Intrinsic influences on establishment and dispersal success in fragmented landscapes: A spatially-explicit individual-based approach

2016 ◽  
Author(s):  
Audrey Lustig
Keyword(s):  
Spatially Explicit ◽  
Fragmented Landscapes ◽  
Dispersal Success

Incorporating behavior-based indices of connectivity into spatially explicit population models

2012 ◽  
Vol 90 (2) ◽  
pp. 222-236 ◽  
Author(s):  
C.E. Rizkalla ◽  
R.K. Swihart
Keyword(s):  
Population Models ◽  
Spatially Explicit ◽  
Patch Occupancy ◽  
Ecological Processes ◽  
Forest Patch ◽  
Fragmented Landscapes ◽  
Direct Observations ◽  
Behavior Based ◽  
Potential Methods ◽  
Parameter Values

Measuring connectivity in fragmented landscapes remains a central problem in ecology. Connectivity metrics range from descriptors of landscape structure to direct observations of a species’ ability to move to and colonize a forest patch. We constructed individual-based spatially explicit population models for a guild of forest rodents in Indiana to test the ability of structural and actual, or behavioral, measures of connectivity to predict patch and landscape occupancy and abundance. Model accuracy was assessed using comparisons with data from trapping studies. Predicted abundances within patches correlated with empirical data for five out of six species, but predicted patterns of patch occupancy corresponded with observations for only one species. Discrepancies may be due to inaccurate parameter values or the absence from the models of ecological processes such as conspecific attraction and competition. Nonetheless, the models demonstrated the utility of patch immigration as a measure of connectivity in explaining population abundance in fragmented landscapes. We discuss potential methods of collecting these behavior-based data.

scholarly journals Habitat specialization interacts with habitat amount to determine dispersal success of rodents in fragmented landscapes

2013 ◽  
Vol 94 (3) ◽  
pp. 714-726 ◽  
Author(s):  
Thomas Püttker ◽  
Adriana A. Bueno ◽  
Camila dos Santos de Barros ◽  
Simone Sommer ◽  
Renata Pardini
Keyword(s):  
Habitat Specialization ◽  
Habitat Amount ◽  
Fragmented Landscapes ◽  
Dispersal Success

scholarly journals Effects of mis-alignment between dispersal traits and landscape structure on dispersal success in fragmented landscapes

2019 ◽  
Vol 6 (1) ◽  
pp. 181702 ◽  
Author(s):  
Justine L. Atkins ◽  
George L. W. Perry ◽  
Todd E. Dennis
Keyword(s):  
Landscape Structure ◽  
Extinction Risk ◽  
Suitable Habitat ◽  
Biological Traits ◽  
Heterogeneous Environments ◽  
Fragmented Landscapes ◽  
Habitat Patches ◽  
Trade Offs ◽  
Risk Of Predation ◽  
Dispersal Success

Dispersal is fundamental to population dynamics and hence extinction risk. The dispersal success of animals depends on the biophysical structure of their environments and their biological traits; however, comparatively little is known about how evolutionary trade-offs among suites of biological traits affect dispersal potential. We developed a spatially explicit agent-based simulation model to evaluate the influence of trade-offs among a suite of biological traits on the dispersal success of vagile animals in fragmented landscapes. We specifically chose traits known to influence dispersal success: speed of movement, perceptual range, risk of predation, need to forage during dispersal, and amount of suitable habitat required for successful settlement in a patch. Using the metric of relative dispersal success rate, we assessed how the costs and benefits of evolutionary investment in these biological traits varied with landscape structure. In heterogeneous environments with low habitat availability and scattered habitat patches, individuals with more equal allocation across the trait spectrum dispersed most successfully. Our analyses suggest that the dispersal success of animals in heterogeneous environments is highly dependent on hierarchical interactions between trait trade-offs and the geometric configurations of the habitat patches in the landscapes through which they disperse. In an applied sense, our results indicate potential for ecological mis-alignment between species' evolved suites of dispersal-related traits and altered environmental conditions as a result of rapid global change. In many cases identifying the processes that shape patterns of animal dispersal, and the consequences of abiotic changes for these processes, will require consideration of complex relationships among a range of organism-specific and environmental factors.

Agent-Based Computational Model

2017 ◽  
Author(s):  
Joshua M. Epstein
Keyword(s):  
Computational Model ◽  
Bounded Rationality ◽  
Time Scales ◽  
Spatially Explicit ◽  
Agent Based ◽  
Affective Component ◽  
Elementary Type ◽  
Social Component ◽  
Different Time Scales

This part describes the agent-based and computational model for Agent_Zero and demonstrates its capacity for generative minimalism. It first explains the replicability of the model before offering an interpretation of the model by imagining a guerilla war like Vietnam, Afghanistan, or Iraq, where events transpire on a 2-D population of contiguous yellow patches. Each patch is occupied by a single stationary indigenous agent, which has two possible states: inactive and active. The discussion then turns to Agent_Zero's affective component and an elementary type of bounded rationality, as well as its social component, with particular emphasis on disposition, action, and pseudocode. Computational parables are then presented, including a parable relating to the slaughter of innocents through dispositional contagion. This part also shows how the model can capture three spatially explicit examples in which affect and probability change on different time scales.

scholarly journals Territories of state-led aquaculture risk management: Thailand’s Plang Yai program

2020 ◽  
pp. 239965442096524
Author(s):  
Mariska JM Bottema ◽  
Simon R Bush ◽  
Peter Oosterveer
Keyword(s):  
Risk Management ◽  
Policy Instruments ◽  
Spatially Explicit ◽  
Financial Risks ◽  
Shared Resources ◽  
Globalizing World ◽  
Farmer Behavior ◽  
Key Policy ◽  
The Individual ◽  
High Degree

The Thai aquaculture sector faces a range of production, market and financial risks that extend beyond the private space of farms to include public spaces and shared resources. The Thai state has attempted to manage these shared risks through its Plang Yai (or ‘Big Area’) agricultural extension program. Using the lens of territorialization, this paper investigates how, through the Plang Yai program, risk management is institutionalized through spatially explicit forms of collaboration amongst farmers and between farmers and (non-)state actors. We focus on how four key policy instruments brought together under Plang Yai delimited multiple territories of risk management over shrimp and tilapia production in Chantaburi and Chonburi provinces. Our findings demonstrate how these policy instruments address risks through dissimilar but overlapping territories that are selectively biased toward facilitating the individual management of production risks, whilst enabling both the individual and collective management of market and financial risks. This raises questions about the suitability of addressing aquaculture risks by controlling farmer behavior through state-led designation of singular, spatially explicit areas. The findings also indicate the multiple roles of the state in territorializing risk management, providing a high degree of flexibility, which is especially valuable in landscapes shared by many users, connected to (global) value chains and facing diverse risks. In doing so we demonstrate that understanding the territorialization of production landscapes in a globalizing world requires a dynamic approach recognizing the multiplicity of territories that emerge in risk management processes.

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