| 1. |
- Biggs, Duan, et al.
(författare)
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Are We Entering an Era of Concatenated Global Crises?
- 2011
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Ingår i: Ecology and Society. - 1708-3087. ; 16:2, s. 10-
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Tidskriftsartikel (refereegranskat)abstract
- An increase in the frequency and intensity of environmental crises associated with accelerating human-induced global change is of substantial concern to policy makers. The potential impacts, especially on the poor, are exacerbated in an increasingly connected world that enables the emergence of crises that are coupled in time and space. We discuss two factors that can interact to contribute to such an increased concatenation of crises: (1) the increasing strength of global vs. local drivers of change, so that changes become increasingly synchronized; and (2) unprecedented potential for the propagation of crises, and an enhanced risk of management interventions in one region becoming drivers elsewhere, because of increased connectivity. We discuss the oil-food-financial crisis of 2007 to 2008 as an example of a concatenated crisis with origin and ultimate impacts in far removed parts of the globe. The potential for a future of concatenated shocks requires adaptations in science and governance including (a) an increased tolerance of uncertainty and surprise, (b) strengthening capacity for early detection and response to shocks, and (c) flexibility in response to enable adaptation and learning.
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| 2. |
- Biggs, Reinette, et al.
(författare)
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Toward Principles for Enhancing the Resilience of Ecosystem Services
- 2012. - 37
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Ingår i: Annual Review Environment and Resources. - : Annual Reviews. - 1543-5938 .- 1545-2050. ; 37, s. 421-448
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Forskningsöversikt (refereegranskat)abstract
- Enhancing the resilience of ecosystem services (ES) that underpin human well-being is critical for meeting current and future societal needs, and requires specific governance and management policies. Using the literature, we identify seven generic policy-relevant principles for enhancing the resilience of desired ES in the face of disturbance and ongoing change in social-ecological systems (SES). These principles are (P1) maintain diversity and redundancy, (P2) manage connectivity, (P3) manage slow variables and feedbacks, (P4) foster an understanding of SES as complex adaptive systems (CAS), (P5) encourage learning and experimentation, (P6) broaden participation, and (P7) promote polycentric governance systems. We briefly define each principle, review how and when it enhances the resilience of ES, and conclude with major research gaps. In practice, the principles often co-occur and are highly interdependent. Key future needs are to better understand these interdependencies and to operationalize and apply the principles in different policy and management contexts.
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| 3. |
- Conversi, Alessandra, et al.
(författare)
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A holistic view of marine regime shifts
- 2015
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Ingår i: Philosophical Transactions of the Royal Society of London. Biological Sciences. - : The Royal Society. - 0962-8436 .- 1471-2970. ; 370:1659
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Forskningsöversikt (refereegranskat)abstract
- Understanding marine regime shifts is important not only for ecology but also for developing marine management that assures the provision of ecosystem services to humanity. While regime shift theory is well developed, there is still no common understanding on drivers, mechanisms and characteristic of abrupt changes in real marine ecosystems. Based on contributions to the present theme issue, we highlight some general issues that need to be overcome for developing a more comprehensive understanding of marine ecosystem regime shifts. We find a great divide between benthic reef and pelagic ocean systems in how regime shift theory is linked to observed abrupt changes. Furthermore, we suggest that the long-lasting discussion on the prevalence of top-down trophic or bottom-up physical drivers in inducing regime shifts may be overcome by taking into consideration the synergistic interactions of multiple stressors, and the special characteristics of different ecosystem types. We present a framework for the holistic investigation of marine regime shifts that considers multiple exogenous drivers that interact with endogenous mechanisms to cause abrupt, catastrophic change. This framework takes into account the time-delayed synergies of these stressors, which erode the resilience of the ecosystem and eventually enable the crossing of ecological thresholds. Finally, considering that increased pressures in the marine environment are predicted by the current climate change assessments, in order to avoid major losses of ecosystem services, we suggest that marine management approaches should incorporate knowledge on environmental thresholds and develop tools that consider regime shift dynamics and characteristics. This grand challenge can only be achieved through a holistic view of marine ecosystem dynamics as evidenced by this theme issue.
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| 4. |
- Dakos, Vasilis, et al.
(författare)
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Ecosystem tipping points in an evolving world
- 2019
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Ingår i: Nature Ecology & Evolution. - : Springer Science and Business Media LLC. - 2397-334X. ; 3:3, s. 355-362
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Forskningsöversikt (refereegranskat)abstract
- There is growing concern over tipping points arising in ecosystems because of the crossing of environmental thresholds. Tipping points lead to abrupt and possibly irreversible shifts between alternative ecosystem states, potentially incurring high societal costs. Trait variation in populations is central to the biotic feedbacks that maintain alternative ecosystem states, as they govern the responses of populations to environmental change that could stabilize or destabilize ecosystem states. However, we know little about how evolutionary changes in trait distributions over time affect the occurrence of tipping points and even less about how big-scale ecological shifts reciprocally interact with trait dynamics. We argue that interactions between ecological and evolutionary processes should be taken into account in order to understand the balance of feedbacks governing tipping points in nature.
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| 5. |
- de Boer, Erik J., et al.
(författare)
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Rapid succession of plant associations on the small ocean island of Mauritius at the onset of the Holocene
- 2013
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Ingår i: Quaternary Science Reviews. - : Elsevier BV. - 0277-3791 .- 1873-457X. ; 68, s. 114-125
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Tidskriftsartikel (refereegranskat)abstract
- The island of Mauritius offers the opportunity to study the poorly understood vegetation response to climate change on a small tropical oceanic island. A high-resolution pollen record from a 10 m long peat core from Kanaka Crater (560 m elevation, Mauritius, Indian Ocean) shows that vegetation shifted from a stable open wet forest Last Glacial state to a stable closed-stratified-tall-forest Holocene state. An ecological threshold was crossed at similar to 11.5 cal ka BP, propelling the forest ecosystem into an unstable period lasting similar to 4000 years. The shift between the two steady states involves a cascade of four abrupt (<150 years) forest transitions in which different tree species dominated the vegetation for a quasi-stable period of respectively similar to 1900, similar to 1100 and similar to 900 years. We interpret the first forest transition as climate-driven, reflecting the response of a small low topography oceanic island where significant spatial biome migration is impossible. The three subsequent forest transitions are not evidently linked to climate events, and are suggested to be driven by internal forest dynamics. The cascade of four consecutive events of species turnover occurred at a remarkably fast rate compared to changes during the preceding and following periods, and might therefore be considered as a composite tipping point in the ecosystem. We hypothesize that wet gallery forest, spatially and temporally stabilized by the drainage system, served as a long lasting reservoir of biodiversity and facilitated a rapid exchange of species with the montane forests to allow for a rapid cascade of plant associations.
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| 6. |
- Gladstone-Gallagher, Rebecca V., et al.
(författare)
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Social-ecological connections across land, water, and sea demand a reprioritization of environmental management
- 2022
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Ingår i: Elementa. - : University of California Press. - 2325-1026. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- Despite many sectors of society striving for sustainability in environmental management, humans often fail to identify and act on the connections and processes responsible for social–ecological tipping points. Part of the problem is the fracturing of environmental management and social–ecological research into ecosystem domains (land, freshwater, and sea), each with different scales and resolution of data acquisition and distinct management approaches. We present a perspective on the social–ecological connections across ecosystem domains that emphasize the need for management reprioritization to effectively connect these domains. We identify critical nexus points related to the drivers of tipping points, scales of governance, and the spatial and temporal dimensions of social–ecological processes. We combine real-world examples and a simple dynamic model to illustrate the implications of slow management responses to environmental impacts that traverse ecosystem domains. We end with guidance on management and research opportunities that arise from this cross-domain lens to foster greater opportunity to achieve environmental and sustainability goals.
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| 7. |
- Gsell, Alena Sonia, et al.
(författare)
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Evaluating early-warning indicators of critical transitions in natural aquatic ecosystems
- 2016
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424. ; 113:50, s. 8089-8095
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Tidskriftsartikel (refereegranskat)abstract
- Ecosystems can show sudden and persistent changes in state despite only incremental changes in drivers. Such critical transitions are difficult to predict, because the state of the system often shows little change before the transition. Early-warning indicators (EWIs) are hypothesized to signal the loss of system resilience and have been shown to precede critical transitions in theoretical models, paleo-climate time series, and in laboratory as well as whole lake experiments. The generalizability of EWIs for detecting critical transitions in empirical time series of natural aquatic ecosystems remains largely untested, however. Here we assessed four commonly used EWIs on long-term datasets of five freshwater ecosystems that have experienced sudden, persistent transitions and for which the relevant ecological mechanisms and drivers are well understood. These case studies were categorized by three mechanisms that can generate critical transitions between alternative states: competition, trophic cascade, and intraguild predation. Although EWIs could be detected in most of the case studies, agreement among the four indicators was low. In some cases, EWIs were detected considerably ahead of the transition. Nonetheless, our results show that at present, EWIs do not provide reliable and consistent signals of impending critical transitions despite using some of the best routinely monitored freshwater ecosystems. Our analysis strongly suggests that a priori knowledge of the underlying mechanisms driving ecosystem transitions is necessary to identify relevant state variables for successfully monitoring EWIs.
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| 8. |
- Lenton, Timothy M., et al.
(författare)
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A resilience sensing system for the biosphere
- 2022
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Ingår i: Philosophical Transactions of the Royal Society of London. Biological Sciences. - : The Royal Society. - 0962-8436 .- 1471-2970. ; 377:1857
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Tidskriftsartikel (refereegranskat)abstract
- We are in a climate and ecological emergency, where climate change and direct anthropogenic interference with the biosphere are risking abrupt and/or irreversible changes that threaten our life-support systems. Efforts are underway to increase the resilience of some ecosystems that are under threat, yet collective awareness and action are modest at best. Here, we highlight the potential for a biosphere resilience sensing system to make it easier to see where things are going wrong, and to see whether deliberate efforts to make things better are working. We focus on global resilience sensing of the terrestrial biosphere at high spatial and temporal resolution through satellite remote sensing, utilizing the generic mathematical behaviour of complex systems—loss of resilience corresponds to slower recovery from perturbations, gain of resilience equates to faster recovery. We consider what subset of biosphere resilience remote sensing can monitor, critically reviewing existing studies. Then we present illustrative, global results for vegetation resilience and trends in resilience over the last 20 years, from both satellite data and model simulations. We close by discussing how resilience sensing nested across global, biome-ecoregion, and local ecosystem scales could aid management and governance at these different scales, and identify priorities for further work.
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| 9. |
- Mesman, Jorrit P., 1993-, et al.
(författare)
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The role of internal feedbacks in shifting deep lake mixing regimes under a warming climate
- 2021
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Ingår i: Freshwater Biology. - : John Wiley & Sons. - 0046-5070 .- 1365-2427. ; 66:6, s. 1021-1035
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Forskningsöversikt (refereegranskat)abstract
- Climate warming is causing changes in the physics of deep lakes, such as longer summer stratification, increased water column stability, reduced ice cover, and a shallower depth of winter overturns. An ultimate consequence of warming would be a transition to a different mixing regime. Here we investigate the role of physical, chemical, and biological feedback mechanisms that unfold during a shift in mixing regime, and whether these feedbacks could prompt and stabilise the new regime. Although climate, interannual temperature variation, and lake morphometry are the main determinants of a mixing regime, when climate change causes shifts in mixing regime, internal feedback mechanisms may gain in importance and modify lake ecosystem functioning.We review the role of these feedbacks in three mixing regime shifts: from polymictic to seasonally stratified, from dimictic to monomictic, and from holomictic to oligomictic or meromictic.Polymictic lakes of intermediate depth (c. 3–10 m mean depth) could experience seasonal stratification if a stratification event triggers phytoplankton blooms or dissolved organic matter release, reducing transparency and therefore further heating the surface layer. However, this feedback is only likely to have influence in small and clear lakes, it would be easily disturbed by weather conditions, and the resulting stratified state does not remain stable in the long term, as stratification is lost in winter.The ice-albedo feedback might cause an accelerated shift from ice-covered (dimictic) to ice-free (monomictic) winters in sufficiently deep (mean depth 50 m or more) lakes, where temperature memory is carried over from one winter to the next. Nevertheless, there is an ongoing debate into whether this process can persist during natural weather variations and overcome self-stabilising mechanisms such as thermal insulation by snow. The majority of studies suggest that a gradual transition from dimictic to monomictic is more likely than an abrupt transition.A shift from a holomictic to a meromictic regime can occur if anoxia is triggered by incomplete mixing and an increase in deep-water density—through the accumulation of solutes—exceeds a density decrease by hypolimnetic warming. A shift to meromixis would strongly alter the biology of a lake and might be difficult to reverse. If solutes accumulate only minimally in the hypolimnion, an oligomictic regime is formed, in which years with complete and incomplete mixing alternate.Understanding the importance of feedback mechanisms and the role of biogeochemistry when lakes shift in mixing regime could lead to a better understanding of how climate change affects lake ecosystems.
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| 10. |
- Seekell, David A., et al.
(författare)
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Heteroskedasticity as a leading indicator of desertification in spatially explicit data
- 2015
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Ingår i: Ecology and Evolution. - : Wiley. - 2045-7758. ; 5:11, s. 2185-2192
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Tidskriftsartikel (refereegranskat)abstract
- Regime shifts are abrupt transitions between alternate ecosystem states including desertification in arid regions due to drought or overgrazing. Regime shifts may be preceded by statistical anomalies such as increased autocorrelation, indicating declining resilience and warning of an impending shift. Tests for conditional heteroskedasticity, a type of clustered variance, have proven powerful leading indicators for regime shifts in time series data, but an analogous indicator for spatial data has not been evaluated. A spatial analog for conditional heteroskedasticity might be especially useful in arid environments where spatial interactions are critical in structuring ecosystem pattern and process. We tested the efficacy of a test for spatial heteroskedasticity as a leading indicator of regime shifts with simulated data from spatially extended vegetation models with regular and scale-free patterning. These models simulate shifts from extensive vegetative cover to bare, desert-like conditions. The magnitude of spatial heteroskedasticity increased consistently as the modeled systems approached a regime shift from vegetated to desert state. Relative spatial autocorrelation, spatial heteroskedasticity increased earlier and more consistently. We conclude that tests for spatial heteroskedasticity can contribute to the growing toolbox of early warning indicators for regime shifts analyzed with spatially explicit data.
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