Social-ecological system framework McGinnis, Michael D.; Ostrom, Elinor
Ecology and society,
01/2014, Letnik:
19, Številka:
2
Journal Article
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The social-ecological system (SES) framework investigated in this special issue enables researchers from diverse disciplinary backgrounds working on different resource sectors in disparate geographic ...areas, biophysical conditions, and temporal domains to share a common vocabulary for the construction and testing of alternative theories and models that determine which influences on processes and outcomes are especially critical in specific empirical settings. We summarize changes that have been made to this framework and discuss a few remaining ambiguities in its formulation. Specifically, we offer a tentative rearrangement of the list of relevant attributes of governance systems and discuss other ways to make this framework applicable to policy settings beyond natural resource settings. The SES framework will continue to change as more researchers apply it to additional contexts; the main purpose of this article is to delineate the version that served as the basis for the theoretical innovations and empirical analyses detailed in other contributions to this special issue.
Within the Institutional Analysis and Development (IAD) framework, the concept of an action situation generalizes a game to allow for endogenous changes in its rules. This article re-visits this core ...concept to explore its potential for serving as the foundation for a systematic approach to the construction of more elaborate models of complex policy networks in which overlapping sets of actors have the ability to influence the rules under which their strategic interactions take place. Networks of adjacent action situations can be built on the basis of the seven distinct types of rules that define an action situation or by representing generic governance tasks identified in related research on local public economies. The potential of this extension of the IAD framework is demonstrated with simplified network representations of three diverse policy areas (Maine lobster fisheries, international development assistance, and the contribution of faith-based organizations to U.S. welfare policy).
Ebullition (bubbling) is an important mechanism for the transfer of methane (CH4) from shallow waters to the atmosphere. Because of their stochastic nature, however, ebullition fluxes are difficult ...to accurately resolve. Hydroacoustic surveys have the potential to significantly improve the spatiotemporal observation of emission fluxes, but knowledge of bubble size distribution is also necessary to accurately assess local, regional, and global water body CH4 emission estimates. Therefore, we explore the importance of bubble size and small-scale flux variability on CH4 transport in and emissions from a reservoir with a bubble-size-calibrated echosounder that can efficiently and economically survey greater areas while still resolving individual bubbles. Using a postprocessing method that resolves bubble density, we found that the largest 10% of the >6700 observed bubbles were responsible for more than 65% of the total CH4 transport. Furthermore, the asymmetry of CH4 ebullition flux distribution and the high spatial heterogeneity of those fluxes suggests that inadvertently omitting emission hot spots (i.e., areas of high flux) could lead to significant underestimations of CH4 emissions from localized areas and potentially from entire water bodies. While the bubble sizes resolved by the hydroacoustic method may provide insight into the factors controlling ebullition (e.g., sediment type, carbon sedimentation), the better resolution of small-scale CH4 emission hot spots afforded by hydroacoustics will bring us closer to the true CH4 emission estimates from all shallow waters, be them lakes, reservoirs, or coastal oceans and seas.
There is growing concern about the transfer of methane originating from water bodies to the atmosphere. Methane from sediments can reach the atmosphere directly via bubbles or indirectly via vertical ...turbulent transport. This work quantifies methane gas bubble dissolution using a combination of bubble modeling and acoustic observations of rising bubbles to determine what fraction of the methane transported by bubbles will reach the atmosphere. The bubble model predicts the evolving bubble size, gas composition, and rise distance and is suitable for almost all aquatic environments. The model was validated using methane and argon bubble dissolution measurements obtained from the literature for deep, oxic, saline water with excellent results. Methane bubbles from within the hydrate stability zone (typically below ∼500 m water depth in the ocean) are believed to form an outer hydrate rim. To explain the subsequent slow dissolution, a model calibration was performed using bubble dissolution data from the literature measured within the hydrate stability zone. The calibrated model explains the impressively tall flares (>1300 m) observed in the hydrate stability zone of the Black Sea. This study suggests that only a small amount of methane reaches the surface at active seep sites in the Black Sea, and this only from very shallow water areas (<100 m). Clearly, the Black Sea and the ocean are rather effective barriers against the transfer of bubble methane to the atmosphere, although substantial amounts of methane may reach the surface in shallow lakes and reservoirs.
Oxic lake surface waters are frequently oversaturated with methane (CH
). The contribution to the global CH
cycle is significant, thus leading to an increasing number of studies and stimulating ...debates. Here we show, using a mass balance, on a temperate, mesotrophic lake, that ~90% of CH
emissions to the atmosphere is due to CH
produced within the oxic surface mixed layer (SML) during the stratified period, while the often observed CH
maximum at the thermocline represents only a physically driven accumulation. Negligible surface CH
oxidation suggests that the produced 110 ± 60 nmol CH
L
d
efficiently escapes to the atmosphere. Stable carbon isotope ratios indicate that CH
in the SML is distinct from sedimentary CH
production, suggesting alternative pathways and precursors. Our approach reveals CH
production in the epilimnion that is currently overlooked, and that research on possible mechanisms behind the methane paradox should additionally focus on the lake surface layer.
Stream networks have recently been discovered to be major but poorly constrained natural greenhouse gas (GHG) sources. A fundamental problem is that several measurement approaches have been used ...without cross-comparisons. Flux chambers represent a potentially powerful methodological approach if robust and reliable ways to use chambers on running water can be defined. Here we compare the use of anchored and freely drifting chambers on various streams with different flow velocities. The study clearly shows that (1) anchored chambers enhance turbulence under the chambers and thus elevate fluxes, (2) drifting chambers have a very small impact on the water turbulence under the chamber and thus generate more reliable fluxes, (3) the bias of the anchored chambers greatly depends on chamber design and sampling conditions, and (4) there is a promising method to reduce the bias from anchored chambers by using a flexible plastic foil collar to seal the chambers to the water surface, rather than having rigid chamber walls penetrating into the water. Altogether, these results provide novel guidance on how to apply flux chambers in running water, which will have important consequences for measurements to constrain the global GHG balances.
The Solar Wind Electrons Alphas and Protons experiment on the Parker Solar Probe (PSP) mission measures the three-dimensional electron velocity distribution function. We derive the parameters of the ...core, halo, and strahl populations utilizing a combination of fitting to model distributions and numerical integration for ∼100,000 electron distributions measured near the Sun on the first two PSP orbits, which reached heliocentric distances as small as ∼0.17 au. As expected, the electron core density and temperature increase with decreasing heliocentric distance, while the ratio of electron thermal pressure to magnetic pressure (βe) decreases. These quantities have radial scaling consistent with previous observations farther from the Sun, with superposed variations associated with different solar wind streams. The density in the strahl also increases; however, the density of the halo plateaus and even decreases at perihelion, leading to a large strahl/halo ratio near the Sun. As at greater heliocentric distances, the core has a sunward drift relative to the proton frame, which balances the current carried by the strahl, satisfying the zero-current condition necessary to maintain quasi-neutrality. Many characteristics of the electron distributions near perihelion have trends with solar wind flow speed, βe, and/or collisional age. Near the Sun, some trends not clearly seen at 1 au become apparent, including anticorrelations between wind speed and both electron temperature and heat flux. These trends help us understand the mechanisms that shape the solar wind electron distributions at an early stage of their evolution.
This guide provides definitions or brief explanations of all the major terms and concepts used in the Institutional Analysis and Development (IAD) framework. Also included are terms from the closely ...related frameworks on local public economies, public service industries, grammar of institutions, and social‐ecological systems (SES).
Aims.
We survey the electron heat flux observed by the Parker Solar Probe (PSP) in the near-Sun environment at heliocentric distances of 0.125–0.25 AU.
Methods.
We utilized measurements from the ...Solar Wind Electrons Alphas and Protons and FIELDS experiments to compute the solar wind electron heat flux and its components and to place these in context.
Results.
The PSP observations reveal a number of trends in the electron heat flux signatures near the Sun. The magnitude of the heat flux is anticorrelated with solar wind speed, likely as a result of the lower saturation heat flux in the higher-speed wind. When divided by the saturation heat flux, the resulting normalized net heat flux is anticorrelated with plasma beta on all PSP orbits, which is consistent with the operation of collisionless heat flux regulation mechanisms. The net heat flux also decreases in very high beta regions in the vicinity of the heliospheric current sheet, but in most cases of this type the omnidirectional suprathermal electron flux remains at a comparable level or even increases, seemingly inconsistent with disconnection from the Sun. The measured heat flux values appear inconsistent with regulation primarily by collisional mechanisms near the Sun. Instead, the observed heat flux dependence on plasma beta and the distribution of suprathermal electron parameters are both consistent with theoretical instability thresholds associated with oblique whistler and magnetosonic modes.
Very intense neutrino beams and large neutrino detectors will be needed in order to enable the discovery of CP violation in the leptonic sector. We propose to use the proton linac of the European ...Spallation Source currently under construction in Lund, Sweden, to deliver, in parallel with the spallation neutron production, a very intense, cost effective and high performance neutrino beam. The baseline program for the European Spallation Source linac is that it will be fully operational at 5 MW average power by 2022, producing 2 GeV 2.86 ms long proton pulses at a rate of 14 Hz. Our proposal is to upgrade the linac to 10 MW average power and 28 Hz, producing 14 pulses/s for neutron production and 14 pulses/s for neutrino production. Furthermore, because of the high current required in the pulsed neutrino horn, the length of the pulses used for neutrino production needs to be compressed to a few μs with the aid of an accumulator ring. A long baseline experiment using this Super Beam and a megaton underground Water Cherenkov detector located in existing mines 300–600 km from Lund will make it possible to discover leptonic CP violation at 5 σ significance level in up to 50% of the leptonic Dirac CP-violating phase range. This experiment could also determine the neutrino mass hierarchy at a significance level of more than 3 σ if this issue will not already have been settled by other experiments by then. The mass hierarchy performance could be increased by combining the neutrino beam results with those obtained from atmospheric neutrinos detected by the same large volume detector. This detector will also be used to measure the proton lifetime, detect cosmological neutrinos and neutrinos from supernova explosions. Results on the sensitivity to leptonic CP violation and the neutrino mass hierarchy are presented.
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