Landscape connectivity among remnant populations of guanaco (Lama guanicoe Müller, 1776) in an arid region of Chile impacted by global change

Connectivity between populations plays a key role in the long-term persistence of species in fragmented habitats. It is an issue of concern for the preservation of biodiversity in drylands since landscapes in water limited environments are characterized by low habitat cover, high habitat fragmentation and harsh matrices, and are being rapidly degraded at the global scale. In this study, we modelled landscape connectivity between the 11 remnant coastal and Andean populations of the guanaco Lama guanicoe, an emblematic herbivore indigenous to South America, in Chile's arid Norte Chico. We first produced a habitat surface model to derive a regional surface resistance map; and we then used circuit theory to map functional connectivity, investigate the degree of isolation of the populations, and identify those that most contribute to the network patch connectivity. Predicted suitable habitat for L. guanicoe represented about 25% of the study region (i.e. 29,173 km2), and was heterogeneously distributed along a continuous stretch along the Andes, and discontinuous patches along the coast. As a result, we found that high connectivity current flows in the mid and high Andes formed a wide continuous connectivity corridor enabling connectivity between all the high Andean populations. Coastal populations, in contrast, were predicted to be more isolated. They only connect to medium and high altitude populations, and for two of them, animal movement was linked to the effectiveness of wildlife crossings. Based on the degree of connectivity, population size, and local threats, the coastal and the northernmost populations were identified as being most vulnerable, while the Andean populations appeared to be least at risk, even when located near areas of mining activity. Collectively, our results suggest that functional connectivity is an issue of concern for L. guanicoe in Chile’s Norte Chico, and that future conservation and management plans should adopt a landscape strategy aiming at conserving the functional connectivity between the coastal and Andean populations, and at protecting the habitat patches likely to act as stepping stones within the connectivity network.

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Landscape connectivity among remnant populations of guanaco (Lama guanicoe Müller, 1776) in an arid region of Chile impacted by global change

10.7287/peerj.preprints.3273v2 ◽

2018 ◽

Author(s):

Mara Ines Espinosa Herazo ◽

Nicolas Gouin ◽

Francisco Antonio Squeo Porcile ◽

David López Aspe ◽

Angéline Bertin

Keyword(s):

Functional Connectivity ◽

Animal Movement ◽

Landscape Connectivity ◽

Global Scale ◽

Surface Model ◽

Suitable Habitat ◽

Stepping Stones ◽

Lama Guanicoe ◽

Study Region ◽

Norte Chico

Connectivity between populations plays a key role in the long-term persistence of species in fragmented habitats. It is an issue of concern for the preservation of biodiversity in drylands since landscapes in water limited environments are characterized by low habitat cover, high habitat fragmentation and harsh matrices, and are being rapidly degraded at the global scale. In this study, we modelled landscape connectivity between the 11 remnant coastal and Andean populations of the guanaco Lama guanicoe, an emblematic herbivore indigenous to South America, in Chile's arid Norte Chico. We first produced a habitat surface model to derive a regional surface resistance map; and we then used circuit theory to map functional connectivity, investigate the degree of isolation of the populations, and identify those that most contribute to the network patch connectivity. Predicted suitable habitat for L. guanicoe represented about 25% of the study region (i.e. 29,173 km2), and was heterogeneously distributed along a continuous stretch along the Andes, and discontinuous patches along the coast. As a result, we found that high connectivity current flows in the mid and high Andes formed a wide continuous connectivity corridor enabling connectivity between all the high Andean populations. Coastal populations, in contrast, were predicted to be more isolated. They only connect to medium and high altitude populations, and for two of them, animal movement was linked to the effectiveness of wildlife crossings. Based on the degree of connectivity, population size, and local threats, the coastal and the northernmost populations were identified as being most vulnerable, while the Andean populations appeared to be least at risk, even when located near areas of mining activity. Collectively, our results suggest that functional connectivity is an issue of concern for L. guanicoe in Chile’s Norte Chico, and that future conservation and management plans should adopt a landscape strategy aiming at conserving the functional connectivity between the coastal and Andean populations, and at protecting the habitat patches likely to act as stepping stones within the connectivity network.

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Landscape connectivity among remnant populations of guanaco (Lama guanicoe Müller, 1776) in an arid region of Chile impacted by global change

PeerJ ◽

10.7717/peerj.4429 ◽

2018 ◽

Vol 6 ◽

pp. e4429 ◽

Cited By ~ 1

Author(s):

Mara I. Espinosa ◽

Nicolas Gouin ◽

Francisco A. Squeo ◽

David López ◽

Angéline Bertin

Keyword(s):

Functional Connectivity ◽

Animal Movement ◽

Landscape Connectivity ◽

Global Scale ◽

Population Connectivity ◽

Suitable Habitat ◽

Stepping Stones ◽

Lama Guanicoe ◽

Study Region ◽

Norte Chico

Connectivity between populations plays a key role in the long-term persistence of species in fragmented habitats. This is of particular concern for biodiversity preservation in drylands, since water limited landscapes are typically characterized by little suitable habitat cover, high habitat fragmentation, harsh matrices, and are being rapidly degraded at a global scale. In this study, we modelled landscape connectivity between 11 guanaco Lama guanicoe populations in Chile’s arid Norte Chico, a region that supports the last remnant coastal populations of this emblematic herbivore indigenous to South America. We produced a habitat suitability model to derive a regional surface resistance map, and used circuit theory to map functional connectivity, investigate the relative isolation between populations, and identify those that contribute most to the patch connectivity network. Predicted suitable habitat for L. guanicoe represented about 25% of the study region (i.e., 29,173 km2) and was heterogeneously distributed along a continuous stretch along the Andes, and discontinuous patches along the coast. As a result, we found that high connectivity current flows in the mid and high Andes formed a wide, continuous connectivity corridor, enabling connectivity between all high Andean populations. Coastal populations, in contrast, were more isolated. These groups demonstrate no inter-population connectivity between themselves, only with higher altitude populations, and for two of them, animal movement was linked to the effectiveness of wildlife crossings along the Pan-American highway. Our results indicate that functional connectivity is an issue of concern for L. guanicoe in Chile’s Norte Chico, implying that future conservation and management plans should emphasize strategies aimed at conserving functional connectivity between coastal and Andean populations, as well as the protection of habitat patches likely to act as stepping stones within the connectivity network.

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Global-scale dispersal and connectivity in mangroves

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1812470116 ◽

2018 ◽

Vol 116 (3) ◽

pp. 915-922 ◽

Cited By ~ 19

Author(s):

Tom Van der Stocken ◽

Dustin Carroll ◽

Dimitris Menemenlis ◽

Marc Simard ◽

Nico Koedam

Keyword(s):

Indian Ocean ◽

Western Indian Ocean ◽

Global Scale ◽

Ocean Model ◽

Global Ocean ◽

Future Research ◽

Suitable Habitat ◽

Stepping Stones ◽

Mangrove Species ◽

Climate Conditions

Dispersal provides a key mechanism for geographical range shifts in response to changing environmental conditions. For mangroves, which are highly susceptible to climate change, the spatial scale of dispersal remains largely unknown. Here we use a high-resolution, eddy- and tide-resolving numerical ocean model to simulate mangrove propagule dispersal across the global ocean and generate connectivity matrices between mangrove habitats using a range of floating periods. We find high rates of along-coast transport and transoceanic dispersal across the Atlantic, Pacific, and Indian Oceans. No connectivity is observed between populations on either side of the American and African continents. Archipelagos, such as the Galapagos and those found in Polynesia, Micronesia, and Melanesia, act as critical stepping-stones for dispersal across the Pacific Ocean. Direct and reciprocal dispersal routes across the Indian Ocean via the South Equatorial Current and seasonally reversing monsoon currents, respectively, allow connectivity between western Indian Ocean and Indo-West Pacific sites. We demonstrate the isolation of the Hawaii Islands and help explain the presence of mangroves on the latitudinal outlier Bermuda. Finally, we find that dispersal distance and connectivity are highly sensitive to the minimum and maximum floating periods. We anticipate that our findings will guide future research agendas to quantify biophysical factors that determine mangrove dispersal and connectivity, including the influence of ocean surface water properties on metabolic processes and buoyancy behavior, which may determine the potential of viably reaching a suitable habitat. Ultimately, this will lead to a better understanding of global mangrove species distributions and their response to changing climate conditions.

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Using Bayesian Belief Networks to assess the influence of landscape connectivity on ecosystem service trade-offs and synergies in urban landscapes in the UK

Landscape Ecology ◽

10.1007/s10980-021-01307-6 ◽

2021 ◽

Author(s):

James D. Karimi ◽

Jim A. Harris ◽

Ron Corstanje

Keyword(s):

Functional Connectivity ◽

Ecosystem Service ◽

Urban Areas ◽

Landscape Connectivity ◽

Structural Characteristics ◽

Bird Species ◽

Bayesian Belief Networks ◽

Belief Networks ◽

Patch Area ◽

Trade Offs

Abstract Context Landscape connectivity is assumed to influence ecosystem service (ES) trade-offs and synergies. However, empirical studies of the effect of landscape connectivity on ES trade-offs and synergies are limited, especially in urban areas where the interactions between patterns and processes are complex. Objectives The objectives of this study were to use a Bayesian Belief Network approach to (1) assess whether functional connectivity drives ES trade-offs and synergies in urban areas and (2) assess the influence of connectivity on the supply of ESs. Methods We used circuit theory to model urban bird flow of P. major and C. caeruleus at a 2 m spatial resolution in Bedford, Luton and Milton Keynes, UK, and Bayesian Belief Networks (BBNs) to assess the sensitivity of ES trade-offs and synergies model outputs to landscape and patch structural characteristics (patch area, connectivity and bird species abundance). Results We found that functional connectivity was the most influential variable in determining two of three ES trade-offs and synergies. Patch area and connectivity exerted a strong influence on ES trade-offs and synergies. Low patch area and low to moderately low connectivity were associated with high levels of ES trade-offs and synergies. Conclusions This study demonstrates that landscape connectivity is an influential determinant of ES trade-offs and synergies and supports the conviction that larger and better-connected habitat patches increase ES provision. A BBN approach is proposed as a feasible method of ES trade-off and synergy prediction in complex landscapes. Our findings can prove to be informative for urban ES management.

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Fencing affects African wild dog movement patterns and population dynamics

Oryx ◽

10.1017/s0030605320000320 ◽

2021 ◽

pp. 1-9

Author(s):

Helen M. K. O'Neill ◽

Sarah M. Durant ◽

Stefanie Strebel ◽

Rosie Woodroffe

Keyword(s):

Population Dynamics ◽

Large Scale ◽

Animal Movement ◽

Landscape Connectivity ◽

Ecological Impact ◽

Movement Patterns ◽

Wrong Side ◽

African Wild Dog ◽

Wild Dog ◽

Wild Dogs

Abstract Wildlife fences are often considered an important tool in conservation. Fences are used in attempts to prevent human–wildlife conflict and reduce poaching, despite known negative impacts on landscape connectivity and animal movement patterns. Such impacts are likely to be particularly important for wide-ranging species, such as the African wild dog Lycaon pictus, which requires large areas of continuous habitat to fulfil its resource requirements. Laikipia County in northern Kenya is an important area for wild dogs but new wildlife fences are increasingly being built in this ecosystem. Using a long-term dataset from the area's free-ranging wild dog population, we evaluated the effect of wildlife fence structure on the ability of wild dogs to cross them. The extent to which fences impeded wild dog movement differed between fence designs, although individuals crossed fences of all types. Purpose-built fence gaps increased passage through relatively impermeable fences. Nevertheless, low fence permeability can lead to packs, or parts of packs, becoming trapped on the wrong side of a fence, with consequences for population dynamics. Careful evaluation should be given to the necessity of erecting fences; ecological impact assessments should incorporate evaluation of impacts on animal movement patterns and should be undertaken for all large-scale fencing interventions. Where fencing is unavoidable, projects should use the most permeable fencing structures possible, both in the design of the fence and including as many purpose-built gaps as possible, to minimize impacts on wide-ranging wildlife.

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Is There an Equivalence between Measures of Landscape Structural and Functional Connectivity for Plants in Conservation Assessments of the Cerrado?

Land ◽

10.3390/land9110459 ◽

2020 ◽

Vol 9 (11) ◽

pp. 459

Author(s):

Thais Martins Issii ◽

Erico Fernando Lopes Pereira-Silva ◽

Carlos Tomás López de Pablo ◽

Rozely Ferreira dos Santos ◽

Elisa Hardt

Keyword(s):

Functional Connectivity ◽

Empirical Data ◽

Landscape Connectivity ◽

Structural Connectivity ◽

Long Distance ◽

Dispersal Capacity ◽

Plant Dispersal ◽

Optimal Resource ◽

History Of ◽

Conservation Assessments

Landscape connectivity can be assessed based on the physical connection (structural connectivity) or the maintenance of flow among habitats depending on the species (functional connectivity). The lack of empirical data on the dispersal capacity of species can lead to the use of simple structural measures. Comparisons between these approaches can improve decision-making processes for the conservation or restoration of habitats in fragmented landscapes, such as the Cerrado biome. This study aimed to understand the correspondence between the measures of landscape structural and functional connectivity for Cerrado plants. Three landscapes with cerradão patches in a pasture matrix were selected for the application of these metrics based on the functional connectivity of four profiles of plant dispersal capacity. The results showed divergent interpretations between the measures of landscape structural and functional connectivity, indicating that the assessment of biodiversity conservation and landscape connectivity is dependent on the set of metrics chosen. Structurally, the studied landscapes had the same number of cerradão patches but varied in optimal resource availability, isolation, heterogeneity, and aggregation. Functional connectivity was low for all profiles (based on the integral index of connectivity—IIC) and null for species with a low dispersal capacity (based on the connectance index—CONNECT), indicating that species with a medium- to long-distance dispersal capacity may be less affected by the history of losses and fragmentation of the Cerrado in the pasture matrix. The functional connectivity metrics used allowed a more robust analysis and, apparently, better reflected reality, but the lack of empirical data on dispersal capacity and the difficulty in choosing an indicator organism can limit their use in the management and planning of conservation and restoration areas.

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How Does the Rate of Photovoltaic Installations and Coupled Batteries Affect Regional Energy Balancing and Self-Consumption of Residential Buildings?

Energies ◽

10.3390/en13112738 ◽

2020 ◽

Vol 13 (11) ◽

pp. 2738

Author(s):

Andrea Reimuth ◽

Veronika Locherer ◽

Martin Danner ◽

Wolfram Mauser

Keyword(s):

Land Surface ◽

Residential Buildings ◽

Land Surface Model ◽

Surface Model ◽

Energy Balancing ◽

Residential Energy ◽

Study Region ◽

Regional Energy ◽

Pv Systems ◽

Set Up

The strong expansion of residential rooftop photovoltaic (PV) and battery storage systems of recent years is expected to rise further. However, it is not yet clear to which degree buildings will be equipped with decentral energy producers. This study seeks to quantify the effects of different PV and battery installation rates on the residential residual loads and grid balancing flows. A land surface model with an integrated residential energy component is applied, which maintains spatial peculiarities and allows a building-specific set-up of PV systems, batteries, and consumption loads. The study area covers 3163 residential buildings located in a municipality in the south of Germany. The obtained results show minor impacts on the residual loads for a PV installation rate of less than 10%. PV installation rates of one third of all residential buildings of the study region lead to the highest spatial balancing via the grid. The rise in self-consumption when utilizing batteries leads to declined grid balancing between the buildings. For high PV installation rates, regional balancing diminishes, whereas energy excesses rise to 60%. They can be decreased up to 10% by the utilization of battery systems. Therefore, we recommend subsidy programs adjusted to the respective PV installation rates.

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Ability of the land surface model ISBA-A-gs to simulate leaf area index at the global scale: Comparison with satellites products

Journal of Geophysical Research Atmospheres ◽

10.1029/2005jd006691 ◽

2006 ◽

Vol 111 (D18) ◽

Cited By ~ 94

Author(s):

Anne-Laure Gibelin ◽

Jean-Christophe Calvet ◽

Jean-Louis Roujean ◽

Lionel Jarlan ◽

Sietse O. Los

Keyword(s):

Leaf Area Index ◽

Leaf Area ◽

Land Surface ◽

Land Surface Model ◽

Global Scale ◽

Surface Model ◽

Area Index

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Defining spring foraging habitat and prioritization of conservation sites for Tricolored Blackbirds in California, USA

The Condor ◽

10.1093/condor/duz054 ◽

2019 ◽

Vol 121 (4) ◽

Cited By ~ 1

Author(s):

Chad B Wilsey ◽

Nicole L Michel ◽

Katie Krieger ◽

Lotem Taylor ◽

Liling Lee ◽

...

Keyword(s):

Surface Water ◽

Land Cover ◽

Landscape Connectivity ◽

Percent Cover ◽

Private Land ◽

Foraging Habitat ◽

Critical Feature ◽

Study Region ◽

Colonial Nesting ◽

Surrounding Landscape

Abstract The Tricolored Blackbird (Agelaius tricolor) is a range-restricted, colonial-nesting species in decline. Colonies include tens of thousands of individuals that forage in the surrounding landscape, at times commuting miles between nesting and foraging grounds. We explored the role of landscape composition on colony occupancy and mapped core and potential spring foraging habitat in California, USA. We used observations of spring Tricolored Blackbird nesting colonies from 2008, 2011, and 2014 and characterized changes in the surrounding landscape during an extended drought. Then, we constructed occurrence and abundance models in order to map core foraging habitat across 4 ecoregions in California. Finally, we used simulated land cover changes to identify potential habitat under restoration scenarios. Across the 3 survey years, surface water declined over time at unoccupied colony locations but remained stable at occupied colony locations, confirming that permanent surface water was a critical feature of persistent Tricolored Blackbird colonies. Average percent cover of nearly all land cover types suitable for foraging, as well as frequency of dairies and median NDVI, were all higher in current or historical colony sites than elsewhere. The proportion of surrounding alfalfa, grasslands, and surface water were the elements of foraging habitat best able to predict Tricolored Blackbird early breeding season colony presence and colony size. Core foraging habitat covered over 6 million acres in the study region, but only 18% was occupied in 2014. This result suggests a need to study additional factors determining colony occurrence and persistence, such as landscape connectivity, distributions of nesting substrates, and risk from predators. The vast majority (93.1%) of Tricolored Blackbird core habitat occurred on private land; therefore, saving the species will require engagement and partnership with private landowners.

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