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1.
Ronan Marrec Gaël Caro Paul Miguet Isabelle Badenhausser Manuel Plantegenest Aude Vialatte Vincent Bretagnolle Bertrand Gauffre 《Landscape Ecology》2017,32(12):2383-2398
Context
Agroecosystems are dynamic, with yearly changing proportions of crops. Explicit consideration of this temporal heterogeneity is required to decipher population and community patterns but remains poorly studied.Objectives
We evaluated the impact on the activity-density of two dominant carabid species (Poecilus cupreus and Anchomenus dorsalis) of (1) local crop, current year landscape composition, and their interaction, and (2) inter-annual changes in landscape composition due to crop rotations.Methods
Carabids were sampled using pitfall-traps in 188 fields of winter cereals and oilseed rape in three agricultural areas of western France contrasting in their spatial heterogeneity. We summarized landscape composition in the current and previous years in a multi-scale perspective, using buffers of increasing size around sampling locations.Results
Both species were more abundant in oilseed rape, and in landscapes with a higher proportion of oilseed rape in the previous year. P. cupreus abundance was negatively influenced by oilseed rape proportion in the current year landscape in winter cereals and positively by winter cereal proportion in oilseed rape. A. dorsalis was globally impacted at finer scales than P. cupreus.Conclusions
Resource concentration and dilution-concentration processes jointly appear to cause transient dynamics of population abundance and distribution among habitat patches. Inter-patch movements across years appear to be key drivers of carabids’ survival and distribution, in response to crop rotation. Therefore, the explicit consideration of the spatiotemporal dynamics of landscape composition can allow future studies to better evidence ecological processes behind observed species patterns and help developing new management strategies.2.
Jason J. Kolbe Paul VanMiddlesworth Andrew C. Battles James T. Stroud Bill Buffum Richard T. T. Forman Jonathan B. Losos 《Landscape Ecology》2016,31(8):1795-1813
Context
Urban landscapes are a mixture of built structures, human-altered vegetation, and remnant semi-natural areas. The spatial arrangement of abiotic and biotic conditions resulting from urbanization doubtless influences the establishment and spread of non-native species in a city.Objectives
We investigated the effects of habitat structure, thermal microclimates, and species coexistence on the spread of a non-native lizard (Anolis cristatellus) in the Miami metropolitan area of South Florida (USA).Methods
We used transect surveys to estimate lizard occurrence and abundance on trees and to measure vegetation characteristics, and we assessed forest cover and impervious surface using GIS. We sampled lizard body temperatures, habitat use, and relative abundance at multiple sites.Results
At least one of five Anolis species occupied 79 % of the 1035 trees surveyed in primarily residential areas, and non-native A. cristatellus occupied 25 % of trees. Presence and abundance of A. cristatellus were strongly associated with forest patches, dense vegetation, and high canopy cover, which produced cooler microclimates suitable for this species. Presence of A. cristatellus was negatively associated with the ecologically similar non-native A. sagrei, resulting in reduced abundance and a shift in perch use of A. cristatellus.Conclusions
The limited spread of A. cristatellus in Miami over 35 years is due to the patchy, low-density distribution of wooded habitat, which limits dispersal by diffusion. The presence of congeners may also limit spread. Open habitats—some parks, yards and roadsides—contain few if any A. cristatellus, and colonization of isolated forest habitat appears to depend on human-mediated dispersal.3.
4.
Pablo M. Vergara Luis O. Meneses Audrey A. Grez Madelaine S. Quiroz Gerardo E. Soto Christian G. Pérez-Hernández Paola A. Diaz Ingo J. Hahn Andrés Fierro 《Landscape Ecology》2017,32(2):279-293
Context
Interactions between landscape-scale processes and fine-grained habitat heterogeneity are usually invoked to explain species occupancy in fragmented landscapes. In variegated landscapes, however, organisms face continuous variation in micro-habitat features, which makes necessary to consider ecologically meaningful estimates of habitat quality at different spatial scales.Objectives
We evaluated the spatial scales at which forest cover and tree quality make the greatest contribution to the occupancy of the long-horned beetle Microplophorus magellanicus (Coleoptera: Cerambycidae) in a variegated forest landscape.Methods
We used averaged data of tree quality (as derived from remote sensing estimates of the decay stage of single trees) and spatially independent pheromone-baited traps to model the occurrence probability as a function of multiple cross-scale combinations between forest cover and tree quality (with scales ranging between 50 and 400 m).Results
Model support and performance increased monotonically with the increasing scale at which tree quality was measured. Forest cover was not significant, and did not exhibit scale-specific effects on the occurrence probability of M. magellanicus. The interactive effect between tree quality and forest cover was stronger than the independent (additive) effects of tree quality and particularly forest cover. Significant interactions included tree quality measured at spatial scales ≥200 m, but cross-scale interactions occurred only in four of the seven best-supported models.Conclusions
M. magellanicus respond to the high-quality trees available in the landscape rather than to the amount of forest per se. Conservation of viable metapopulations of M. magellanicus should consider the quality of trees at spatial scales >200 m.5.
Xia-li Luan Alexander Buyantuev Albert Hans Baur Birgit Kleinschmit Haijun Wang Sheng Wei Maosong Liu Chi Xu 《Landscape Ecology》2018,33(7):1211-1224
Context
Emissions of greenhouse gases in urban areas play an important role in climate change. Increasing attention has been given to urban landscape structure–emission relationships (SERs). However, it remains unknown if and to what extent SERs are dependent on observational scale.Objective
To assess how changing observational scales (in terms of spatial and thematic resolutions) of urban landscape structure affect SERs.Methods
We examined correlations between 16 landscape metrics and greenhouse gas emissions across 52 European cities, through (1) systematic manipulation of spatial and thematic resolutions of the urban land use/cover (ULUC) dataset, and (2) comparison between available standard ULUC datasets with different spatial resolutions.Results
Our analyses showed that the observed SERs significantly depend on both thematic and spatial resolutions of the ULUC data. For the 16 landscape metrics, we found diverse spatial/thematic scaling relations exhibiting monotonic, hump-shaped or scale-invariant trends. For different landscape metrics, the SERs were strongest at different spatial scales, suggesting that there is no consistent scaling relation over those observational scales.Conclusions
SERs are highly sensitive to spatial and thematic resolutions of landscape data. To avoid the problem of ‘ecological fallacy,’ important caveats should be taken for interpretations based on single landscape metrics. Particular consideration should be paid to metrics that are easily interpretable, predictable in scaling behaviors, and important for shaping SERs, such as PLAND, ED, and LPI. Systematic investigations on scaling behaviors of SERs over well-defined scale domains are encouraged in future studies linking greenhouse gas emissions and urban landscape structure.6.
Wiebke Kämper Patrizia K. Werner Andrea Hilpert Catrin Westphal Nico Blüthgen Thomas Eltz Sara Diana Leonhardt 《Landscape Ecology》2016,31(10):2245-2258
Context
Abundance and diversity of bumblebees have been declining over the past decades. To successfully conserve bumblebee populations, we need to understand how landscape characteristics affect the quantity and quality of floral resources collected by colonies and subsequently colony performance.Objectives
We therefore investigated how amount and composition of pollen collected by buff-tailed bumblebee Bombus terrestris colonies was affected by the surrounding landscape (i.e. the proportion of forest, urban, semi-natural habitats) and how they were related to colony growth.Methods
Thirty B. terrestris colonies were placed at grassland sites differing in surrounding landscape. Colonies were established in spring when availability of flowering plants was highest, and their weight gain was monitored for 1 month. We additionally recorded the quantity and compared plant taxonomic composition and nutritional quality (i.e. amino acid composition) of pollen stored.Results
Bumblebee colonies varied little in the pollen spectra collected despite differences in surrounding landscape composition. They collected on average 80 % of pollen from woody plants, with 34 % belonging to the genus Acer. Early colony growth positively correlated with total amount of woody pollen and protein collected and decreased with increasing proportions of semi-natural habitats and total amino acid concentrations.Conclusions
Our results suggest that woody plant species represent highly important pollen sources for the generalist forager B. terrestris early in the season. We further show that colony growth of B. terrestris is predominantly affected by the quantity, not quality, of forage, indicating that several abundant plant species flowering throughout the bumblebees’ foraging season may cover the colonies’ nutritional needs.7.
Context
Intensification and specialisation of agriculture and forest use has led to profound structural and compositional changes in European landscapes. In particular, sharp, narrow edges adjacent to relatively homogenous vegetation types progressively replace transitional habitats, crucial for a plethora of species and ecological processes. Quercus robur and Q. petraea regeneration niches make them best adapted to such transitional habitats. However, contemporary oaks’ importance, including their regeneration, is usually considered within limits of forest habitats.Objective
Defining habitats, landscape patterns and processes fostering oak regeneration and ‘oakscape’ development.Methods
We assessed the state-of-the art of the topical literature with respect to various aspects of oak regeneration based on a refined list of 234 titles from the Web of Science database.Results
The review confirmed that the vast majority of studies focus on forest habitats, disregarding the fact that substantial part of acorns are being carried away and seeded by birds in non-forest habitats.Conclusions
The common acceptance of the simplistic landscape mosaic model, based on segregated homogenous vegetation categories and clear-cut lines separating patches, impedes proper assessment of landscape changes, referring to ‘untypical’, transitional habitats—the true oaks’ domain. Hence, restoring and sustaining European ‘oakscape’ should result from the overall landscape management, based on a better adapted gradient approach to landscape studies. Applying such an approach, we identified a set of habitats fostering successful oak regeneration and recruitment without direct human support, contributing to the contemporary ‘oakscape’, represented mostly by non-forest, either natural or anthropogenic habitats.8.
George Olah Annabel L. Smith Gregory P. Asner Donald J. Brightsmith Robert G. Heinsohn Rod Peakall 《Landscape Ecology》2017,32(2):445-456
Context
Dispersal is essential for species persistence and landscape genetic studies are valuable tools for identifying potential barriers to dispersal. Macaws have been studied for decades in their natural habitat, but we still have no knowledge of how natural landscape features influence their dispersal.Objectives
We tested for correlations between landscape resistance models and the current population genetic structure of macaws in continuous rainforest to explore natural barriers to their dispersal.Methods
We studied scarlet macaws (Ara macao) over a 13,000 km2 area of continuous primary Amazon rainforest in south-eastern Peru. Using remote sensing imagery from the Carnegie Airborne Observatory, we constructed landscape resistance surfaces in CIRCUITSCAPE based on elevation, canopy height and above-ground carbon distribution. We then used individual- and population-level genetic analyses to examine which landscape features influenced gene flow (genetic distance between individuals and populations).Results
Across the lowland rainforest we found limited population genetic differentiation. However, a population from an intermountain valley of the Andes (Candamo) showed detectable genetic differentiation from two other populations (Tambopata) located 20–60 km away (F ST = 0.008, P = 0.001–0.003). Landscape resistance models revealed that genetic distance between individuals was significantly positively related to elevation.Conclusions
Our landscape resistance analysis suggests that mountain ridges between Candamo and Tambopata may limit gene flow in scarlet macaws. These results serve as baseline data for continued landscape studies of parrots, and will be useful for understanding the impacts of anthropogenic dispersal barriers in the future.9.
Kristen A. DaVanon Lindsey K. Howard Karen E. Mabry Robert L. Schooley Brandon T. Bestelmeyer 《Landscape Ecology》2016,31(10):2343-2354
Context
Mechanisms of ecosystem change in urbanizing landscapes are poorly understood, especially in exurban areas featuring residential or commercial development set in a matrix of modified and natural vegetation. We asked how development altered trophic interactions and ecosystem processes in the matrix.Objectives
We examined the effect of varying degrees of exurban development (housing density) on a trophic system that included an apex mammalian predator (coyote, Canis latrans), mammalian herbivores (lagomorphs and rodents), and herbaceous plants. We tested the hypothesis that plant recruitment would be negatively affected by exurban development due either to increases in herbivores associated with increased resource availability (a bottom–up effect) or to a reduction in predators that avoid humans (a top–down effect).Methods
In Las Cruces, New Mexico, USA, four replicate sites were located in each of three urbanization levels: high density exurban, low density exurban, and wildland dominated by Chihuahuan Desert vegetation. Seedling trays measured herbivory rates, live trapping estimated abundance of pocket mice and kangaroo rats, and remotely-triggered wildlife cameras estimated the activity of lagomorphs and coyotes.Results
Increased herbivory on seedlings and decreased herbaceous plant recruitment were observed in high density exurban areas. Overall rodent abundance, seed consumption rates, and activity of the lagomorph Lepus californicus did not vary with urbanization level. Activity by another lagomorph, Sylvilagus audubonii, and coyotes was highest in dense exurban areas, consistent with a bottom–up effect.Conclusions
Exurban development can have important indirect effects on trophic interactions occurring in adjacent, untransformed ecosystems. Similar to earlier studies, such effects in the Chihuahuan Desert may be mediated by bottom–up processes associated with anthropogenic inputs.10.
Scott B. Maresh Nelson Jaime J. Coon Courtney J. Duchardt James R. Miller Diane M. Debinski Walter H. Schacht 《Landscape Ecology》2018,33(10):1799-1813
Context
Humans have altered grasslands in recent decades through crop conversion, woody encroachment, and plant invasions. Concurrently, grassland birds have experienced range-wide declines. Studies have reported effects of plant invasions and land conversion on nest ecology, but few have assessed relative impacts of these changes.Objectives
We compared impacts of invasive plants and landscape context on nest survival of a grassland songbird, the dickcissel (Spiza americana). We also compared effects on parasitism by brown-headed cowbirds (Molothrus ater) and tested whether parasitism affects survival.Methods
From 2013–2016, we monitored 477 dickcissel nests. We measured nest-site vegetation (including woody plants, tall fescue Schedonorus arundinaceous, and other invasive grasses) and measured landscape context at broad scales.Results
Nest survival declined with increasing tall fescue cover at nest sites, and parasitism was more common at nests with greater fescue and woody cover. Some evidence suggested a negative effect of row-crop cover within 1000 m on nest survival, but no landscape patterns unambiguously affected survival. Woodland cover and wooded-edge prevalence were associated with reduced parasitism risk. Parasitized nests had smaller clutches, failed more frequently, and produced fewer fledglings than non-parasitized nests.Conclusions
Determining the impacts of invasive plants and other anthropogenic changes on grassland birds will aid in prioritizing management to improve habitat quality. Our results indicate that optimizing landscape context around habitats may not affect dickcissel nest survival strongly, except perhaps through effects on parasitism. In contrast, controlling tall fescue and shrubs within grasslands could benefit birds by increasing nest success and reducing parasitism.11.
Lia Montti Verónica Piriz Carrillo Jorgelina Gutiérrez-Angonese N. Ignacio Gasparri Roxana Aragón H. Ricardo Grau 《Landscape Ecology》2017,32(11):2167-2185
Context
Knowing which factors determine the spread of plant invaders is a relevant issue in global ecology. Cultural landscapes both influence and are affected by exotic species. Although bioclimatic boundaries, seed sources and landscape configuration all control the invasion process, they have been mostly studied separately and independently from their distant drivers.Objectives
We followed a multiscale approach to describe the invasion dynamics of the Asian tree (Ligustrum lucidum) in subtropical NW Argentina cultural landscapes by: (1) identifying the potential bioclimatic area of invasion, (2) mapping the currently invaded area in peri-urban focal sectors, and (3) quantitatively describing the landscape-scale patterns of invasion in relation to environmental and cultural variables.Method
Niche models were used to map potential invasion area, remote sensing, GIS and field surveys to map patterns of invasion and their association to landscape and environmental variables.Results
Climate suitability to L. lucidum extends over important ranges of the studied area, but currently invaded areas are mostly restricted to clusters around the main cities. The historical and demographic features of cities (e.g., date foundation, population) are important in predicting invaded forest location and spread. At local scale, invasion is associated to abandoned fields nearby urban centers, roads and rivers.Conclusions
The invasion patterns of L. lucidum reflect the combined effect of historical socioeconomic connections between Asia and America, as well as the local cultural landscape history and configuration. Teleconnected cultural landscapes need to be explored as a theoretical framework for the study of biological invasions in the Anthropocene.12.
Rachel A. Loehman Robert E. Keane Lisa M. Holsinger Zhiwei Wu 《Landscape Ecology》2017,32(7):1447-1459
Context
Interactions among disturbances, climate, and vegetation influence landscape patterns and ecosystem processes. Climate changes, exotic invasions, beetle outbreaks, altered fire regimes, and human activities may interact to produce landscapes that appear and function beyond historical analogs.Objectives
We used the mechanistic ecosystem-fire process model FireBGCv2 to model interactions of wildland fire, mountain pine beetle (Dendroctonus ponderosae), and white pine blister rust (Cronartium ribicola) under current and future climates, across three diverse study areas.Methods
We assessed changes in tree basal area as a measure of landscape response over a 300-year simulation period for the Crown of the Continent in north-central Montana, East Fork of the Bitterroot River in western Montana, and Yellowstone Central Plateau in western Wyoming, USA.Results
Interacting disturbances reduced overall basal area via increased tree mortality of host species. Wildfire decreased basal area more than beetles or rust, and disturbance interactions modeled under future climate significantly altered landscape basal area as compared with no-disturbance and current climate scenarios. Responses varied among landscapes depending on species composition, sensitivity to fire, and pathogen and beetle suitability and susceptibility.Conclusions
Understanding disturbance interactions is critical for managing landscapes because forest responses to wildfires, pathogens, and beetle attacks may offset or exacerbate climate influences, with consequences for wildlife, carbon, and biodiversity.13.
Context
Conservation corridors must facilitate long-distance dispersal movements to promote gene flow, prevent inbreeding, and allow animals to shift ranges with climate change. Least-cost models are used to identify areas that support long-distance movement. These models rely on estimates of landscape resistance, which are typically derived from habitat suitability.Objectives
We examine two key steps in estimating resistance from habitat suitability: choosing a procedure to estimate habitat suitability, and choosing a transformation function to translate habitat suitability into resistance.Methods
We used linear and nonlinear functions to convert three types of habitat suitability estimates (from expert opinion, resource selection functions, and step selection functions) into resistances for elk (Cervus canadensis) and desert bighorn sheep (Ovis canadensis nelsoni). We evaluated the resulting resistance maps on an independent set of observed long-distance, prospecting movements.Results
A negative exponential function best described the relationship between resistance values and habitat suitability for desert bighorn sheep indicating long-distance movers readily travel through moderately-suitable areas and avoid only the least suitable habitat. For desert bighorn sheep, all three suitability estimates performed better than chance, and resource and step selection functions outperformed expert opinion. For elk, all three suitability estimates performed the same as chance.Conclusions
When designing corridors to facilitate long-distance movements of mobile animals, we recommend transforming habitat suitability into resistance with a negative exponential function. Use of an exponential transformation means that larger fractions of the landscape offer low resistance, allowing greater flexibility in where a corridor is located.14.
Xenia K. Volk Johannes P. Gattringer Annette Otte Sarah Harvolk-Schöning 《Landscape Ecology》2018,33(3):371-387
Context
Methods for measuring restoration success that include functional connectivity between species’ populations are rare in landscape ecology and restoration practices. We developed an approach that analyzes connectivity between populations of target species and their dispersal probabilities to assess restoration success based on easily accessible input data. Applying this method to landscape development scenarios can help optimize restoration planning.Objectives
We developed an assessment for restoration success and restoration planning based on functional connectivity between species’ populations and spatially explicit scenarios. The method was used in a case study to test its applicability.Methods
Based on data on available habitat, species’ occurrence and dispersal ranges, connectivity metrics and dispersal probabilities for target species are calculated using the software Conefor Sensinode. The metrics are calculated for scenarios that reflect possible changes in the landscape to provide a basis for future restoration planning. We applied this approach to floodplain meadows along the Upper Rhine for four plant species and three future scenarios.Results
In the case study, habitats of the target species were poorly connected. Peucedanum officinale and Sanguisorba officinalis were more successful in recolonizing new habitats than Iris spuria and Serratula tinctoria. The scenarios showed that restoration of species-rich grassland was beneficial for dispersal of the target species. As expected in the agriculturally dominated study area, restoration of former arable land significantly increased dispersal probabilities.Conclusions
In the case study, the developed approach was easily applicable and provided reasonable results. Its implementation will be helpful in decision-making for future restoration planning.15.
Context
Disturbances create spatial variation in environments that may influence animal foraging. Granivory by rodents can influence seed supply and thus plant establishment. However, effects of disturbance patterns on rodent seed removal in western North American conifer forests are generally unknown.Objectives
We conducted a study in lodgepole pine (Pinus contorta var. latifolia) forests of Greater Yellowstone (Wyoming, USA) to answer: (1) How do seed removal and rodent activity vary between recently burned and adjacent unburned forests and with distance from fire perimeter? (2) Which microhabitat conditions explain variability in seed removal and rodent activity?Methods
One or two years after wildfires, we established transects (n = 23) with four stations each: at 10 and 40 m from the fire perimeter in both burned and unburned forest. At stations, we deployed trays with lodgepole pine seeds and cameras pointed at trays for 28 days and quantified habitat structure and seed abundance.Results
Seed removal, which averaged 85%, and diurnal rodent activity did not differ between burned and unburned forests or with distance from the fire perimeter; however, nocturnal rodent activity was lower in burned forests. Seed removal and diurnal rodent activity were not associated with any microhabitat conditions we measured. However, nocturnal rodent activity was associated with microhabitat in both burned and unburned forests.Conclusions
High seed removal rates suggested that rodent foraging was not reduced by high-severity wildfire. If observed seed removal represents natural conditions, post-dispersal seed predation could influence post-fire recruitment of a widespread foundation tree species.16.
Pablo Yair Huais 《Landscape Ecology》2018,33(7):1023-1028
Context
Multi-scale analyses are a common approach in landscape ecology. Their aim is to find the appropriate spatial scale for a particular landscape attribute in order to perform a correct interpretation of results and conclusions.Objectives
I present an R function that performs statistical analysis relating a biological response with a landscape attribute at a set of specified spatial scales and extracts the statistical strength of the models through a specified criterion index. Also, it draws a plot with the value of these indexes, allowing the user to choose the most appropriate spatial scale. This paper introduces the usage of multifit and demonstrates its functionality through a case study.Conclusions
The spatial scale at which ecologists conduct studies may change study outcomes and conclusions. Because of this, landscape ecologists commonly conduct multi-scale studies in order to establish an appropriate spatial scale for particular biological or ecological responses. The tool presented here allows ecologists to simultaneously run several statistical models for a response variable and a specified set of spatial scales, automating the process of multi-scale analysis.17.
Darren R. Grafius Ron Corstanje Gavin M. Siriwardena Kate E. Plummer Jim A. Harris 《Landscape Ecology》2017,32(9):1771-1787
Context
Connectivity is fundamental to understanding how landscape form influences ecological function. However, uncertainties persist due to the difficulty and expense of gathering empirical data to drive or to validate connectivity models, especially in urban areas, where relationships are multifaceted and the habitat matrix cannot be considered to be binary.Objectives
This research used circuit theory to model urban bird flows (i.e. ‘current’), and compared results to observed abundance. The aims were to explore the ability of this approach to predict wildlife flows and to test relationships between modelled connectivity and variation in abundance.Methods
Circuitscape was used to model functional connectivity in Bedford, Luton/Dunstable, and Milton Keynes, UK, for great tits (Parus major) and blue tits (Cyanistes caeruleus), drawing parameters from published studies of woodland bird flows in urban environments. Model performance was then tested against observed abundance data.Results
Modelled current showed a weak yet positive agreement with combined abundance for P. major and C. caeruleus. Weaker correlations were found for other woodland species, suggesting the approach may be expandable if re-parameterised.Conclusions
Trees provide suitable habitat for urban woodland bird species, but their location in large, contiguous patches and corridors along barriers also facilitates connectivity networks throughout the urban matrix. Urban connectivity studies are well-served by the advantages of circuit theory approaches, and benefit from the empirical study of wildlife flows in these landscapes to parameterise this type of modelling more explicitly. Such results can prove informative and beneficial in designing urban green space and new developments.18.
Patrick D. Culbert Ine Dorresteijn Jacqueline Loos Murray K. Clayton Joern Fischer Tobias Kuemmerle 《Landscape Ecology》2017,32(2):429-444
Context
Ecological impacts of past land use can persist for centuries. While present-day land use is relatively easy to quantify, characterizing historical land uses and their legacies on biodiversity remains challenging. Southern Transylvania in Romania is a biodiversity-rich area which has undergone major political and socio-economic changes, from the Austro-Hungarian Empire to two World Wars, communist dictatorship, capitalist democracy, and EU accession—all leading to widespread land-use changes.Objectives
We investigated whether present-day community composition of birds, plants, and butterflies was associated with historical land use.Methods
We surveyed birds, plants, and butterflies at 150 sites and classified those sites as forest, arable land, or managed grassland for six epochs using historical maps from the 1870s, 1930s, and 1970s, satellite imagery from 1985 to 2000, and field visits in 2012. Sites were labelled permanent if they had the same land use at all epochs and non-permanent otherwise. We used clustering and PERMANOVA based on community similarity to test for associations between community composition and land-use history.Results
We found significant differences (p = 0.030) in bird communities between permanent and non-permanent forest sites, and permanent and non-permanent grassland sites (p = 0.051). No significant associations were found among plants or butterflies and land-use history.Conclusions
Bird communities were associated with historical land use, though plants and butterflies were not. Historical land-use change in our study area was likely not sufficiently intense to cross relevant ecological thresholds that would lead to legacy effects in present-day plant and butterfly communities.19.
Alexander G. Watts Santiago Saura Claire Jardine Patrick Leighton Lisa Werden Marie-Josée Fortin 《Landscape Ecology》2018,33(11):1925-1938
Context
In the ecology of Lyme disease emergence, it remains unclear to what extent spread of the tick vector (Ixodes scapularis) and the pathogen (Borrelia burgdorferi) are dependent upon the dispersal of vertebrate hosts in spatially heterogeneous landscapes. Yet, empirical measure of these complex ecologically driven spread processes present conceptual and methodological challenges despite important public health implications.Objectives
To examine the relationship between landscape characteristics and tick-borne disease spread, we modeled the influence of landscape connectivity for a simplified vertebrate host community (white-footed mouse—Peromyscus leucopus, American robin—Turdus migratorius, white-tailed deer—Odocoileus virginianus) on the potential spread of the tick population compared to the pathogen in a spatially-structured landscape.Methods
We parameterized a hybrid demographic-dispersal connectivity model by combining a series of reported host dispersal and tick burden estimates with empirically-measured tick abundance and pathogen prevalence sampled from a Lyme-endemic island landscape in Thousand Islands National Park (Ontario, Canada) and simulated several tick- and pathogen-spread scenarios.Results
The extent of tick spread by mice [amount of reachable habitat (ARH)?=?18.0%] is considerably similar to that of robins (ARH?=?18.7%), while deer support the greatest tick spread extent (ARH?=?82.0%). Infected mice carrying ticks support the highest pathogen spread (ARH?=?19.8%). Short-distance pathogen spread and long-distance tick spread were facilitated by intermediate stepping stone habitat fragments.Conclusions
We provide evidence that host functional connectivity mediates tick spread differently than pathogen spread, and depends strongly on landscape configuration. Our study therefore emphasizes the importance of landscape spatial heterogeneity on the ecological processes that influence regional tick-borne disease spread.20.