RS1a (2007)
NERC PROJECT STUDENTSHIPS
APPLICATION
(RESPONSIVE MODE AND DIRECTED)
Please indicate the category of studentship requested (please delete as appropriate)
Responsive Mode Project:
Yes
Directed Project:
No
Name of Directed programme (if applicable):
Department where award will be held:
Institution’s Name:
ENV
University of East Anglia
Full Postal Address:
School of Environmental Sciences
University of East Anglia
Norwich NR3 4PL
Departmental E-mail Address:
jacquie.burgess@uea.ac.uk
Head of Department’s Name:
Prof Jacquie Burgess
Please complete this form for each student, in not less than 10 point typescript and submit with the grant
application.
The general conditions and regulations relating to NERC studentships are set out in the current edition of the
NERC Studentships handbook and it is implicit in the submission of an application that they are accepted by
the institution. The handbook can be found at: http://www.nerc.ac.uk/funding/application/studentships/
PART 1 – TO BE COMPLETED BY THE INSTITUTION
(The institution must also complete part 3)
1.
PROJECT DETAILS
Title of Project:
Impact of higher trophic-level complexity on the stability of marine plankton assemblages
Summary Of Research Programme (up to 1.5 pages): A brief description of the proposed research is required, including details of research training.
Any associated research grants should be mentioned with reference numbers, if available.
Marine plankton assemblages form the base of marine food webs. They play a major role in the earth’s
climate, and guarantee the availability of a vital part of human food resources. These food webs are dynamic
systems, and the stability of plankton assemblages may not only depend on external environmental factors, but
also on the interactions with higher trophic levels. The importance of higher trophic-level complexity for
plankton assemblages is still poorly understood, since interactions are difficult to quantify, and vary over
temporal and spatial scales [1]. Recent studies in food-web ecology suggest that higher trophic levels can
impact food-web stability through asymmetries in interaction strengths [2,3]. It has been argued that patterns
in energy flow and biomass structure play an important role in this, because they keep the strength of
potentially destabilising positive feedbacks low [3,4].
The current Ph.D. studentship will study the impact of higher trophic levels on phytoplankton assemblages.
Associated proposal G634605 will evaluate stability of phytoplankton assemblages by taking the approach of
Neutel of quantifying feedbacks originally based on soil ecosystems [3,4,5] to the realm of marine
ecosystems, focussing on model sensitivity and data analysis. This attached studentship is an integrated part of
this and will focus on a more theoretical and generic exploration of the importance of higher trophic-level
complexity and energy-flow structure on stability of the lower trophic levels. The project will 1. take a generic
phytoplankton-assemblage model as the core model, 2. assess higher trophic level complexity by subsequently
adding predatory compartments of up to three larger size classes, 3. utilise a 1-D version of the model to
examine the dynamic consequences of the addition of predator groups and 4. incorporate the effects of lifehistory patterns and simple behaviour. It is the explicit aim of the project to separate (de)stabilisation that may
only affect the higher trophic levels themselves, from the effect of added complexity on the core plankton
web.
The student will start by extracting annual average network properties from contrasting sites within the global
generic PlankTOM-10 model, taking part in and learning from the work of the PDRA (see G634605). The
sites will be chosen on the basis of contrasting regions of production and higher trophic level biomass and
identified through literature studies and analyses of the model output and could include contrasting areas such
as the shelf areas of the north-east Atlantic, the Southern Ocean, a coastal upwelling region and lower
production regions of the ocean gyres. Next, the student will analyse these contrasting networks and examine
the effects of addition of predatory links, and assessing energy flows using allometric scaling relations to
parameterise the vital rates for different types of predators [6, 7]. This will require adjustment of the balance
of flows around the major prey groups that close the upper levels of the network to ensure the network flows
are consistent.
In the next step, dynamic models will be explored. This work will be based mainly on the 1-D versions of the
PlankTOM-5 and -10 models, but will also consider the 1-D NEMURO-FISH model (through links provided
by Dr Sergio Vallina at UEA). The analyses will consider whether addition of predator classes has a
significant effect on the overall stability of the food web network, with a particular focus on the interaction
effects on the lower-trophic levels. The PlankTOM models will be driven by environmental variables for the
same contrasting regions considered in the first step (see above). Part of this analysis will consider the effect
of reducing or increasing population sizes or predation rates of the higher trophic-level compartments. This
will allow us to simulate simple scenarios of over-fishing or climate change, and assess their impacts on lower
trophic-level (i.e the core models for phytoplankton assemblages) resilience. As a final stage the effects of
life-history patterns and behaviour will be explored. This will be done by incorporating temporal
heterogeneity in predator feeding rates, and by incorporating spatial heterogeneity through its effects on
functional responses. In all of these steps, stability of the core (lower trophic level) model will be evaluated, in
relation to complexity, biomass structure, asymmetries in interaction strengths, and loop-weight versus looplength spectra.
During the project the student will be closely involved in the associated project (G634605). The student will
be mainly working with the Research Co-Investigator Anje-Margriet Neutel, at the British Antarctic Survey.
The student will benefit from the knowledge of higher trophic level marine ecology at BAS, and in particular
of that of the Co-PI, Eugene Murphy (who is PI at BAS). The student will be working in an environment of
excellent empirical expertise and learn from various specialists in animal marine physiology and ecology
within the BAS core Program DISCOVERY 2010, which Prof Murphy leads. The group includes experts
working on higher trophic-level predators such as species of fish, marine mammals and seabirds, who will be
able to provide basic data and knowledge on modelling of higher trophic-level species. There will be close
contact and cooperation with the main PI, PDRA, and students in the group of Prof. Corinne Le Quéré. The
project combines applied ecosystem ecology with more fundamental community modeling, and the student
will learn a number of different approaches and modelling techniques, combining dynamic modelling
(PlankTOM model), steady-state and community matrix analysis, and allometric scaling theory. The
quantification of feedbacks to analyse stability is a new approach and the student will be part of the
development of this approach in the marine environment.
References
[1] Holt R. D. & Lawton, J. H. The ecological consequences of shared natural enemies. Ann. Rev. Ecol. Sys.
25: 495-520 (1994)
[2] Rooney, N., McCann, K., Gellner, G. & Moore, J.C. Structural asymmetry and the stability of diverse food
webs. Nature 442, 265-269 (2006).
[3] Neutel A. M., Heesterbeek, J.A.P., van de Koppel, J., et al. Reconciling complexity with stability in
naturally assembling food webs. Nature 449 (7162): 599-602 (2007).
[4] Neutel, A. M., Heesterbeek, J. A. P. & de Ruiter, P. C. Stability in real food webs: Weak links in long
loops. Science 296, 1120-1123 (2002).
[5] de Ruiter, P. C., Neutel, A. M. & Moore, J. C. Energetics, patterns of interaction strengths, and stability in
real ecosystems. Science 269, 1257-1260 (1995).
[6] Yodzis, P. & Innes, S. Body size and consumer-resource dynamics. Am. Nat. 139, 1151-1175 (1992).
[7] de Roos AM, Schellekens T, van Kooten T, et al. Food-dependent growth leads to overcompensation in
stage-specific Biomass when mortality increases: The influence of maturation versus reproduction regulation.
Am. Nat. 170 (3): E59-E76 (2007)
Proposed Start Date of Award*:
2.
01 October 2008
The award must fall within the duration of the research grant
NERC SERVICES / FACILITIES REQUIRED (e.g. Radiocarbon, Stable Isotope, Remote Sensing Data)
If ‘Yes’, please give details.
Has an application for this work been made to the relevant facility?
Estimated Cost £
Y
N
N
3. Name of all supervisors
(including any CASE)
Present post
Length of
research
experience
Number of students currently being supervised who are in
the:
1st year
Prof. Corinne Le Quéré
Professor at
UEA
Dr Anje-Margriet Neutel Biosphere
Complexity
Analyst at BAS
Professor Eugene
Principal
Murphy
Investigator BAS Core
Programme
4.
2nd year
3rd year
3rd year+
TOTAL
15 years
1
4
2
0
7
13 years
0
0
0
0
0
23 years
0
0
2
1
3
Recent publications by supervisor(s) relevant to research area:
Berlow, E., Neutel, A. M., Cohen, J. E., et al. (2004). Interaction strengths in food webs: Issues and opportunities.
Journal of Animal Ecology 73, 585-598.
Croxall J.P., Trathan P.N. & Murphy E.J. (2002). Environmental change and Antarctic seabird populations. Science,
297 (5586): 1510-1514.
De Ruiter, P. C., Neutel, A. M. & Moore, J. C. (1994). Modelling food webs and nutrient cycling in agro-ecosystems.
Trends in Ecololgy and Evolution 9, 378-383.
De Ruiter, P. C., Neutel, A. M. & Moore, J. C. (1995). Energetics, patterns of interaction strengths, and stability in real
ecosystems. Science 269, 1257-1260.
Hassink, J., Neutel, A. M. & De Ruiter, P. C. (1994). C and N mineralization in sandy and loamy grassland soils: the role
of microbes and microfauna. Soil Biology and Biochemistry 26, 1565-1571.
Hill, S.L., Murphy, E.J., Reid, K., Trathan, P.N., & Constable, A.J. (2006) Modelling Southern Ocean ecosystems: krill,
the food-web, and the impacts of harvesting. Biological Reviews, 81, 581-608.
Murphy, E.J. (1995). Spatial - Structure of the Southern Ocean Ecosystem: Predator-Prey Linkages in Southern Ocean
Food Webs, Journal of Animal Ecology, 64: 333-347.
Murphy, E.J. & Reid, K. (2001) Modelling Southern Ocean krill population dynamics: biological processes generating
fluctuations in the South Georgia ecosystem. Marine Ecology Progress Series, 217:175-189.
Murphy E.J., Trathan, P.N., Watkins, J.L, Reid, K, Meredith, M.P., Forcada, J., Thorpe, S.E., Johnston, N. & Rothery, P.
2007b Climatically-driven fluctuations in Southern Ocean ecosystems. Proc. of the Royal Soc. B: Biological
Sciences
Neutel, A. M., Roerdink, J. B. T. M. & De Ruiter, P. C. (1994). Global stability of two-level detritus-decomposer food
chains. Journal of Theoretical Biology 171, 351-353.
Neutel, A. M., Heesterbeek, J. A. P. & De Ruiter, P. C. (2002). Stability in real food webs: Weak links in long loops.
Science 296, 1120-1123.
Neutel A. M., Heesterbeek, J.A.P., van de Koppel, J., et al. (2007). Reconciling complexity with stability in naturally
assembling food webs. Nature 449 (7162): 599-602.
Priddle, J., Boyd, I. L., Whitehouse, M. J., Murphy, E. J. & Croxall, J. P. 1998a Estimates of Southern Ocean primary
production - constraints from predator carbon demand and nutrient drawdown. Journal of Marine Systems 17, 275288.
Trathan, P. N., Forcada, J. and Murphy, E. J. 2007 Environmental forcing and Southern Ocean marine predator
populations: effects of climate change and variability. Phil Transactions of the Royal Society B 362.
doi:10.1098/rstb.2006.1953.
5. Relevance of this application to the proposed or any current research grant (give reference number if known). Please provide
any additional comments which Council should take into account when considering this application, including how you expect
the project to contribute (if at all) to national wellbeing, wealth creation and/or public service, indicating any potential end user
outputs.
This studentship will complement the sensitivity analysis to model complexity in the tied NERC application
G634605. It will provide a theoretical analysis of the impact of higher trophic-level model complexity on
phytoplankton-assemblage stability.
This studentship would benefit from the on-going development in the main project (G634605) and add
substantial value to it, because it will provide insight into how much biological structure is needed to
understand ecosystem functioning. The studentship will also benefit from the close links with a large group
of scientists working on Southern Ocean ecosystems, including expertise at all trophic levels in the food
web.
The modelling results will provide a basis to guide empirical research programs in that they will pin-point
the gaps in empirical knowledge, and map out the properties and spatial and temporal scales for which we
can expect an impact of higher trophic-level organisms on core ecosystem functioning and stability.
PART 2 – TO BE COMPLETED BY THE CASE PARTNER(S)
6.
CO-OPERATING BODY (CASE) DETAILS - to be completed by the CASE partner(s) where applicable
Name and Address of Co-operating (CASE) body:
1.
2.
Co-operating (CASE) Body Supervisor (s)
Title:
1.
Initials:
1.
Surname:
1.
Department
1.
Current Position
1.
2.
2.
2.
2.
2.
Tel:
1.
Fax:
1.
E-mail:
1.
2.
2.
2.
Description of work to be undertaken by the student at the premises of the CASE body and its role within the project:
Nature and frequency of contacts between the CASE body, student and supervisor (must be maintained throughout the duration of the award as
appropriate to the demands of the project):
Financial and other contributions from the CASE body (NOTE: CASE bodies must make a minimum contribution of £1000pa towards the student’s
maintenance, and it is expected that any additional support that is required for the student’s travel and subsistence whilst working at the CASE body’s
premises will be provided by the CASE partner).
Total value of funds to student for whole award
Has this company/organisation co-operated on a previous CASE studentship?
£
Y
N
PART 3 – TO BE COMPLETED BY THE INSTITUTION
7. CLASSIFICATION SCHEME FOR NERC SCIENCE
Please classify your proposal under the four headings of:
Science Area - Secondary Classification - Science Topic and ENRI (Earth & Natural Resource Issues).
Science Area (%one or more as relevant, totalling 100%)
Atmospheric
Earth
Freshwater
40
Marine
Secondary Classification (tick any as relevant)
Terrestrial
Polar N Polar S
Cross
Research
Council
Cofunded
ENRI (% as relevant, totalling 100%)
Biodiversity
40
60%
Science Based
Archaeology
60
See table below for codes
Science Topic (%one or more as relevant, totalling
100%)
Code
Code
Code
Code
3
5
6
10%
Earth
Observation
30%
Environmental
Risks & Hazards
Natural
Resource
Management
Global
Change
Pollution & Waste
60
%
SCIENCE TOPICS: SUMMARY LIST
For a list of definitions see: http://www.nerc.ac.uk/funding/application/topics.asp
Code
Science Topic
Code
Science Topic
Atmospheric kinetics
Ocean – atmosphere interactions
1
27
Behavioural ecology
Ocean circulation
2
28
Biogeochemical cycles
Palaeoenvironments
3
29
Boundary layer meteorology
Palaeobiology
4
30
Climate and climate change
Physics and chemistry of Earth materials
5
31
Community ecology
Planetary science
6
32
Conservation ecology
Pollution
7
33
Earth engineering
Population genetics and evolution
8
34
Earth resources
Population ecology
9
35
Earth surface processes
Quaternary science
10
36
Ecosystem-scale processes and land use
Radiative processes and effects
11
37
Ecotoxicology
Regional weather and extreme events
12
38
Environment and health
Science-based Archaeology
13
39
Environmental biotechnology
Sediments and sedimentary processes
14
40
Environmental genomics
Soils
15
41
Environmental informatics
Stratospheric processes
16
42
Environmental microbiology
Survey and monitoring
17
43
Environmental physiology
Systematics and taxonomy
18
44
Geohazards
Technology for environmental applications
19
45
Glacial and cryospheric systems
Tectonic processes
20
46
Hydrogeology
Tropospheric processes
21
47
Hydrological processes
Upper atmosphere processes and geospace
22
48
Land - atmosphere interactions
Volcanic processes
23
49
Land - ocean interactions
Water in the atmosphere
24
50
Large scale atmospheric dynamics and transport
Water quality
25
51
Mantle and core processes
26