scholarly journals An extended patch-dynamic framework for food chains in fragmented landscapes

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Jinbao Liao ◽  
Jiehong Chen ◽  
Zhixia Ying ◽  
David E. Hiebeler ◽  
Ivan Nijs
Keyword(s):  
Current Model ◽  
Habitat Destruction ◽  
Pair Approximation ◽  
Species Dispersal ◽  
Patch Occupancy ◽  
Community Patterns ◽  
Fragmented Landscapes ◽  
Dynamic Framework ◽  
Patch Dynamic ◽  
Patch Connectivity

Abstract Habitat destruction, a key determinant of species loss, can be characterized by two components, patch loss and patch fragmentation, where the former refers to the reduction in patch availability, and the latter to the division of the remaining patches. Classical metacommunity models have recently explored how food web dynamics respond to patch loss, but the effects of patch fragmentation have largely been overlooked. Here we develop an extended patch-dynamic model that tracks the patch occupancy of the various trophic links subject to colonization-extinction-predation dynamics by incorporating species dispersal with patch connectivity. We found that, in a simple food chain, species at higher trophic level become extinct sooner with increasing patch loss and fragmentation due to the constraint in resource availability, confirming the trophic rank hypothesis. Yet, effects of fragmentation on species occupancy are largely determined by patch loss, with maximal fragmentation effects occurring at intermediate patch loss. Compared to the spatially explicit simulations that we also performed, the current model with pair approximation generates similar community patterns especially in spatially clustered landscapes. Overall, our extended framework can be applied to model more complex food webs in fragmented landscapes, broadening the scope of existing metacommunity theory.

scholarly journals Erratum: Corrigendum: An extended patch-dynamic framework for food chains in fragmented landscapes

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Jinbao Liao ◽  
Jiehong Chen ◽  
Zhixia Ying ◽  
David E. Hiebeler ◽  
Ivan Nijs
Keyword(s):  
Food Chains ◽  
Fragmented Landscapes ◽  
Dynamic Framework ◽  
Patch Dynamic

scholarly journals Breeding biology and post-fledging dispersal of red-crowned parakeets (Cyanoramphus novaezelandiae) translocated to a fenced mainland sanctuary

2021 ◽  
Author(s):  
◽  
Ellen Irwin
Keyword(s):  
Reproductive Success ◽  
Human Impacts ◽  
Release Site ◽  
Habitat Destruction ◽  
Breeding Biology ◽  
Food Sources ◽  
Lifetime Reproductive Success ◽  
Species Dispersal ◽  
Dispersal Patterns ◽  
Mammalian Predators

<p>With human impacts like habitat destruction and climate change contributing to range contractions in species, translocations stand out as an important tool for conserving species suffering from these effects. However, an understanding of the life history of many threatened species prior to translocation is often lacking, but critical for translocation success. For example, dispersal away from the release site—particularly when a protected release site is surrounded by unmanaged habitat—can result in translocation failure, and therefore successful translocation practice must include an understanding of a species’ dispersal patterns. I conducted a study examining the breeding biology and post-fledging dispersal of a population of red-crowned parakeets Cyanoramphus novaezelandiae), or kakariki, recently translocated to a mainland sanctuary in Wellington, New Zealand. The sanctuary, ZEALANDIA, is fenced to exclude invasive mammalian predators; however, birds can and do leave. Approximately one-third of juveniles that dispersed outside the sanctuary were killed by predators. Kakariki post-fledging dispersal was male-biased, possibly driven by inbreeding avoidance, and distance dispersed decreased with increasing body condition. Parental age may have also influenced offspring dispersal. In addition, I found that kakariki reproductive success may be affected by age, and estimated lifetime reproductive success was >30 fledglings by age five. Conservation initiatives could work on controlling predators in currently unprotected reserves and around food sources that kakariki targeted, particularly in summer and autumn when many plants are fruiting and recently fledged juveniles are more active. Future translocations should consider selecting younger birds to translocate to take advantage of their high lifetime reproductive success and therefore improve viability of populations.</p>

Using experimental reintroductions to resolve the roles of habitat quality and metapopulation dynamics on patch occupancy in fragmented landscapes

2021 ◽  
Author(s):  
Doug P. Armstrong ◽  
Rebecca L. Boulton ◽  
Nikki McArthur ◽  
Susanne Govella ◽  
Nic Gorman ◽  
...  
Keyword(s):  
Habitat Quality ◽  
Metapopulation Dynamics ◽  
Patch Occupancy ◽  
Fragmented Landscapes

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.

A patch-dynamic framework for food web metacommunities

2009 ◽  
Vol 3 (4) ◽  
pp. 223-237 ◽  
Author(s):  
Pradeep Pillai ◽  
Michel Loreau ◽  
Andrew Gonzalez
Keyword(s):  
Food Web ◽  
Dynamic Framework ◽  
Patch Dynamic

scholarly journals Predicting patch occupancy in fragmented landscapes at the rangewide scale for an endangered species: an example of an American warbler

2011 ◽  
Vol 18 (2) ◽  
pp. 158-167 ◽  
Author(s):  
Bret A. Collier ◽  
Julie E. Groce ◽  
Michael L. Morrison ◽  
John C. Newnam ◽  
Andrew J. Campomizzi ◽  
...  
Keyword(s):  
Endangered Species ◽  
Patch Occupancy ◽  
Fragmented Landscapes

Patch-occupancy dynamics in fragmented landscapes

1994 ◽  
Vol 9 (4) ◽  
pp. 131-135 ◽  
Author(s):  
Ilkka Hanski
Keyword(s):  
Patch Occupancy ◽  
Fragmented Landscapes ◽  
Occupancy Dynamics

scholarly journals Non-shared dispersal networks with heterogeneity promote species coexistence in hierarchical competitive communities

2019 ◽  
Author(s):  
Helin Zhang ◽  
Jinbao Liao
Keyword(s):  
Species Coexistence ◽  
Spatial Competition ◽  
Network Size ◽  
Natural Ecosystems ◽  
Species Dispersal ◽  
Patch Occupancy ◽  
Scale Free ◽  
Species Area ◽  
Shared Networks ◽  
Species Specific

AbstractThe competition-colonization trade-off has been a classic paradigm to understand the maintenance of biodiversity in natural ecosystems. However, species-specific dispersal heterogeneities are not well integrated into our general understanding of how spatial coexistence emerges between competitors. Combining both network and metapopulation approaches, we construct a spatially explicit, patch-occupancy dynamic model for communities with hierarchically preemptive competition, to explore species coexistence in shared vs. non-shared dispersal networks with contrasting heterogeneities (including regular, random, exponential and scale-free networks). Our model shows that species with the same demography (i.e. identical colonization and extinction rates) cannot coexist stably in shared networks (i.e. the same dispersal pathways), regardless of dispersal heterogeneity. In contrast, increasing dispersal heterogeneity (even at very low levels of heterogeneity) in non-shared networks can greatly promote spatial coexistence, owing to the segregation-aggregation mechanism by which each species is restricted to self-organized clusters with a core of the most connected patches. However, these competitive patterns are largely mediated by species life-history attributes, for example, a unimodal biodiversity response to an increase of species dispersal rate emerges in non-shared heterogeneous networks, with species richness peaking at intermediate dispersal levels. Interestingly, increasing network size can foster species coexistence, leading to a monotonic increase in species-area curves. This strongly suggests that, unexpectedly, many more species can co-occur than the number of limiting resources. Overall, this modelling study, filling the gap between network structure and spatial competition, provides new insights into the coexistence mechanisms of spatial heterogeneity.

Stochastic Spatiotemporal Patterns of Metapopulation Occupancy in Dynamic Wetlandscapes

2020 ◽  
Author(s):  
Leonardo Enrico Bertassello ◽  
James Jawtiz ◽  
Enrico Bertuzzo ◽  
Gianluca Botter ◽  
Jason Hoverman ◽  
...  
Keyword(s):  
Spatial Organization ◽  
Spatiotemporal Patterns ◽  
Species Dispersal ◽  
Patch Occupancy ◽  
Patchy Habitat ◽  
Patchy Habitats ◽  
Patch Occupancy Model ◽  
Dynamic Landscapes ◽  
Dynamic Stochastic

&lt;p&gt;Dynamic internal feedbacks and stochastic external shocks drive the spatial organization and heterogeneity of patchy habitats, and thus the temporal variability of patch suitability and accessibility. Such spatiotemporal shifts impact species dispersal among patches and metapopulation persistence. Here, we extended the widely recognized concepts of patch-occupancy and metapopulation capacity from static to dynamic patchy habitats, with isolated wetlands embedded in uplands as the case study. We present a new metapopulation modeling approach by linking a hydrological model for wetland variability with a dynamic stochastic patch-occupancy model. In two case study wetlandscapes, we evaluate (1) spatiotemporal dynamics of wetland hydrologic regimes, and patch suitability and connectivity driven by stochastic hydroclimatic forcing, and (2) spatiotemporal patterns of patch occupancy and&amp;#160;metapopulation dispersal dynamics. Our modeling results reveal the importance of specific connected patches that serve as persistent hubs and form the backbone of dispersal corridors to support species dispersal in fragmented dynamic landscapes. Our analyses reveal that the interplay between stochastic hydroclimatic forcing and patchy habitat structure could drive species to extinction when specific thresholds are crossed.&lt;/p&gt;

scholarly journals Fragmented landscapes, road mortality and patch connectivity: modelling influences on the dispersal of Eurasian lynx

2004 ◽  
Vol 41 (4) ◽  
pp. 711-723 ◽  
Author(s):  
STEPHANIE KRAMER-SCHADT ◽  
ELOY REVILLA ◽  
THORSTEN WIEGAND ◽  
URS BREITENMOSER
Keyword(s):  
Road Mortality ◽  
Eurasian Lynx ◽  
Fragmented Landscapes ◽  
Patch Connectivity
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