Post on 01-Jul-2020
Leonard J. Scinto Jennifer Richards, Evelyn Gaiser, Yong Cai,
Tom Philippi, Joel TrexlerFlorida International University
scintol@fiu.edu
Peter I. Kalla and Daniel J. ScheidtUSEPA Region 4
Trends in Biogeochemical Processes Across the Greater Everglades Landscape:
Results of R-EMAP III
Everglades Protection Area
R-EMAP III •Dry (109 sites) and Wet (119 sites) seasons 2005.
•228 stations total sampling.
•Soil, porewater, Floc, surface water, periphyton, and mosquitofishsampled, vegetation studied.
R-EMAP III• Generalized Random Tesselation Stratified (GRTS) sampling to
provide a spatially balanced sample coverage and thus is efficient for contouring or determining broad spatial trends.
• Equal inclusion probabilities within subregions.
• A primary focus is on P and Hg.
• Contributes to CERP
• Identifies relationships between environmental stressors and parameters.
• Enzyme activities (MUFP and MUFC) and C-dynamics. (Sinsabaugh and Findlay 1995; Penton and Newman 2007; Amador and Jones 1993).
nMean ± SDArea
7623.3 ± 10.6 cENP
10042.1 ± 8.5 bWCA3
2541.6 ± 9.7 abWCA2
2547.3 ± 4.0 aLNWR
%
Soil TC•No seasonally significant difference overall or by area, n = 226.
•Soil TP was strongly inversely correlated with TC in LNWR (r = -0.814, p <0.001), positively correlated at WCA2 (r = 0.459, p<0.001) and ENP (r = 0.517, p<0.001) and not correlated in WCA3.
Soil TP
•No seasonally significant difference overall or by area, n = 228.
nMean ± SDArea
78312 ± 149 bENP
100461 ± 182 aWCA3
25489 ± 241 aWCA2
25520 ± 257 aLNWR
µg TP g-1 dw
Historically P entering into the northern Everglades was estimated to be 129 metric tons per year. During the mid ’90s - 376 metric tons per year was coming from drained agricultural land (Davis 1994). Since implementation of BMPS in the 1990s some reduction in P loading (Walker 1999).
EAA < 280, 000 ha (or about 25% of the original Everglades) 80% of this is farmed in sugarcane. Also sod, vegetables, and rice.
0
1
2
3
0.00
0.10
0.20
0.30
0.40
0.50
0 200 400 600 800 1000 1200 1400 1600
WET
0
10
20
30
40
50
0
4
8
12
16
20
0 200 400 600 800 1000 1200 1400 1600
CH
4or
CO
2Pr
oduc
tion,
µm
ol g
-1dw
h-1
Soil Total P, µg-1 g-1 dw
MU
FC o
r MU
FP, µ
mol
g-1
dwh-1
DRY,WET, R2 = 0.190, p<0.001
NS
WET, R2 = 0.178, p<0.001DRY,WET, R2 = 0.158, p<0.001
R2 = 0.177, p<0.001
DRY,WET, NS
NS
Soil
Floc
nMean ± SDArea
2434.1 ± 6.0 cENP
6839.1 ± 7.0 bWCA3
1339.0 ± 4.7 bcWCA2
1344.4 ± 2.3 aLNWR
%
nMean ± SDArea
24497 ± 300ENP
68585 ± 252WCA3
13721 ± 411WCA2
13836 ± 460LNWR
µg TP g-1 dw
Floc TC
Floc TP
Neither Floc TC nor TP contents varied seasonally for all samples or by areas therefore n = 128.
Floc TP contents varied significantly between sites (p = 0.008) but without power for post-hoc tests (Dunnets).
0
50
100
150
200
250
300
350
0.00
0.40
0.80
1.20
1.60
2.00
0 500 1000 1500 2000 2500
0.00
1.00
2.00
3.00
4.00
5.00
6.00
7.00
CH
4or
CO
2Pr
oduc
tion,
µm
ol g
-1dw
h-1
MU
FC o
r MU
FP, µ
mol
g-1
dwh-1
DRY,WET, R2 = 0.158, p<0.001
R2 = 0.177, p<0.001
DRY,WET, R2 = 0.142, p=0.003
R2 = 0.233, p<0.001
Floc
DRY,WET, NS
NS
WET, NS
0
2
4
6
8
10
12
14
16
0 500 1000 1500 2000 2500
DRY,WET, R2 = 0.173, p=0.002
R2 = 0.350, p<0.001
FLOC Total P, µg-1 g-1 dw
Floc CO2 Production, µmol g-1 dw h-1
WCA-1 (Loxahatchee NWR)
SawgrassSloughCattail
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 300
200
400
600
800
1000
1200So
il T
P (m
g k g
-1)
C=695e(-0.52*d) + 288r2 = 0.79, P <0.001
0200400600800
1000120014001600
0 2 4 6 8 10 12 14
C=889e(-1.74*d) + 417r2 = 0.89, P = 0.10
WCA-2A
0100200300400500600700800900
1000
0 2 4 6 8 10 12 14 16
Distance from Source Canals, km
ENP-Shark River SloughC=746e(-1.65*d) + 210r2 = 0.82, P < 0.001
Childers et al. 2003 JEQ
1.7 - 2.8 4.2 - 5.9 7.1 - 8.2
00
7070
8080
9090
100100
Soil
Floc
Macrophyte
Consumer
Water
Periphyton
Perc
ent o
f tot
al e
cosy
stem
P st
andi
ng st
ock
Unenriched Transitional Typha
Degree of Enrichment
(g TP m-2)
Soil Total and Methyl Hg positively correlated (p <0.001) with Soil TP and Soil CH4 production. Floc Total Hg positively correlated to Floc TP (p = 0.02) but Methyl Hg was not.
Surf
ace
Wat
er D
OC
, mg
L-1
0
20
40
LNWR WCA2 WCA3 ENP
812
1112
45 52
9
42
<0.001 <0.001
ns
ns
Surface WaterDissolved Organic C
“More Labile”
“Less Biologically Active”
Surface Water Dissolved Organic C Quality
Rudolf JaffeYouhei Yamashita
•Nutrient loading (P) influences rates of microbially-mediated processes which can effect ecosystem chemical processing on landscape scales.
•Soil and Floc CO2 evolution rates were greater during the wet season than during the dry.
•The wet season CO2 evolution from Floc averaged approximately 2 to 10 times that of soil on a dry mass per unit area basis.
•Generally CO2 and CH4 production and MUFP and MUFC activities were significantly correlated in soil and floc, that is, where activity is high for soils it is also for Floc.
Summary
•Seasonality in CO2, CH4, and DOC is likely a function of Wet and Dry cycles and this should therefore be considered in water management, i.e. will the short hydroperiod marsh be maintained.
•P demand, rapid recycling, and retention mechanisms allow strong chemical gradients to develop in the oligotrophicEverglades.
•Additionally, water management may change the character of DOC and other chemical constituents.
Summary