SLIDE 1
Introduction: the unseen diversity!
!Woese&1987& !Woese&1987&
Responses of Microbial Communities to Increases in Nitrogen Loads in - - PDF document
Responses of Microbial Communities to Increases in Nitrogen Loads in - - PDF document
Responses of Microbial Communities to Increases in Nitrogen Loads in Salt Marshes Jennifer L. Bowen University of Massachusetts Boston ! Symposium on C/N Cycling and Ecosystem Valuation of Tidal Wetlands in the Northeast Waquoit Bay National
SLIDE 2
SLIDE 3
Resistance!
no!change!in! composi+on!
- r!func+on!
temporarily!altered! composi+on!
Resilience!
return!to!ini+al!!state! permanently!altered! composi+on!
Redundancy!
no!change!in!func+on!
change!in!form! and!func+on! Microbial! composi+on!
Microbial! composi+on! !modified&from&Allison&and&Mar6ny&2008&
Introduction: The 3Rs — essential information or unnecessary detail?! Methods: We can assess the 3 Rs, and whether they matter to ecosystem services, by looking at microbial genetics!
NH4
+!
NH2OH! NO2
- !
NO3
- !
NO! N44
+!
NO2
- !
N2H2! N2O! N2!
nirS& nirK& norB& nosZ& amoA&
N2! NH2OH! N2!
N fixation! Denitrification! Anammox!
NH3
!
Nitrification! DNRA!
Modified&from&Philippot&et&al.&2007&
SLIDE 4
Methods: Sippewissett Salt Marsh plots!
4 treatments!
Fertilization began in 1971!
- 1. CONTROL
!!
~ 0.86 g N/m2/wk!
- 2. LOW (LF)!
- 3. HIGH (HF)!
!~2.52 g N/m2/wk!
- 4. XHIGH (FX)!
~7.56 g N/m2/wk!
SLIDE 5
Methods: deep sequencing of functional gene diversity! Sequences O TUs
200 400 600 800 4000 8000 12000 marsh plot nirS
mp5 mp6 mp7 mp8 mp9 PA clone SHC2 clone SHCS clone SK clone
individual clone nirS
mp3 mp2 mp1
- -Weisman et al. (In press)!
No matches within 80% similarity
0.1Marinobacter (>90%) S c a l i n d u a ( > 9 % ) D e c h l
- r
- m
- n
a s ( > 8 5 % ) No matches within 80% similarity No matches within 80% similarity
Marsh sediments Estuarine sediments Eastern Tropical S. Pacific OMZ Arabian Sea OMZ
Results: There is a LOT of unseen diversity, especially in marshes!
SLIDE 6
Results: diversity and richness of nirS genes vary tremendously!
20000 40000 60000 500 1000 1500 Arabian Sea Chesapeake Bay ETSP
- Sipp. salt marsh
Number of OTUs Number of sequences
Shannon Chao
Aggregate score
1.89 1.40 4.07 4.94 20 18 238 862
mp2_high mp6_xhigh mp8_xhigh mp3_cont mp1_low mp7_cont mp5_low mp9_high mp9_high mp5_low mp7_cont mp1_low mp3_cont mp8_xhigh mp6_xhigh mp2_high
0.85 0.93 0.9 0.84 0.82 0.72 0.59 0.84 0.94 0.95 0.8 0.81 0.63 0.59 0.85 0.96 0.97 0.8 0.8 0.63 0.72 0.89 0.96 0.96 0.69 0.8 0.81 0.82 0.88 0.9 0.94 0.69 0.8 0.8 0.84 0.87 0.77 0.94 0.96 0.97 0.95 0.9 0.88 0.77 0.9 0.96 0.96 0.94 0.93 0.88 0.87 0.88 0.89 0.85 0.84 0.85
4 8 12
Count More similar
Results: Some effect of fertilization on denitrifiers!
SLIDE 7
Results: But also a strong elevation effect!
PC1 (33%) PC2 (19%)
- low
high control low xhigh control xhigh high
- (cm above MSL)
55
- 75
elevation
- Introduction: DNF in marine systems accounts for 60% of fixed N loss!
- 1_low
- 3_control
5_low
- 7_control
- 8
9
- 31
33
- 37
38
- 51
53
- 57
58 59
- NorB
- 1(LF)
- 7
- 19
- 57
59
- 97
- 115
- 151
SLIDE 8
Acknowledgements!
- 1. Funding for this research came from:
- 1. National Science Foundation
- 1. DEB-0717155 to (JLB, JEH, and HGM)
- 2. DBI-0400819 (to JLB)
- 3. DEB-1019624 (to JLB, BBW)
- 4. Multiple NSF grants to BBW
- 2. Princeton University Council on Science and Technology (to JLB)
- 3. UMass Boston Startup Fund (to JLB)
Additional thanks: Ivan Valiela, John Teal, Brian Howes, Dale Goehringer and many others at WHOI, MBL and SMAST for initiating and maintaining the Sippewisset. Additional assistance from D. Weisman, and M. Yasuda (UMB), S. Huse, L. Murphy, P. Neal, and C. Holmes (MBL), the lab groups of B. Ward and F. M.M. Morel (Princeton Universityt Fertilization plots as well as the Gifford and Hughes families for access to the plots.