Earthworms as Ecoengineers Following Remediation
-
Upload
brian-bovaird -
Category
Technology
-
view
285 -
download
3
description
Transcript of Earthworms as Ecoengineers Following Remediation
![Page 1: Earthworms as Ecoengineers Following Remediation](https://reader034.fdocuments.us/reader034/viewer/2022042601/5562f12fd8b42ad26c8b54d9/html5/thumbnails/1.jpg)
Earthworms as Ecoengineers in the Restoration of Oil and Brine-
Impacted Soils Following RemediationNitya AlahariKerry Sublette
Eleanor JenningsCenter for Applied Biogeosciences
University of TulsaGreg ThomaDuane Wolf
University of ArkansasKathleen Duncan
University of OklahomaTim Todd
Kansas State UniversityMac A. Callaham, Jr.USDA-Forest Service
![Page 2: Earthworms as Ecoengineers Following Remediation](https://reader034.fdocuments.us/reader034/viewer/2022042601/5562f12fd8b42ad26c8b54d9/html5/thumbnails/2.jpg)
Remediation of Oil and Brine Spills
• Oil– Fertilizer
• Increase rates• Prevents depletion of soil nutrient pool
– Organic matter• Increases O2 infiltration• Decay products help rebuild soil structure• Substrate for soil fauna
– Tilling• Aeration• Mixing• Distribute oil in the soil to create more oil-water interface
![Page 3: Earthworms as Ecoengineers Following Remediation](https://reader034.fdocuments.us/reader034/viewer/2022042601/5562f12fd8b42ad26c8b54d9/html5/thumbnails/3.jpg)
Remediation of Oil and Brine Spills
• Brine– Organic matter
• Increases permeability to water• Decay products help rebuild soil structure• Substrate for soil fauna
– Tilling• Mixing• Improving permeability
– Fertilizer• Promote biodegradation of organic matter• Prevents impact on soil nutrient pool
– Gypsum• Combat sodicity
![Page 4: Earthworms as Ecoengineers Following Remediation](https://reader034.fdocuments.us/reader034/viewer/2022042601/5562f12fd8b42ad26c8b54d9/html5/thumbnails/4.jpg)
Restoration of Oil- and Brine-impacted Sites
• Both the original spill and the remediation process disrupt soilecology– Disruptions in N and P cycling– Reduced diversity of soil microbes and invertebrates– Loss of vegetation
• All levels of ecosystem affected– Producers– Consumers– Decomposers
• Is restoration of the soil ecosystem the real definition of “clean” for a high value site?– Left to nature restoration is a lengthy process
![Page 5: Earthworms as Ecoengineers Following Remediation](https://reader034.fdocuments.us/reader034/viewer/2022042601/5562f12fd8b42ad26c8b54d9/html5/thumbnails/5.jpg)
Increasing the Rate of Restoration of Soil Ecosystems
• Are earthworms the answer?– Earthworm castings
• contain higher concentrations of SOM and bioavailable nutrients than the surrounding bulk soil
• exhibit greater microbial activity and higher rates of respiration than bulk soil
• lead to the formation of stable soil aggregates which increase the permeability of the soil to air and water
– Earthworm burrows create pathways for root growth, water movement, and nutrient transport
– Earthworm-related effects stimulate the uptake of nutrients by plants which results in increased growth rates of plants and greater levels of biomass
– All of these effects are in proportion to the density of earthworms in the soil and can persist for long periods of time
![Page 6: Earthworms as Ecoengineers Following Remediation](https://reader034.fdocuments.us/reader034/viewer/2022042601/5562f12fd8b42ad26c8b54d9/html5/thumbnails/6.jpg)
Project Objectives
• Determine the appropriate amendments to optimize the re-introduction of earthworms to oil- and brine-impacted sites which have been remediated but not fully restored.
• These data will – Lead to a cost-effective protocol for re-
introduction and cultivation of earthworms in these sites
– Demonstrate the benefits of earthworm re-introduction on re-vegetation of these sites in terms of increased plant biomass and greater species diversity.
![Page 7: Earthworms as Ecoengineers Following Remediation](https://reader034.fdocuments.us/reader034/viewer/2022042601/5562f12fd8b42ad26c8b54d9/html5/thumbnails/7.jpg)
Previous Work (Callaham et al., 2002*)
• Greenhouse study of the survival and effects of earthworms (Eisenia fetida) in landfarm soil containing TPH concentrations averaging 33,000 mg/kg.
• Results:– earthworms will survive in bioremediated soil with high
residual TPH concentrations; – organic matter is necessary for their long-term survival; – earthworm activity resulted in greater accumulation of
above- and below-ground plant biomass.
*Env. Toxicology and Chem., 21, 1658-1663 (2002)
![Page 8: Earthworms as Ecoengineers Following Remediation](https://reader034.fdocuments.us/reader034/viewer/2022042601/5562f12fd8b42ad26c8b54d9/html5/thumbnails/8.jpg)
Added NaCl(g/kg of
soil)
Fraction of replicate microcosms showing
evidence of reproduction*
Mean survival(%)
0 4/4 90.0
1 4/4 95.0
3 2/4 90.0
5 0/4 97.5
7.5 0/4 95.0
10 0/4 95.0
15 0/4 90.0
*Art Stewart (Oak Ridge National Lab)
Results of 17-d Test to Determine Sensitivity of the Earthworm Eisenia
fetida to NaCl in soil*
![Page 9: Earthworms as Ecoengineers Following Remediation](https://reader034.fdocuments.us/reader034/viewer/2022042601/5562f12fd8b42ad26c8b54d9/html5/thumbnails/9.jpg)
Test Sites
• G7– 2000 spill of produced fluids (W/O ratio of 10-15)– Four treatments: combinations of hay, fertilizer (13:13:13),
and no treatment– Treatment terminated in 2004
• LF– Site of crude oil landfarm closed in 1997– Final TPH (EPA 418.1) < 9000 mg/kg
![Page 10: Earthworms as Ecoengineers Following Remediation](https://reader034.fdocuments.us/reader034/viewer/2022042601/5562f12fd8b42ad26c8b54d9/html5/thumbnails/10.jpg)
Treatments / Experimental Design
• Worms only• Fertilizer only• Hay only• Worms + Hay• Worms + Fertilizer• Fertilizer + Hay• Worms + Hay
+Fertilizer• No treatment
• Four blocks each site
• Four replicates of each treatment in each block
• Sacrificial sampling of one replicate of each treatment per block per site
![Page 11: Earthworms as Ecoengineers Following Remediation](https://reader034.fdocuments.us/reader034/viewer/2022042601/5562f12fd8b42ad26c8b54d9/html5/thumbnails/11.jpg)
BlockG7
Na+
(mg/kg)N=3
Cl-(mg/kg)N=3
BlockLF
TPH*(mg/kg)N=4
1 711 ± 198 900 ± 298 5 11546 ± 24042 652 ± 39 788 ± 94 6 16634 ± 21843 633 ± 201 576 ± 171 7 9535 ± 19034 567 ± 79 301 ± 84 8 16511 ± 5350
Initial Test Site Conditions
*CH2Cl2 extractables (gravimetric)
TPH (EPA 418.1) < 9000 mg/kg
![Page 12: Earthworms as Ecoengineers Following Remediation](https://reader034.fdocuments.us/reader034/viewer/2022042601/5562f12fd8b42ad26c8b54d9/html5/thumbnails/12.jpg)
Block 1 Block 2 Block 3 Block 4
G7
Worms + Hay + Fertilizer
Worms + Hay
Worms + Fertilizer
Hay + Fertilizer
Worms
Hay
Fertilizer
No Treatment
![Page 13: Earthworms as Ecoengineers Following Remediation](https://reader034.fdocuments.us/reader034/viewer/2022042601/5562f12fd8b42ad26c8b54d9/html5/thumbnails/13.jpg)
G7
![Page 14: Earthworms as Ecoengineers Following Remediation](https://reader034.fdocuments.us/reader034/viewer/2022042601/5562f12fd8b42ad26c8b54d9/html5/thumbnails/14.jpg)
LF
![Page 15: Earthworms as Ecoengineers Following Remediation](https://reader034.fdocuments.us/reader034/viewer/2022042601/5562f12fd8b42ad26c8b54d9/html5/thumbnails/15.jpg)
Project Timeline
• Rip and till sites; homogenize to extent possible• Install earthworm enclosures and add amendments
(fertilizer and/or hay)– G7: May 2, 2005 – LF: May 31, 2005
• Inoculate with Eisenia fetida ( 5 worms per enclosure per worm treatment); cover with panty hose– G7: June 23, 2005– Lf: July 7, 2005
• First sampling– G7: July 21, 2005– LF: August 2, 2005
• Second sampling– G7: Oct. 15, 2005– LF: Oct. 14, 2005
![Page 16: Earthworms as Ecoengineers Following Remediation](https://reader034.fdocuments.us/reader034/viewer/2022042601/5562f12fd8b42ad26c8b54d9/html5/thumbnails/16.jpg)
Why Eisenia fetida?
• Readily available commercially all over the U.S. for a reasonable cost ($15-$20/1000 worms).
• Easily cultivated by inexperienced personnel
• Requires high concentrations of soil organic matter and is likely to be replaced by indigenous species when they begin to migrate into the restored sites
![Page 17: Earthworms as Ecoengineers Following Remediation](https://reader034.fdocuments.us/reader034/viewer/2022042601/5562f12fd8b42ad26c8b54d9/html5/thumbnails/17.jpg)
Both sites ripped to 12” and tilledG7
![Page 18: Earthworms as Ecoengineers Following Remediation](https://reader034.fdocuments.us/reader034/viewer/2022042601/5562f12fd8b42ad26c8b54d9/html5/thumbnails/18.jpg)
LF
![Page 19: Earthworms as Ecoengineers Following Remediation](https://reader034.fdocuments.us/reader034/viewer/2022042601/5562f12fd8b42ad26c8b54d9/html5/thumbnails/19.jpg)
Homogenizing soil from Block 5 for earthworm enclosures at LF
![Page 20: Earthworms as Ecoengineers Following Remediation](https://reader034.fdocuments.us/reader034/viewer/2022042601/5562f12fd8b42ad26c8b54d9/html5/thumbnails/20.jpg)
Filling enclosure with homogenized soil at LF
![Page 21: Earthworms as Ecoengineers Following Remediation](https://reader034.fdocuments.us/reader034/viewer/2022042601/5562f12fd8b42ad26c8b54d9/html5/thumbnails/21.jpg)
Earthworm enclosures installed and amendments added at LF
![Page 22: Earthworms as Ecoengineers Following Remediation](https://reader034.fdocuments.us/reader034/viewer/2022042601/5562f12fd8b42ad26c8b54d9/html5/thumbnails/22.jpg)
Entire site covered with hay for moisture and temperature control
![Page 23: Earthworms as Ecoengineers Following Remediation](https://reader034.fdocuments.us/reader034/viewer/2022042601/5562f12fd8b42ad26c8b54d9/html5/thumbnails/23.jpg)
Sampling enclosure; note that space surrounding enclosure has also been sampled
![Page 24: Earthworms as Ecoengineers Following Remediation](https://reader034.fdocuments.us/reader034/viewer/2022042601/5562f12fd8b42ad26c8b54d9/html5/thumbnails/24.jpg)
Site Maintenance
• Barb wire fence to keep out buffalo; electric fence to keep out coyotes
• Each site watered every other day unless there was sufficient rain
![Page 25: Earthworms as Ecoengineers Following Remediation](https://reader034.fdocuments.us/reader034/viewer/2022042601/5562f12fd8b42ad26c8b54d9/html5/thumbnails/25.jpg)
Spring Fall Spring FallNutrients X X X XBrine X X X XTPH X X X XPLFA X X X XDNA XN cycling bacteria
X X X X
Nematodes X X X XPlants X X XEarthworms X X X X
Sampling and Analysis
![Page 26: Earthworms as Ecoengineers Following Remediation](https://reader034.fdocuments.us/reader034/viewer/2022042601/5562f12fd8b42ad26c8b54d9/html5/thumbnails/26.jpg)
G7 Worm Count (July 21, 2005)
F FH H N W WF WFH WH
Treatment
0
2
4
6
8
10
12
14W
orm
Cou
nt
E. fetida A. trapezoides Diplocardia sp.
E. fetida is missing in action (mostly)
Local species have moved in – more so in G7 than LF
![Page 27: Earthworms as Ecoengineers Following Remediation](https://reader034.fdocuments.us/reader034/viewer/2022042601/5562f12fd8b42ad26c8b54d9/html5/thumbnails/27.jpg)
0
2
4
6
8
10
12
16-18 18-20 20-22 22-24 24-26 26-28 28-30 30-32
Percent Moisture
No.
of O
bser
vatio
ns o
f W
orm
s
G7LF
Frequency of worm observations related to soil moisture
On average soil moistures in LF were 4% lower than in G7 (avg. 26%)
![Page 28: Earthworms as Ecoengineers Following Remediation](https://reader034.fdocuments.us/reader034/viewer/2022042601/5562f12fd8b42ad26c8b54d9/html5/thumbnails/28.jpg)
FH F H N
G7 Modified Treatment
20
22
24
26
28
30%
Moi
stur
e Mean Mean±SE
*If native worms are widely distributed at the sites and enter and exit enclosures freely, then there are only four treatments
![Page 29: Earthworms as Ecoengineers Following Remediation](https://reader034.fdocuments.us/reader034/viewer/2022042601/5562f12fd8b42ad26c8b54d9/html5/thumbnails/29.jpg)
FH F H N
G7 Modified Treatment
5
10
15
20
25
30
35
40
45P
(mg/
kg)
Mean Mean±SE a a
b b
![Page 30: Earthworms as Ecoengineers Following Remediation](https://reader034.fdocuments.us/reader034/viewer/2022042601/5562f12fd8b42ad26c8b54d9/html5/thumbnails/30.jpg)
FH F H N
G7 Modified Treatment
4
6
8
10
12
14
16
18NH
4-N
(mg/
kg)
Mean Mean±SE a a
bb
Simple decomposition of hay with a C/N of 25-30 should result in net immobilization
![Page 31: Earthworms as Ecoengineers Following Remediation](https://reader034.fdocuments.us/reader034/viewer/2022042601/5562f12fd8b42ad26c8b54d9/html5/thumbnails/31.jpg)
FH F H N
G7 Modified Treatment
1.0
1.2
1.4
1.6
1.8
2.0
2.2
2.4NO
3-N
(mg/
kg)
Mean Mean±SE
aa
ab
b
![Page 32: Earthworms as Ecoengineers Following Remediation](https://reader034.fdocuments.us/reader034/viewer/2022042601/5562f12fd8b42ad26c8b54d9/html5/thumbnails/32.jpg)
FH F H N
G7 Modified Treatment
1.30
1.35
1.40
1.45
1.50
1.55
1.60
1.65
1.70
1.75
1.80To
tal C
arbo
n (%
) Mean Mean±SE
aa
a
a
p=0.31
![Page 33: Earthworms as Ecoengineers Following Remediation](https://reader034.fdocuments.us/reader034/viewer/2022042601/5562f12fd8b42ad26c8b54d9/html5/thumbnails/33.jpg)
FH F H N
G7 Modified Treatment
0.096
0.100
0.104
0.108
0.112
0.116
0.120
0.124To
tal N
(%)
Mean Mean±SE
aa
aa
p=0.27
![Page 34: Earthworms as Ecoengineers Following Remediation](https://reader034.fdocuments.us/reader034/viewer/2022042601/5562f12fd8b42ad26c8b54d9/html5/thumbnails/34.jpg)
FH F H N
LF Modified Treatment
20
30
40
50
60
70
80
90
100
110
120P
(mg/
kg)
Mean Mean±SE
a
a
b
b
![Page 35: Earthworms as Ecoengineers Following Remediation](https://reader034.fdocuments.us/reader034/viewer/2022042601/5562f12fd8b42ad26c8b54d9/html5/thumbnails/35.jpg)
FH F H N
G7 Modified Treatment
0
100
200
300
400
500
600
700
800To
tal N
emat
odes
(# /
100
g)
Mean Mean±SE
a
b
b b
![Page 36: Earthworms as Ecoengineers Following Remediation](https://reader034.fdocuments.us/reader034/viewer/2022042601/5562f12fd8b42ad26c8b54d9/html5/thumbnails/36.jpg)
FH F H N
G7 Modified Treatment
1.3
1.4
1.5
1.6
1.7
1.8
1.9
2.0
2.1N
emat
ode
Mat
urity
Inde
x Mean Mean±SE
a
ab
b
b
![Page 37: Earthworms as Ecoengineers Following Remediation](https://reader034.fdocuments.us/reader034/viewer/2022042601/5562f12fd8b42ad26c8b54d9/html5/thumbnails/37.jpg)
Preliminary Conclusions
• Earthworms will invade and survive in remediated oil- or brine-impacted soil– organic matter– moisture
• Earthworm activity increases bioavailability of nutrients in these damaged sites (?)
![Page 38: Earthworms as Ecoengineers Following Remediation](https://reader034.fdocuments.us/reader034/viewer/2022042601/5562f12fd8b42ad26c8b54d9/html5/thumbnails/38.jpg)
1 2 3 4
Block
0
5
10
15
20
25
30G
7 W
orm
Bur
row
s(1
ft2 d
iam
eter
circ
le)
Oct
ober
200
5 Mean Mean±SE
![Page 39: Earthworms as Ecoengineers Following Remediation](https://reader034.fdocuments.us/reader034/viewer/2022042601/5562f12fd8b42ad26c8b54d9/html5/thumbnails/39.jpg)
5 6 7 8Block
0
5
10
15
20
25
30LF
Wor
m B
urro
ws
(1 ft
2 dia
met
er c
ircle
)O
ctob
er 2
005
Mean Mean±SE
![Page 40: Earthworms as Ecoengineers Following Remediation](https://reader034.fdocuments.us/reader034/viewer/2022042601/5562f12fd8b42ad26c8b54d9/html5/thumbnails/40.jpg)
Acknowledgement
This work was funded by
the Integrated Petroleum Environmental Consortium (IPEC)
![Page 41: Earthworms as Ecoengineers Following Remediation](https://reader034.fdocuments.us/reader034/viewer/2022042601/5562f12fd8b42ad26c8b54d9/html5/thumbnails/41.jpg)
Extra Slides
![Page 42: Earthworms as Ecoengineers Following Remediation](https://reader034.fdocuments.us/reader034/viewer/2022042601/5562f12fd8b42ad26c8b54d9/html5/thumbnails/42.jpg)
WFH WF WH W FH F H N
Treatment
0
10
20
30
40
50
60P
(mg/
kg)
Mean Mean±SE
![Page 43: Earthworms as Ecoengineers Following Remediation](https://reader034.fdocuments.us/reader034/viewer/2022042601/5562f12fd8b42ad26c8b54d9/html5/thumbnails/43.jpg)
WFH WF WH W FH F H N
Treatment
2
4
6
8
10
12
14
16
18
20
22
24N
H4-
N (m
g/kg
) Mean Mean±SE
![Page 44: Earthworms as Ecoengineers Following Remediation](https://reader034.fdocuments.us/reader034/viewer/2022042601/5562f12fd8b42ad26c8b54d9/html5/thumbnails/44.jpg)
WFH WF WH W FH F H N
Treatment
21
22
23
24
25
26
27
28
29
30%
Moi
stur
e Mean Mean±SE
![Page 45: Earthworms as Ecoengineers Following Remediation](https://reader034.fdocuments.us/reader034/viewer/2022042601/5562f12fd8b42ad26c8b54d9/html5/thumbnails/45.jpg)
WFH WF WH W FH F H N
Treatment
0
200
400
600
800
1000
1200
1400To
tal N
emat
odes
(# /
100
g)
Mean Mean±SE
![Page 46: Earthworms as Ecoengineers Following Remediation](https://reader034.fdocuments.us/reader034/viewer/2022042601/5562f12fd8b42ad26c8b54d9/html5/thumbnails/46.jpg)
WFH WF WH W FH F H N
Treatment
1.2
1.4
1.6
1.8
2.0
2.2
2.4N
emat
ode
Mat
urity
Inde
x
Mean Mean±SE
![Page 47: Earthworms as Ecoengineers Following Remediation](https://reader034.fdocuments.us/reader034/viewer/2022042601/5562f12fd8b42ad26c8b54d9/html5/thumbnails/47.jpg)
WFH WF WH W FH F H N
Treatment
200
250
300
350
400
450
500
550EC
(1:1
, um
hos/
cm)
Mean Mean±SE
![Page 48: Earthworms as Ecoengineers Following Remediation](https://reader034.fdocuments.us/reader034/viewer/2022042601/5562f12fd8b42ad26c8b54d9/html5/thumbnails/48.jpg)
WFH WF WH W FH F H N
G7 Treatment
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9To
tal C
arbo
n (%
)
Mean Mean±SE
![Page 49: Earthworms as Ecoengineers Following Remediation](https://reader034.fdocuments.us/reader034/viewer/2022042601/5562f12fd8b42ad26c8b54d9/html5/thumbnails/49.jpg)
G7 July 21, 2005 Sampling
WFH WF WH W FH F H N
Treatment
10
12
14
16
18
20
22
24
26
28
30%
Moi
stur
e
ab ab ab b ab ac c ac
![Page 50: Earthworms as Ecoengineers Following Remediation](https://reader034.fdocuments.us/reader034/viewer/2022042601/5562f12fd8b42ad26c8b54d9/html5/thumbnails/50.jpg)
LF August 2, 2005 Sampling
WFH WF WH W FH F H N
Treatment
10
12
14
16
18
20
22
24
26
28
30%
Moi
stur
e
a a a a a a a b