Biogeochemistry of Wetlands

Transcription

1 Institute of Food and Agricultural Sciences (IFAS) Biogeochemistry of Wetlands Si Science and da Applications ADVANCES IN BIOGEOCHEMISTRY Wetland Biogeochemistry Laboratory Soil and Water Science Department t University of Florida Instructor : Patrick Inglett pinglett@ufl.edu 6/22/2008 P.W. WBL Inglett 1 1 S. Harris: 6/22/2008 P.W. Inglett 2 1

2 6/22/2008 P.W. Inglett 3 Molecular Approaches: Environmental sample NA extraction Cloning Sequencing Characterization of specific organisms having the gene probes PCR q-pcr DGGE t-rflp Abundance/ expression of specific gene Relative abundances of 6/22/2008 P.W. Inglett groups expressing gene 4 2

3 Molecular Approaches: Consortia c, Epifluorescence micrograph after hybridization with the general bacterial probe EUBmix (blue), the specific bacterial probe DBACT-193 (red) and the specific archaeal probe DARCH-872 (green). The bacterial partner is pink, as it hybridizes with both the general and specific bacterial probes. d, Epifluorescence micrograph after hybridization with the general archaeal probe ARCH915 (blue), the specific archaeal probe DARCH-872 (red) and the general bacterial probe EUBmix (green). The archaeal partner is pink because it hybridizes with both the general and specific archaeal probes. Scale bars, 5 m. See Methods for specification of probes. Raghoebarsing et al Nature 440, /22/2008 P.W. Inglett 5 Isotopic Approaches: Natural Abundance Levels Monitored groundwater Nitrate in wells near drainage ditches 6/22/2008 P.W. Inglett 6 Sidle et al Wetlands 20:

4 Isotopic Approaches: Enriched Levels C Time C Time C 6/22/2008 Time P.W. Inglett 7 Isotopic Approaches: Enriched Levels Buckley, et al Appl. Env. Microbiol. 73: /22/2008 P.W. Inglett 8 4

5 Cooperative relationship? RC O O - P O - O - EPS ALGAE Glycolate O O - P O - O - BACTERIA 6/22/2008 P.W. Inglett 9 Group-Specific C Tracing (using Phospholipid Fatty Acids, PLFA) 1500 Cyanophytes 18:2w 6 Green 18:1w Algae 1 9c Green 18:3w Algae δc time (h) δc time (h) δc time (h) δc Gram(+) i15:0bacteria δc time (h) -100 Gram(-) Bacteria 16:1w 7c time (h) Gram(-) 18:1w Bacteria 5c time (h) 6/22/2008 P.W. Inglett 10 δc 5

6 Coupled Biogeochemical Cycles Mutual dependency of one cycle on another (feedbacks and controls) or one organism on another (microbes, algae, and vegetation) Linkages between biogeochemical processes and biotic communities (vegetation, algae, and microbes) Cycles at different scales (molecular to landscape) 6/22/2008 P.W. Inglett 11 Biogeochemical Gradients Hydrologic gradients Climate gradients Nutrient gradients Biotic community gradients Spatial gradients Temporal gradients Scales 6/22/2008 P.W. Inglett 12 6

7 Coupled Cycles Ecosystem Processes: Nutrient Competition Plant Org-N NH 4 + NO 3 - Microbial Biomass Nitrifiers Denitrifiers N 2 /N 2 O 6/22/2008 P.W. Inglett Ecosystem Coupling: Salt Marsh Nutrient Limitation? Plant Cont Cont Sundareshwar, et al Science 299: /22/2008 P.W. Inglett 14 7

8 Coupled Cycles: Salt Marsh Nutrient Limitation? Control w/ P Control Sundareshwar, et al Science 299: w/ Glucose 6/22/2008 P.W. Inglett 15 Coupled Cycles: Salt Marsh Nutrient Limitation? P Plant C NH 4 + NO 3 - N-fixers Nitrifiers Denitrifiers N 2 /N 2 O Sundareshwar, et al Science 299: /22/2008 P.W. Inglett 16 8

9 Improving Models Lithology Hydrology Land Use 6/22/2008 P.W. Inglett 17 Improving Models Vegetation Organic matter Rhizosphere interactions 6/22/2008 P.W. Inglett 18 9

10 Improving Models Photos courtesy of G. W. Hurt 6/22/2008 P.W. Inglett 19 Improving Models WELL-DRAINED SOIL Fe 3+ Mn 4+ RECENTLY DRAINED Mn 4+ Fe 3+ Fe 2+ Mn 2+ Mn 2+ Fe 2+ Aerobic RECENTLY FLOODED Fe 3+ Mn 4+ Fe 2+ Fe3+ Mn 4+ Mn 2+ Anaerobic Aerobic Anaerobic Aerobic FLOODED FOR LONG PERIOD Fe 2+ Mn 2+ 6/22/2008 P.W. Inglett 20 Anaerobic 10

11 Improving Models 6/22/2008 P.W. Inglett /22/2008 P.W. Inglett 22 11

12 Real-Time Data 05:00 08:00 6/22/2008 P.W. Inglett 23 11:00 6/22/2008 P.W. Inglett 24 12

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15 6/22/2008 P.W. Inglett 29 The Future Identification of organism and pathway diversityit Refine methods to partition and trace element flows Integrate the concepts of coupled cycles into our temporal and landscape models Real time simulations/predictions 6/22/2008 P.W. Inglett 30 15