following plots are on creekbank areas that are collapsing: C18. No plots were replaced. Oct 27, 2008: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were lost due to creekbank erosion, catastrophic wrack disturbance, or catastrophic wildlife activity: C25, C26. The following plots were disturbed by wrack: C17, C18, C36. The following plots were distrurbed by wildlife (some may have no shoots): none. The following plots are on creekbank areas that are collapsing: none. No plots were replaced. GCE2 -- Oct 01, 2000: Permanent plots were established in two nominal marsh zones based on marsh structure -- creek zone and high marsh -- and eight plots were randomly located in each zone and marked with stakes. Oct 01, 2001: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. No significant disturbance was observed, and no plots were replaced. Oct 18, 2002: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack (some have no shoots): C4, C5, C6. The following creekbank plots are on creekbank areas that are collapsing: C2, C6. The following plots were lost due to creekbank erosion or catastrophic wrack disturbance: C1 (replaced with C11). No disturbance by animal activity was observed. Oct 19, 2003: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following creekbank plots are on creekbank areas that are collapsing: C2. No disturbance by wrack or wildlife activity was observed, and no plots were replaced. Oct 22, 2004: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack: C4, C6, C8. No disturbance by wildlife activity was observed, and no plots were replaced. Oct 21, 2005: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots are on creekbank areas that are collapsing: C2, C4. No disturbance by wrack or wildlife activity was observed, no plots were lost due to creekbank erosion, and no plots were replaced. Oct 17, 2006: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack: C12, C4, C6. The following plots were lost due to creekbank erosion, catastrophic wrack disturbance, or catastrophic wildlife activity: C2. The following plots were lost for unknown reasons: C8. No plots were disturbed by wildlife, and no plots were replaced. Oct 23, 2007: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were lost due to creekbank erosion, catastrophic wrack disturbance, or catastrophic wildlife activity: C4, C12, C13, C18. The following plots were disturbed by wrack or wildlife activity: C6, C7, C11, C22, C23. The following plots are on creekbank areas that are collapsing: C18. No plots were replaced. Oct 28, 2008: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were lost due to creekbank erosion, catastrophic wrack disturbance, or catastrophic wildlife activity: C22, C28. The following plots were disturbed by wrack: none. The following plots were distrurbed by wildlife (some may have no shoots): none. The following plots are on creekbank areas that are collapsing: none. No plots were replaced. Oct 15, 2009: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. No plots were disturbed or lost, and none were replaced. GCE3 -- Oct 01, 2000: Permanent plots were established in two nominal marsh zones based on marsh structure -- creek zone and high marsh -- and eight plots were randomly located in each zone and marked with stakes. Oct 01, 2001: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. No significant disturbance was observed, and no plots were replaced. Oct 20, 2002: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack (some have no shoots): C4, C5, C6, C7, C8. The following plots were disturbed by wildlife (some have no shoots): M2, M5, M6, M7, M8 (snails). The following creekbank plots are on creekbank areas that are collapsing: C8. No plots were replaced. Oct 19, 2003: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack (some have no shoots): C3, C4. The following plots were disturbed by wildlife (some have no shoots): M5, M6. The following creekbank plots are on creekbank areas that are collapsing: C8. No plots were lost due to creekbank erosion or catastrophic wrack inundation, and not plots were replaced. Oct 24, 2004: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack: C1, C2, C3, C4, C5, C6, C7. The following plots were disturbed by wildlife (some have no shoots): M5, M7. No plots were lost due to creekbank erosion or catastrophic wrack inundation, and not plots were replaced. Oct 21, 2005: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. No disturbance by wrack or wildlife activity was observed, no plots were lost due to creekbank erosion, and no plots were replaced. Oct 15, 2006: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack: C1, C2, C3, C4, C5, C6 (plot C3 has no shoots). The following plots were lost due to creekbank erosion, catastrophic wrack disturbance, or catastrophic wildlife activity: C6. No plots were disturbed by wildlife, and no plots were replaced. Oct 24, 2007: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack or wildlife activity: C1, C2, C3, C4. No plots were lost and none were replaced. Oct 26, 2008: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were lost due to creekbank erosion, catastrophic wrack disturbance, or catastrophic wildlife activity: none. The following plots were disturbed by wrack: C1, C2, C3. The following plots were distrurbed by wildlife (some may have no shoots): M5. The following plots are on creekbank areas that are collapsing: none. No plots were replaced. GCE4 -- Oct 01, 2000: Permanent plots were established in two nominal marsh zones based on marsh structure -- creek zone and high marsh -- and eight plots were randomly located in each zone and marked with stakes. Oct 01, 2001: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. No significant disturbance was observed, and no plots were replaced. Oct 18, 2002: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack (some have no shoots): C4. The following plots were disturbed by wildlife (some have no shoots): M6, M8 (snails). No plots were disturbed by creekbank erosion or replaced. Oct 18, 2003: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following creekbank plots are on creekbank areas that are collapsing: C5, C8. No disturbance by wrack or wildlife activity were observed, and no plots were replaced. Oct 25, 2004: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack: C4. The following creekbank plots are on creekbank areas that are collapsing: C6. No plots were distrurbed by wildlife and no plots were lost or replaced. Oct 21, 2005: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots are on creekbank areas that are collapsing: C6. No disturbance by wrack or wildlife activity was observed, no plots were lost due to creekbank erosion, and no plots were replaced. Oct 16, 2006: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack: C2, C3, C16. No plots were lost or disturbed by wildlife, and none were replaced. Oct 22, 2007: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were lost due to creekbank erosion, catastrophic wrack disturbance, or catastrophic wildlife activity: C5, C7, C16. The following plots were disturbed by wrack or wildlife activity: C15, C26, M1, M3. No plots were replaced. Oct 27, 2008: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were lost due to creekbank erosion, catastrophic wrack disturbance, or catastrophic wildlife activity: C2. The following plots were disturbed by wrack: none. The following plots were distrurbed by wildlife (some may have no shoots): M3 (no shoots). The following plots are on creekbank areas that are collapsing: none. No plots were replaced. GCE5 -- Oct 01, 2000: Permanent plots were established in two nominal marsh zones based on marsh structure -- creek zone and high marsh -- and eight plots were randomly located in each zone and marked with stakes. Oct 01, 2001: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. No significant disturbance was observed, and no plots were replaced. Oct 15, 2002: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following creekbank plots are on creekbank areas that are collapsing: C6, C7. No disturbance by wrack inundation or animal activity was observed, and no plots were replaced. Oct 18, 2003: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following creekbank plots are on creekbank areas that are collapsing: C7. No disturbance by wrack or wildlife activity were observed, and no plots were replaced. Oct 23, 2004: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following creekbank plots are on creekbank areas that are collapsing: C7. No disturbance by wrack or wildlife activity were observed, and no plots were replaced. Oct 21, 2005: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack: C7, C8. No plots were distrurbed by wildlife, none were lost due to creekbank erosion, and none were replaced. Oct 17, 2006: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack: C1, C2. The following plots were lost due to creekbank erosion, catastrophic wrack disturbance, or catastrophic wildlife activity: C6. No plots were disturbed by wildlife and none were replaced. Oct 21, 2007: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack or wildlife activity: C2, C4, C5, M2. No plots were lost and none were replaced. Oct 28, 2008: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were lost due to creekbank erosion, catastrophic wrack disturbance, or catastrophic wildlife activity: none. The following plots were disturbed by wrack: C3, C5. The following plots were distrurbed by wildlife (some may have no shoots): none. The following plots are on creekbank areas that are collapsing: none. No plots were replaced. Oct 15, 2009: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots are on creekbank areas that are collapsing: C3. No plots were disturbed by wildlife and no plots were lost and replaced. GCE6 -- Oct 01, 2000: Permanent plots were established in two nominal marsh zones based on marsh structure -- creek zone and high marsh -- and eight plots were randomly located in each zone and marked with stakes Oct 01, 2001: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were lost due to catastrophic disturbance and replaced with new plots as indicated: zone 1, plot 3 (not replaced). Oct 19, 2002: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack (some have no shoots): C1. The following plots were disturbed by wildlife (some have no shoots): M6, M7, M8 (snails). The following creekbank plots are on creekbank areas that are collapsing: C4, C5. No plots were replaced. Oct 17, 2003: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wildlife (some have no shoots): M8. The following creekbank plots are on creekbank areas that are collapsing: C5. The following plots were lost due to creekbank erosion or catastrophic wrack inundation and were replaced: C2, C4 (replaced with C12, C14). Oct 22, 2004: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack: C1, C12, C23, C5, C6, C8. The following plots were disturbed by wildlife (some have no shoots): M8. No plots were lost due to creekbank erosion, and none were replaced. Oct 21, 2005: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack: C5, C12. The following plots were disturbed by wildlife: M8. No plots were lost due to creekbank erosion, and none were replaced. Oct 15, 2006: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack: C1, C23, C6, C7 (C1, C23 have no plants). The following plots were disturbed by wildlife (some have no shoots): M8. The following creekbank plots are on creekbank areas that are collapsing: C12, C14, C5. No plots were lost and none were replaced. Oct 23, 2007: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were lost due to creekbank erosion, catastrophic wrack disturbance, or catastrophic wildlife activity: C5, C14, C22. The following plots were disturbed by wrack or wildlife activity: C15, C16, C23, M8. No plots were replaced. Oct 26, 2008: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were lost due to creekbank erosion, catastrophic wrack disturbance, or catastrophic wildlife activity: C24. The following plots were disturbed by wrack: C22. The following plots were distrurbed by wildlife (some may have no shoots): M8 (no shoots). The following plots are on creekbank areas that are collapsing: C22, C23. No plots were replaced. GCE7 -- Oct 01, 2000: Permanent plots were established in two nominal marsh zones based on marsh structure -- creek zone and high marsh -- and eight plots were randomly located in each zone and marked with stakes Oct 01, 2001: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. No significant disturbance was observed, and no plots were replaced. Oct 17, 2002: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. No significant disturbance was observed, and no plots were replaced. Oct 17, 2003: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. No evidence of plot disturbance was observed, and no plots were replaced. Oct 23, 2004: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. No evidence of plot disturbance was observed, and no plots were replaced. Oct 21, 2005: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. No plots were distrurbed by wildlife, none were lost due to creekbank erosion, and none were replaced. Oct 14, 2006: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following creekbank plots are on creekbank areas that are collapsing: C7. No plots were disturbed by wrack or wildlife, and none were replaced. Oct 20, 2007: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. No plots were lost or disturbed by wrack or wildlife, and none were replaced. Oct 25, 2008: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were lost due to creekbank erosion, catastrophic wrack disturbance, or catastrophic wildlife activity: none. The following plots were disturbed by wrack: none. The following plots were distrurbed by wildlife (some may have no shoots): none. The following plots are on creekbank areas that are collapsing: none. No plots were replaced. Oct 14, 2009: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. No plots were disturbed or lost, and none were replaced. GCE9 -- Oct 01, 2000: Permanent plots were established in two nominal marsh zones based on marsh structure -- creek zone and high marsh -- and eight plots were randomly located in each zone and marked with stakes. Oct 01, 2001: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were lost due to catastrophic disturbance and replaced with new plots as indicated: zone 1, plot 4 (added new plot 14). New plots were not in exactly the same locations as lost plots, and so have new numbers. Oct 17, 2002: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack (some have no shoots): C5, C6, C8. The following creekbank plots are on creekbank areas that are collapsing: C1, C6. The following plots were lost due to creekbank erosion or catastrophic wrack disturbance: C3 (replaced with C13). No disturbance by wildlife activity was observed. Oct 18, 2003: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack (some have no shoots): C1, C2, C6, C13. The following creekbank plots are on creekbank areas that are collapsing: C1, C2, C6. The following plots were lost due to creekbank erosion or catastrophic wrack inundation and were replaced: C5, C7, C8 (replaced with C15, C17, C18). No disturbance by wildlife activity was observed. Oct 23, 2004: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack: C13, C14, C6. No disturbance by wildlife activity was observed, and no plots were lost or replaced. Oct 21, 2005: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack: C2, C18. No plots were distrurbed by wildlife, none were lost due to creekbank erosion, and none were replaced. Oct 14, 2006: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack: C14. No plots were disturbed by wildlife or lost, and none were replaced. Oct 21, 2007: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack or wildlife activity: C1, C2, C13. No plots were lost and none were replaced. Oct 25, 2008: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were lost due to creekbank erosion, catastrophic wrack disturbance, or catastrophic wildlife activity: none. The following plots were disturbed by wrack: C1, C2. The following plots were distrurbed by wildlife (some may have no shoots): none. The following plots are on creekbank areas that are collapsing: C1, C13, C16. No plots were replaced. Oct 15, 2009: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were lost due to creekbank erosion, catastrophic wrack disturbance, or catastrophic wildlife activity: C1, C13. The following plots were disturbed by wrack: C16. No plots were otherwise disturbed by wildlife or are on creekbank areas that are collapsing and none were replaced. GCE10 -- Oct 01, 2000: Permanent plots were established in two nominal marsh zones based on marsh structure -- creek zone and high marsh -- and eight plots were randomly located in each zone and marked with stakes Oct 01, 2001: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. No significant disturbance was observed, and no plots were replaced. Oct 20, 2002: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack (some have no shoots): C1, C2, C3, C4, C5, C6, C8. The following plots were disturbed by wildlife (some have no shoots): M5 (snails). No disturbance by creekbank erosion or collapse was observed, and no plots were replaced. Oct 19, 2003: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack (some have no shoots): C3, M1. The following plots were disturbed by wildlife (some have no shoots): M5. The following creekbank plots are on creekbank areas that are collapsing: C2. No plots were replaced. Oct 22, 2004: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack: C7. No disturbance by wildlife was observed, and no plots were lost or replaced. Oct 21, 2005: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. No plots were distrurbed by wildlife, none were lost due to creekbank erosion, and none were replaced. Oct 15, 2006: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. Note that a new zone (zone 3) was added at site GCE10 in 2005. This is a juncus zone in the high marsh. Oct 24, 2007: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack or wildlife activity: C1, C2, C3, C4, C8, M1, M2. The following plots are on creekbank areas that are collapsing: C13. No plots were lost and none were replaced. Oct 26, 2008: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were lost due to creekbank erosion, catastrophic wrack disturbance, or catastrophic wildlife activity: none. The following plots were disturbed by wrack: none. The following plots were distrurbed by wildlife (some may have no shoots): none. The following plots are on creekbank areas that are collapsing: none. No plots were replaced. i. Climate: Climate summary for Sapelo Island, Georgia, based on NWS data from 1980-2010: Daily-aggregated Values: Mean (sample standard deviation) mean air temperature: 20.09°C (7.28°C) minimum air temperature: 15.02°C (7.96°C) maximum air temperature: 24.82°C (6.98°C) total precipitation: 3.26mm (10.3mm) Yearly-aggregated Daily Values: Mean (sample standard deviation) total precipitation (1980-2010): 1124mm (266mm) 2. Experimental or Sampling Design a. Design Characteristics: In this study, we examined the mechanisms mediating the distribution of tidal marsh plants across estuarine landscapes in Georgia, USA, using a combination of field transplant experiments and monitoring to test the predictions of the competition-to-stress hypothesis that 1) the upstream limits of plant distribution are determined by competition, and 2) the downstream limits of plant distribution are set by abiotic stress. We located six pairs of sites along the salinity gradient of the estuary, and refer to the salinity zones represented by these pairs of sites as freshwater, brackish, salt-1, salt-2, salt-3 and salt-4. b. Permanent Plots: At each site, we established 4 removal plots (3×3 m) and 4 control plots. The plots were located on the marsh platform of each site, parallel to the riverbank, with treatments interspersed. The removal plots were created by applying a systemic herbicide in August 2006, seven months before the experiment started, and maintained by clipping any new shoots that grew into the plots every month during the course of the experiments. c. Data Collection Duration and Frequency: We collected soil cores to measure soil salinity from each plot monthly during the course of the experiment. In the end of growing season (October), we harvested all aboveground live plant material of the transplants. Beginning of Observations: Aug 01, 2006 End of Observations: Oct 15, 2009 3. Research Methods a. Field and Laboratory Methods: Method 1: Field Transplant Experiments -- We transplanted 8 plant species into these plots. We collected Zizaniopsis, Pontederia, and Cicuta from freshwater marshes; Juncus and Schoenoplectus from brackish marshes; and Spartina, Batis and Sarcocornia from salt marshes. For each species, healthy individuals within a narrow range of size were collected with associated soil blocks (10×10×10 cm for small species; up to 30 × 30 × 30 cm for the largest species) at the beginning of each growing season (March) from a single location with a salinity regime typical of the distribution of that species. Thus, all the Zizaniopsis plants were collected from a single freshwater site; all the Juncus plants from a single brackish site; all the Batis from a single salt marsh site, and so on. One individual plant of each species was randomly assigned into each plot at each site (total n=12 sites×2 treatments×4 replicates = 96 plants of each species). We transplanted Zizaniopsis, Juncus and Spartina in 2007; Pontederia, Schoenoplectus and Batis in 2008; and Cicuta and Sarcocornia in 2009, dividing the work over 3 years to make the experiments logistically tractable. The individuals of the 2-3 different species in each plot were placed 1-2 m apart from each other within the plot to minimize any interactions between them. We monitored the performance of the transplants and maintained the plots monthly during the course of the experiment. At the end of the growing season (October), all aboveground live plant material was harvested, dried for 3 days at 60 degrees C and weighed. Method 2: Soil Porewater Salinity -- We collected soil cores from each plot monthly during the course of the experiment. A metal trowel was used to remove soil at least 10cm deep. Soil porewater salinity was measured by determining water content gravimetrically, rehydrating dried soils in a known volume of distilled water, measuring the salinity of the supernatant, and back-calculating to the original pore-water volume. Method 3: Flooding Intensity -- To quantify flooding, the proportion of time that study plots were flooded was determined by comparing the elevations of study plots (determined for each replicate plot at each site with a Real-Time Kinematic GPS with a vertical error of ~2 cm) with water-level recorded by Seabird MicroCAT sondes (Sea-Bird Electronics, Bellevue, Washington, USA; recording at 30-min intervals) deployed near the study sites during the growing season of 2009. Plots were scored as ‘‘flooded’’ any time that the sea level measured at the sonde was greater than the measured elevation of the plot. Method 4: Marsh Productivity -- We also estimated marsh productivity along the estuary by measuring aboveground biomass of the ambient marsh vegetation. In August 2009, we harvested aboveground biomass from six 131 m quadrats near the experimental plots at each site. Biomass was dried for 3 d at 60 degrees C and weighed. b. Instrumentation: Method 1: none Method 2: Refractometer Manufacturer: Vista (Model: A355ATC) Parameter: Salinity (Accuracy: 1 PSU, Readability: 1 PSU, Range: 0-100 PSU) Method 3: Onset Temperature Logger Manufacturer: Onset Computer Corp. (Model: TBI32-20 +50) Parameter: Temperature (Accuracy: +- 0.4 degrees C at 20 degrees C, Range: -20 to 70 degrees C) SBE MicroCAT 37-SM (S/N 2539, with pump) Manufacturer: Sea-Bird Electronics (Model: 37-SM MicroCAT) Last Calibration: Aug 19, 2002 Parameter: Conductivity (Accuracy: 0.0003 S/m, Readability: 0.00001 S/m, Range: 0 to 7 S/m) Protocol: Prior to each timed measurement the conductivity cell is opened and water is pumped for 0.5 sec, then conductivity is measured using an ultra-precision Wien-Bridge oscillator with frequency counted by a high-stability reference crystal (<2 ppm/year drift rate). The cell is closed between measurements and tributyl tin antifoulant is released into the tubing. Parameter: Pressure (water) (Accuracy: 0.2m, Readability: 0.0004m, Range: 0 to 20m) Protocol: Pressure is measured using a micro-machined silicon diaphragm with embedded strain elements, and temperature compensation is performed by the SBE MicroCAT onboard cpu. Parameter: Temperature (water) (Accuracy: 0.002°C, Readability: 0.0001°C, Range: -5 to 35°C) Protocol: Temperature is measured by applying an AC excitation to a hermetically-sealed VISHAY reference resistor and an ultra-stable aged thermistor (drift rate typically less than 0.002°C/year). SBE MicroCAT 37-SM (S/N 3342) Manufacturer: Sea-Bird Electronics (Model: 37-SM MicroCAT) Last Calibration: Mar 05, 2004 Parameter: Conductivity (Accuracy: 0.0003 S/m, Readability: 0.00001 S/m, Range: 0 to 7 S/m) Protocol: Prior to each timed measurement the conductivity cell is opened and water is pumped for 0.5 sec, then conductivity is measured using an ultra-precision Wien-Bridge oscillator with frequency counted by a high-stability reference crystal (<2 ppm/year drift rate). The cell is closed between measurements and tributyl tin antifoulant is released into the tubing. Parameter: Pressure (water) (Accuracy: 0.2m, Readability: 0.0004m, Range: 0 to 20m) Protocol: Pressure is measured using a micro-machined silicon diaphragm with embedded strain elements, and temperature compensation is performed by the SBE MicroCAT onboard cpu. Parameter: Temperature (water) (Accuracy: 0.002°C, Readability: 0.0001°C, Range: -5 to 35°C) Protocol: Temperature is measured by applying an AC excitation to a hermetically-sealed VISHAY reference resistor and an ultra-stable aged thermistor (drift rate typically less than 0.002°C/year). SBE MicroCAT 37-SM (S/N 1667) Manufacturer: Sea-Bird Electronics (Model: 37-SM MicroCAT) Last Calibration: Apr 08, 2005 Parameter: Conductivity (Accuracy: 0.0003 S/m, Readability: 0.00001 S/m, Range: 0 to 7 S/m) Protocol: Water passively circulates through an open internal-field conductivity cell equipped with an external tributyl tin antifoulant dispenser, and conductivity is measured using an ultra-precision Wien-Bridge oscillator with frequency counted by a high-stability reference crystal (<2 ppm/year drift rate). Parameter: Pressure (water) (Accuracy: 0.2m, Readability: 0.0004m, Range: 0 to 20m) Protocol: Pressure is measured using a micro-machined silicon diaphragm with embedded strain elements, and temperature compensation is performed by the SBE MicroCAT onboard cpu. Parameter: Temperature (water) (Accuracy: 0.002°C, Readability: 0.0001°C, Range: -5 to 35°C) Protocol: Temperature is measured by applying an AC excitation to a hermetically-sealed VISHAY reference resistor and an ultra-stable aged thermistor (drift rate typically less than 0.002°C/year). SBE MicroCAT 37-SM (S/N 1790) Manufacturer: Sea-Bird Electronics (Model: 37-SM MicroCAT) Last Calibration: Mar 31, 2006 Parameter: Conductivity (Accuracy: 0.0003 S/m, Readability: 0.00001 S/m, Range: 0 to 7 S/m) Protocol: Water passively circulates through an open internal-field conductivity cell equipped with an external tributyl tin antifoulant dispenser, and conductivity is measured using an ultra-precision Wien-Bridge oscillator with frequency counted by a high-stability reference crystal (<2 ppm/year drift rate). Parameter: Pressure (water) (Accuracy: 0.2m, Readability: 0.0004m, Range: 0 to 20m) Protocol: Pressure is measured using a micro-machined silicon diaphragm with embedded strain elements, and temperature compensation is performed by the SBE MicroCAT onboard cpu. Parameter: Temperature (water) (Accuracy: 0.002°C, Readability: 0.0001°C, Range: -5 to 35°C) Protocol: Temperature is measured by applying an AC excitation to a hermetically-sealed VISHAY reference resistor and an ultra-stable aged thermistor (drift rate typically less than 0.002°C/year). SBE MicroCAT 37-SM (S/N 1791) Manufacturer: Sea-Bird Electronics (Model: 37-SM MicroCAT) Last Calibration: Aug 17, 2005 Parameter: Conductivity (Accuracy: 0.0003 S/m, Readability: 0.00001 S/m, Range: 0 to 7 S/m) Protocol: Water passively circulates through an open internal-field conductivity cell equipped with an external tributyl tin antifoulant dispenser, and conductivity is measured using an ultra-precision Wien-Bridge oscillator with frequency counted by a high-stability reference crystal (<2 ppm/year drift rate). Parameter: Pressure (water) (Accuracy: 0.2m, Readability: 0.0004m, Range: 0 to 20m) Protocol: Pressure is measured using a micro-machined silicon diaphragm with embedded strain elements, and temperature compensation is performed by the SBE MicroCAT onboard cpu. Parameter: Temperature (water) (Accuracy: 0.002°C, Readability: 0.0001°C, Range: -5 to 35°C) Protocol: Temperature is measured by applying an AC excitation to a hermetically-sealed VISHAY reference resistor and an ultra-stable aged thermistor (drift rate typically less than 0.002°C/year). SBE MicroCAT 37-SM (S/N 1793) Manufacturer: Sea-Bird Electronics (Model: 37-SM MicroCAT) Last Calibration: Feb 24, 2001 Parameter: Conductivity (Accuracy: 0.0003 S/m, Readability: 0.00001 S/m, Range: 0 to 7 S/m) Protocol: Water passively circulates through an open internal-field conductivity cell equipped with an external tributyl tin antifoulant dispenser, and conductivity is measured using an ultra-precision Wien-Bridge oscillator with frequency counted by a high-stability reference crystal (<2 ppm/year drift rate). Parameter: Pressure (water) (Accuracy: 0.2m, Readability: 0.0004m, Range: 0 to 20m) Protocol: Pressure is measured using a micro-machined silicon diaphragm with embedded strain elements, and temperature compensation is performed by the SBE MicroCAT onboard cpu. Parameter: Temperature (water) (Accuracy: 0.002°C, Readability: 0.0001°C, Range: -5 to 35°C) Protocol: Temperature is measured by applying an AC excitation to a hermetically-sealed VISHAY reference resistor and an ultra-stable aged thermistor (drift rate typically less than 0.002°C/year). SBE MicroCAT 37-SM (S/N 1794) Manufacturer: Sea-Bird Electronics (Model: 37-SM MicroCAT) Last Calibration: Apr 19, 2006 Parameter: Conductivity (Accuracy: 0.0003 S/m, Readability: 0.00001 S/m, Range: 0 to 7 S/m) Protocol: Water passively circulates through an open internal-field conductivity cell equipped with an external tributyl tin antifoulant dispenser, and conductivity is measured using an ultra-precision Wien-Bridge oscillator with frequency counted by a high-stability reference crystal (<2 ppm/year drift rate). Parameter: Pressure (water) (Accuracy: 0.2m, Readability: 0.0004m, Range: 0 to 20m) Protocol: Pressure is measured using a micro-machined silicon diaphragm with embedded strain elements, and temperature compensation is performed by the SBE MicroCAT onboard cpu. Parameter: Temperature (water) (Accuracy: 0.002°C, Readability: 0.0001°C, Range: -5 to 35°C) Protocol: Temperature is measured by applying an AC excitation to a hermetically-sealed VISHAY reference resistor and an ultra-stable aged thermistor (drift rate typically less than 0.002°C/year). SBE MicroCAT 37-SM (S/N 1795) Manufacturer: Sea-Bird Electronics (Model: 37-SM MicroCAT) Last Calibration: Oct 08, 2004 Parameter: Conductivity (Accuracy: 0.0003 S/m, Readability: 0.00001 S/m, Range: 0 to 7 S/m) Protocol: Water passively circulates through an open internal-field conductivity cell equipped with an external tributyl tin antifoulant dispenser, and conductivity is measured using an ultra-precision Wien-Bridge oscillator with frequency counted by a high-stability reference crystal (<2 ppm/year drift rate). Parameter: Pressure (water) (Accuracy: 0.2m, Readability: 0.0004m, Range: 0 to 20m) Protocol: Pressure is measured using a micro-machined silicon diaphragm with embedded strain elements, and temperature compensation is performed by the SBE MicroCAT onboard cpu. Parameter: Temperature (water) (Accuracy: 0.002°C, Readability: 0.0001°C, Range: -5 to 35°C) Protocol: Temperature is measured by applying an AC excitation to a hermetically-sealed VISHAY reference resistor and an ultra-stable aged thermistor (drift rate typically less than 0.002°C/year). SBE MicroCAT 37-SM (S/N 1796) Manufacturer: Sea-Bird Electronics (Model: 37-SM MicroCAT) Last Calibration: Apr 08, 2005 Parameter: Conductivity (Accuracy: 0.0003 S/m, Readability: 0.00001 S/m, Range: 0 to 7 S/m) Protocol: Water passively circulates through an open internal-field conductivity cell equipped with an external tributyl tin antifoulant dispenser, and conductivity is measured using an ultra-precision Wien-Bridge oscillator with frequency counted by a high-stability reference crystal (<2 ppm/year drift rate). Parameter: Pressure (water) (Accuracy: 0.2m, Readability: 0.0004m, Range: 0 to 20m) Protocol: Pressure is measured using a micro-machined silicon diaphragm with embedded strain elements, and temperature compensation is performed by the SBE MicroCAT onboard cpu. Parameter: Temperature (water) (Accuracy: 0.002°C, Readability: 0.0001°C, Range: -5 to 35°C) Protocol: Temperature is measured by applying an AC excitation to a hermetically-sealed VISHAY reference resistor and an ultra-stable aged thermistor (drift rate typically less than 0.002°C/year). SBE MicroCAT 37-SM (S/N 1996) Manufacturer: Sea-Bird Electronics (Model: 37-SM MicroCAT) Last Calibration: Oct 08, 2004 Parameter: Conductivity (Accuracy: 0.0003 S/m, Readability: 0.00001 S/m, Range: 0 to 7 S/m) Protocol: Water passively circulates through an open internal-field conductivity cell equipped with an external tributyl tin antifoulant dispenser, and conductivity is measured using an ultra-precision Wien-Bridge oscillator with frequency counted by a high-stability reference crystal (<2 ppm/year drift rate). Parameter: Pressure (water) (Accuracy: 0.2m, Readability: 0.0004m, Range: 0 to 20m) Protocol: Pressure is measured using a micro-machined silicon diaphragm with embedded strain elements, and temperature compensation is performed by the SBE MicroCAT onboard cpu. Parameter: Temperature (water) (Accuracy: 0.002°C, Readability: 0.0001°C, Range: -5 to 35°C) Protocol: Temperature is measured by applying an AC excitation to a hermetically-sealed VISHAY reference resistor and an ultra-stable aged thermistor (drift rate typically less than 0.002°C/year). SBE MicroCAT 37-SM (S/N 1997) Manufacturer: Sea-Bird Electronics (Model: 37-SM MicroCAT) Last Calibration: Dec 06, 2001 Parameter: Conductivity (Accuracy: 0.0003 S/m, Readability: 0.00001 S/m, Range: 0 to 7 S/m) Protocol: Water passively circulates through an open internal-field conductivity cell equipped with an external tributyl tin antifoulant dispenser, and conductivity is measured using an ultra-precision Wien-Bridge oscillator with frequency counted by a high-stability reference crystal (<2 ppm/year drift rate). Parameter: Pressure (water) (Accuracy: 0.2m, Readability: 0.0004m, Range: 0 to 20m) Protocol: Pressure is measured using a micro-machined silicon diaphragm with embedded strain elements, and temperature compensation is performed by the SBE MicroCAT onboard cpu. Parameter: Temperature (water) (Accuracy: 0.002°C, Readability: 0.0001°C, Range: -5 to 35°C) Protocol: Temperature is measured by applying an AC excitation to a hermetically-sealed VISHAY reference resistor and an ultra-stable aged thermistor (drift rate typically less than 0.002°C/year). SBE MicroCAT 37-SM (S/N 2398, with pump) Manufacturer: Sea-Bird Electronics (Model: 37-SM MicroCAT) Last Calibration: Apr 16, 2002 Parameter: Conductivity (Accuracy: 0.0003 S/m, Readability: 0.00001 S/m, Range: 0 to 7 S/m) Protocol: Prior to each timed measurement the conductivity cell is opened and water is pumped for 0.5 sec, then conductivity is measured using an ultra-precision Wien-Bridge oscillator with frequency counted by a high-stability reference crystal (<2 ppm/year drift rate). The cell is closed between measurements and tributyl tin antifoulant is released into the tubing. Parameter: Pressure (water) (Accuracy: 0.2m, Readability: 0.0004m, Range: 0 to 20m) Protocol: Pressure is measured using a micro-machined silicon diaphragm with embedded strain elements, and temperature compensation is performed by the SBE MicroCAT onboard cpu. Parameter: Temperature (water) (Accuracy: 0.002°C, Readability: 0.0001°C, Range: -5 to 35°C) Protocol: Temperature is measured by applying an AC excitation to a hermetically-sealed VISHAY reference resistor and an ultra-stable aged thermistor (drift rate typically less than 0.002°C/year). SBE MicroCAT 37-SM (S/N 2413, with pump) Manufacturer: Sea-Bird Electronics (Model: 37-SM MicroCAT) Last Calibration: May 02, 2002 Parameter: Conductivity (Accuracy: 0.0003 S/m, Readability: 0.00001 S/m, Range: 0 to 7 S/m) Protocol: Prior to each timed measurement the conductivity cell is opened and water is pumped for 0.5 sec, then conductivity is measured using an ultra-precision Wien-Bridge oscillator with frequency counted by a high-stability reference crystal (<2 ppm/year drift rate). The cell is closed between measurements and tributyl tin antifoulant is released into the tubing. Parameter: Pressure (water) (Accuracy: 0.2m, Readability: 0.0004m, Range: 0 to 20m) Protocol: Pressure is measured using a micro-machined silicon diaphragm with embedded strain elements, and temperature compensation is performed by the SBE MicroCAT onboard cpu. Parameter: Temperature (water) (Accuracy: 0.002°C, Readability: 0.0001°C, Range: -5 to 35°C) Protocol: Temperature is measured by applying an AC excitation to a hermetically-sealed VISHAY reference resistor and an ultra-stable aged thermistor (drift rate typically less than 0.002°C/year). Method 4: none c. Taxonomy and Systematics: Method 1: not applicable Method 2: not applicable Method 3: not applicable Method 4: not applicable d. Permit History: Method 1: not applicable Method 2: not applicable Method 3: not applicable Method 4: not applicable 4. Project Personnel a. Personnel: 1: Hongyu Guo 2: Steven C. Pennings 3: Jane Buck 4: Christine Ewers 5: Alana R. Lynes 6: Brittany DeLoach McCall 7: Daniel F. Saucedo 8: Jacob Shalack 9: Huy Vu 10: Kazimierz Wieski 11: Yihui Zhang 12: Christine M. Hladik 13: Lan Zhenjiang 14: Wade M. Sheldon, Jr. b. Affiliations: 1: University of Houston, Houston, Texas 2: University of Houston, Houston, Texas 3: University of Houston 4: Christian-Albrechts University 5: University of Houston, Houston, Texas 6: University of Houston, Houston, Texas 7: University of Georgia Marine Institute, Sapelo Island, Georgia 8: University of Georgia Marine Institute, Sapelo Island, Georgia 9: University of Houston, Houston, Texas 10: University of Houston, Houston, Texas 11: Xiamen University 12: Georgia Southern University, Statesboro, Georgia 13: University of Houston 14: University of Georgia, Athens, Georgia III. Data Set Status and Accessibility A. Status 1. Latest Update: 24-Sep-2013 2. Latest Archive Date: 24-Sep-2013 3. Latest Metadata Update: 24-Sep-2013 4. Data Verification Status: New Submission B. Accessibility 1. Storage Location and Medium: Stored at GCE-LTER Data Management Office Dept. of Marine Sciences Univ. of Georgia Athens, GA 30602-3636 USA on media: electronic data download (WWW) or compact disk 2. Contact Person: Name: Wade M. Sheldon, Jr. Address: Dept. of Marine Sciences University of Georgia Athens, Georgia 30602-3636 Country: USA Email: sheldon@uga.edu 3. Copyright Restrictions: not copyrighted 4. Restrictions: All publications based on this data set must cite the contributor and Georgia Coastal Ecosystems LTER project, and two copies of the manuscript must be submitted to the GCE-LTER Information Management Office. a. Release Date: Affiliates: Sep 01, 2013, Public: Sep 01, 2015 b. Citation: Data provided by the Georgia Coastal Ecosystems Long Term Ecological Research Project, supported by funds from NSF OCE 0620959 (data set PLT-GCET-1309) c. Disclaimer: The user assumes all responsibility for errors in judgement based on interpretation of data and analyses presented in this data set. 5. Costs: free electronic data download via WWW, distribution on CD may be subject to nominal processing and handling fee IV. Data Structural Descriptors A. Data Set File 1. File Name: PLT-GCET-1309_Biomass_1_0.CSV 2. Size: 768 records 3. File Format: ASCII text (comma-separated value format) 3a. Delimiters: single comma 4. Header Information: 5 lines of ASCII text 5. Alphanumeric Attributes: 6. Quality Control Flag Codes: 7. Authentication Procedures: 8. Calculations: 9. Processing History: Software version: GCE Data Toolbox Version 3.7.0 (22-Jul-2013) Data structure version: GCE Data Structure 1.1 (29-Mar-2001) Original data file processed: PLT-GCET-1309_biomass.txt (768 records) Data processing history: 24-Sep-2013: new GCE Data Structure 1.1 created ('newstruct') 24-Sep-2013: 768 rows imported from ASCII data file 'PLT-GCET-1309_biomass.txt' ('imp_ascii') 24-Sep-2013: 81 metadata fields in file header parsed ('parse_header') 24-Sep-2013: data structure validated ('gce_valid') 24-Sep-2013: Q/C flagging criteria applied, 'flags' field updated ('dataflag') 24-Sep-2013: automatically assigned study date metadata descriptors based on the range of date values in date/time columns (add_studydates) 24-Sep-2013: Description of column Plot_number edited ('ui_editor') 24-Sep-2013: imported Dataset, Project, Site, Study, Status, Supplement metadata descriptors from the GCE Metabase ('imp_gcemetadata') 24-Sep-2013: updated 56 metadata fields in the Dataset, Project, Site, Status, Study, Supplement sections ('addmeta') 24-Sep-2013: flags for columns Survival_time and Biomass converted to data columns, flag codes updated in metadata ('flags2cols') 24-Sep-2013: updated 6 metadata fields in the Data sections ('addmeta') 24-Sep-2013: updated 15 metadata fields in the Status, Data sections to reflect attribute metadata ('updatecols') 24-Sep-2013: parsed and formatted metadata ('listmeta') B. Variable Information 1. Variable Name: column 1. Species column 2. Site_name column 3. Treatment column 4. Plot_number column 5. Survival_time column 6. Flag_Survival_time column 7. Biomass column 8. Flag_Biomass column 9. Transplant_date column 10. Harvest_date 2. Variable Definition: column 1. plant species column 2. name of site column 3. neighbor treatments (with neighbors or without neighbors) column 4. number of plot at each site column 5. survival time of the transplants in the experiment column 6. QA/QC flags for survival time of the transplants in the experiment (flagging criteria, where "x" is Survival_time: x<1="I", x>7="I", x<1="Q", x>7="Q") column 7. final aboveground biomass (dry mass) of the transplans in the experiment column 8. QA/QC flags for final aboveground biomass (dry mass) of the transplans in the experiment (flagging criteria, where "x" is Biomass: x<0="I", x>632.71="I", x<0="Q", x>632.71="Q") column 9. date when the plants were transplanted column 10. date when the transplants were harvested 3. Units of Measurement: column 1. none column 2. none column 3. none column 4. none column 5. month column 6. none column 7. g column 8. none column 9. MM/DD/YYYY column 10. MM/DD/YYYY 4. Data Type a. Storage Type: column 1. alphanumeric column 2. alphanumeric column 3. alphanumeric column 4. integer column 5. floating-point column 6. alphanumeric column 7. floating-point column 8. alphanumeric column 9. alphanumeric column 10. alphanumeric b. Variable Codes: c. Numeric Range: column 1. (none) column 2. (none) column 3. (none) column 4. 1 to 4 column 5. 1 to 7 column 6. (none) column 7. 0 to 632.71 column 8. (none) column 9. (none) column 10. (none) d. Missing Value Code: 5. Data Format a. Column Type: column 1. text column 2. text column 3. text column 4. numerical column 5. numerical column 6. text column 7. numerical column 8. text column 9. text column 10. text b. Number of Columns: 10 c. Decimal Places: column 1. 0 column 2. 0 column 3. 0 column 4. 0 column 5. 0 column 6. 0 column 7. 2 column 8. 0 column 9. 0 column 10. 0 6. Logical Variable Type: column 1. free text (none) column 2. free text (none) column 3. free text (none) column 4. nominal (discrete) column 5. data (continuous) column 6. coded value (none) column 7. data (continuous) column 8. coded value (none) column 9. datetime (none) column 10. datetime (none) 7. Flagging Criteria: column 1. none column 2. none column 3. none column 4. x<1="Q", x>4="Q" column 5. x<1="I", x>7="I", x<1="Q", x>7="Q" column 6. none column 7. x<0="I", x>632.71="I", x<0="Q", x>632.71="Q" column 8. none column 9. none column 10. none C. Data Anomalies: We recorded the aboveground biomass of the dead plants as zero, and harvest date as "NaN". V. Supplemental Descriptors A. Data Acquisition 1. Data Forms: Paper log sheets, Excel spreadsheets 2. Form Location: Lab of Steven Pennings, Dept. of Biology and Biochemistry, University of Houston, Houston TX 3. Data Entry Validation: B. Quality Assurance/Quality Control Procedures: C. Supplemental Materials: D. Computer Programs: JMP8 E. Archival Practices: F. Publications: not specified G. History of Data Set Usage 1. Data Request History: not specified 2. Data Set Update History: none 3. Review History: none 4. Questions and Comments from Users: none