Anthropogenic Land Use Change Research Articles

Emerging zoonotic diseases originating in mammals: a systematic review of effects of anthropogenic land-use change.

Zoonotic pathogens and parasites that are transmitted from vertebrates to humans are a major public health risk with high associated global economic costs. The spread of these pathogens and risk of transmission accelerate with recent anthropogenic land‐use changes (LUC) such as deforestation, urbanisation, and agricultural intensification, factors that are expected to increase in the future due to human population expansion and increasing demand for resources.We systematically review the literature on anthropogenic LUC and zoonotic diseases, highlighting the most prominent mammalian reservoirs and pathogens, and identifying avenues for future research.The majority of studies were global reviews that did not focus on specific taxa. South America and Asia were the most‐studied regions, while the most‐studied LUC was urbanisation. Livestock were studied more within the context of agricultural intensification, carnivores with urbanisation and helminths, bats with deforestation and viruses, and primates with habitat fragmentation and protozoa.Research into specific animal reservoirs has improved our understanding of how the spread of zoonotic diseases is affected by LUC. The behaviour of hosts can be altered when their habitats are changed, impacting the pathogens they carry and the probability of disease spreading to humans. Understanding this has enabled the identification of factors that alter the risk of emergence (such as virulence, pathogen diversity, and ease of transmission). Yet, many pathogens and impacts of LUC other than urbanisation have been understudied.Predicting how zoonotic diseases emerge and spread in response to anthropogenic LUC requires more empirical and data synthesis studies that link host ecology and responses with pathogen ecology and disease spread. The link between anthropogenic impacts on the natural environment and the recent COVID‐19 pandemic highlights the urgent need to understand how anthropogenic LUC affects the risk of spillover to humans and spread of zoonotic diseases originating in mammals.

Climate Extremes and Compound Hazards in a Warming World

Climate extremes threaten human health, economic stability, and the well-being of natural and built environments (e.g., 2003 European heat wave). As the world continues to warm, climate hazards are expected to increase in frequency and intensity. The impacts of extreme events will also be more severe due to the increased exposure (growing population and development) and vulnerability (aging infrastructure) of human settlements. Climate models attribute part of the projected increases in the intensity and frequency of natural disasters to anthropogenic emissions and changes in land use and land cover. Here, we review the impacts, historical and projected changes,and theoretical research gaps of key extreme events (heat waves, droughts, wildfires, precipitation, and flooding). We also highlight the need to improve our understanding of the dependence between individual and interrelated climate extremes because anthropogenic-induced warming increases the risk of not only individual climate extremes but also compound (co-occurring) and cascading hazards. ▪ Climate hazards are expected to increase in frequency and intensity in a warming world. ▪ Anthropogenic-induced warming increases the risk of compound and cascading hazards. ▪ We need to improve our understanding of causes and drivers of compound and cascading hazards.

A multidimensional framework for measuring biotic novelty: How novel is a community?

Anthropogenic changes in climate, land use, and disturbance regimes, as well as introductions of non-native species can lead to the transformation of many ecosystems. The resulting novel ecosystems are usually characterized by species assemblages that have not occurred previously in a given area. Quantifying the ecological novelty of communities (i.e., biotic novelty) would enhance the understanding of environmental change. However, quantification remains challenging since current novelty metrics, such as the number and/or proportion of non-native species in a community, fall short of considering both functional and evolutionary aspects of biotic novelty. Here, we propose the Biotic Novelty Index (BNI), an intuitive and flexible multidimensional measure that combines (a) functional differences between native and non-native introduced species with (b) temporal dynamics of species introductions. We show that the BNI is an additive partition of Rao's quadratic entropy, capturing the novel interaction component of the community's functional diversity. Simulations show that the index varies predictably with the relative amount of functional novelty added by recently arrived species, and they illustrate the need to provide an additional standardized version of the index. We present a detailed R code and two applications of the BNI by (a) measuring changes of biotic novelty of dry grassland plant communities along an urbanization gradient in a metropolitan region and (b) determining the biotic novelty of plant species assemblages at a national scale. The results illustrate the applicability of the index across scales and its flexibility in the use of data of different quality. Both case studies revealed strong connections between biotic novelty and increasing urbanization, a measure of abiotic novelty. We conclude that the BNI framework may help building a basis for better understanding the ecological and evolutionary consequences of global change.

Wetland plant community variation across replicate urban to rural gradients: non-native species as both drivers and passengers in systems impacted by anthropogenic land-use

Anthropogenic land-use change impacts ecological communities in urban and rural landscapes, and wetlands are particularly vulnerable despite the valuable ecosystem services they provide. Urbanized non-wetland systems are often enriched in non-native plant species, and similar patterns in wetlands would have implications for ecosystem function and biodiversity. We evaluated landscape-scale patterns of plant community diversity across gradients of rural to urban land-use, testing whether diversity was related to environmental conditions indicative of surrounding land-use. We surveyed vegetation and collected soil samples from 45 wetlands throughout Ohio, USA. Sites were categorized based on surrounding land-use as intense urban, moderate urban, or rural, representing 15 replicate urban to rural gradients. Non-native richness was 56% greater and non-native relative abundance 74% greater in intense urban sites compared to rural sites. Structural equation modeling indicated that high non-native relative abundance caused reductions in native plant richness but not native Shannon diversity, which was instead related to high concentrations of urban-associated soil contaminants such as cadmium and sodium. Our results support both versions of the driver-passenger model of invasion impacts, depending on the response: native richness is directly limited by competition with non-native species (the driver model), while native diversity is limited more by urban-associated stressors that also affect non-natives (the passenger model). The few wetlands remaining in highly urban areas thus experience a range of constraints affecting multiple dimensions of wetland health. We argue it is in these sites specifically where the benefits of restoring wetland ecosystems will be maximized.

Influences of forest cover on soil freeze-thaw dynamics and greenhouse gas emissions through the regulation of snow regimes: A comparison study of the farmland and forest plantation

Vegetation cover has implications for seasonally frozen soil dynamics and greenhouse gas emissions. We examined the frozen soil dynamics and N2O and CO2 efflux in a forest plantation (Populus ssp.) and farmland. The experiments were carried out at a forest reclamation site in Zhangbei county, Hebei province, China, from November 2017 to May 2018. Compared to the farmland, the forest plantation prolonged the retention of frozen soil because the shallower snow and the longer duration of snow cover in the forest contributed to a deeper frost depth and delayed soil thawing. The canopy also sheltered the frozen soil from the extreme fluctuations in freeze-thaw cycles (FTCs) during the snow-free period. Contrasting snow regimes and FTC dynamics contributed to variations in CO2 and N2O between the forest plantation and the farmland. Path analysis showed that the soil water content and soil temperature were the main regulators of N2O and CO2 emissions, respectively, in both land-use types. By contrast, soil substrate and microorganism biomass minimally influenced N2O and CO2 efflux. In conclusion, forest cover influences frozen soil dynamics and greenhouse gas emissions by buffering temperature fluctuations in both snow-covered and snow-free periods. This study further highlights the potential importance of anthropogenic land-use changes in influencing the cold season energy balance and gas efflux in future milder winter climates.

Development and testing scenarios for implementing land use and land cover changes during the Holocene in Earth system model experiments

Abstract. Anthropogenic changes in land use and land cover (LULC) during the pre-industrial Holocene could have affected regional and global climate. Existing scenarios of LULC changes during the Holocene are based on relatively simple assumptions and highly uncertain estimates of population changes through time. Archaeological and palaeoenvironmental reconstructions have the potential to refine these assumptions and estimates. The Past Global Changes (PAGES) LandCover6k initiative is working towards improved reconstructions of LULC globally. In this paper, we document the types of archaeological data that are being collated and how they will be used to improve LULC reconstructions. Given the large methodological uncertainties involved, both in reconstructing LULC from the archaeological data and in implementing these reconstructions into global scenarios of LULC, we propose a protocol to evaluate the revised scenarios using independent pollen-based reconstructions of land cover and climate. Further evaluation of the revised scenarios involves carbon cycle model simulations to determine whether the LULC reconstructions are consistent with constraints provided by ice core records of CO2 evolution and modern-day LULC. Finally, the protocol outlines how the improved LULC reconstructions will be used in palaeoclimate simulations in the Palaeoclimate Modelling Intercomparison Project to quantify the magnitude of anthropogenic impacts on climate through time and ultimately to improve the realism of Holocene climate simulations.

PALEOENVIRONMENTAL IMPLICATIONS OF TIME-AVERAGING AND TAPHONOMIC VARIATION OF SHELL BEDS IN LAKE TANGANYIKA, AFRICA

ABSTRACTThe lake bottom along structural platforms in Lake Tanganyika, Africa, is carpeted with numerous large shell beds, known to be of late Holocene age, but of uncertain assemblage process. The shell beds may be the result of sedimentological (physical) assembly processes, or biological processes, or both. Previous work focused on the distribution of shell-rich facies, and showed time averaging of the surficial shell bioclasts over the last ∼ 1600 calendar years BP. We focus on an extensive shell deposit along a deltaic platform in Kungwe Bay, Tanzania and examine time-averaging and taphonomy of Neothauma tanganyicense shells to constrain sedimentological and biological processes forming concentrations of shells. New radiocarbon dating indicates that Neothauma shells are time-averaged over the last ∼ 3000 calendar years. Younger shells predominate shallow-water and exhibit unimodal age distributions, while shells from deeper-water exhibit a broader age distribution. Taphonomic results indicate that water depth and distance from the delta river mouth influence shell abrasion and encrustation with more encrustation developing away from sediment input points. Shells with black coatings and reddish-orange oxidation patinas suggest local burial and exposure. The age-frequency distributions of the shells suggest production rates of the shells vary over time and with water depth, tracking climatically driven lake-level changes (e.g., Little Ice Age, ∼ 100–650 BP). In addition, age-distributions suggest that (1) mixing of different populations are more prevalent along the steeper deltaic slopes, and (2) recent decreasing production rates may reflect anthropogenic land-use change and attendant sedimentation, which has implications for Neothauma itself, and for organisms that are obligate occupants of the shell beds. These results suggest both climatic and depositional processes play unique roles in the distribution and accumulation of shell beds in Lake Tanganyika, which informs interpretation of similar paleoenvironments in the geologic record.

Pine savanna plant community disassembly after fire suppression

AbstractQuestionsBiodiversity is being lost rapidly due to anthropogenic changes in land use, climate, and other environmental conditions. In fire‐maintained ecosystems, altered fire regimes accelerate native species loss — community disassembly — and promote recruitment of fire‐sensitive species. In this study, we ask whether fire suppression results in changes over time in functional trait composition of ground‐layer species and whether these changes differ in longleaf pine savannas invaded by hardwoods from those invaded by sand pines.LocationFive Floridian locations on the southeastern coastal plain of the United States.MethodsAt each location we selected a fire‐maintained and fire‐suppressed savanna and measured percent plant cover by ground‐story species in 1,000 m2 plots. For 102 of these species, we measured 10 functional traits — height, growth form, specific leaf area, leaf dry matter content (LDMC), leaf water content, leaf ignition time, leaf mass consumed by fire, light compensation points (LCPs), non‐structural carbohydrate concentrations in under‐ground organs, and seed mass.ResultsFire exclusion was associated with reductions in both functional diversity and species richness. We identified 38 species exclusive to frequently burned sites: these species showed high LDMC values, high LCPs, high leaf mass consumed, and low leaf ignition time values. Lack of fire was associated with loss of 6 of the 12 C4 native grass species. Species and functional trait composition were affected by both time‐since‐fire and whether post‐fire communities were invaded by broadleaved trees (Quercus spp. and Liquidambar styraciflua) or by sand pine (Pinus clausa).ConclusionsWe demonstrated the effects of altered disturbance regimes on savanna plant species and functional trait composition. This trait‐based approach advanced our understanding of how altered disturbance regimes can alter plant communities. Although 38 shade‐intolerant and flammable native savanna species were absent by 10 years since fire, 12 such species persisted even 40 years after fire exclusion.

Flood Consequences of Land-Use Changes at a Ski Resort: Overcoming a Geomorphological Threshold (Portainé, Eastern Pyrenees, Iberian Peninsula)

The sensitive mountain catchment of Portainé (Eastern Pyrenees, Iberian Peninsula) has recently experienced a significant change in its torrential dynamics due to human disturbances. The emplacement of a ski resort at the headwaters led to the surpassing of a geomorphological threshold, with important consequences during flood events. Consequently, since 2008, channel dynamics have turned into sediment-laden, highly destructive torrential flows. In order to assess this phenomenon and o acquire a holistic understanding of the catchment’s behaviour, we carried out a field work-based multidisciplinary study. We considered the interaction of the various controlling factors, including bedrock geology, geomorphological evolution, derived soils and coluvial deposits, rainfall patterns, and the hydrological response of the catchment to flood events. Moreover, anthropogenic land-use changes, its consequential hydrogeomorphic effects and the role of vegetation were also taken into account. Robust sedimentological and geomorphological evidence of ancient dense debris flows show that the basin has shifted around this threshold, giving rise to two different behaviours or equilibrium conditions throughout its history: alternating periods of moderate, bedload-laden flows and periods of high sediment-laden debris flow dynamics. This shifting could have extended through the Holocene. Finally, we discuss the possible impact of climate and global change, as the projected effects suggest future soil and forest degradation; this, jointly with more intense rainfalls in these mountain environments, would exacerbate the future occurrence of dense sediment-laden flows at Portainé, but also in other nearby, similar basins.

Identifying and characterizing dust point sources in the southwestern United States using remote sensing and GIS

Documenting geomorphology and land use/land cover associated with the aeolian dust sources is needed to build more robust models simulating wind erosion and dust emission. It is also important to set the base for future studies aiming to quantify the effect of anthropogenic land-use change on dust emission. In this research, dust point sources were detected in the Southern Great Plains and Chihuahuan Desert regions of the United States (U.S.) for 2001–2016, encompassing a period of extreme drought. Dust points were detected using overlay analysis of brightness temperature difference images of MODIS and MODIS true color images for the days where dust plumes were visible. This study aims to identify low emission surfaces as well as high emission surfaces in terms of geomorphology and land cover. A total of 1508 dust points were detected, where 1258 points are located in the Southern Great Plains, and 187 points are located in the Chihuahuan Desert. Point pattern analysis showed a significant cluster of these points in West Texas (Nearest Neighbor Ratio = 0.33, р < 0.001) where cultivated lands and grasslands are the dominant land cover and aeolian sand sheet is the dominant geomorphic class. Ephemeral lakes (i.e., playas) produce the most dust sources per unit area. Cultivated croplands enclose 43% of the dust points, while shrublands and grasslands, combined, enclose 45% of the points. Results from this study confirms the importance of playas as a dynamic source of dust in southwestern U.S. Moreover, this study suggests that anthropogenic factors play a major role in dust emission within southwestern U.S, although bare lands in particular that are not subjected to anthropogenic factors (e.g., the White Sands dune field) are also emitting dust. Future research is needed to statistically analyze the contribution of different land-cover types on dust emission in the region.

Landscape Change and Vegetation-Channel Interactions in an Estuarine System

We examine the extent of land cover change and sedimentation within the Tijuana River Estuary due to the significant development within Mexico that has increased sedimentation that could alter estuary elevation. We examined aerial imagery to determine major changes in estuary land cover over time (1995–2016), examined sedimentation patterns by calculating vegetation roughness of two dominant lower marsh species: Salicornia pacifica and Spartina foliosa and directly measured sediment deposition within plant stands at multiple elevations and determined how vegetation may be interrupting flow and affecting deposition. Upper elevation scrub has increased slightly through time while marsh area has decreased. Plant roughness for S. foliosa was significantly higher and, based on modeling, each species creates different water surface and channel velocity conditions that could alter deposition patterns. Vegetation inventories and sediment size deposition analysis within vegetation patches show that S. foliosa occupies those areas closest to the channel, is most frequently inundated, and has the smallest sediment sizes present. Sediment size increases with distance from the channel and where it becomes more commonly dominated by S. pacifica. These areas, typically 0.5-1 m above channel bottom elevation, experience the highest volume of sediment deposition. Modeling and direct measurements of deposition indicate that water velocity is impacted by plant stands and deposition is occurring in areas close to the channel. Because these deposition patterns may eventually result in changes in estuary elevation, continual monitoring should be carried out to determine how vegetation-induced sediment behavior, combined with anthropogenic land-use change and sea level rise, influence estuary elevation and land cover.

Effects of rarity form on species' responses to land use.

Anthropogenic land-use change causes substantial changes in local and global biodiversity. Rare and common species can differ in sensitivity to land-use change; rare species are expected to be affected more negatively. Rarity may be defined in terms of geographic range size, population density, or breadth of habitat requirements. How these 3 forms of rarity interact in determining global responses to land use is yet to be assessed. Using global data representing 912 vertebrate species, we tested for differences in responses to land use of species characterized by different types of rarity. Land-use responses were fitted using generalized linear mixed-effects models, allowing responses to vary among groups of species with different forms of rarity. Species considered rare with respect to all 3 forms of rarity showed particularly strong declines in disturbed land uses (>40% of species and 30% of individuals in the most disturbed land uses). In contrast, species common both geographically and numerically and with broad habitat requirements showed strong increases (up to 90% increase in species and 40% in abundance in some land uses). Our results suggest that efforts to understand the vulnerability of species to environmental changes should account for different types of rarity where possible. Our results also have potentially important implications for ecosystem functioning, given that rare species may play unique roles within ecosystems.

Effects of two centuries of global environmental variation on phenology and physiology of Arabidopsis thaliana.

Intraspecific trait variation is caused by genetic and plastic responses to environment. This intraspecific diversity is captured in immense natural history collections, giving us a window into trait variation across continents and through centuries of environmental shifts. Here we tested if hypotheses based on life history and the leaf economics spectrum explain intraspecific trait changes across global spatiotemporal environmental gradients. We measured phenotypes on a 216-year time series of Arabidopsis thaliana accessions from across its native range and applied spatially varying coefficient models to quantify region-specific trends in trait coordination and trait responses to climate gradients. All traits exhibited significant change across space or through time. For example, δ15 N decreased over time across much of the range and leaf C:N increased, consistent with predictions based on anthropogenic changes in land use and atmosphere. Plants were collected later in the growing season in more recent years in many regions, possibly because populations shifted toward more spring germination and summer flowering as opposed to fall germination and spring flowering. When climate variables were considered, collection dates were earlier in warmer years, while summer rainfall had opposing associations with collection date depending on regions. There was only a modest correlation among traits, indicating a lack of a single life history/physiology axis. Nevertheless, leaf C:N was low for summer- versus spring-collected plants, consistent with a life history-physiology axis from slow-growing winter annuals to fast-growing spring/summer annuals. Regional heterogeneity in phenotype trends indicates complex responses to spatiotemporal environmental gradients potentially due to geographic genetic variation and climate interactions with other aspects of environment. Our study demonstrates how natural history collections can be used to broadly characterize trait responses to environment, revealing heterogeneity in response to anthropogenic change.

Indigenous Knowledge Systems and Conservation of Settled Territories in the Bolivian Amazon

Landscapes settled by indigenous communities represent nuanced inter-relationships between culture and environment, where balance is achieved through Indigenous Knowledge Systems (IKS). Through IKS, native peoples worldwide live, farm, and consume resources in a manner that is responsive to natural systems and, as such, their lands present less deforestation and more sustainable production per capita than is exhibited by non-indigenous practices. In Bolivia, the Origin Farmer Indigenous Territory (TIOC) communities of Yaminahua-Machineri and Takana-Cavineño, located in the North Amazon, are facing external threats of non-indigenous anthropogenic land use change, such as road-building and industrial-scale resource extraction. In order to understand the potential environmental and cultural loss to these territories, the present work seeks to determine the present, base-line conservation state within these Bolivian communities, and forecast land use change and its consequences until the year 2030. This was undertaken using a three-stage protocol: (a) the TIOC communities’ current forest-based livelihoods, characteristics and management were determined using on-site observation techniques and extensive literature review; (b) the historical land use change (LUC) from natural vegetation to anthropogenic use was estimated using multitemporal satellite imagery; and, finally, (c) geographically explicit non-indigenous anthropogenic land-use change threat was extrapolated until 2030 using the GEOMOD modeler from the TerraSet software. Preliminary results show that both TIOCs case-sites are fairly conserved due to their forest dependence. However, deforestation and degradation could be evidenced, particularly within TIOC areas not officially recognized by the central government, due to pressures from surrounding, new non-indigenous settlements, road infrastructure, connection to markets, and the threat of the oil exploitation. Projected LUC suggest serious threats to the unrecognized TIOC areas if community governance is not reinforced, and if extractivist and non-indigenous development patterns continue to be promoted by state and central government.

Effect of land-use and land-cover change on mangrove blue carbon: A systematic review.

Mangroves shift from carbon sinks to sources when affected by anthropogenic land-use and land-cover change (LULCC). Yet, the magnitude and temporal scale of these impacts are largely unknown. We undertook a systematic review to examine the influence of LULCC on mangrove carbon stocks and soil greenhouse gas (GHG) effluxes. A search of 478 data points from the peer-reviewed literature revealed a substantial reduction of biomass (82%±35%) and soil (54%±13%) carbon stocks due to LULCC. The relative loss depended on LULCC type, time since LULCC and geographical and climatic conditions of sites. We also observed that the loss of soil carbon stocks was linked to the decreased soil carbon content and increased soil bulk density over the first 100cm depth. We found no significant effect of LULCC on soil GHG effluxes. Regeneration efforts (i.e. restoration, rehabilitation and afforestation) led to biomass recovery after ~40years. However, we found no clear patterns of mangrove soil carbon stock re-establishment following biomass recovery. Our findings suggest that regeneration may help restore carbon stocks back to pre-disturbed levels over decadal to century time scales only, with a faster rate for biomass recovery than for soil carbon stocks. Therefore, improved mangrove ecosystem management by preventing further LULCC and promoting rehabilitation is fundamental for effective climate change mitigation policy.

Carnivore community response to anthropogenic landscape change: species-specificity foils generalizations

Human exploitation of landscapes result in widespread species range loss and spatial community redistribution. Reduced species occupancy for large ranging terrestrial carnivore communities in disturbed or fragmented landscapes is a common outcome but the underlying mechanisms are ambiguous and the complexity of interacting mechanisms often under-appreciated. To examine for similarity in spatial responses of carnivores to human-mediated landscape disturbance, we hypothesize common mechanism(s) to manifest at the community-level. To then incorporate a competitive surface, we evaluate the relative role interspecific interactions may play, where some species are benefited by altered habitat conditions. We deployed camera-trap arrays across a systematic grid-based study design to quantify carnivore occurrence. We tested hypotheses to understand spatial patterns of carnivore occurrence, in relation to biophysical and anthropogenic landscape factors, using multivariate analysis and species distribution models under an information-theoretic approach. Differential response was found within the carnivore community, with some species occurring more frequently in disturbed landscapes while others displayed landscape scale avoidance of more highly disturbed areas. Interspecific interactions played an additive role to human-mediated response by some carnivores—suggesting generalist, human-adapted species, exaggerate interference interactions for other more sensitive species. Generalizable patterns are highly sought as clues to consistent mechanisms effecting changes to spatial distributions, but evidence weighs heavily in favour of species-specificity in responses implicating mechanisms that likewise vary for each species. Our findings underscore the value of a trait-based and community-level approach to understanding and managing the effects of anthropogenic land-use change on vertebrate biodiversity.

Hare don't care! Consumption of a rare, desert milkweed containing phytochemicals by the black-tailed jackrabbit

We recorded video providing the first conclusive evidence that the black-tailed jackrabbit (Lepus californicus) consumes Mojave milkweed (Asclepias nyctaginifolia) containing phytochemicals in the Ivanpah Valley, Mojave Desert, California, USA. We discuss possible chemical and biological interactions between the black-tailed jackrabbit and Mojave milkweed. We explore potential ecological effects of black-tailed jackrabbit herbivory on Mojave milkweed, including competition with the monarch butterfly (Danaus plexippus) and its close relative the queen butterfly (Danaus gilippus), and how these ecological interactions may be affected by anthropogenic land-use and land-cover change in arid environments of the western United States.

Felling trees, furthering malaria: links between deforestation and disease in developing nations

Malaria represents a leading illness and cause of death throughout areas of the Global South. Since malaria is transmitted through the bite of the Anopheles mosquito, environmental conditions are paramount in understanding malaria vulnerabilities. A burgeoning area of research connects anthropogenic deforestation and subsequent land-use changes to the expansion of mosquito habitats and malaria outbreaks. This paper explores those literatures, and also examines the drivers of deforestation in the Global South to demonstrate how population pressures, agricultural production, and rural migration patterns underlie motivations for deforestation and land transformation in poorer countries.

Simplification of vector communities during suburban succession.

Suburbanization is happening rapidly on a global scale, resulting in changes to the species assemblages present in previously undeveloped areas of land. Community-level changes after anthropogenic land-use change have been studied in a variety of organisms, but the effects on arthropods of medical and veterinary importance remain poorly characterized. Shifts in diversity, abundance, and community composition of such arthropods, like mosquitoes, can significantly impact vector-borne disease dynamics due to varying vectorial capacity between different species. In light of these potential implications for vector-borne diseases, we investigated changes in mosquito species assemblage after suburbanization by sampling mosquitoes in neighborhoods of different ages in Wake County, North Carolina, US. We found that independent of housing density and socioeconomic status, mosquito diversity measures decreased as suburban neighborhoods aged. In the oldest neighborhoods, the mosquito assemblage reached a distinct suburban climax community dominated by the invasive, peridomestic container-breeding Aedes albopictus, the Asian tiger mosquito. Aedes albopictus is a competent vector of many pathogens of human concern, and its dominance in suburban areas places it in close proximity with humans, allowing for heightened potential of host-vector interactions. While further research is necessary to explicitly characterize the effects of mosquito community simplification on vector-borne disease transmission in highly suburbanized areas, the current study demonstrates that suburbanization is disrupting mosquito communities so severely that they do not recover their diversity even 100 years after the initial disturbance. Our understanding of the community-level effects of anthropogenic land-use change on arthropod vectors will become increasingly important as we look to mitigate disease spread in a global landscape that is continually developed and altered by humans.

White-footed mouse (Peromyscus leucopus) habitat selection and Amur honeysuckle (Lonicera maackii) canopy use in an urban forest

Urban parks undergo significant changes in their community composition and habitat structure as a result of anthropogenic land-use changes. Amur honeysuckle (Lonicera maackii) dominates invaded urban parks and changes the vegetative community. This study examines the impact of L. maackii on white-footed mouse (Peromyscus leucopus) foraging behavior and habitat selection. Detailed vegetative and structural surveys allowed for analysis of habitat use. A capture-mark-recapture study was conducted in both the terrestrial and arboreal environment. We found that P. leucopus increased preference for the honeysuckle canopy when berries and leaves were present, but the primary habitat component selected for was coarse woody debris (CWD). Peromyscus leucopus appeared to avoid areas heavily trafficked by people, regardless of habitat. We demonstrated that urban P. leucopus could adjust to the presence of a dominant invasive plant, but still appeared to retain a threshold tolerance for human presence. The arboreal behavior of P. leucopus suggests L. maackii can provide desirable habitat and has practical implications for nesting birds through egg predation. Strong avoidance of human paths by P. leucopus has practical implications for Lyme disease transmission.