@article {4402, title = {Shifts in wind energy potential following land-use driven vegetation dynamics in complex terrain}, journal = {Science of The Total Environment}, volume = {639}, year = {2018}, month = {Jan-10-2018}, pages = {374 - 384}, abstract = {

Many mountainous regions with high wind energy potential are characterized by multi-scale variabilities of vegetation in both spatial and time dimensions, which strongly affect the spatial distribution of wind resource and its time evolution. To this end, we developed a coupled interdisciplinary modeling framework capable of assessing the shifts in wind energy potential following land-use driven vegetation dynamics in complex mountain terrain. It was applied to a case study area in the Romanian Carpathians. The results show that the overall shifts in wind energy potential following the changes of vegetation pattern due to different land-use policies can be dramatic. This suggests that the planning of wind energy project should be integrated with the land-use planning at a specific site to ensure that the expected energy production of the planned wind farm can be reached over its entire lifetime. Moreover, the changes in the spatial distribution of wind and turbulence under different scenarios of land-use are complex, and they must be taken into account in the micro-siting of wind turbines to maximize wind energy production and minimize fatigue loads (and associated maintenance costs). The proposed new modeling framework offers, for the first time, a powerful tool for assessing long-term variability in local wind energy potential that emerges from land-use change driven vegetation dynamics over complex terrain. Following a previously unexplored pathway of cause-effect relationships, it demonstrates a new linkage of agro- and forest policies in landscape development with an ultimate trade-off between renewable energy production and biodiversity targets. Moreover, it can be extended to study the potential effects of micro-climatic changes associated with wind farms on vegetation development (growth and patterning), which could in turn have a long-term feedback effect on wind resource distribution in mountainous regions.

}, issn = {00489697}, doi = {10.1016/j.scitotenv.2018.05.083}, url = {https://linkinghub.elsevier.com/retrieve/pii/S0048969718317182https://api.elsevier.com/content/article/PII:S0048969718317182?httpAccept=text/xmlhttps://api.elsevier.com/content/article/PII:S0048969718317182?httpAccept=text/plain}, author = {Fang, Jiannong and Peringer, Alexander and Stupariu, Mihai-Sorin and P{\u a}tru-Stupariu, Ileana and Buttler, Alexandre and Golay, Francois and Port{\'e}-Agel, Fernando} } @article {4404, title = {Disturbance-grazer-vegetation interactions maintain habitat diversity in mountain pasture-woodlands}, journal = {Ecological Modelling}, volume = {359}, year = {2017}, month = {Jan-09-2017}, pages = {301 - 310}, abstract = {

Low-intensity livestock grazing is a widespread management tool in order to maintain habitat diversity in mountain pasture-woodlands for nature conservation purposes. Historical photographs indicate that forest disturbance significantly contributed to forest-grassland mosaic pattern formation. Disturbance-grazer interactions are however poorly understood and the effects of logging or windthrow are rarely considered in management plans. Moreover, disturbance-grazer interactions are crucial for the maintenance of open habitats in the upcoming \“rewilding\” approach of nature conservation. We aimed to understand the effects of forest gap creation by the breakdown of senile trees or by single-tree cutting and of large forest openings by windthrow or logging on mosaic pattern formation in pasture-woodlands that were grazed by cattle and dominated by tree species with distinct regeneration ecology (Picea abies vs. Fagus sylvatica). We used the process-based model of pasture-woodland vegetation dynamics WoodPaM and newly implemented a forest disturbance routine. We simulated disturbance and grazing scenarios in an artificial mountain landscape and analyzed mosaic patterns with landscape metrics. We found that grazing in absence of disturbance promoted simply structured mosaics that were preconditioned by topography. Only large-scale forest disturbance disrupted this pattern and maintained the historical heterogeneous distribution of grassland communities across all habitat conditions (especially species-rich mountain grasslands on poor soil). This prerequisite is stronger in pasture-woodlands where the ecology of the dominant tree species promotes forest-grassland segregation (F. sylvatica in our case) and less in naturally thin-canopy mountain forest close to the tree line (P. abies). In wilderness areas, the very low density of grazers may limit the maintenance of open habitats regardless disturbance.

}, issn = {03043800}, doi = {10.1016/j.ecolmodel.2017.06.012}, url = {https://linkinghub.elsevier.com/retrieve/pii/S030438001730100Xhttps://api.elsevier.com/content/article/PII:S030438001730100X?httpAccept=text/xmlhttps://api.elsevier.com/content/article/PII:S030438001730100X?httpAccept=text/plain}, author = {Peringer, Alexander and Buttler, Alexandre and Gillet, Fran{\c c}ois and P{\u a}tru-Stupariu, Ileana and Schulze, Kiowa A. and Stupariu, Mihai-Sorin and Rosenthal, Gert} } @article {4405, title = {Landscape-scale simulation experiments test Romanian and Swiss management guidelines for mountain pasture-woodland habitat diversity}, journal = {Ecological Modelling}, volume = {330}, year = {2016}, month = {Jan-06-2016}, pages = {41 - 49}, abstract = {

Distinct guidelines have been proposed in Romania and Switzerland for the management of pasture-woodlands that either focused on the regulation of grazing pressure (Romanian production perspective) or overall tree cover (Swiss conservation perspective). However, the landscape structural diversity and the cover of forest-grassland ecotones, which are both crucial for nature conservation value, were not explicitly considered.

We aimed to compare the country-specific management guidelines regarding their efficiency for the conservation of the structurally diverse forest-grassland mosaics in the light of recent land-use and climate change.

In strategic simulation experiments using the process-based model of pasture-woodland ecosystems WoodPaM, we analyzed the relationships among drivers for the formation of mosaic patterns (grazing intensity, climate change) and the resulting landscape properties (tree cover, forest-grassland ecotones, mosaic structure) during the past until today (2000 AD).

The results showed that tree canopy densification following recent climate warming is likely to trigger landscape structural shifts. Medium grazing pressure promoted the development of the full range of pasture-woodland habitats and is therefore confirmed as a management strategy that balances agronomic demands and nature conservation value. Tree cover is rejected as a criteria to monitor pasture-woodland conservation status, because its relationship to landscape structural diversity and to the cover of forest-grassland ecotones did not hold for changing climate.

Our results suggest \“experimental-retrospective\” analysis as a useful tool to test conclusions from expert knowledge.

}, issn = {03043800}, doi = {10.1016/j.ecolmodel.2016.03.013}, url = {https://linkinghub.elsevier.com/retrieve/pii/S0304380016300795}, author = {Peringer, Alexander and Gillet, Fran{\c c}ois and Rosenthal, Gert and Stoicescu, Ioana and P{\u a}tru-Stupariu, Ileana and Stupariu, Mihai-Sorin and Buttler, Alexandre} } @article {4406, title = {Multi-scale feedbacks between tree regeneration traits and herbivore behavior explain the structure of pasture-woodland mosaics}, journal = {Landscape Ecology}, volume = {31}, year = {2016}, month = {Jan-05-2016}, pages = {913 - 927}, abstract = {

The pasture-woodlands of Central Europe are low-intensity grazing systems in which the structural richness of dynamic forest-grassland mosaics is causal for their high biodiversity. Distinct mosaic patterns in Picea abies- and Fagus sylvatica-dominated pasture-woodlands in the Swiss Jura Mountains suggest a strong influence of tree species regeneration ecology on landscape structural properties. At the landscape scale, however, cause-effect relationships are complicated by habitat selectivity of livestock.

}, issn = {0921-2973}, doi = {10.1007/s10980-015-0308-z}, url = {http://link.springer.com/10.1007/s10980-015-0308-z}, author = {Peringer, Alexander and Schulze, Kiowa A. and Stupariu, Ileana and Stupariu, Mihai-Sorin and Rosenthal, Gert and Buttler, Alexandre and Gillet, Fran{\c c}ois} } @article {4342, title = {Informing Marine Spatial Planning (MSP) with numerical modelling: A case-study on shellfish aquaculture in Malpeque Bay (Eastern Canada)}, journal = {Marine Pollution Bulletin}, volume = {100}, year = {2015}, month = {11/2015}, pages = {200 - 216}, issn = {0025326X}, doi = {10.1016/j.marpolbul.2015.08.048}, author = {Ram{\'o}n Filgueira and Guyondet, Thomas and C{\'e}dric Bacher and Comeau, Luc A.} } @article {4263, title = {A fully-spatial ecosystem-DEB model of oyster (Crassostrea virginica) carrying capacity in the Richibucto Estuary, Eastern Canada}, journal = {Journal of Marine Systems}, volume = {136}, year = {2014}, month = {08/2014}, pages = {42 - 54}, abstract = {The success of shellfish aquaculture as well as its sustainability relies on adjusting the cultured biomass to local ecosystem characteristics. Oyster filter-feeding activity can control phytoplankton concentration, reaching severe depletion in extreme situations, which can threaten ecological sustainability. A better understanding of oyster{\textendash} phytoplankton interaction can be achieved by constructing ecosystem models. In this study, a fully-spatial hydro- dynamic biogeochemical model has been constructed for the Richibucto Estuary in order to explore oyster carry- ing capacity. The biogeochemical model was based on a classical nutrient{\textendash}phytoplankton{\textendash}zooplankton{\textendash}detritus (NPZD) approach with the addition of a Dynamic Energy Budget (DEB) model of Crassostrea virginica. Natural variation of chlorophyll was used as a benchmark to define a sustainability threshold based on a resilience frame- work. Scenario building was applied to explore carrying capacity of the system. However, the complex geomor- phology of the Richibucto Estuary and the associated heterogeneity in water residence time, which is integral in estuarine functioning, indicate that the carrying capacity assessment must be specific for each area of the system. The model outcomes suggest that water residence time plays a key role in carrying capacity estimations through its influence on ecological resistance.}, issn = {09247963}, doi = {10.1016/j.jmarsys.2014.03.015}, author = {R. Filgueira and Guyondet, T. and Comeau, L.A. and J. Grant} } @article {4264, title = {Implementation of marine spatial planning in shellfish aquaculture management: modeling studies in a Norwegian fjord}, journal = {Ecological Applications}, volume = {24}, year = {2014}, pages = {832{\textendash}843}, abstract = {Shellfish carrying capacity is determined by the interaction of a cultured species with its ecosystem, which is strongly influenced by hydrodynamics. Water circulation controls the exchange of matter between farms and the adjacent areas, which in turn establishes the nutrient supply that supports phytoplankton populations. The complexity of water circulation makes necessary the use of hydrodynamic models with detailed spatial resolution in carrying capacity estimations. This detailed spatial resolution also allows for the study of processes that depend on specific spatial arrangements, e.g., the most suitable location to place farms, which is crucial for marine spatial planning, and consequently for decision support systems. In the present study, a fully spatial physical-biogeochemical model has been combined with scenario building and optimization techniques as a proof of concept of the use of ecosystem modeling as an objective tool to inform marine spatial planning. The object of this exercise was to generate objective knowledge based on an ecosystem approach to establish new mussel aquaculture areas in a Norwegian fjord. Scenario building was used to determine the best location of a pump that can be used to bring nutrient-rich deep waters to the euphotic layer, increasing primary production, and consequently, carrying capacity for mussel cultivation. In addition, an optimization tool, parameter estimation (PEST), was applied to the optimal location and mussel standing stock biomass that maximize production, according to a preestablished carrying capacity criterion. Optimization tools allow us to make rational and transparent decisions to solve a well-defined question, decisions that are essential for policy makers. The outcomes of combining ecosystem models with scenario building and optimization facilitate planning based on an ecosystem approach, highlighting the capabilities of ecosystem modeling as a tool for marine spatial planning.}, doi = {10.1890/13-0479.1}, url = {http://www.esajournals.org/doi/pdf/10.1890/13-0479.1}, author = {Ram{\'o}n Filgueira and Jon Grant and {\O}ivind Strand} } @article {4243, title = {Physiological indices as indicators of ecosystem status in shellfish aquaculture sites}, journal = {Ecological Indicators}, volume = {39}, year = {2014}, month = {04/2014}, pages = {134 - 143}, abstract = {The filtration activity of cultured mussels may exert a strong control on phytoplankton populations. Given that phytoplankton constitutes the base of marine food webs, carrying capacity in shellfish aquaculture sites has been commonly studied in terms of phytoplankton depletion. However, spatial and temporal variability of phytoplankton concentration in coastal areas present a methodological constraint for using phytoplankton depletion as an indicator in monitoring programs, and necessitates intensive field campaigns. The main goal of this study is to explore the potential of different bivalve performance indices for use as alternatives to phytoplankton depletion as cost-effective indicators of carrying capacity. For that, a fully spatial hydrodynamic{\textendash}biogeochemical coupled model of Tracadie Bay, an intensive mussel culture embayment located in Prince of Edward Island (Canada), has been constructed and scenario building has been used to explore the relationship between phytoplankton depletion and bivalve performance. Our underlying premise is that overstocking of bivalves leads to increased competition for food resources, i.e. phytoplankton, which may ultimately have a significant effect on bivalve growth rate and performance. Following this working hypothesis, the relationships among bay-scale phytoplankton depletion and three bivalve physiological indices, one static, condition index, and two dynamic, tissue mass and shell length growth rates, have been simulated. These three metrics present methodological advantages compared to phytoplankton depletion for incorporation into monitoring programs. Although significant correlations among phytoplankton depletion and the three physiological indices have been observed, shell length growth rate is shown as the most sensitive indicator of carrying capacity, followed by tissue mass growth rate and then by condition index. These results demonstrate the potentiality of using bivalve physiological measurements in monitoring programs as indicators of ecosystem status.}, issn = {1470160X}, doi = {10.1016/j.ecolind.2013.12.006}, url = {http://www.sciencedirect.com/science/article/pii/S1470160X13004962}, author = {R. Filgueira and Guyondet, T. and Comeau, L.A. and J. Grant} } @article {4242, title = {Storm-induced changes in coastal geomorphology control estuarine secondary productivity}, journal = {Earth{\textquoteright}s Future}, year = {2014}, month = {01/2014}, pages = {n/a - n/a}, abstract = {Estuarine ecosystems are highly sensitive not only to projected effects of climate change such as ocean warming, acidification, and sea-level rise but also to the incidence of nor{\textquoteright}easter storms and hurricanes. The effects of storms and hurricanes can be extreme, with immediate impact on coastal geomorphology and water circulation, which is integral to estuarine function and consequently to provision of ecosystem services. In this article, we present the results of a natural estuarine-scale experiment on the effects of changes in coastal geomorphology on hydrodynamics and aquaculture production. A bay in Prince Edward Island, Canada, was altered when a nor{\textquoteright}easter storm eroded a second tidal inlet through a barrier island. Previous field and modeling studies allowed a comparison of prestorm and post-storm circulation, food limitation by cultured mussels, and aquaculture harvest. Dramatic increases in mussel production occurred in the year following the opening of the new inlet. Model studies showed that post-storm circulation reduced food limitation for cultured mussels, allowing greater growth. Climate change is expected to have severe effects on the delivery of marine ecosystem services to human populations by changing the underlying physical-biological coupling inherent to their functioning.}, doi = {10.1002/2013EF000145}, url = {http://onlinelibrary.wiley.com/doi/10.1002/2013EF000145/abstract;jsessionid=DBD0FB7B2443BD9C9D658F85A42F41FD.f04t04}, author = {Ram{\'o}n Filgueira and Guyondet, Thomas and Comeau, Luc A. and Jon Grant} } @article {4241, title = {Ecosystem modelling for ecosystem-based management of bivalve aquaculture sites in data-poor environment}, journal = {Aquacult Environ Interact}, volume = {4}, year = {2013}, pages = {117-133}, chapter = {117}, abstract = {Although models of carrying capacity have been around for some time, their use in aquaculture management has been limited. This is partially due to the cost involved in generating and testing the models. However, the use of more generic and flexible models could facilitate the implementation of modelling in management. We have built a generic core for coupling biogeochemical and hydrodynamic models using Simile (www.simulistics.com), a visual simulation environment software that is well-suited to accommodate fully spatial models. Specifically, Simile integrates PEST (model-independent parameter estimation, Watermark Numerical Computing, www.pesthomepage.org), an optimization tool that uses the Gauss-Marquardt-Levenberg algorithm and can be used to estimate the value of a parameter, or set of parameters, in order to minimize the discrepancies between the model results and a dataset chosen by the user. The other critical aspect of modelling exercises is the large amount of data necessary to set up, tune and groundtruth the ecosystem model. However, ecoinformatics and improvements in remote sensing procedures have facilitated acquisition of these datasets, even in data-poor environments. In this paper we describe the required datasets and stages of model development necessary to build a biogeochemical model that can be used as a decision-making tool for bivalve aquaculture management in data-poor environments.}, doi = {10.3354/aei00078}, url = {http://www.int-res.com/abstracts/aei/v4/n2/p117-133/}, author = {R. Filgueira and J. Grant and R. Stuart and M. S. Brown} } @article {4213, title = {A physical{\textendash}biogeochemical coupling scheme for modeling marine coastal ecosystems}, journal = {Ecological Informatics}, volume = {7}, year = {2012}, pages = {71-80}, doi = {http://dx.doi.org/10.1016/j.ecoinf.2011.11.007}, url = {http://www.sciencedirect.com/science/article/pii/S1574954111000975}, author = {Ram{\'o}n Filgueira and Jon Grant and C{\'e}dric Bacher and Michel Carreau} } @article {1899, title = {A Box Model for Ecosystem-Level Management of Mussel Culture Carrying Capacity in a Coastal Bay}, journal = {Ecosystems}, year = {2009}, abstract = {

The carrying capacity of shellfish aquaculture is determined by the interaction of cultured species with the ecosystem, particularly food availability to suspension feeders. A multiple box dynamic ecosystem model was constructed to examine the carrying capacity for mussel (Mytilus edulis) aquaculture in Tracadie Bay, Prince of Edward Island, Canada. Criteria for carrying capacity were based on chlorophyll concentration. The model was run in two different years (1998 and 1999) in which time series for three points inside the bay and a point outside the bay were available. This data set allows spatial validation of the ecosystem model and assessment of its sensitivity to changes in boundary conditions. The model validation process indicated that the differential equations and parameters used in the simulation provided robust prediction of the ecological dynamics within the bay. Results verified that mussel biomass exerts top-down control of phytoplankton populations.

}, doi = {10.1007/s10021-009-9289-6}, author = {Ramon Filgueira and Jon Grant} } @inbook {1536, title = {Chapter Seven Integrated Modelling Frameworks for Environmental Assessment and Decision Support}, booktitle = {Developments in Integrated Environmental Assessment}, volume = {3}, year = {2008}, pages = {101-118}, publisher = { Elsevier}, organization = { Elsevier}, chapter = {7}, abstract = {

In this chapter we investigate the motivation behind the development of modelling frameworks that explicitly target the environmental domain. Despite many commercial and industrial-strength frameworks being available, we claim that there is a definite niche for environmental-specific frameworks. We first introduce a general definition of what is an environmental integrated modelling framework, leading to an outline of the requirements for a generic software architecture for such frameworks. This identifies the need for a knowledge layer to support the modelling layer and an experimentation layer to support the execution of models.

The chapter then focuses on the themes of knowledge representation, model management and model execution. We advocate that appropriate knowledge representation and management tools can facilitate model integration and linking. We stress that a model development process adhering to industry standards and good practices, called \“model engineering,\” is to be pursued. We focus on the requirements of the experimental frame, which can ensure transparency and traceability in the execution of simulation scenarios and optimisation problems associated with complex integrated assessment studies.

A promising trend for knowledge representation is the use of ontologies that have the capacity to elicit the meaning of knowledge in a manner that is logical, consistent and understandable by computers and the knowledge worker community. This new path in knowledge-based computing will support retention of institutional knowledge, while putting modelling back in the hands of modellers. Environmental modelling will then become a conceptual activity, focusing on model design rather than model implementation, with code generation being delegated to some degree to ontology-aware tools. In this respect, we envision the whole model lifecycle to change drastically, becoming more of a theoretical activity and less of a coding-intensive, highly engineering-oriented task.

}, keywords = {environmental integrated modelling frameworks, knowledge representation, model engineering, model management, modelling frameworks}, isbn = {9780080568867}, doi = {doi:10.1016/S1574-101X(08)00607-8}, author = {A. E. Rizzoli and G. Leavesley and J. C. Ascough II and R. M. Argent and I. N. Athanasiadis and V. Brilhante and F. H. A. Claeys and O. David and M. Donatelli and P. Gijsbers and D. Havlik and A. Kassahun and P. Krause and N. W. T. Quinn and H. Scholten and R. S. Sojda and F. Villa}, editor = {A. J. Jakeman and A. A. Voinov and A. E. Rizzoli and S. H. Chen} } @proceedings {1560, title = {CONCEPT MAPS FOR COMBINING HARD AND SOFT SYSTEM THINKING IN THE MANAGEMENT OF SOCIO-ECOSYSTEMS}, year = {2008}, url = {http://cmc.ihmc.us/cmc2008papers/cmc2008-p190.pdf}, author = {Franco Salerno and Emanuele Cuccillato and Robert Muetzelfeldt and Francesco Giannino and Birendra Bajracharya and Paolo Caroli and Gaetano Viviano and Anna Staiano and Fabrizio Carten{\`\i}, and Stefano Mazzoleni and Gianni Tartari} } @article {1539, title = {A box model of carrying capacity for suspended mussel aquaculture in Lagune de la Grande-Entr{\'e}e, Iles-de-la-Madeleine, Qu{\'e}bec }, journal = {Ecological Modelling,}, volume = {200}, year = {2007}, month = {1/2007}, pages = {193-206}, abstract = {

An object-oriented model of environment\–mussel aquaculture interactions and mussel carrying-capacity within Lagune de la Grande-Entr\ée (GEL), Iles-de-la-Madeleine, Qu\ébec, was constructed to assist in development of sustainable mussel culture in this region. A multiple box ecosystem model for GEL tied to the output of a hydrodynamic model was constructed using Simile software, which has inherent ability to represent spatial elements and specify water exchange between modelled regions. Mussel growth and other field data were used for model validation. Plackett\–Burman sensitivity analysis demonstrated that a variety of bioenergetic parameters of zooplankton and phytoplankton submodels were important in model outcomes. Model results demonstrated that mussel aquaculture can be further developed throughout the lagoon. At present culture densities, phytoplankton depletion is minimal, and there is little food limitation of mussel growth. Results indicated that increased stocking density of mussels in the existing farm will lead to decreased mass per individual mussel. Depending on the location of new farm emplacement within the lagoon, implementation of new aquaculture sites either reduced mussel growth in the existing farm due to depletion of phytoplankton, or exhibited minimum negative impact on the existing farm. With development throughout GEL, an excess of phytoplankton was observed during the year in all modelled regions, even at stocking densities as high as 20\ mussels\ m\−3. Although mussels cultured at this density do not substantially impact the ecosystem, their growth is controlled by the flux of phytoplankton food and abundance of zooplankton competitors. This model provides an effective tool to examine expansion of shellfish farming to new areas, balancing culture location and density.

}, keywords = {Aquaculture, Carrying-capacity, Ecosystem model, Magdalen Islands, Mussels}, doi = {doi:10.1016/j.ecolmodel.2006.07.026}, author = {Jon Grant and Kristian J. Curran and Thomas L. Guyondet and Guglielmo Tita and C{\'e}dric Bacher and Vladimir Koutitonsky and Michael Dowd} } @article {1538, title = {The EROI of U.S. offshore energy extraction: A net energy analysis of the Gulf of Mexico}, journal = {Ecological Economics}, volume = {63}, year = {2007}, month = {08/2007}, pages = {355-364}, abstract = {

In 2004, the U.S. Department of the Interior{\textquoteright}s Minerals Management Service estimated that 49\% of the oil and 57\% of the natural gas yet to be discovered offshore in the United States are located in the Gulf of Mexico Outer Continental Shelf region. While the existence of these energy resources is critical to the nation{\textquoteright}s future economic well being, of equal importance is the amount of already extracted energy that will be required to deliver the new fuel to society in a useful form. The difference between the two energy quantities is the net supply. In many respects, net energy is the most relevant measure of fuel supply because it represents the energy available to produce final-demand economic goods and services. Unfortunately, there currently exists no standard procedure for determining net energy, and so the data are extremely limited and inconsistent. In this paper, we present an \“energy return on investment\”, or \“EROI\”-based approach. EROI is defined as the ratio of gross energy produced by an energy supply process to the total, direct plus indirect, energy cost of its production. If the EROI of an energy supply process is known, then it{\textquoteright}s net energy output can be derived easily given gross production data. Below, we specify an empirical computer model programmed to simulate the productivity dynamics of offshore energy extraction in the Gulf of Mexico and estimate the EROI of the \"offshore process\" over a twenty-year period (1985\–2004). At the conclusion of the simulation, the model calculates the EROI of the process to range from 10 to 25, depending on how energy costs have been defined. In comparison, it has been estimated that the EROI of U.S. domestic petroleum extraction in the 1930s was approximately 100.

}, keywords = {EROI, Net energy, Offshore energy extraction}, doi = {doi:10.1016/j.ecolecon.2007.02.015}, author = {Mark Gately} }