Effects Of Landscape Heterogeneity Research Articles

Effects of Landscape Heterogeneity and Disperser Movement on Seed Dispersal

The primacy of endozoochory for the maintenance and expansion of many woody plant populations is well known, but seed dispersal is not well understood for most species. This is especially true for rare species, where small population size and low fruit production can limit field- or observation-based experiments. Additionally, the effect of environmental heterogeneity on disperser movement is rarely investigated but has been shown to improve estimates of plant population spatial patterns and dynamics. We used simulation experiments to explore the effects of environmental heterogeneity and disperser movement on Lindera subcoriacea seed dispersal, a rare shrub from the southeastern United States with avian-dispersed seeds. Our experiments incorporated environmental heterogeneity and simulated disperser movement for five bird species, based on either landscape permeability or straight path rules. We anticipated that permeability-based movement would result in greater dispersal distances and seed dispersal effectiveness, which characterizes both quantity and quality. Generally, we did not find differences in seed dispersal between permeability and straight path experiments. However, we did find that permeability-based experiments had greater deposition into suitable habitat during flight (23 vs. 1%). These rare but longer distance depositions may be especially important for plants that are influenced by gap or interpopulation dynamics. We also found consistently greater dispersal into high quality habitats regardless of disperser species in permeability experiments, implying that incorporating species-specific assessments of landscape utilization (occupancy) could influence the effectiveness of seed dispersal. Our study suggests that including environmental heterogeneity in seed dispersal models can provide additional insights not provided by avian parameters (e.g., gut capacity, seed retention time, and flight speed) commonly used to inform dispersal models.

Diversifying agroecological systems: Plant-pollinator network organisation and landscape heterogeneity matter

Agroecology is a process-based agriculture that implements agrobiodiversification to stabilize ecosystem processes and crop yield, leading to sustainable food systems. Traditionally, agrobiodiversification focused on increasing within-farm plant richness, which may increase local species richness of higher trophic levels. However, it is increasingly recognized that stabilizing ecosystem processes involving plant-animal interactions –e.g., pollination- requires practices that consider the organisation of interactions and heterogeneity effects at landscape level. In this work, we investigated how plant-pollinator interactions organised in agricultural landscapes harbouring agroecological farms and how landscape heterogeneity modulated interactions organisation. We characterized the organisation of 36 plant-pollinator networks describing interactions in nine agricultural landscapes -i.e., agroecological farms and their surroundings- across four flowering peak periods in the Agri-food region of central Córdoba, Argentina. We evaluated (1) centrality to network organisation of plant and pollinator only registered interacting in agroecological farms, farm surroundings (unique species) or in both locations (shared species); and (2) network organisation across gradients of landscape configurational (mean edge density) and compositional (forest proportion) heterogeneity. We found that plant-pollinator networks at landscape scale showed nested structures. Shared plant and pollinator species were the less represented in such networks but were central to networks organisation, i.e., they were connected to most species and with the highest frequency. Results also showed that network organisation changed with landscape configurational heterogeneity. Higher landscape mean edge density was associated with higher total and unique plant richness in networks and lower richness of shared plants. Network connectance and nestedness decreased with higher landscape mean edge density, i.e., plant and pollinator species interacted with less species, shared less interaction partners with more specialist species and showed lower interaction frequency with generalist partners in more heterogeneous landscapes. Our study showed that in agricultural landscapes harbouring agroecological farms (1) a few species inhabiting and showing interactions in both agroecological farms and their surroundings are key to the organisation of plant-pollinator interactions, and (2) landscape heterogeneity modulates such organisation. As interaction networks dynamic is influenced by network organisation, landscape configurational heterogeneity may modulate the stability of the pollination process and ultimately agroecological production. Thus, the agrobiodiversification of agroecological systems may benefit from considering the complexity of plant-pollinator interdependencies across agricultural landscapes and the effects of landscape heterogeneity on such complexity.

The Effects of Landscape Heterogeneity on East China Anuran Communities: Identifying Spatial Scales in an Urbanizing Landscape

Cities are growing rapidly worldwide, with over half of the human population living in cities. Amphibians are the most threatened vertebrates on our planet and are particularly vulnerable to the effects of urbanization. While it is known that landscape features and scales are important for amphibians in urban areas, we do not adequately understand how the urban landscape affects diversity patterns, nor have we identified which spatial scale is most appropriate for evaluating how amphibians respond to urban environments. In this study, we examined the relationships between anuran abundance/richness and landscape features at four spatial scales in Shanghai, China. In order to determine the relative importance of landscape variables and the most appropriate spatial scale, a multi-model inference approach was used to evaluate and compare model weighted mean coefficients. Our results show that large spatial scales, i.e., 1500 m and 2000 m, best predicted relative anuran abundance and richness, while the total anuran abundance responded most strongly to landscape variables at smaller scales, i.e., 500 m and 1000 m. Patch richness and the interspersion and juxtaposition index play a large role in predicting the anuran species’ richness and abundance. The abundance of P. nigromaculatus, F. multistriata, and B. gargarizans increased with patch richness. Species richness and total abundance were most strongly related to the interspersion and juxtaposition index. Our research highlights the importance of identifying the most suitable spatial scale in urban environments because not all anuran respond to the same spatial scale. We found that the relationships between anuran relative abundance and species and urban habitat features are not consistent with the prediction of other landscapes (e.g., farmland, forest, and island). Additionally, constructing diverse habitat patches and more neighboring habitats may maintain or improve anuran communities in urbanizing landscapes.

Effects of Landscape Heterogeneity at Multiple Spatial Scales on Paddy field-breeding Frogs in a Large Alluvial Plain in Japan

Effects of Landscape Heterogeneity at Multiple Spatial Scales on Paddy field-breeding Frogs in a Large Alluvial Plain in Japan

Cooling intensity of hybrid landscapes in a metropolitan area: Relative contribution and marginal effect

• Cooling intensity variance in hybrid landscapes was explored at the regional scale. • 5 indicators were chosen to cluster 8 hybrid landscapes using the K-medoids method. • FCD and PSSA are the indicators with a high impact on regional thermal environment. • Holding the forest canopy density around 0.4 is the optimal solution for cooling. • The economically optimal size of the shade is around 60% of the unit area. Rapid urbanization has exacerbated the urban heat islands (UHIs) effect. In the wind and thermal environment of integrated city-regions, UHIs and green infrastructure (GI) interact with each other. Cooling islands, formed mainly by GI with various landscape elements, can effectively reduce land surface temperature (LST) and promote local air circulation. The landscape elements hybridize and are jointly influenced by climate, distribution, and topography. However, little is known about the pattern of hybrid landscapes that have a sufficient cooling intensity to effectively mitigate the UHI effect. As such, this study selected the Taiyuan metropolitan area and constructed a research framework that clusters hybrid landscapes and quantifies the range of indicators of the optimal cooling intensity. The results were as follows: (1) Maintaining the forest canopy density above 0.4 is an effective measure to regulate the regional thermal environment; (2) In regions with complex topography, the shaded areas of vegetation and shaded slopes (over 60%) provide a stronger effect in reducing LST; and (3) The effect of landscape heterogeneity on LST needs to be considered. Finding more effective cooling methods in hybrid landscapes is still a question that needs to be explored in future research.

The value of climate responses of individual trees to detect areas of climate-change refugia, a tree-ring study in the Brazilian seasonally dry tropical forests

Forests worldwide are facing increasingly frequent climate extremes due to global warming. The negative effects of climate change on tropical forests have been extensively reported by both permanent plots and tree-ring studies that targeted forest's responses to climate. While they focus mostly on community and population levels, the effects of landscape heterogeneity on trees’ sensitivity to climate is often not accounted for, overlooking the diverse responses of individual trees to climate variation. We tested the hypotheses that trees may differ in sensitivity to climate and that some microenvironmental conditions may exert the role of climate-change refugia. We built the first tree-ring chronology of Amburana cearensis trees sampled across a Seasonally Dry Tropical Forest (SDTF) in Brazil. We ensure a robust tree-ring dating using dendrochronological methods and 14C dating of trees inhabiting various conditions characterized here through the seasonality of the local Normalized Difference Vegetation Index. At the population level, the standard tree-ring chronology suggests that tree growth depends on rainfall and temperature, leading to a common conclusion that drier and warmer conditions would impact interannual tree growth in the tropics. However, the cluster analyses revealed groups of individual trees with distinct growth sensitivities to climate. The most sensitive trees were the individuals located in the highly seasonal vegetation of the epikarst, in contrast to the complacent trees (non-sensitive to regular interannual climate variability) inhabiting the less-seasonal vegetation in the deep soil epikarst and valley. Based on these groups of trees, we built two mean chronologies and assessed their climate-growth relationships. In accordance with the individual analysis, the tree-ring chronology of complacent trees showed no association with wet season precipitation and only moderate association with temperature. The areas supporting these complacent trees of A. cearensis in the less seasonal vegetation correspond to a quarter of the entire sampling site. The climate buffering capacity of these refugia may only be compromised in years of climate extremes when all sampled trees share low growth rates during years with anomalous low rainfall and high temperature. Assessing individual’s climate sensitivity is therefore paramount for a comprehensive understanding of the heterogeneous responses of tropical forests to climate change. The hidden individual tree responses in the population can help identify priority areas of management in a rapidly changing environment.

Effects of landscape heterogeneity on population genetic structure and demography of Amazonian phyllostomid bats

Anthropogenic landscape changes resulting in habitat degradation, loss and fragmentation might decrease connectivity and effective sizes of wild populations, threatening local biodiversity. Assumed large distributions of both species and habitats have probably discouraged studies correlating altered landscapes’ structure and composition to patterns of genetic diversity in the Neotropics. Yet, considering the increasingly high rates of deforestation and habitat conversion in Amazonia, investigating local and regional-scale effects of habitat conversion on Amazonian mammals is of paramount importance. Here, we use widespread, non-threatened, phyllostomid bats to understand how current forest dynamics are influencing genetic diversity patterns and functional connectivity of eastern Amazonian volant mammals. Four frugivorous species, Carollia perspicillata, Rhinophylla pumilio, Dermanura gnoma and Artibeus obscurus, were sampled across a heterogeneously fragmented region. Twelve more or less isolated rainforest remnants surrounded by urban areas, pastures, crops, secondary forests and other land uses comprise the studied landscapes, and are compared using a landscape genetics approach applied to mitochondrial DNA loci. Here, we report species-specific consequences of habitat fragmentation. Although the overall levels of genetic diversity were high, our data show that (i) population structure is heterogeneous across the altered landscapes; (ii) landscapes with higher habitat availability harbour populations with higher genetic diversity; and (iii) the populations assessed might be demographically declining.

Effects of landscape heterogeneity and breeding habitat diversity on rice frog abundance and body condition in agricultural landscapes of Yangtze River Delta, China.

Amphibians play a key role in structuring biological assemblages of agricultural landscapes, but they are threatened by global agricultural intensification. Landscape structure is an important variable influencing biodiversity in agricultural landscapes. However, in the Yangtze River Delta, where a "farmland-orchard-fishpond" agricultural pattern is common, the effects of landscape construction on anuran populations are unclear. In this study, we examined the effects of agricultural landscape parameters on the abundance and body condition of the rice frog (Fejervarya multistriata), which is a dominant anuran species in farmland in China. Employing a visual encounter method, we surveyed rice frog abundance for 3 years across 20 agricultural landscapes. We also calculated the body condition index (BCI) of 188 male frog individuals from these agricultural landscapes. Landscape variables, comprising landscape compositional heterogeneity (using the Shannon diversity index of all land cover types except buildings and roads), landscape configurational heterogeneity (using landscape edge density), breeding habitat diversity (using the number of 5 waterbody types available as breeding habitats), and areas of forest were also measured for each 1-km radius landscape. We found that the amount of forest in each agricultural landscape had a significant positive relationship with rice frog abundance, and breeding habitat diversity was positively related to the BCI of male rice frogs. However, body condition was negatively impacted by landscape configurational heterogeneity. Our results suggested the importance of nonagricultural habitats in agricultural landscapes, such as waterbodies and forest, to benefit rice frog population persistence.

Temporal variation of the effects of landscape composition on lacewings (Chrysopidae: Neuroptera) in vineyards

Abstract Increasing landscape heterogeneity, both in terms of composition and configuration, can promote natural enemies and biological control in agricultural landscapes. However, relatively poor information exists about the effects of landscape heterogeneity on lacewings, which are a major group of predators. Furthermore, temporal changes of landscape effects on natural enemy dynamics remain largely unexplored. Here, we investigated how landscape composition and configuration affect lacewings and their biological control potential on leafhoppers. Lacewings and leafhoppers were sampled from April to July in 10 vineyards located in southwestern France. The vineyards were selected along a gradient of a proportion of semi‐natural habitats in the landscape. The proportion of semi‐natural habitats positively affected the abundance of adults and eggs, as well as species richness, of lacewings, alone or in interaction with the sampling month. Landscape configuration was never found to enhance abundance or species richness of lacewings. Finally, the predator–prey ratio increased through time but did not respond to landscape composition or configuration. Our study highlights that the proportion of semi‐natural habitats increases both abundance and diversity of lacewings in vineyard landscapes but that this effect varies over time. This result indicates the need to assess the variability of landscape effects over time to maximize biological pest control services in agricultural landscapes.

Landscape homogenization due to agricultural intensification disrupts the relationship between reproductive success and main prey abundance in an avian predator

BackgroundSelecting high-quality habitat and the optimal time to reproduce can increase individual fitness and is a strong evolutionary factor shaping animal populations. However, few studies have investigated the interplay between land cover heterogeneity, limitation in food resources, individual quality and spatial variation in fitness parameters. Here, we explore how individuals of different quality respond to possible mismatches between a cue for prey availability (land cover heterogeneity) and the actual fluctuating prey abundance.ResultsWe analyse timing of breeding and reproductive success in a migratory population of Eurasian kestrels (Falco tinnunculus) breeding in nest-boxes, over a full three-year abundance cycle of main prey (voles), and consider several components of individual quality, including body condition, blood parasite infection, and genetic diversity (n = 448 adults) that act on different time scales. Older individuals, and kestrel parents in higher body condition started egg-laying earlier than younger birds and those in lower body condition. Additionally, egg-laying was initiated earlier during the increase and decrease phases (2011 and 2012) than during the low phase of the vole cycle (2013). Nestling survival (ratio of eggs that fledged successfully) was higher in early nests and in heterogeneous landscapes (i.e., mosaic of different habitat types), which was evident during the increase and decrease phases of the vole cycle, but not during the low vole year.ConclusionsWe found a strong positive effect of landscape heterogeneity on nestling survival, but only when voles were relatively abundant, whereas a difference in the timing of breeding related to territory landscape heterogeneity was not evident. Therefore, landscape heterogeneity appeared as the main driver of high reproductive performance under favourable food conditions. Our results show that landscape homogenization linked to agricultural intensification disrupts the expected positive effect of vole abundance on reproductive success of kestrels.

Landscape heterogeneity effects on keystone rodent species: agro-ecological zoning for conservation of open grasslands

Grasslands are one of the most threatened ecosystems in the world. Spatial prioritization of high quality habitat in agricultural landscapes is needed to protect grassland biodiversity. Within this context, we focused on European ground squirrel, a keystone species in steppe and salt steppe ecosystems. Using historical data and habitat field mapping, this study evaluates species distribution and site occupancy along the southern margin of the species range (Serbia) and identifies priority conservation zones in an intensively used landscape. Using gap analysis to evaluate changes in distribution over time and land protection status of the occupied area, we found that the regional species range has been constricted by 70%, and that 43% of mapped areas were outside of conservation networks. We also used a landscape structure model and multivariate analysis to identify the effects of spatial heterogeneity on occupancy. After mapping potential conservation zones with a buffer radius of 4.6 km—the scale with significant effects on occupancy—we identified 19 potential agro-ecological zones that cover the full range of mapped species habitats. The proposed agro-ecological zones differ in percentage of occupancy, which was found to increase with the overall landscape heterogeneity. This study contributes to the ongoing effort to broaden the understanding of the ecology and conservation of the European ground squirrel and the grasslands they rely on. Conservation planning should be designed to protect grasslands occupied by ground squirrels, ensure that the agricultural matrix is permeable, and to sustain or enhance landscape heterogeneity.

农业景观异质性对生物多样性与生态系统服务的影响研究进展

PDF HTML阅读 XML下载 导出引用 引用提醒 农业景观异质性对生物多样性与生态系统服务的影响研究进展 DOI: 10.5846/stxb201806211354 作者: 作者单位: 河南大学黄河中下游数字地理技术教育部重点实验室;河南大学环境与规划学院,河南大学教育科学学院,河南大学黄河中下游数字地理技术教育部重点实验室;河南大学环境与规划学院 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目（31600374，41771202）；河南省教育厅科学技术研究重点项目（16A180022）；河南省博士后科研项目（2015049） Impact of agricultural landscape heterogeneity on biodiversity and ecosystem services Author: Affiliation: Key Laboratory of Geospatial Technology for the Middle and Lower Yellow River Regions,Ministry of Education,Henan University;China;College of Environment and Planning,Henan University;China,,Key Laboratory of Geospatial Technology for the Middle and Lower Yellow River Regions,Ministry of Education,Henan University;China;College of Environment and Planning,Henan University;China Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:农业景观是人类生活所需资料的最主要来源地，农业景观及其提供的生物多样性和生态系统服务是影响人类福祉的最主要因素之一。系统梳理了景观异质性变化对生物多样性和生态系统服务影响的相关研究，总结指出：（1）农业景观格局变化会强烈的影响着区域生物多样性和生态系统服务，但总体上更关注了空间异质性，对于时间和功能异质性的研究仍需加强；（2）尺度效应、大尺度上景观背景的差异、种间差异、营养级联效应等会对景观异质性和生物多样性、生态系统服务间的关系产生显著的、综合的、交互的影响效应。未来区域农业景观中如何通过景观构建和管理措施的施行来确保生物多样性与生态系统服务供给的持续稳定仍需进一步加强以下内容的研究：景观异质性变化在时间上和功能上的影响效应及其阈值的探讨；跨尺度、多因素、多物种类群与多生态系统服务的综合及其交互作用；不同生物类群和不同生态系统服务间的权衡；景观异质性提高与有效生境面积下降及其引起的生物随机丧失间的权衡等问题。 Abstract:Biodiversity and ecosystem services, a frontier and hotspot of international ecology and geography research, are key to realizing the healthy development of regional ecosystems. The well-being and survival of humanity depend upon the stability and sustainability of services provided by the agricultural landscape. This study systematically reviewed research on the effects of landscape heterogeneity on biodiversity and ecosystem services. We found that changes in the agricultural landscape pattern strongly impact regional biodiversity and ecosystem services. However, previous studies have focused more on spatial heterogeneity; research on the temporal and functional heterogeneity of landscapes still needs to be strengthened. In addition, the scale effects, differences in the large-scale landscape context, interspecific differences, and trophic cascade effects have significant, comprehensive, and interactive effects on the relationships between landscape heterogeneity and biodiversity and ecosystem services. In the future, research on how to ensure a stable and sustainable supply of biodiversity and ecosystem services through the methods of landscape reconstruction and agricultural landscape management at the regional scale should be further strengthened. Specifically, four potential limitations to further expansion must be addressed, including the effects of temporal and functional heterogeneity on biodiversity, ecosystem services and their thresholds at the landscape scale; the cross-scale, multi-factor, multi-species, and multi-scale integration and interactions; the trade-offs of different biological groups and different ecosystem services; and the trade-offs between improving landscape heterogeneity and decreasing the effective habitat area, as well as the loss of biodiversity caused by declining habitat area. 参考文献 相似文献 引证文献

Metapop: An individual-based model for simulating the evolution of tree populations in spatially and temporally heterogeneous landscapes.

Metapop is a stochastic individual-based simulation program. It uses quantitative genetics theory to produce an explicit description of the typical life cycle of monoecious and hermaphroditic plant species. Genome structure, the relationship between genotype and phenotype, and the effects of landscape heterogeneity on each individual can be finely parameterized by the user. Unlike most existing simulation packages, Metapop can simulate phenotypic plasticity, which may have a genetic component, and assortative mating, two important features of tree species. Each simulation is parameterized through text files, and raw data are generated recurrently, describing the allelic state of each quantitative trait locus involved in phenotypic variability. The data can be generated in Genepop or Fstat format, and may thus be analysed with other existing packages. Metapop also automatically computes a range of populations statistics, enabling the user to monitor evolutionary dynamics directly, from gene to metapopulation level.

Effect of landscape heterogeneity on termite tunnel pattern: Simulation study

Abstract Although the environment in which termites live is very heterogeneous, most experimental studies on the termite tunnel patterns have been conducted on homogeneous sand substrates. In order to explore how the heterogeneity affects tunnel patterns, I developed an agent-based model to simulate termite tunneling behavior at the individual level. In this model, grid space consists of easy and difficult areas for tunneling. Heterogeneity, H, was defined as the degree of the mixture of the two areas. The tunnel patterns formed by changing the number of termites, N, and H were quantitatively characterized by territory circularity and the territory area. These patterns were categorized into two groups, one with a small territory area and high circularity (group 1) and the other with a large area and low circularity (group 2). Considering the previous study that the termite populations with high N values have high territorial scalability, it can be said that the territories belonging to group 2 have higher foraging abilities and viability than those belonging to group 1. The simulation results showed that the tunnel patterns generated for small N and high H belonged to group 2. This implies that the heterogeneity can make a positive contribution to the expansion of the foraging area by effectively focusing the foraging energy of a termite population. I briefly discussed the mechanism of this positive role and the limitations of this simulation study. In addition, I discussed issues that need to be resolved in the near future to overcome the limitations.

Effects of Landscape Heterogeneity on Common Shrew (Sorex araneus) Population Dynamics

The effects of landscape heterogeneity on changes in the common shrew population were researched. Multiyear (1987–2017) time series data on species abundance in the plain and piedmont areas of the Pechora-Ilych State Nature Biosphere Reserve have been analyzed using the Fourier spectral analysis method. A cyclic component of three years and another one of lower value at five years were identified in the common shrew population dynamics in the piedmont area. In the plain area, changes in the animal population are more chaotic and periodic components are poorly manifested in the time series. The influence of landscape heterogeneity on the species population and its amplitude of fluctuation were also identified; these parameters are significant in the piedmont area and negligible on the plain.

Landscape Diversity for Reduced Risk of Insect Damage: A Case Study of Spruce Bud Scale in Latvia

Spruce bud scale (Physokermes piceae (Schrnk.)) has gained attention due to recent outbreaks in the eastern Baltic Sea region—Poland, Lithuania, and Latvia. In the spring of 2010, it spread rapidly across Latvia, affecting large areas of Norway spruce stands. Therefore, the aim of our study was to assess the effects of landscape heterogeneity on the damage caused by spruce bud scale in Norway spruce stands. In this study, we evaluated landscape metrics for middle-aged (40 to 70 years old) Norway spruce-dominated stands (>70% of stand’s basal area) in four of the most affected forest massifs and two unaffected forest massifs. We used a binary logistic generalized linear mixed effects model (GLMMs) to assess the effect of environmental factors on the abundance of the spruce bud scale. Our results show that increased local diversity within 100 m of a forest patch apparently reduced the probability of spruce bud scale presence. We also found that the diversity within 1000 m of a patch was associated with an increased probability of spruce bud scale damage. A quantitative analysis of landscape metrics in our study indicated that greater landscape-scale diversity of stands may reduce insect damages.

The effect of landscape heterogeneity on population density and habitat preferences of the European hare (Lepus europaeus) in contrasting farmlands

We assessed the effect of habitat heterogeneity and predator density on the European hare (Lepus europaeus), a declining farmland specialist, in intensive farmlands in Central Europe. Using spotlight surveys we explored population density and habitat preference of the European hare in spring and autumn during 2014–2015 in seven farmland regions, of which six were located in the Czech Republic and one in Austria. The average population density of European hares significantly differed between study regions in the Czech Republic and Austria, however, we found no differences in population density between autumn and spring. In particular, the average European hare population density in study regions in the Czech Republic varied between 6.8–17.0 individuals/100ha, whereas in Austria the population density reached 65.3 individuals/100ha. Differences between spring and autumn population densities were not significant. European hare population density was significantly negatively affected by mean patch size and positively by area of arable land. We did not find a significant effect of red fox (Vulpes vulpes) presence on the numbers of European hares in individual regions. Habitat preferences differed among regions with contrasting population densities and field sizes, hares in regions of high density and small fields were more equally distributed among available habitats compared to regions of low or intermediate density and large fields. To conclude, conservation measures focusing on enhancing habitat heterogeneity by reducing field size may be an effective tool to support populations of European hares in arable farmland landscapes.

Dynamic, spatial models of parasite transmission in wildlife: Their structure, applications and remaining challenges.

Individual differences in contact rate can arise from host, group and landscape heterogeneity and can result in different patterns of spatial spread for diseases in wildlife populations with concomitant implications for disease control in wildlife of conservation concern, livestock and humans. While dynamic disease models can provide a better understanding of the drivers of spatial spread, the effects of landscape heterogeneity have only been modelled in a few well-studied wildlife systems such as rabies and bovine tuberculosis. Such spatial models tend to be either purely theoretical with intrinsic limiting assumptions or individual-based models that are often highly species- and system-specific, limiting the breadth of their utility. Our goal was to review studies that have utilized dynamic, spatial models to answer questions about pathogen transmission in wildlife and identify key gaps in the literature. We begin by providing an overview of the main types of dynamic, spatial models (e.g., metapopulation, network, lattice, cellular automata, individual-based and continuous-space) and their relation to each other. We investigate different types of ecological questions that these models have been used to explore: pathogen invasion dynamics and range expansion, spatial heterogeneity and pathogen persistence, the implications of management and intervention strategies and the role of evolution in host-pathogen dynamics. We reviewed 168 studies that consider pathogen transmission in free-ranging wildlife and classify them by the model type employed, the focal host-pathogen system, and their overall research themes and motivation. We observed a significant focus on mammalian hosts, a few well-studied or purely theoretical pathogen systems, and a lack of studies occurring at the wildlife-public health or wildlife-livestock interfaces. Finally, we discuss challenges and future directions in the context of unprecedented human-mediated environmental change. Spatial models may provide new insights into understanding, for example, how global warming and habitat disturbance contribute to disease maintenance and emergence. Moving forward, better integration of dynamic, spatial disease models with approaches from movement ecology, landscape genetics/genomics and ecoimmunology may provide new avenues for investigation and aid in the control of zoonotic and emerging infectious diseases.

Combined effects of waggle dance communication and landscape heterogeneity on nectar and pollen uptake in honey bee colonies.

The instructive component of waggle dance communication has been shown to increase resource uptake of Apis mellifera colonies in highly heterogeneous resource environments, but an assessment of its relevance in temperate landscapes with different levels of resource heterogeneity is currently lacking. We hypothesized that the advertisement of resource locations via dance communication would be most relevant in highly heterogeneous landscapes with large spatial variation of floral resources. To test our hypothesis, we placed 24 Apis mellifera colonies with either disrupted or unimpaired instructive component of dance communication in eight Central European agricultural landscapes that differed in heterogeneity and resource availability. We monitored colony weight change and pollen harvest as measure of foraging success. Dance disruption did not significantly alter colony weight change, but decreased pollen harvest compared to the communicating colonies by 40%. There was no general effect of resource availability on nectar or pollen foraging success, but the effect of landscape heterogeneity on nectar uptake was stronger when resource availability was high. In contrast to our hypothesis, the effects of disrupted bee communication on nectar and pollen foraging success were not stronger in landscapes with heterogeneous compared to homogenous resource environments. Our results indicate that in temperate regions intra-colonial communication of resource locations benefits pollen foraging more than nectar foraging, irrespective of landscape heterogeneity. We conclude that the so far largely unexplored role of dance communication in pollen foraging requires further consideration as pollen is a crucial resource for colony development and health.

Grape moth density in Bordeaux vineyards depends on local habitat management despite effects of landscape heterogeneity on their biological control

Summary Biological control of crop pests is a major ecosystem service affected by several variables acting at multiple spatial scales. Among these variables, heterogeneity at the habitat and landscape scales are known key drivers of trophic interactions and pest density in agroecosystems. However, studies that try to disentangle their relative effects in perennial cropping systems are scarce and nothing is known about their impacts on insect pest density and pesticide applications. We examined the effect of heterogeneity at these two scales on grape moths, one of the most damaging insect pests in European vineyards, and their biological control in 20 vineyards during three consecutive years. We used local vegetation management and the proportion of semi‐natural habitats in the surrounding landscape as proxies of heterogeneity at the habitat and landscape scales. Grape moth density was measured over time, as well as biological control services provided by different groups: birds, invertebrate predators, parasitoids and entomopathogenic fungi. Over the 3 years, grape moth density was mainly determined by local heterogeneity, with significantly fewer larvae of the first generation established in vineyards with full compared to partial grass cover. Despite these effects, biological control of grape moths was not primarily affected by local vegetation management but by landscape heterogeneity, and the direction of this effect varied over time. Notably, predation by birds increased with landscape heterogeneity in spring, depending on local vegetation management, while attacks by pathogenic fungi decreased with landscape heterogeneity during winter. Synthesis and applications. Our results suggest that bottom‐up processes related to habitat heterogeneity drive grape moth occurrence much more than top‐down processes. These results have important implications for the ecological intensification of vineyard landscapes. We found that maintaining full grass cover within vineyards reduced grape moth density to a level below common intervention thresholds. Landscape heterogeneity in the close vicinity of vineyards contributed to improved biological pest control by birds, but depended on local vegetation management. Moreover, opposing effects of landscape management on biological pest control services over time revealed that strategies based only on manipulating landscape heterogeneity might not be the optimal option to limit grape moth density in vineyards.