Transcript Identifying potential environmental impacts of large - TSEC

TSEC Biosys
TSEC Biosys
TSEC-BIOSYS:
Environmental Impacts of Bioenergy Crops in
the UK
www.tsec-biosys.ac.uk
Rebecca Rowe
M. Hanley, D. Goulson, G. Taylor
University of Southampton
Biomass role in the UK energy futures
The Royal Society, London: 28th & 29th July 2009
1
Overview
Introduction
Knowledge gaps
Aims
Study sites
Survey completed
Key findings
Summary main outputs
TSEC Biosys
TSEC Biosys
Environmental Impacts of Bioenergy
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TSEC Biosys
Biofuel Crops
Short Rotation
Coppice
Miscanthus
(Wheat, oilseed rape, sugar
beet)
Energy and Carbon Balance
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Hydrology
(At catchment scale)
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Biodiversity
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Environmental Impact
Soil Organic Carbon
Nitrogen leaching
Visual Impacts
Avian
Flora
Invertebrates
Mammal and Amphibians
  Positive impact,, Negative Impact,  No Change, * Limited data
 R. Rowe, et al (2009). Renewable & Sustainable Energy Rev. 13, 271-290
Knowledge Gaps:
Willow SRC & Biodiversity
 Limited information on large commercial sites
– Small non-commercial sites
– Commercial sites studied contained many young plantations
 Range of species
– Flora, avian, Lepidoptera and pest species well studied
– Soil invertebrates, mammals and non-pest invertebrates less
well studied
 Few direct comparisons between SRC and arable land
and none for set-aside land
 Few studies on ecosystem processes (herbivory,
decomposition, predation)
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Aims
To assess impacts of mature commercial
willow SRC plantations on winged
invertebrates and ground flora in
comparison to alternative land uses
To explore possible effects of willow SRC
ecosystem processes
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Field Sites
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 Three sites each containing
– Willow SRC plantation
– Arable field containing cereal crops
– Set-aside field
 Willow plantations
– Commercial plantations
– Greater than 5 ha in size
– Sites at least 5 years old (1998-2000)
Willow SRC
Surveys Conducted
 Species Composition (Summer 2006)
– Winged Invertebrates (e.g. Wasps)
• Abundance
• Distribution of Orders/Size classes
– Ground Flora (Weeds)
• Species richness and abundance
• Plant strategies
 Ecosystem Processes (Summer 2007)
– Herbivory and Decomposition
– Predation (2007- 2008)
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Key Findings: Winged Invertebrates
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 Abundance of winged invertebrates were similar
between land-uses,
 Invertebrates abundance in Willow SRC increased with
height

Height
Distance
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
Land-use F2,4 = 0.004 P 0.96
Land-use*distances F8,16 = 2.93 P 0.032
H*L F4,8 =10.37 P 0.003
Distribution of Winged Invertebrate Orders
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Mean number of individuals per trap (SE)
Order
English
Willow SRC
Arable
Set-aside
Hymenoptera (>5mm)
Bees and wasps
4.73
(0.28)
0.99
(0.16)
1.65
(0.18)
Hymenoptera (<5mm)
Bees and wasps
33.95
(1.57)
16.04
(0.84)
11.80
(0.47)
Hemiptera (> 5mm)
True bugs
Diptera (<5mm)
Flies
Coleoptera (>5mm)
Beetles
Thysanoptera
Thrips
Diptera (>5mm)
Flies
Hemiptera (<5mm)
True bugs
Lepidoptera (>5mm)
Butterflies
Psocoptera
Book lice
3.31
(0.23)
27.40
(1.82)
1.00
(0.14)
1.14
(0.24)
66.72
(4.28)
3.63
(0.27)
0.69
(0.08)
1.06
(0.21)
0.68
(0.10)
42.15
(1.90)
2.35
(0.17)
2.15
(0.26)
19.50
(3.07)
1.91
(0.17)
0.40
(0.07)
0.54
(0.06)
2.02
(0.28)
45.42
(2.72)
3.42
(0.41)
2.33
(0.25)
39.24
(2.45)
3.11
(0.36)
1.14
(0.16)
0.53
(0.07)
increased in willow SRC,
decreased in Willow,
similar abundance in all land-uses
Ground Flora: Species Richness &
Abundance
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 Species richness
– Similar in all headlands
– In the cultivated area set-aside land > willow SRC > arable land
 Ground flora biomass
– Similar in set-aside and willow SRC, reduced in arable land
Species Richness
F2,4 = 13.64 P 0.016
Biomass
F2,4 = 24.65 P 0.006
Plant Strategies (1)
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 Fraction of plant cover provided by each of three
plants strategies
– Life history, life form and establishment
strategy (Grime et al.1990).
Plant Strategies (2)
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Fraction of cover per 4m-2 quadrate
 Perennial species dominate in willow SRC
Life History
Perennial
Annual
Plant Strategies (3)
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 Grass cover was highest in the headlands of all land-
Fraction of cover per 4m-2 quadrate
uses
 No overall effect of land-use, with all land-uses showing
a mix of forbs and grasses
Life Form
Grass
Forb
Plant Strategies (4)
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 Willow SRC higher fraction of competitive species few
Fraction of cover per 4m-2 quadrate
ruderal species
Establishment Strategy
Competitive
Ruderal
Stress Tolerate
Generalist
C+ F 2, 4 = 9.53 P = 0.030, R+ F 2, 4 = 19.53 P= 0.009
Plant Strategies (5)
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 In contrast to other land-uses, willow plantations
1.2
1.2
1
1
0.8
Competitive
Ruderal
0.8
0.6
0.4
Perennial
0.6
Annual
0.2
0.2
0
0
Forb
Grass
0m
5m
25 m
50 m
W
A
S
W
A
S
headland
W
A
S
100/ 61
m
W
A
S
50 m
W
A
S
25 m
W
A
S
W
A
S
W
A
S
5m
W
A
S
0m
W
A
S
headland
W
A
S
0.4
W
A
S
Fraction of cover per 4m -2 quadrate
were dominated by a mix of perennial grass and
forbs with competitive and generalist
establishment strategies
 Result suggest that levels of disturbance in
willow SRC affect plant species and species
richness
100/ 61
m
Stress
Tolerate
Generalist
Conclusions (2006)
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 Result suggest Willow SRC can help to
increase farm scale biodiversity.
– By providing a habitat where plant species
and invertebrate Orders uncommon in arable
land can persist
Are these reflected in changes in
ecosystem processes?
Ecosystem Processes
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TSEC Biosys
 The movement of nutrients, energy or matter
between compartments within a ecosystem.
 Understand the rates of these processes is first
step in managing ecosystems for maximum
benefit for both biodiversity and yield.
Seedling Survival
Plant Species
Nitrogen Cycling
Carbon Storage
Pest Species Density
Mammal and Avian Diversity
Herbivory
Pressure
Methods: Ecosystem Processes
 Herbivory: lettuce seedlings were exposed in
the field to assess herbivory pressure by
molluscs, mammals and invertebrates
 Decomposition: litter bags were placed in the
field to assess decomposition rates by macro
and meso-micro fauna (1mm, and 5mm)
 Predation: fly pupae were exposed in the field
to assess small mammal and ground
invertebrate predation
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Key Findings: Herbivory
 Summer herbivory pressure was similar in all land-use
 Mollusc grazing was found to be the most significant
factor affecting seedling survival in all land-uses
Herbivory Pressure
Willow SRC
Arable
Set-aside
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Key Findings: Decomposition
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 Summer decomposition rates are reduced in arable land
in comparison to the other land-uses due to reduced
macrofauna and mesofauna activity
Decomposition rates
Key Findings: Predation
 Predation rates highest in arable land > willow SRC >
set-aside for both small mammals and ground
invertebrates
Predation pressure
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TSEC Biosys
Detailed Predation Study (2008)
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Predation assay with enclosure design to
separate small mammals and large and
small ground invertebrates
Ground invertebrate activity and density
(Pit-fall trapping and soil searches)
Small mammal activity and density (Mark
and recapture)
Land-use, diurnal, seasonal
Percentage of pupa taken
Seasonal Predation Rates
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Mammal Abundance
Cultivated area
Spring
Summer
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Autumn
Mean captures per site given as captures per 100 trap rounds adjusted for sprung traps
Wood Mouse
Common Shrew
Pygmy Shrew
Water Shrew
Bank Vole
Field Vole
Mammal Abundance
Cultivated Area
Spring
Summer
ns
Autumn
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TSEC Biosys
Mammal Abundance
Cultivated Area
Spring
Summer
Autumn
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Percentage of individuals trapped
Small Mammal: Breeding
16
21 49 5
8 6
Number of individuals
40
9
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TSEC Biosys
Summary of Key Outputs
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TSEC Biosys
 Assessed the current knowledge bases on the
environmental impacts of bioenergy crops (Rowe et al
2009)
 Mature commercial willow SRC plantations are beneficial
for farm-scale biodiversity
– Variation in the winged invertebrate and plant communities of
willow SRC in comparison to alternative land-uses
 Highlighted the relative important of small mammals in
predation in willow SRC
 Identified willow SRC as a breeding site for several small
mammal species.
Acknowledgments
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TSEC Biosys
 Land Owners,
– Russell Fraser, Dave Barrett and Fred Walter (CRL)
 Field Assistance
– Suzie Milner, Alex Wan, Sarah-Jane Yorke, Matt Aylott, Lisa
Durrant, Stefan George, Katie Finn, Stacey Travers, Judy
Gallimore, Carl Wardill, Jo Seymour, Matt Guy, Dr Donna Clarke
 Supervisors:
– Prof. Gail Taylor, Dr. Mick Hanley, Dr. Dave Goulson
 NERC and TSEC
Thank you for your attention!
TSEC Biosys
TSEC Biosys
TSEC Biosys
TSEC Biosys
www.tsec-biosys.ac.uk
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