Effects Of Landscape Features Research Articles

Effects of landscape features on the structure and function of bird seed dispersal networks in fragmented forests

Forest fragmentation has resulted in reduced natural habitats and alterations in landscape structure. Although the effects of landscape features on the structure of seed dispersal networks are well known, the effects on functional consequences of these networks remain unclear. In this study, we compared the structures of seed dispersal networks of three fragmented habitats (high-, medium-, and low-fragmented habitats). We used an integrative index (seed dispersal potential, SDP) to evaluate the network functions of the three habitats. We also studied how the structure and function of seed dispersal networks respond to different landscape features. Approximately 23, 26, and 22 bird species were recorded foraging for 9, 25, and 22 plant species, resulting in 315, 665, and 546 foraging events in high-, medium-, and low-fragmentation habitats, respectively. The structure and function of seed dispersal networks of the three fragmented habitats significantly differ. For instance, the network in a highly fragmented habitat exhibits high connectance and nestedness, whereas the network in a low-fragmentation habitat exhibits high modularity and specialization. Furthermore, the network function (the SDP value for frugivorous species) varies for each habitat. Frugivorous species exhibit a lower seed dispersal potential in highly fragmented habitats, as indicated by their low total SDP values. Most importantly, the structure and function of the seed dispersal network are differently affected by landscape variables. Increasing habitat fragmentation leads to a reduction in the structure of seed dispersal networks. However, medium levels of fragmentation can enhance the network function. Overall, our study highlights the importance of considering both structural and functional aspects of mutualistic networks to understand the landscape effects of habitat fragmentation. The SDP index provides a comprehensive approach to study the functions of mutualistic networks and is a useful tool for future forest management.

Effects of Landscape Features on Bird Community in Winter Urban Parks.

Urban parks, as critical components of the urban green space, have practical significance in studying the influence of landscape characteristics on birds. Nine urban parks in Fuzhou, China, were used as study objects to explore the influence of landscape features (patch, landscape, and surrounding environment indices) on bird communities. The results showed that (1) from December 2021 to February 2022, we found a total of 2874 individuals belonging to 61 species of 9 orders, 32 families, which were dominated by the birds of Passeriformes (37 species of 24 families, accounting for 89.91% of the total number of individuals) and resident birds in Fuzhou urban parks (n = 30; 85.46%); (2) The park area, park perimeter, woodland area, grassland area, and the park shape index increased as the distance to the city center increases; (3) Bird diversity responds differently to different landscape features. The total abundance of birds, the abundance of winter migrant birds, and the richness of winter migrant birds increased with the park area. And the park shape index affects positively for the the α-diversity of birds and the abundance of resident birds. Woodland proportion and waterbody shape index affected positively on the richness and α-diversity of resident birds. To promote the diversity of regional birds, it is recommended that the construction and planning of urban parks should enlarge the park area as much as possible, increase the proportion of woodland, and make shorelines more irregular. Our study could serve as a reference for the construction of biodiversity enhancements in core green areas of urban parks.

Effect of landscape features on the genetic structure of forest duikers (Cephalophinae) in Moukalaba forest, Gabon

Effect of landscape features on the genetic structure of forest duikers (Cephalophinae) in Moukalaba forest, Gabon

The Effect of Landscape Features Implemented in Egyptian Parks on Satisfying the Human Needs and Well-being

Recently, parks have been recognized as one of the main contributors in the strategic objectives of urban projects, since they provide job opportunities, place attractiveness, increase the real estate market and property values, tourist development, increase the since of social belonging between the residents, improving the public health and the quality of the residents’ life. The presented research is aiming to investigate the effect of Landscape features on the quality of life (QOL) inside Egyptian parks. This study has been inspired by early theorists like “Maslow” and other theorists who have followed Maslow’s footsteps. They analysed and measured the concept of quality of life (QOL)into two well-known terms “human needs” and “well-being”. The study explores the impact of landscape features towards “human needs and well-being”. Lately, Egypt is suffering from inflation and economic crisis which affect the Egyptians life style. Most of the Egyptian society is living a stressful life; this study will examine whether the Egyptian parks help Egyptians as an escape way where all the negative vibes are going to meet with nature resulting in a positive outcome. This research used qualitative investigation method to measure the impact of implementing landscape features in Egyptian parks on enhancing the quality of the Egyptian life by measuring the (QOL) with regards to “human needs and well-being”. The presented research investigated the impact of landscape elements implemented in Al-Azhar Park and Family Park on “human needs and well-being”. That shall pave the way to investors, policymakers, architecture and civil practitioners to realize the potentials of designing and constructing parks in Egyptian urban environment, as an efficient tool to improve the quality of Egyptian life.

Optimizing conservation in species-specific agricultural landscapes.

Recovery of grassland birds in agricultural landscapes is a global imperative. Agricultural landscapes are complex, and the value of resource patches may vary substantially among species. The spatial extent at which landscape features affect populations (i.e., scale of effect) may also differ among species. There is a need for regional-scale conservation planning that considers landscape-scale and species-specific responses of grassland birds to environmental change. We developed a spatially explicit approach to optimizing grassland conservation in the context of species-specific landscapes and prioritization of species recovery and applied it to a conservation program in Kentucky (USA). We used a hierarchical distance-sampling model with an embedded scale of effect predictor to estimate the relationship between landscape structure and abundance of eastern meadowlarks (Sturnella magna), field sparrows (Spizella pusilla), and northern bobwhites (Colinus virginianus). We used a novel spatially explicit optimization procedure rooted in multi-attribute utility theory to design alternative conservation strategies (e.g., prioritize only northern bobwhite recovery or assign equal weight to each species' recovery). Eastern meadowlarks and field sparrows were more likely to respond to landscape-scale resource patch adjacencies than landscape-scale patch densities. Northern bobwhite responded to both landscape-scale resource patch adjacencies and densities and responded strongly to increased grassland density. Effects of landscape features on local abundance decreased as distance increased and had negligible influence at 0.8 km for eastern meadowlarks (0.7-1.2 km 95% Bayesian credibility intervals [BCI]), 2.5 km for field sparrows (1.5-5.8 km 95% BCI), and 8.4 km for bobwhite (6.4-26 km 95% BCI). Northern bobwhites were predicted to benefit greatly from future grassland conservation regardless of conservation priorities, but eastern meadowlark and field sparrow were not. Our results suggest similar species can respond differently to broad-scale conservation practices because of species-specific, distance-dependent relationships with landscape structure. Our framework is quantitative, conceptually simple, customizable, and predictive and can be used to optimize conservation in heterogeneous ecosystems while considering landscape-scale processes and explicit prioritization of species recovery.

Effects of landscape features and flooding on the genetic structure of a small wetland rodent, the harvest mouse (Micromys minutus)

ContextThe natural patchiness of wetlands and flooding events are likely to strongly affect the genetic structure of their terrestrial species. However, these effects are not well understood yet, especially for small mammals.ObjectivesWe investigated at different spatial scales the genetic structure of the harvest mouse (Micromys minutus), a threatened small mammal strongly tied to wetlands, and the effects on gene flow of flooding and of the different types of landscape elements composing a wetland.Methods309 harvest mice were sampled in eight sites in Western Europe. Their genetic structure and diversity at 15 microsatellite loci were analyzed at a regional spatial scale and at a local scale, where the resistance of land cover and flooding to gene flow was also assessed, with the optimization procedure implemented in ResistanceGA.ResultsAt a regional scale, our study revealed a strong genetic differentiation between populations from Northern Europe to the Mediterranean Sea. At the local scale, in a flooded wetland in France, the species exhibited a large genetic cluster over at least 45 km2, in spite of a large river crossing it. Winter floods explained genetic structure better than landscape features alone, with a stronger resistance to gene flow in reed beds where vegetation level above water was high: contrary to meadows, from which individuals are forced to escape, reed beds can be “golden prisons”, i.e. refuges during floods but with very low possibility of movements.ConclusionsSeveral parameters influencing the functioning of a flooded population of harvest mouse are here highlighted that can also be useful for the development of plans to safeguard wetland ecosystems.

Effects of Landscape Features on the Roadside Soil Heavy Metal Distribution in a Tropical Area in Southwest China

Soil heavy metals along roadsides pose a great threat to ecosystems while their spatial variations and influencing factors still remain unclear in some regions, especially in tropical areas with complex landscape characteristics. Our study was carried out to determine how the land use, vegetation characteristics, topographical factors and distance to the road affect the soil heavy metal distribution. Taking Jinghong county in Yunnan Province, Southwest China as a case, soil samples were collected at different distances off roads and canonical correspondence analysis (CCA) methods were used to determine the relative importance of different factors. Our results showed that heavy metal sources were obtained mainly from the road, based on the principle component analysis (PCA) identification. There were no obvious trends of soil quality index (SQI) with distance to the road in natural soils, while SQI nutrients and SQI metals in farmlands had a decreasing and increasing trend, respectively, which could both be expressed by logarithm models. However, soil properties showed little differences for road levels while they showed significant differences under land use types. The CCA further showed that heavy metal variations in natural soils were jointly affected by distance, plant coverage, relative elevation and soil properties in decreasing order.

Landscape features affecting bird diversity and abundance at an urban landfill site: a case study in Central Iran

ABSTRACT Capsule Landfill sites can support a large and diverse bird community but the surrounding habitat and disturbance are also important in determining how sites are used. Aims To investigate the bird diversity, richness and abundance at an open waste landfill site located in Isfahan, Iran. Methods The effects of landscape features on bird richness and composition were examined using generalized linear models and redundancy analysis (RDA). Results Thirty bird species were identified using the landfill site. The Rook Corvus frugilegus and European Starling Sturnus vulgaris were the two most abundant species, with relative abundance of 28.5 and 27.5% respectively. Species composition and abundance varied spatially, with the RDA ordination identifying three clusters of species based on environmental associations. Bird diversity was highest at sites with relatively high levels of tree cover, with shorter distances to organic waste and water, and low human disturbance. Conclusions Although, birds may be primarily attracted to waste disposal sites for feeding, they are able to use the landfill surrounding habitats for other ecological requirements. Understanding factors related to bird diversity and abundance in landfills can help to inform decisions relating to conservation, population control, and other types of management.

Effects of landscape features on gene flow among urban frog populations

AbstractThe anthropogenic fragmentation of habitats has altered the distribution and size of populations of many species worldwide. To predict fate of populations and establish management practices that ensure their viability, we need to understand the demographic and genetic consequences of fragmentation. In this study, we analyzed whether the spatial configuration of remnant habitat patches within a fragmented landscape has shaped the patterns of genetic diversity and differences in local populations of the Montane brown frog (Rana ornativentris) in Tokyo, Japan. The species inhabits secondary forests and is particularly affected by fragmentation due to its habitat selectivity and low dispersal capability. We determined allele frequencies of six microsatellites to estimate genetic diversity of 33 local populations and pairwise genetic distances among them. Habitat suitability maps were developed based on two models, one with only climatic and topography as predictor variables (HSn), the second incorporating the potential barrier effect of urbanization as an additional variable (HSu). Ecological distances were calculated using the circuit theory applied to the habitat suitability maps. We found that within‐population genetic diversity decreases as the HSu habitat suitability decreases. Moreover, pairwise population genetic distance showed the highest correlations with resistance (i.e., ecological) distances when the HSu map was used. Our results confirmed the expectation that urbanized lands are barriers to gene flow, and that habitat fragmentation restricts inter‐population dispersal, thus reducing the genetic diversity of local populations. Our results also demonstrate that landscape genetics is a useful approach for identifying key factors affecting dispersal.

Functional connectivity and home range inferred at a microgeographic landscape genetics scale in a desert-dwelling rodent.

Gene flow in animals is limited or facilitated by different features within the landscape matrix they inhabit. The landscape representation in landscape genetics (LG) is traditionally modeled as resistance surfaces (RS), where novel optimization approaches are needed for assigning resistance values that adequately avoid subjectivity. Also, desert ecosystems and mammals are scarcely represented in LG studies. We addressed these issues by evaluating, at a microgeographic scale, the effect of landscape features on functional connectivity of the desert‐dwelling Dipodomys merriami. We characterized genetic diversity and structure with microsatellites loci, estimated home ranges and movement of individuals using telemetry—one of the first with rodents, generated a set of individual and composite environmental surfaces based on hypotheses of variables influencing movement, and assessed how these variables relate to individual‐based gene flow. Genetic diversity and structure results evidenced a family‐induced pattern driven by first‐order‐related individuals, notably determining landscape genetic inferences. The vegetation cover and soil resistance optimized surface (NDVI) were the best‐supported model and a significant predictor of individual genetic distance, followed by humidity and NDVI+humidity. Based on an accurate definition of thematic resolution, we also showed that vegetation is better represented as continuously (vs. categorically) distributed. Hence, with a nonsubjective optimization framework for RS and telemetry, we were able to describe that vegetation cover, soil texture, and climatic variables influence D. merriami's functional connectivity at a microgeographic scale, patterns we could further explain based on the home range, habitat use, and activity observed between sexes. We describe the relationship between environmental features and some aspects of D. merriami‘s behavior and physiology.

Effect of landscape features on genetic structure of the goitered gazelle (Gazella subgutturosa) in Central Iran

The populations of goitered gazelle suffered significant decline due to natural and anthropogenic factors over the last century. Investigating the effects of barriers on gene flow among the remaining populations is vital for conservation planning. Here we adopted a landscape genetics approach to evaluate the genetic structure of the goitered gazelle in Central Iran and the effects of landscape features on gene flow using 15 polymorphic microsatellite loci. Spatial autocorrelation, isolation by distance (IBD) and isolation by resistance (IBR) models were used to elucidate the effects of landscape features on the genetic structure. Ecological modeling was used to construct landscape permeability and resistance map using 12 ecogeographical variables. Bayesian algorithms revealed three genetically homogeneous groups and restricted dispersal pattern in the six populations. The IBD and spatial autocorrelation revealed a pattern of decreasing relatedness with increasing distance. The distribution of potential habitats was strongly correlated with bioclimatic factors, vegetation type, and elevation. Resistance distances and graph theory were significantly related with variation in genetic structure, suggesting that gazelles are affected by landscape composition. The IBD showed greater impact on genetic structure than IBR. The Mantel and partial Mantel tests indicated low but non-significant effects of anthropogenic barriers on observed genetic structure. We concluded that a combination of geographic distance, landscape resistance, and anthropogenic factors are affecting the genetic structure and gene flow of populations. Future road construction might impede connectivity and gene exchange of populations. Conservation measures on this vulnerable species should consider some isolated population as separate management units.

Effects of landscape features on gene flow of valley oaks (Quercus lobata)

Landscape features affect habitat connectivity and patterns of gene flow and hence influence genetic structure among populations. We studied valley oak (Quercus lobata), a threatened species of California (USA) savannas and oak woodlands, with a distribution forming a ring around the Central Valley grasslands. Our main goal was to determine the role of topography and land cover on patterns of gene flow and to test whether elevation or land cover forms stronger barriers to gene flow among valley oak populations. We sampled valley oaks in 12 populations across the range of this species, genotyped each tree at eight nuclear microsatellite loci, and created a series of resistance surfaces by assigning different resistance values to land cover type and elevation. We also estimated recent migration rates and evaluated them with regard to landscape features. There was a significant but weak relationship between Euclidian distance and genetic distance. There was no relationship between genetic distances and land cover, but a significant relationship between genetic distances and elevation resistance. We conclude that gene flow is restricted by high elevations in the northern part of the valley oak range and by high elevations and the Central Valley further south. Migration rate analysis indicated some gene flow occurring east–west but we suggest that the high connectivity in the northern Central Valley is facilitating the formation of these links. We predict that southern populations may become more differentiated in the future through genetic isolation and local adaptation taking place in the face of climate change.

Landscape Features and Processes Influencing Forest Pest Dynamics

Insects and pathogens (pests) in forest ecosystems can impact tree fitness and greatly increase rates of tree mortality. Pest dynamics vary significantly across spatial and temporal scales due to influences from a range of landscape features. Here, with a focus on recent research, primarily from coniferous forest ecosystems, I review the influence of landscape features and their interactions with global change pressures on forest pest dynamics. Landscape genetics have revealed evidence of local adaptation and spatially aggregated patterns in phenotypes within tree populations. Thus, I also consider the role of phenotypic adaptations as features of the landscape affecting forest pest dynamics. Landscape influences on pest dynamics are illustrated by three case-studies representing pests with different feeding strategies, levels of host-specialization, and dispersal potential. The effects of landscape features on forest pest-host interactions are anticipated to grow increasingly complicated in an era of rapid environmental change. Despite recent advances in remote sensing, genomics, and analytical tools, significant gaps remain in our understanding of the complex interactions of pest-host systems with landscape features under global change pressures. Filling these gaps requires continued research into the landscape ecology of forest pests, along with increased efforts to understand the role of pest and host functional traits in pest population dynamics. Thus, I conclude with a conceptual framework for generating testable hypotheses regarding factors affecting the relative influence of landscape features on forest pest dynamics and the predictability of spatiotemporal patterns in forest pest dynamics.

Roe deer population structure in a highly fragmented landscape

Northern Belgium (Flanders) is one of the most densely populated and urbanized regions in Europe. Many species are therefore likely to suffer from anthropogenic pressure and habitat destruction and fragmentation. Although many large mammals are recolonizing in parts of Europe, including Belgium, due to adaptation, a relaxation of persecution and habitat restoration, we have little actual data concerning the effects of landscape features on their population structure. We analysed the genetic structure of discrete roe deer (Capreolus capreolus) populations in the Eastern part of Flanders, with special emphasis on the impact of habitat fragmentation and anthropogenic barriers. The sampled populations were clearly genetically differentiated. Genetic structure could be explained by purely distance-based landscape modelling, but a simpler model focusing solely on barrier effects of large transportation infrastructure explained nearly as much genetic variance. In contrast, analyses based on least-cost landscape modelling failed to yield a significant effect. Overall, the results suggest considerable landscape-level effects of transportation infrastructure.

The Interplay of Landscape Features and Social System on the Genetic Structure of a Primate Population: An Agent-Based Simulation Study Using “Tamarins”

Tamarins are small-bodied, forest-dwelling, callitrichines that live in groups containing one to a few adult individuals of each sex. Within these groups, reproduction is usually heavily skewed toward a single dominant male and dominant female, females commonly give birth to cooperatively reared twin offspring, and individuals of both sexes disperse, most often to adjacent groups. Throughout their geographic range, tamarin species are being subject to habitat loss and fragmentation, which may influence their ability to survive and disperse successfully. Here, we use a spatially explicit agent-based population genetics simulation toolkit (GENESYS) to explore the potential effects of social structure and landscape features on the population genetic structure of tamarin primates. We first model the population genetic consequences of tamarin social organization in a homogeneous landscape unconstrained by any barriers to gene flow. We then repeat our analyses using the same social system parameters but in different landscapes that either introduce a barrier to gene flow that restricts dispersal from one half of the model world to the other or divide the world into regions with differing “permeabilities” to dispersal. Our results demonstrate that, in our simulated populations, the social system of tamarins results in the clear and rapid genetic differentiation of social groups within a very short time frame. Over time, the limited dispersal of both males and females leads to a pattern of isolation by distance, as expected from a stepping-stone model of gene flow among groups. Introducing a barrier results in a somewhat more complex pattern: isolation by distance still obtains among social groups within regions on each side of the barrier, but the barrier has a much more significant effect on the structuring of genetic variation, leading to strong genetic differentiation among groups on opposite sides that becomes more pronounced over time. Introducing a region of limited dispersal permeability also results in strong differentiation of groups across that region, even though gene flow throughout the landscape is still possible. Our study demonstrates the utility of the GENESYS toolkit for modeling, in silico, the genetic consequences of many features of the social systems of primates and other group-living animals and for simultaneously exploring the effects of landscape features on spatial genetic structure.

Resistance is futile: effects of landscape features on gene flow of the northern bobwhite

Habitat for the northern bobwhite (Colinus virginianus) has declined and changed drastically in spatial structure throughout the last century. Undoubtedly such changes have impacted bobwhite and may have altered their ability to access available habitat. We investigated whether landscape resistance, geographic distance, or interstate highway barriers were related to dispersal and gene flow of bobwhite in central and southern Illinois. Landscape resistance was determined from two empirically informed models depicting habitat suitability for bobwhite. During 2007–2008, hunters submitted bobwhite tissue samples from which we amplified 11 microsatellites. The relationship between individual genetic distances and spatial variables was analyzed with Mantel tests and causal modeling was used to verify the spatial variables influencing gene flow. Genetic distance was correlated with geographic distance but showed no relationship with interstate highway barriers. Habitat suitability did not enhance gene flow, and was inversely related in some partial Mantel tests. We suggest that bobwhite dispersal from suitable habitat patches may be less frequent than from suboptimal habitats. Bobwhite may be able to access suitable habitat across gaps of unsuitable habitat but distance limits their dispersal. Because available habitat for bobwhites may have a greater likelihood of being colonized when closer to occupied habitat, we suggest that lands closer to occupied habitat should be targeted for conservation or habitat improvement efforts.

Empirical estimation of dispersal resistance surfaces: a case study with red-cockaded woodpeckers

Persistence of wildlife populations depends on the degree to which landscape features facilitate animal movements between isolated habitat patches. Due to limited data availability, the effect of landscape features on animal dispersal is typically estimated using expert opinion. With sufficient data, however, resistance surfaces can be estimated empirically. After modeling suitable prospecting habitat using an extensive dataset from the federally endangered red-cockaded woodpecker (Picoides borealis), we used data from over 800 prospecting events from 34 radio-tagged birds to identify the best relationship between habitat suitability and resistance surfaces. Our results demonstrated that juvenile female P. borealis prospecting for new territories beyond their natal territories preferred to traverse through forests with tall canopy and minimal midstory vegetation. The non-linear relationship between habitat suitability and resistance surfaces was the most biologically relevant transformation, which in turn identified the specific forest composition that promoted and inhibited prospecting and dispersal behavior. These results corresponded with over 60 % of dispersal events from an independent dataset of short-distance dispersal events. This new understanding of P. borealis prospecting behavior will help to identify areas necessary for maintaining habitat connectivity and to implement effective management strategies. Our approach also provides a framework to not only estimate and evaluate resistance surfaces based on species-specific responses to intervening landscape features, but also addresses an often-neglected step, selecting a biologically relevant function to transform habitat suitability model into a resistance surface.

Effects of landscape features and demographic history on the genetic structure of Testudo marginata populations in the southern Peloponnese and Sardinia

Testudo marginata, the largest European land tortoise, is suffering habitat degradation and destruction. Some populations, in markedly degraded habitats, are characterized by divergent morphotypes. However, the evolutionary significance of these morphotypes is of debate. Using 11 polymorphic microsatellites, we studied: (1) marginated tortoises from Sardinia that display a divergent morphotype – this population was potentially introduced from Greece; and (2) an area in the southern Peloponnese that includes a small and degraded zone in which marginated tortoises are dwarf. Genetic analyses run without any a priori assignment clearly acknowledge the specimens sampled in the territory of the dwarf form as a single group whilst Sardinian specimens are clustered with other specimens from the northern part of the area sampled in Greece. Demographic analyses suggest that Sardinian tortoises originated recently from some of the populations sampled in the northern part of the area sampled in Greece. Over locations sampled in Greece, a landscape-genetic analysis allowed us to detect potential landscape features that may reduce gene flow between the dwarf form territory and surrounding areas. Our results suggest that the territory of the dwarf form is particularly propitious for marginated tortoises and that conservation regulations in Greece should be reinforced to protect this area from increasing impact of human activities changing from traditional agriculture to mechanization and extensive use of chemicals. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, 105, 591–606.

Fine scale population genetic structure of pumas in the Intermountain West

In this study, I examined the population genetic structure of subpopulations of pumas (Pumaconcolor) in Idaho and surrounding states. Patterns of genetic diversity, population structure, levels of inbreeding, and the relationship between genetic differentiation and dispersal distance within and between 15 subpopulations of pumas were compared. Spatial analyses revealed that the Snake River plain was an important barrier to movement between northern and southern regions of Idaho. In addition, subpopulations south of the Snake River plain exhibited lower levels of genetic diversity, higher levels of inbreeding, and a stronger pattern of isolation by distance relative to subpopulations north of the Snake River plain. Lower levels of diversity and restricted gene flow are likely the result of historically lower population sizes in conjunction with more recent changes in habitat use and available dispersal corridors for movement. The subdivision of puma populations north and south of the Snake River plain, along with the patterns of genetic diversity within regions, indicate that landscape features are affecting the population genetic structure of pumas in Idaho. These results indicate that information about the effects of landscape features on the distribution of genetic diversity should be considered when designing plans for the management and conservation of pumas.

Effects of Landscape Features on the Distribution and Sustainability of Ungulate Hunting in Northern Congo

Understanding the spatial dimensions of hunting and prey population dynamics is important in order to estimate the sustainability of hunting in tropical forests. We investigated how hunting offtake of vertebrates differed in mixed forest and monodominant forest (composed of Gilbertiodendron dewevrei) and over different spatial extents within the hunting catchment around the logging town of Kabo, Congo. In 9 months of recall surveys with hunters, we gathered information on over 1500 hunting trips in which ungulates were 65% of the species killed and 82% of harvested biomass. Hunters supplied information on animals killed and the hunting trip, including the area visited (i.e., hunting zone; 11 separate zones within a 506 km(2) catchment or commonly hunted area). Over 65% of all animals were killed in monodominant forest, which made up 28% of the hunting catchment, and zones with small amounts of monodominant forest were used most frequently by hunters. Given the large offtakes from monodominant forests, we suggest that animal dispersal may be maintaining high, localized harvests in these areas. We believe hunters preferred to hunt in monodominant forest because the understory was accessible and that areas with small amounts of monodominant forest and large amounts of mixed forest were more productive. The variation in hunting pressure we found between and within hunting zones differs from past examinations of spatial variation in hunting offtake, where entire hunting catchments were considered population sinks and areas with low to no hunting (no-take zones) were outside hunting catchments. Future use of no-take zones to manage hunting should incorporate variability in offtake within hunting catchments.