This PhD offers opportunity to research a frontline question in ecology: What makes an ecosystem resistant to change when faced with natural or anthropogenically generated stress and disturbance? Specifically: is resilience generated by a few key species, or is it derived from overall biodiversity? You will address these questions, focusing on salt marshes that have great importance to the natural protection of our coastline, which is threatened by erosion from emerging climate change. You will join a dynamic and highly interactive team of students and researchers that are interested in the wider functioning of the coastal zone environment. Candidates with ecological, hydrological and/or physical interests are warmly encouraged to apply for this multi-disciplinary studentship.
STUDY BACKGROUND
Our coasts are eroding at an alarming rate. Salt marshes provide natural coastal protection and environmental management seeks to maximise this ‘ecosystem service’. Many marshes appear resilient to coastal erosion: episodes of area loss are followed by periods of compensatory re-growth (1). Other marshes suffer permanent area loss. The biological influence on such marsh-scale erosion and resilience processes are unclear, although there are indications that species composition can influence marsh processes: some species are particularly efficient at reducing wave energy and trapping sediment (2), and geographical spread of the invasive cordgrass, Spartina anglica, has been associated with marsh area expansion (3). It is possible that plant diversity will enhance sediment stability and facilitate resilience: Plant roots bind sediments (4) and high plant diversity, with a morphologically varied root-net, might provide a more holistic stabilisation of sediment than single species communities. The majority of studies have examined the role of community composition on ecological processes at small scales and in controlled conditions (5), to avoid the influence of natural environmental variation on experimental responses. Yet, the degree of biological control of ecological processes will greatly depend on environmental setting. For instance: ecosystem recovery from disturbance is strongly influenced by nutrient/productivity regimes (6), marsh accretion rates are linked to local sediment supply (7), and marsh lateral erodability is affected by sediment grain size (4) and organic content (7). This PhD will therefore examine the biological control of marsh erosion at realistic landscape scales.
AIMS AND OBJECTIVES
The study will examine the role of saltmarsh community composition on marsh resilience to erosion, using manipulative experiments, and direct and remote observations of community responses to stress and disturbance. Main objectives:
(1) To GIS-map the area changes of eroding and accreting marshes, and to correlate these changes to historical information on community composition and environmental characteristics.
(2) To measure the hydrological energy, sediment stability and rate of fine-scale erosion in marshes of different erosion-accretion histories.
(3) To test in controlled laboratory and field conditions the erodability of communities with different species and sediment particulate and organic composition.
(4) To synthesise the collected data into simple ecological modelling of community control of marsh resilience.
TRAINING
You will be trained in experimental ecology, GIS, and the use of field and laboratory hydrological instruments and flumes. Email for further methodological details.
This studentship with the School of Ocean Sciences at Bangor University will be funded on a competitive basis by NERC for an October 2012 start. Studentships will be offered based on the excellence of individual candidate applications. Please apply directly to mwskov@bangor.ac.uk in the form of a covering letter and CV, including the names and contact details of two referees. Referees will not be contacted until candidates have been shortlisted for interview.
For eligibility please see http://www.nerc.ac.uk/funding/available/postgrad/eligibility.asp
(1) van Koppel J et al. (2005) American Naturalist 165: E1-E12
(2) Bouma TJ et al. (2005) Ecology 86:2187-2199
(3) Rosso PH et al. (2006) Remote Sensing of Environment 100:295 – 306
(4) Feagin et al. (2009) PNAS 106:10109–10113
(5) Hector A and Bagchi R (2007) Nature 448:188-191
(6) Alberti J et al. (2011) Journal of Vegetation Science 22:216–224
(7) Kirwan M and Temmerman S (2009) Quaternary Science Reviews 28:1801–1808
http://www.bangor.ac.uk/oceansciences/pgrad/PhD_studentships.php
STUDY BACKGROUND
Our coasts are eroding at an alarming rate. Salt marshes provide natural coastal protection and environmental management seeks to maximise this ‘ecosystem service’. Many marshes appear resilient to coastal erosion: episodes of area loss are followed by periods of compensatory re-growth (1). Other marshes suffer permanent area loss. The biological influence on such marsh-scale erosion and resilience processes are unclear, although there are indications that species composition can influence marsh processes: some species are particularly efficient at reducing wave energy and trapping sediment (2), and geographical spread of the invasive cordgrass, Spartina anglica, has been associated with marsh area expansion (3). It is possible that plant diversity will enhance sediment stability and facilitate resilience: Plant roots bind sediments (4) and high plant diversity, with a morphologically varied root-net, might provide a more holistic stabilisation of sediment than single species communities. The majority of studies have examined the role of community composition on ecological processes at small scales and in controlled conditions (5), to avoid the influence of natural environmental variation on experimental responses. Yet, the degree of biological control of ecological processes will greatly depend on environmental setting. For instance: ecosystem recovery from disturbance is strongly influenced by nutrient/productivity regimes (6), marsh accretion rates are linked to local sediment supply (7), and marsh lateral erodability is affected by sediment grain size (4) and organic content (7). This PhD will therefore examine the biological control of marsh erosion at realistic landscape scales.
AIMS AND OBJECTIVES
The study will examine the role of saltmarsh community composition on marsh resilience to erosion, using manipulative experiments, and direct and remote observations of community responses to stress and disturbance. Main objectives:
(1) To GIS-map the area changes of eroding and accreting marshes, and to correlate these changes to historical information on community composition and environmental characteristics.
(2) To measure the hydrological energy, sediment stability and rate of fine-scale erosion in marshes of different erosion-accretion histories.
(3) To test in controlled laboratory and field conditions the erodability of communities with different species and sediment particulate and organic composition.
(4) To synthesise the collected data into simple ecological modelling of community control of marsh resilience.
TRAINING
You will be trained in experimental ecology, GIS, and the use of field and laboratory hydrological instruments and flumes. Email for further methodological details.
Funding Notes:
This studentship with the School of Ocean Sciences at Bangor University will be funded on a competitive basis by NERC for an October 2012 start. Studentships will be offered based on the excellence of individual candidate applications. Please apply directly to mwskov@bangor.ac.uk in the form of a covering letter and CV, including the names and contact details of two referees. Referees will not be contacted until candidates have been shortlisted for interview.
For eligibility please see http://www.nerc.ac.uk/funding/available/postgrad/eligibility.asp
References:
(1) van Koppel J et al. (2005) American Naturalist 165: E1-E12
(2) Bouma TJ et al. (2005) Ecology 86:2187-2199
(3) Rosso PH et al. (2006) Remote Sensing of Environment 100:295 – 306
(4) Feagin et al. (2009) PNAS 106:10109–10113
(5) Hector A and Bagchi R (2007) Nature 448:188-191
(6) Alberti J et al. (2011) Journal of Vegetation Science 22:216–224
(7) Kirwan M and Temmerman S (2009) Quaternary Science Reviews 28:1801–1808
http://www.bangor.ac.uk/oceansciences/pgrad/PhD_studentships.php
Application Deadline:
01 February 2012
