A fuzzy adaptive management framework is proposed for evaluating the vulnerability of an ecosystem to losing ecological integrity
as a result of climate change in an historical period (ex post evaluation) and selecting the best compensatory management action for reducing potential adverse impacts of future climate
change on ecological integrity in a future period (ex ante evaluation). The ex post evaluation uses fuzzy logic to test hypotheses about the extent of past ecosystem vulnerability to losing ecological integrity
and the ex ante evaluation uses the fuzzy minimax regret criterion to determine the best compensatory management action for alleviating potential
adverse impacts of climate change on ecosystem vulnerability to losing ecological integrity in a future period. The framework
accounts for uncertainty regarding: (1) the relationship between ecosystem vulnerability to losing ecological integrity and
ecosystem resilience; (2) the relationship between ecosystem resilience and the extent to which observed indicators of ecological
integrity depart from their thresholds; (3) the extent of future climate change; and (4) the potential impacts of future climate
change on ecological integrity and ecosystem resilience. The adaptive management element of the framework involves using the
ex post and ex ante evaluations iteratively in consecutive time segments of the future time period to determine if and when it is beneficial
to adjust compensatory management actions to climate change. A constructed example is used to demonstrate the framework. 相似文献
A conceptual model of the morphological development of the riparian margins of newly cut river channels is presented, suggesting
early feedbacks between vegetation growth and bank form. To test the model, observations of long and cross profiles, bank
sediment and seed deposition, and bank vegetation development were collected over the first 2 years of river flows through
a reach of the River Cole, West Midlands, UK. The newly created channel had a sinuous planform and varying asymmetric trapezoidal
cross section in sympathy with the planform. No imposed bedforms or bank reseeding were included in the design. Over the 2
years, development of bedforms was rapid, with bed sediment sorting and bank profile adjustment occurring more steadily and
progressively. Six classes of bank profile were identified by the end of the study period, illustrating close associations
with sediment aggradation, vegetation colonization, and growth patterns. Vegetation colonization of the banks was seeded predominantly
from local sources during the summer and from hydrochory (transport by the river) during the winter. Colonizing vegetation
on the riverbanks appeared to act as a significant propagule source by the second summer and as an increasingly important
roughness element, trapping both propagules and sediment, within the second year and providing early feedback into bank evolution.
As a result, the time required for riparian margin development in the conceptual model was found to be considerably longer
than observed in the study river. In addition, the role of surface wash/bank failure in modifying the bank profile and transporting
seeds onto the upper bank face during the first year of bank development was found to be important in initiating rapid bank
vegetation colonization and surface stabilization. This set of processes had not been incorporated in the initial conceptual
model. In relation to channel restoration, this research illustrates that in small temperate rivers of modest energy the provision
of an initial, sinuous corridor is sufficient to induce rapid development of fluvial features and vegetation cover without
the need to construct bed forms or to seed the banks. 相似文献
Oil spills at sea remain a serious threat to coastal settlements and sensitive ecosystems. Although the impacts of spills are contingent upon a variety of environmental factors and the chemical composition of the oil itself, spill effects can be long lasting in the pelagic zone with broad impacts on sensitive bacterial, microbial, plant, and animal communities. Efforts to contain, deflect, protect, and mitigate the effects of oil are increasingly important, given the massive social, economic, and environmental fallout connected to large spills. The purpose of this paper is to provide geographic perspective for protecting coastal areas with exclusion booms during oil spill events. Specifically, we introduce a generalized, extendable, spatial optimization model that simultaneously minimizes spill effects on vulnerable shorelines and the total costs associated with dispatching booms. The multiobjective model is solved with a weighting method to produce a Pareto optimal curve that reveals how the costs and protection operations change under different priorities. A simulated tanker spill near Mobile Bay, AL, USA, is used as an illustrative example.
Commonly used methods of evaluating the degree of consistency of protected area ecosystems with social and ecological carrying capacities are likely to result in decision errors. This occurs because such methods do not account for imprecision and uncertainty in inferring the degree of ecosystem consistency from an observed ecosystem indicator. This paper proposes a fuzzy adaptive management approach to determine whether a protected area ecosystem is consistent with ecological and social carrying capacities and, if not, to identify management actions that are most likely to achieve consistency when there is uncertainty about the current degree of consistency and how alternative management actions are likely to influence that consistency. The proposed approach is illustrated using a hypothetical example that uses an ecosystem indicator that reflects combinations of different levels of user satisfaction and conservation of threatened and endangered species. Application of the proposed fuzzy adaptive management approach requires a protected area manager to: (1) identify alternative management actions for achieving ecosystem consistency with social and ecological carrying capacities in each of several management zones in a protected area; (2) randomly assign alternative management actions to management zones; (3) define fuzzy sets for the ecosystem indicator and degree of ecosystem consistency, and fuzzy relations between the ecosystem indicator and the degree of ecosystem consistency; (4) monitor the indicator in each management zone; (5) define fuzzy sets based on the observed indicator in each management zone; and (6) combine the fuzzy sets defined on the observed indicator and the fuzzy relations between the indicator and the degree of ecosystem consistency to reach conclusions about the most likely degree of consistency for alternative management actions in each management zone. The fuzzy adaptive management approach proposed here is advantageous when the benefits of avoiding the decision errors inherent with crisp and stochastic decision rules outweigh the added cost of implementing the approach. 相似文献
Political and economic transitions have had substantial impacts on forest conservation. Where transitions are underway or anticipated, historical precedent and methods for systematically assessing future trends should be used to anticipate likely threats to forest conservation and design appropriate and prescient policy measures to counteract them. Myanmar is transitioning from an authoritarian, centralized state with a highly regulated economy to a more decentralized and economically liberal democracy and is working to end a long‐running civil war. With these transitions in mind, we used a horizon‐scanning approach to assess the 40 emerging issues most affecting Myanmar's forests, including internal conflict, land‐tenure insecurity, large‐scale agricultural development, demise of state timber enterprises, shortfalls in government revenue and capacity, and opening of new deforestation frontiers with new roads, mines, and hydroelectric dams. Averting these threats will require, for example, overhauling governance models, building capacity, improving infrastructure‐ and energy‐project planning, and reforming land‐tenure and environmental‐protection laws. Although challenges to conservation in Myanmar are daunting, the political transition offers an opportunity for conservationists and researchers to help shape a future that enhances Myanmar's social, economic, and environmental potential while learning and applying lessons from other countries. Our approach and results are relevant to other countries undergoing similar transitions. 相似文献
Effective management of large protected conservation areas is challenged by political, institutional and environmental complexity
and inconsistency. Knowledge generation and its uptake into management are crucial to address these challenges. We reflect
on practice at the interface between science and management of the Greater Blue Mountains World Heritage Area (GBMWHA), which
covers approximately 1 million hectares west of Sydney, Australia. Multiple government agencies and other stakeholders are
involved in its management, and decision-making is confounded by numerous plans of management and competing values and goals,
reflecting the different objectives and responsibilities of stakeholders. To highlight the complexities of the decision-making
process for this large area, we draw on the outcomes of a recent collaborative research project and focus on fire regimes
and wild-dog control as examples of how existing knowledge is integrated into management. The collaborative research project
achieved the objectives of collating and synthesizing biological data for the region; however, transfer of the project’s outcomes
to management has proved problematic. Reasons attributed to this include lack of clearly defined management objectives to
guide research directions and uptake, and scientific information not being made more understandable and accessible. A key
role of a local bridging organisation (e.g., the Blue Mountains World Heritage Institute) in linking science and management
is ensuring that research results with management significance can be effectively transmitted to agencies and that outcomes
are explained for nonspecialists as well as more widely distributed. We conclude that improved links between science, policy,
and management within an adaptive learning-by-doing framework for the GBMWHA would assist the usefulness and uptake of future
research. 相似文献
To identify the timing and location of spawning activity for bonefish (Albula spp.) in the Bahamian archipelago, we used an acoustic telemetry array spanning 44?km2 of shallow tidal creeks, flats, and adjacent deeper coastal waters near Cape Eleuthera. In two successive years, we surgically implanted transmitters in male and female bonefish (n?=?60) and examined their movement patterns within the array. Eight bonefish surgically implanted with transmitters as part of an earlier study were also tracked. In 2009, the telemetry information was complemented with snorkeling observations, underwater video, and manual tracking of the same acoustically tagged fish, as well as fish (n?=?3) gastrically implanted with continuous transmitters. During a period of 4?C7?days spanning the full and new moons, primarily between October and May, bonefish moved from their typical shallow flats and aggregated at sites in close proximity to the deep water drop-off of the Exuma Sound. Localized movements of the large schools of bonefish (often?>1,000 fish) at these presumptive pre-spawning aggregation sites included brief trips (<8?h) just after sunset until just prior to sunrise to the abyssal wall at the edge of the Exuma Sound (i.e.,?>1,000?m depth). Tagged bonefish detected at these aggregation sites were subsequently detected back in the tidal creeks and coastal flats shortly after new and full moons and remained at these more typical shallow sites (i.e.,?<2?m depth). Although we did not directly observe spawning events, we did observe ventral nudging and porpoising behaviors, which are potentially associated with courtship. Timing of the observed movements and possible courtship behaviors was coincident with periods when gametes were well developed. Collectively, our study provides the first objective evidence suggesting that the aggregation and seasonal migration of bonefish to deep shelf environments during certain moon phases is for spawning. 相似文献
Optimal parameters to eliminate machining chatter may be identified using analytical stability models which require the dynamics of the tool-holder-spindle-machine assembly. Receptance coupling substructure analysis (RCSA) provides a useful analytical tool to couple measured spindle-machine dynamics with tool-holder models to predict the tool point frequency response function for the assembly. Previous research has demonstrated a procedure to determine all required spindle receptances from a single measurement, where each mode within the measurement bandwidth was modeled as a fixed-free Euler–Bernoulli beam and fit using a manual, iterative procedure. Here, a particle swarm optimization technique is described for fitting the spindle-machine measurement using a fixed-free Euler–Bernoulli beam model for each mode. The performance of the optimization process and RCSA in predicting the tool tip frequency response is evaluated and the results are presented. 相似文献