Connectivity Restoration Research Articles

Distributed connectivity restoration in networks of movable sensor nodes

In wireless sensor networks, hostile deployment terrains make resource constrained sensor nodes vulnerable to failures. Sometimes, even a single node failure can partition a network into many disjoint segments and can fail the application mission completely. Since, in most scenarios manual intervention is not possible and hence network must have self-healing capability by detecting and recovering faults at its own. In this paper, a distributed connectivity restoration (DCR) scheme is proposed which on node failure(s) reconstructs the network topology by using cascaded node movements enabling self-healing capability in the network. The DCR is based on partial network information including topological overhead associated with each node. The selection of befitting nodes to be relocated during cascaded movement is done strategically by using partial network information such that the relocation and message overheads are reduced. Ns-2 based simulation experiments are performed to evaluate the performance of the proposed scheme and is compared with other baseline approaches.

Facilitation Fish Migration above the Discharge Sill Located on the Ialomiţa River Near Cave Ialomicioara

Abstract Longitudinal connectivity restoration of watercourses is a major duty for scientists (biologists, hydro engineers, chemists etc.) that, by the means of technical exchange via conferences, projects, workshops, universities, and institutions demonstrate the major importance of a natural (non-anthropic) function of the lotic ecosystems. On the Ialomiţa River, the discharge sills located downstream from Padina chalet block the migration of some fish species, such as the brown trout (Salmo trutta) and the bullhead (Cottus gobio), prohibiting access to foraging areas and springs. Water Framework Directive 60/2000 / EC provides a legal framework for restoring “good status” of longitudinal and lateral connectivity of watercourses. Our proposed solution I can be applied to other discharge sills and dams sized between 3m and 6m high, and, where feasible can utilize existing power sources of some discharge sills. Solution II’s concepts allow the dimples inside the concrete plate to serve as a rest and recovery area for migratory species. Such benefits that ensure upstream/downstream fish migration while allowing discharge management to continue is unattainable in conventional systems. After solution II is applied the discharge sill does not lose any baseline characteristics while maintaining the original hydro-technical design objective, flood dissipation.

Novel approach for replacement of a failure node in wireless sensor network

In the recent years, there has been a growing interest in wireless sensor networks (WSN). Network's lifetime depends on energy efficiency and load balancing where connectivity is a very important factor. However, such connectivity can be lost due to the failure of some sensor nodes which creates disruptions to the network operations, lead to a reconfiguration of the network by generating energy losses, or in another case, the network mission fails. Energy conservation is a very important problem in WSN. In this paper, we propose a new solution for the connectivity problem when failure nodes are considered. The replacement of failed nodes is done in two phases: the first one is the search of redundant nodes using the clusterheads; the second phase is a restoration of connectivity. Performance evaluation of the proposed replacement approach shows that the results are globally satisfactory.

Adaptive Connectivity Restoration from Node Failure(s) in Wireless Sensor Networks.

Recently, there is a growing interest in the applications of wireless sensor networks (WSNs). A set of sensor nodes is deployed in order to collectively survey an area of interest and/or perform specific surveillance tasks in some of the applications, such as battlefield reconnaissance. Due to the harsh deployment environments and limited energy supply, nodes may fail, which impacts the connectivity of the whole network. Since a single node failure (cut-vertex) will destroy the connectivity and divide the network into disjoint blocks, most of the existing studies focus on the problem of single node failure. However, the failure of multiple nodes would be a disaster to the whole network and must be repaired effectively. Only few studies are proposed to handle the problem of multiple cut-vertex failures, which is a special case of multiple node failures. Therefore, this paper proposes a comprehensive solution to address the problems of node failure (single and multiple). Collaborative Single Node Failure Restoration algorithm (CSFR) is presented to solve the problem of single node failure only with cooperative communication, but CSFR-M, which is the extension of CSFR, handles the single node failure problem more effectively with node motion. Moreover, Collaborative Connectivity Restoration Algorithm (CCRA) is proposed on the basis of cooperative communication and node maneuverability to restore network connectivity after multiple nodes fail. CSFR-M and CCRA are reactive methods that initiate the connectivity restoration after detecting the node failure(s). In order to further minimize the energy dissipation, CCRA opts to simplify the recovery process by gridding. Moreover, the distance that an individual node needs to travel during recovery is reduced by choosing the nearest suitable candidates. Finally, extensive simulations validate the performance of CSFR, CSFR-M and CCRA.

Evaluating the effectiveness of restoring longitudinal connectivity for stream fish communities: towards a more holistic approach

A more holistic approach towards testing longitudinal connectivity restoration is needed in order to establish that intended ecological functions of such restoration are achieved. We illustrate the use of a multi-method scheme to evaluate the effectiveness of ‘nature-like’ connectivity restoration for stream fish communities in the River Deerness, NE England. Electric-fishing, capture-mark-recapture, PIT telemetry and radio-telemetry were used to measure fish community composition, dispersal, fishway efficiency and upstream migration respectively. For measuring passage and dispersal, our rationale was to evaluate a wide size range of strong swimmers (exemplified by brown trout Salmo trutta) and weak swimmers (exemplified by bullhead Cottus perifretum) in situ in the stream ecosystem. Radio-tracking of adult trout during the spawning migration showed that passage efficiency at each of five connectivity-restored sites was 81.3–100%. Unaltered (experimental control) structures on the migration route had a bottle-neck effect on upstream migration, especially during low flows. However, even during low flows, displaced PIT tagged juvenile trout (total n=153) exhibited a passage efficiency of 70.1–93.1% at two nature-like passes. In mark-recapture experiments juvenile brown trout and bullhead tagged (total n=5303) succeeded in dispersing upstream more often at most structures following obstacle modification, but not at the two control sites, based on a Laplace kernel modelling approach of observed dispersal distance and barrier traverses. Medium-term post-restoration data (2–3years) showed that the fish assemblage remained similar at five of six connectivity-restored sites and two control sites, but at one connectivity-restored headwater site previously inhabited by trout only, three native non-salmonid species colonized. We conclude that stream habitat reconnection should support free movement of a wide range of species and life stages, wherever retention of such obstacles is not needed to manage non-native invasive species. Evaluation of the effectiveness of fish community restoration in degraded streams benefits from a similarly holistic approach.

Node Stability Aware Energy Efficient Single Node Failure Recovery Approach for WSANs

The inter-actor connectivity is absolutely crucial in wireless sensor and actor networks for timely responses to events generated in the network. Due to the sparse nature of the network, the failure of one or more actor nodes results in network partitioning problem very frequently. To provide effective connectivity between disjoint segments, a self-healing solution is required with a small number of involved actor nodes. Also, their travelling distances should be small. To find stable actor nodes with their small moving distance for recovery is an NP-hard problem for large scale problems. However, the present literature requires broadcasting of route request packets to find the nodes or location for recovery, which consumes more network energy and consequently decreases the network lifetime. In this study, we propose an algorithm called Node Stability aware Connectivity Restoration Algorithm (NSCRA) to tackle such network partitioning problem in an energy efficient way with stable actor nodes. The stability of node(s) is calculated by using controlled packet forwarding probability (i.e. node route request) that is based upon neighbour energy decay rate. The selection of node is based on its backup power to avoid further network partitioning (i.e. overlapped or collocated failures) during recovery. Our proposed approach performs not only energy efficient recovery due to the participation of stable nodes, but also reduces the message overhead of the network. The experimental simulation results show that proposed approach outperforms other existing state-of-the-art approaches.

Enhanced brain-derived neurotrophic factor delivery by ultrasound and microbubbles promotes white matter repair after stroke

Ultrasound-targeted microbubble destruction (UTMD) has been shown to be a promising tool to deliver proteins to select body areas. This study aimed to analyze whether UTMD was able to deliver brain-derived neurotrophic factor (BDNF) to the brain, enhancing functional recovery and white matter repair, in an animal model of subcortical stroke induced by endothelin (ET)-1. UTMD was used to deliver BDNF to the brain 24 h after stroke. This technique was shown to be safe, given there were no cases of hemorrhagic transformation or blood brain barrier (BBB) leakage. UTMD treatment was associated with increased brain BDNF levels at 4 h after administration. Targeted ultrasound delivery of BDNF improved functional recovery associated with fiber tract connectivity restoration, increasing oligodendrocyte markers and remyelination compared to BDNF alone administration in an experimental animal model of white matter injury.

Obstacle Aware Connectivity Restoration for Disjoint Wireless Sensor Networks Using a Mix of Stationary and Mobile Nodes

In many applications, wireless sensor networks (WSNs) are deployed in inhospitable environments and therefore the nodes are at increased risk of failure. Large scale damage may partition a network into disjoint segments, which has very negative effect on the application. Mobile nodes have been exploited to act as mobile data collectors (MDCs) among segments to restore the connectivity of WSNs in the previous works. However, almost all of the works assumed that mobile nodes travel via a direct path, which may not be the case in real-world applications. In order to improve the applicability of the recovery strategy, obstacles should be taken into account. In this paper, we present an obstacle aware connectivity restoration strategy (OACRS) to fit these requirements. Our algorithm is designed for the scenarios that the number of available relays is less than the number of relays required to construct stable links and more than the number of segments. At first we construct and optimize the obstacle-avoiding minimum spanning tree of the segments and then determine the relays which keep static and the ones which act as MDCs. Finally we optimize the tour path of MDCs. The effectiveness of the proposed algorithm is validated through simulation experiments.

Monitoring Demographic and Genetic Responses of a Threatened Inland Trout to Habitat Reconnection

AbstractFreshwater fishes living in streams and rivers can be affected strongly by isolation, which causes a disproportionate degree of fragmentation in such dendritic systems. Isolation disrupts important ecological and migratory processes as well as the ability to access refuge habitats during disturbances. The restoration of habitat connectivity, then, should be a productive strategy for improving the resiliency of freshwater fish populations, but the local and broader ecological benefits of barrier removal are still poorly understood. We report on a long‐term, spatially intensive effort to monitor the responses of inland trout to stream habitat reconnection at a watershed scale, using both demographic and genetic techniques. Individual‐based genetic assignment uncovered clear evidence of movement into the primary tributary of interest, which had been blocked by an assumedly complete barrier, but the source population generating this movement varied over time. A linear mixed‐effect model suggested trout densities in this target stream increased threefold and the population sustained more large migratory‐sized individuals after habitat reconnection. Densities overall did not respond to fire or variable spring flows which occurred during the course of the study, but a negative parameter estimate for “year” suggested a possible decline in densities over the study period (although 95% CIs barely overlapped with 0). Population genetic metrics showed no change in population differentiation or metrics of genetic diversity in most cases, except for a significant decline in allelic richness in the target population. The effective biological reconnection documented in our study should improve population resiliency in the future, but we discuss the benefits of spatially intensive monitoring at a watershed scale and combined inference from both demographic and genetic metrics to uncover unexpectedly complex fish responses to habitat reconnection.Received September 18, 2015; accepted December 10, 2015 Published online April 27, 2016

Distributed Secure Coordinated Control for Multiagent Systems Under Strategic Attacks.

This paper studies a distributed secure consensus tracking control problem for multiagent systems subject to strategic cyber attacks modeled by a random Markov process. A hybrid stochastic secure control framework is established for designing a distributed secure control law such that mean-square exponential consensus tracking is achieved. A connectivity restoration mechanism is considered and the properties on attack frequency and attack length rate are investigated, respectively. Based on the solutions of an algebraic Riccati equation and an algebraic Riccati inequality, a procedure to select the control gains is provided and stability analysis is studied by using Lyapunov's method.. The effect of strategic attacks on discrete-time systems is also investigated. Finally, numerical examples are provided to illustrate the effectiveness of theoretical analysis.

Importance of partial barriers and temporal variation in flow when modelling connectivity in fragmented river systems

(1)The potential for catchment-scale connectivity modelling to help plan the restoration of connectivity in fragmented river systems is not yet well understood. In the present study the importance of two interrelated aspects of such modelling in determining predictions of connectivity are explored: (1) uncertainty in the passability of partial barriers (such as fish passes) and how the passabilities of series of partial barriers combine, and (2) temporal variation in connectivity due to flow.(2)Connectivity for Atlantic salmon (Salmo salar L.) and European perch (Perca fluviatilis L.) are modelled under alternative restoration strategies in the heavily impounded Don Catchment UK using two different methods for simulating the combined passability of series of partial barriers. Catchment-scale hydraulic and connectivity modelling were integrated using a novel method to account for the effect of flow on connectivity, achieved by consideration of flow-fish pass efficiency relationships and the treatment of gaps between habitat patches as partial barrier.(3)Modelled connectivity is very sensitive to uncertainty in barrier passability and the method used to simulate the combined passability of series of partial barriers. Flow also has a strong and complex effect on connectivity, with predicted temporal patterns being particularly dependent on how the combined impact of series of barriers is modelled. The sensitivity of the modelling constrains its capacity to predict the outcome of alternative connectivity restoration strategies. Nevertheless it does serve as a tool to think critically about connectivity restoration. If applied thoughtfully in full awareness of its limitations it can still be used assist in the planning and appraisal of alternative restoration options.(4)The modelling also provides a number of important practical insights. It shows that series of fish passes may be ineffective unless they operate at very high efficiencies. Small changes to flow-fish pass efficiency relationships can have a large effect on temporal patterns in connectivity. Overall fish pass efficiency is comprised of attraction and passage efficiencies which may differ in the extent to which they are determined by random processes. This likely has significant implications for the nature of the combined passability of series of fish passes.

Accounting for continuous species' responses to management effort enhances cost-effectiveness of conservation decisions

Limited resources available for conservation require prioritizing location and level of conservation management efforts to abate threats to species. Ideally, the optimal level of management effort to allocate to an action should be informed by the species' responses to actions. This would enhance cost-effectiveness of conservation recommendations. How continuous species' responses to varying levels of management effort (‘species response curves’) affect the cost of abating threats to species is poorly understood, but critical for cost-effective threat management.We developed an optimization approach to prioritize management efforts based on varying species' response curves. We tested our framework in the Mitchell River catchment, northern Australia, to find the optimal level of effort to allocate to restoration of river connectivity and riparian revegetation to improve persistence of freshwater fish species. We compared the results of our analysis against a traditional approach, which assumes that (1) an action is either fully implemented or not; and (2) when the action is fully implemented the species persists; when the action is not implemented, the species goes locally extinct.We showed that by using species response curves we can abate threats to species at budgets up to 20% lower than when applying the traditional approach. Our approach can aid identifying how much effort (i.e., area managed, timeframe of management or budget invested) to allocate to multiple actions, and where, to cost-effectively abate threats to species. This has the potential to significantly improve biodiversity outcomes when resources are limited, by improving precision of on-ground conservation decisions.

Evaluating the effectiveness of a Larinier super active baffle fish pass for European river lamprey Lampetra fluviatilis before and after modification with wall-mounted studded tiles

To help achieve effective longitudinal river connectivity, evaluation of the efficacy of fishway use by upstream-migrating fishes is needed. Larinier super active baffle (SAB) fishways are relatively cheap retrofit fish passes, suitable for low-head barriers, widespread in Europe and the most commonly fitted technical pass in Britain. Their suitability for non-salmonids, however, is poorly quantified. The efficacy of a 15% gradient SAB fishway and effects of flow regime and water temperature were tested for European river lamprey (Lampetra fluviatilis) using passive integrated transponder (PIT) and acoustic telemetry at a Crump weir on the River Derwent, Northeast England. In migration season 2013–14, over a wide range of flows, 90.1% of 350 tagged lamprey entered the fishway. One fish (0.3%) of those that entered the pass ascended successfully, even though measured water velocity was within laboratory-measured performance conditions for this species. Of 29 acoustic-tagged lamprey that visited the weir over the same period, four (13.8%) ascended it directly, during elevated flows. These data suggest that high turbulence and/or the physical characteristics of baffles may inhibit lamprey ascent of the pass. In migration season 2014–15, we tested the effect of adding studded modular plastic tiles adjacent to the fishway wall, employing PIT antennas separately interrogating the entrance and exit of each of the main fishway and tile routes. 85.8% (169) of 197 tagged lamprey entered the fishway, of which 72/169 (42.6%) entered the tile entrance. Passage efficiency of entrants was 7.1% (12/169), all of which used the tiled route. Reduced local flow velocity in combination with increased availability of resting habitat within the tiles may have facilitated increased passage. Although fishway passage efficiency increased after placement of the modular tiles, it remained half that measured for direct weir passage, both of which are inadequate for connectivity restoration. Quantitative tests of studded tiles placed on the sloping downstream weir face by comparison to control conditions may be more effective and are needed. This study demonstrates the importance of carrying out full-scale field tests to supplement possible solutions developed under laboratory conditions.

Genetic structure of a disjunct peripheral population of mountain sucker Pantosteus jordani in the Black Hills, South Dakota, USA

A peripheral population of mountain sucker, Pantosteus jordani, located in the Black Hills of South Dakota, USA, represents the eastern-most range of the species and is completely isolated from other populations. Over the last 50 years, mountain sucker populations have declined in the Black Hills, and now only occur in 40 % of the historic local range, with densities decreasing by more than 84 %.We used microsatellite DNA markers to estimate genetic diversity and to assess population structure across five streams where mountain suckers persist. We evaluated results in the context of recent ecological surveys to inform decisions about mountain sucker conservation. Significant allele frequency differences existed among sample streams (Global FST = 0.041) but there was no evidence of isolation by distance. Regionally, genetic effective size, Ne, was estimated to be at least 338 breeding individuals, but Ne within streams was expected to be less. Despite almost complete demographic isolation and reduced population size, there appears to be little evidence of inbreeding, but genetic drift and local isolation due to fragmentation probably best explains genetic structure in this peripheral mountain sucker population. Recommended strategies for population enhancement include restoration of stream connectivity and habitat improvement. Moreover, repatriation and assisted movement (i.e., gene flow) of fishes should maximize genetic diversity in stream fragments in the Black Hills region.

Changes in Functional Connectivity in Cultured Neuronal Networks During and After Transient Hypoxia of Varying Depths and Durations

The absence of oxygen in the core of a brain infarct quickly leads to cell death. Remaining but limited perfusion in the penumbra causes energy depletion, and disrupts synaptic transmission. Connectivity loss probably correlates with loss of cognition and restoration of connectivity seems crucial for possible recovery. However, in vivo, connectivity is difficult to assess due to limited access to the neurons and restricted experimental freedom. We studied the effects of hypoxia of varying depth and duration on functional connectivity in cultured neuronal networks on multi-electrode arrays. The first six hours of hypoxia resulted in reduced connectivity, followed by restoration of functional connectivity to baseline values upon re-oxygenation. Under persisting hypoxic conditions, beyond 6 hours some recovery of connectivity occurred, until ~24 hours, when connectivity further declined. In cultures that survived 48 hours of hypoxia, strength of persisting connections tended to remain around baseline values, but the number of remaining connections was significantly lower. The probability that a certain connection survived hypoxia was uncorrelated to its baseline strength. Still, even during hypoxia, new connections were formed. This occurred at a rate seemingly independent of the hypoxic conditions. On average, the loss of baseline connections exceeded the formation of new ones during hypoxia.

낙동강에서 격리된 과거 홍수터의 경계 설정과 토지이용 분석

우리나라의 하천은 대부분 치수를 위한 제방공사를 통해 직강화되어 있다. 하천과 홍수터의 횡적 연결성을 회복하기 위해서는 제방에 의해 격리된 과거 홍수터를 탐색하고 현재 토지이용현황을 파악하는 것이 중요하다. 본 연구의 목적은 낙동강에서 제내지의 격리된 과거 홍수터를 탐색하고 토지이용현황을 분석하는 것이다. 격리된 과거 홍수터는 지리정보시스템 (GIS)을 이용하여 낙동강 유역에서 수치표고모델, 연속수치지도 및 계획홍수위를 중첩하여 산출하였다. 탐색된 격리된 과거 홍수터의 토지이용현황은 토지피복도를 이용하여 분류하였다. 낙동강에서 격리된 과거 홍수터는 총 384지점이 탐색되었으며, 전체면적은 <TEX>$291km^2$</TEX>이었으며, 상류지역에서는 주로 산지에 둘러 쌓인 형태였고, 하류지역에서는 넓은 개활지의 형태로도 분포하였다. 격리된 과거 홍수터의 토지이용은 농경지 (73.9%)와 시가화지역 (12.7%)이 대부분을 차지하였다. 낙동강에서 탐색된 격리된 과거 홍수터와 토지이용현황은 향후 하천 복원 계획에 기초자료로 이용될 수 있을 것이다. For the restoration of lateral connectivity between rivers and floodplains, it is important to find the isolated former floodplain (IFF) and to characterize its land use in Korean rivers which were channelized by levee constructions for flood protection. The aim of this study is to map the IFF and to assess its land use pattern in the Nakdong River, Korea. The isolated former floodplain was explored by being overlapped on a digital elevation model (DEM), digital topographic map and design flood level using a geographical information system (GIS) in the Nakdong River basin. The land use of the identified IFF was classified by land-use map. The total number of IFFs was 384 and their total area was <TEX>$291km^2$</TEX>. While IFFs were usually surrounded by mountain forest in the upper river area, they tended to be located on wide plain areas in the downstream area of Nakdong River. The land use pattern of IFFs was mostly farmland (73.9%) and urban areas (12.7%) in the river. The results of delineation and land use analysis of isolated former floodplain in the Nakdong River will be used as a base line data for planning stream restoration.

Fault-Tolerant Algorithms for Connectivity Restoration in Wireless Sensor Networks.

As wireless sensor network (WSN) is often deployed in a hostile environment, nodes in the networks are prone to large-scale failures, resulting in the network not working normally. In this case, an effective restoration scheme is needed to restore the faulty network timely. Most of existing restoration schemes consider more about the number of deployed nodes or fault tolerance alone, but fail to take into account the fact that network coverage and topology quality are also important to a network. To address this issue, we present two algorithms named Full 2-Connectivity Restoration Algorithm (F2CRA) and Partial 3-Connectivity Restoration Algorithm (P3CRA), which restore a faulty WSN in different aspects. F2CRA constructs the fan-shaped topology structure to reduce the number of deployed nodes, while P3CRA constructs the dual-ring topology structure to improve the fault tolerance of the network. F2CRA is suitable when the restoration cost is given the priority, and P3CRA is suitable when the network quality is considered first. Compared with other algorithms, these two algorithms ensure that the network has stronger fault-tolerant function, larger coverage area and better balanced load after the restoration.

Seasonal Variation in Floodplain Biogeochemical Processing in a Restored Headwater Stream.

Stream and river restoration activities have recently begun to emphasize the enhancement of biogeochemical processing within river networks through the restoration of river-floodplain connectivity. It is generally accepted that this practice removes pollutants such as nitrogen and phosphorus because the increased contact time of nutrient-rich floodwaters with reactive floodplain sediments. Our study examines this assumption in the floodplain of a recently restored, low-order stream through five seasonal experiments. During each experiment, a floodplain slough was artificially inundated for 3 h. Both the net flux of dissolved nutrients and nitrogen uptake rate were measured during each experiment. The slough was typically a source of dissolved phosphorus and dissolved organic matter, a sink of NO3(-), and variable source/sink of ammonium. NO3(-) uptake rates were relatively high when compared to riverine uptake, especially during the spring and summer experiments. However, when scaled up to the entire 1 km restoration reach with a simple inundation model, less than 0.5-1.5% of the annual NO3(-) load would be removed because of the short duration of river-floodplain connectivity. These results suggest that restoring river-floodplain connectivity is not necessarily an appropriate best management practice for nutrient removal in low-order streams with legacy soil nutrients from past agricultural landuse.

Connectivity restoration of floodplain lakes: an assessment based on macroinvertebrate communities

Successful rehabilitation programmes of river–floodplain systems require understanding of environmental impacts of restoring hydrological connectivity. The present study is based on a field experiment carried out between 2008 and 2013 in a floodplain of a lowland river in northern Poland, in which two oxbow lakes isolated in the 1920s were reconnected to the main river channel. Water and macroinvertebrate samples were collected three to four times a year from six sites (n = 114). After reconnection, water quality in the oxbow lakes improved and diversity and abundance of macrozoobenthos increased, especially the density of Oligochaeta, Malacostraca, Trichoptera, Bivalvia and Gastropoda, while the density of Diptera decreased. Water flow and physico-chemical variables were the most important factors explaining their variance. A direct inflow of water into the reconnected oxbow lakes occurred only during the first 2 years of the study, followed by silting and overgrowing of the inlet to the upper arm. We propose that creating semi-lotic side channels connected to the river with one arm and only occasionally flushed with fresh river water is one of the most effective restoration strategies. However, at the whole river scale, the maintenance of diversified hydrological connections is the optimal solution.

Effects of habitat deterioration on the population genetics and conservation of the jaguar

Over the past century, human activities and their side effects have significantly threatened both ecosystems and resident species. Nevertheless, the genetic patterns of large felids that depend heavily on large and well-conserved continuous habitat remain poorly studied. Using the largest-ever contemporary genetic survey of wild jaguars (Panthera onca), we evaluated their genetic diversity and population structure in natural (Brazilian Amazon) and highly modified habitats (e.g. Cerrado, Caatinga) including those close to the northern (Yucatan, Mexico) and southern (Pantanal) edge of the species’ distribution range. Data from our set of microsatellites revealed a pronounced genetic structure, with four genetically differentiated geographic areas. Geographic distance was not the only factor influencing genetic differentiation through the jaguar range. Instead, we found evidence of the effects of habitat deterioration on genetic patterns: while the levels of genetic diversity in the Amazon forest, the largest continuum habitat for the species, are high and consistent with panmixia across large distances, genetic diversity near the edge of the species distribution has been reduced through population contractions. Mexican jaguar populations were highly differentiated from those in Brazil and genetically depauperated. An isolated population from the Caatinga showed the genetic effects of a recent demographic decline (within the last 20–30 years), which may reflect recent habitat degradation in the region. Our results demonstrate that the jaguar is highly sensitive to habitat fragmentation especially in human-dominated landscapes, and that in Brazil, the existing but limited genetic connectivity in the central protected areas should be maintained. These conclusions have important implications for the management of wide-ranging species with high dispersal and low population density. The restoration of ecological connectivity between populations over relatively large scales should be one of the main priorities for species conservation.