Landscape Ecology最新文献

Context

Ecological corridors are one of the most recommended ways to mitigate biodiversity loss. With growing recognition of corridor importance, corridor modeling lags others in the development of robust, quantitative validation methods.

Objective

We propose a post-hoc corridor validation framework, considering the range of methods across data needs and statistical intensity. We demonstrate the importance of post-hoc corridor validation by testing several validation methods on different corridor model outputs.

Methods

We used three different transformations on a Florida black bear (Ursus americanus floidanus) habitat suitability model to create different resistance grids, independent GPS collar data from a case study population, and Circuitscape to create corridor models. We used several validation methods, including a novel method, to compare resulting corridors.

Results

Transformed resistance grids were all correlated, yet differing validation and resistance grids resulted in different recommended corridors. The use of one resistance surface and one validation type can result in the selection of inefficient or ineffective corridors. At a minimum, modelers should determine what proportion of an independent population falls within resulting corridors and should move towards more robust, documented methods as resources allow. The use of multiple validation methods can ensure greater confidence of modeling results.

Conclusions

We encourage the use and further development of the framework presented here to drive the corridor modeling field towards more effective corridor creation and improved conservation outcomes. If validation methods are not improved, the ecological and economic cost of poor corridor science will continue to increase with increasing biodiversity loss.

Context

A large body of literature has shown that forests provide nutritious foods in many low- and middle-income countries. Yet, there is limited evidence on the contributions from different types of forest and tree systems.

Objectives

Here, we focus on individual trees and smaller forest patches outside established forest reserves as well as different forest management systems.

Methods

We do so by combining novel high-resolution data on tree cover with 24-h dietary recall surveys from 465 women in Tanzania.

Results

We show that people with more unclassified tree cover (i.e., individual trees and small forest patches) in their nearby surroundings have more adequate protein, iron, zinc, and vitamin A intakes. We also find that having a nearby forest under Participatory Forest Management (PFM) system is associated with higher adequacy levels of energy, iron, zinc and vitamin A. By contrast, tree cover within other types of forest (e.g., Government Forest Reserves and Government Forest Plantations) is not positively associated with people’s dietary quality.

Conclusions

Our key finding is that having individual trees, smaller forest patches and/or forest under PFM in close proximity is more beneficial for people’s diets than other types of established forests. Our results highlight the nutritional importance of trees outside established forests and question the often-assumed benefits of forests if these are made inaccessible by social barriers (e.g., legislation). Finally, our results emphasize the need to distinguish between different forest management systems when studying forest-diet linkages.

Context

Landscape sensation is essential for the delivery of cultural ecosystem services (CESs), yet the pathways through which these services are delivered remain inadequately understood. Exploring how people obtain CESs from landscapes facilitates better understanding of the tradeoffs and synergies between ecosystem services and landscape sustainability.

Objectives

This study aimed to elucidate the sensory pathways that links landscape attributes to CESs, focusing on the roles of cognitive and affective experiences.

Methods

We analyzed social media comments for the measurement scale of cognition. We employed partial least squares structural equation modeling to integrate sensation, cognition, affect, and satisfaction, using questionnaire data (n = 503).

Results

Cognitive comprehensions and affective responses play a crucial role in interpreting CESs while sensory experiences do not directly determine people’s satisfaction with CESs. The effective pathways are achieved through the sole mediator of cognition or by serial mediators of cognition and affect. Of the two mediators, cognition has a more profound mediating effect than affect.

Conclusions

Both physical and biological components, such as landscape sensory attributes, as well as cognitive and affective responses, influence human-nature interactions. These components should be considered when promoting the sustainability of human-dominated landscapes.

Context

Once common, the northern long-eared bat (Myotis septentrionalis) has experienced declines > 90% due to white-nose syndrome (WNS). This severe mortality has resulted in their listing under the Endangered Species Act and made them a conservation priority. However, their broad distribution, variability in habitat use, and population instability make developing range-wide conservation strategies difficult. To understand how conservation of M. septentrionalis may vary across its range, we examined shifts in M. septentrionalis site occupancy on the edge of their historic range following severe WNS mortality.

Objectives

Our goal was to determine how mortality from white-nose syndrome affects site occupancy of M. septentrionalis at the southern edge of their historic range. Understanding which areas will remain occupied during disease related mortality will help inform management during disease outbreaks.

Methods

We used 11 years (2007–2017) of mist-netting records to construct dynamic occupancy models of M. septentrionalis in northern Georgia, USA. Occupancy was updated annually, with the initial period defined as all years prior to the winter of 2012–2013, which corresponds to when white-nose syndrome entered the study area. We assessed occupancy using landscape metrics at the home range (65 ha) and landscape (491 ha) scales, year since WNS occurrence in the study area, distance to karst, and distance to nearest WNS positive county. We estimated probability of detection using Julian date and sampling effort.

Results

Initial site occupancy was positively associated with percent deciduous forest cover at the home range scale. As M. septentrionalis populations declined from WNS, a site becoming unoccupied was negatively correlated with mean contiguity of forest at the home range scale and largest patch of forest and mean elevation at the landscape scale. Site occupancy declined precipitously in the years following WNS, dropping from 70.75% (41.76–96.98% [95% CI]) occupancy pre-WNS to 0.3% (0.3–20.5% [95% CI]) by the final year of the study.

Conclusions

Our results demonstrated that sites occupied by M. septentrionalis closer to the historic range edge were more vulnerable to becoming unoccupied after disease arrival. We recommend managers on the periphery of the historic range focus conservation efforts on high elevation forested areas nearer to the range core.

Context

Biotic resource exploitation is a critical determinant of species’ distributions. However, quantifying resource exploitation patterns through space and time can be difficult, complicating their incorporation in spatial ecology studies. Therefore, understanding the local drivers of spatial patterns of resource exploitation may contribute to better large-scale species distribution models.

Objectives

We investigated (1) how the resource exploitation patterns of two trophic interactions (plant–insect) are explained by insect behaviour, resource aggregation, and potential insect-insect interactions. We also analyzed how (2) resource patch size and (3) resource accessibility in a heterogeneous landscape affected host exploitation patterns.

Methods

We quantified nectar robbing by insects in the genus Bombus (bumblebees) and seed predation by Brachypterolus vestitus larvae (Antirrhinum beetle) on Antirrhinum majus L. (wild snapdragons) in the Pyrenees Mountains, Catalonia, Spain. We tested hypotheses about resource exploitation by integrating spatial analyses at multiple scales.

Results

Both trophic interactions were aggregated, explained by the aggregation of their resource. At some scales, nectar robbing is more aggregated than the resource. Trophic interaction abundance is proportional to resource patch size, following the ideal free distribution model. Landscape features do not explain the locations exploited. Nectar robbing and seed predation occur together more often than expected.

Conclusions

Our findings suggest that multiple biotic and ecological spatial factors may simultaneously affect resource exploitation at a local scale. These findings should be considered when developing agricultural projects, management plans and conservation policies.

Context

Abandonment of cultural landscape practices has had a notable impact on grasslands and domestic livestock that depend on them. This affects the prerequisites for sustainable transitions of cultural landscapes, which combine traditional livelihoods and novel ones like tourism.

Objectives

The aims of this study were to explore (1) the long-term temporal dynamics of grassland and livestock in a regional gradient from coastal to inland landscapes in Norway and (2) the temporal development of tourism types among regions.

Methods

Using three regions as case studies, with 62 municipalities, we analyzed (1) the temporal dynamics of grassland and livestock using agricultural census data from 1918 to 1999 and (2) two tourism types. Kruskal–Wallis and ANOVA were used to examine whether the relative changes in grassland areas and livestock units, respectively, differed significantly among regions. A PCA was conducted to explore relationships between grassland and livestock types. The proportions of tourist categories were compared.

Results

The grassland area and thematic resolution of census data declined over time. Grassland areas correlated with domestic livestock units. Multivariate analysis explained 68% of the variation in grassland and livestock types among municipalities. There was a notable increase in the number of tourists, with summer tourism dominating where the cultural landscape was well conserved.

Conclusions

Our study underscores the importance of integrating regional historical trajectories for the conservation and use of valuable cultural landscapes, thereby providing sustainable transitions that combine traditional livelihoods and new types as tourism. Additional in-depth studies are needed to understand the detailed drivers of these changes.

Context

Ecosystem services are fundamental for the well-being of residents and are an important basis for making regional sustainable development decisions. Existing studies mainly capture ecosystem services perceived by residents through questionnaires, or quantify the provision of regional ecosystem services through economic evaluation and biophysical evaluation. However, the discrepancy between model calculations and residents' perceptions remains lacking.

Objectives

Rapidly urbanizing watersheds can serve as a prime example for exploring the differences in ecosystem service outcomes between the two perspectives.

Methods

In this study, we quantified the potential supply of nine ecosystem services and residents' perceptions of these services in the Guanting Reservoir basin through biophysical modelling and questionnaire surveys. We then analyzed the discrepancies between the two perspectives through the Wilcoxon signed-rank test.

Results

The results showed that among the vast majority of the population, half of the nine ecosystem services exhibited significant differences in comparisons between perceived values and model-calculated ones. The differences were more prominent for regulating and supporting services among urban residents, while for provisioning and cultural services among rural residents.

Conclusions

These differences highlight the necessity to consider quantitative results from diverse perspectives as well as on the benefits of different groups of interest. In rapidly urbanizing watersheds, infrastructure should be reinforced in rural areas to enhance rural residents’ accessibility of ecosystem services. With regard to urban areas, particular attention should be directed towards changes in regulating and supporting services.

Purpose

Habitat connectivity is integral to current biodiversity science and conservation strategies. Originally, the connectivity concept stressed the role of individual movements for landscape-scale processes. Connectivity determines whether populations can survive in sub-optimal patches (i.e., source-sink effects), complete life cycles relying on different habitat types (i.e., landscape complementation), and benefit from supplementary resources distributed over the landscape (i.e., landscape supplementation). Although the past decades have witnessed major improvements in habitat connectivity modeling, most approaches have yet to consider the multiplicity of habitat types that a species can benefit from. Without doing so, connectivity analyses potentially fail to meet one of their fundamental purposes: revealing how complex individual movements lead to landscape-scale ecological processes.

Methods

To bridge this conceptual and methodological gap, we propose to include multiple habitat types in spatial graph models of habitat connectivity, where nodes traditionally represent a single habitat type. Multiple habitat graphs will improve how we model connectivity and related landscape ecological processes, and how they are impacted by land cover changes.

Results

In three case studies, we use these graphs to model (i) source-sink effects, (ii) landscape supplementation, and (iii) complementation processes, in urban ecosystems, agricultural landscapes, and amphibian habitat networks, respectively. A new version of the Graphab open-source software implements the proposed approach.

Conclusion

Multiple habitat graphs help address crucial conservation challenges (e.g., urban sprawl, biological control, climate change) by representing more accurately the dynamics of populations, communities, and their interactions. Our approach thereby extends the ecologist’s toolbox and aims at fostering the alignment between landscape ecology theory and practice.

Context

The urban landscape plays a crucial role in achieving sustainability goals and aspiring to a zero-emission future. Effective carbon mitigation strategies need a spatially explicit and life-cycle analysis of building emissions, detailed mapping highlights the geographical distribution and specific characteristics of buildings, enabling precise identification and targeted management of emission sources.

Objectives

This study aims to create a framework that reveals the spatial and temporal dimensions of building carbon emissions at each stage of their life cycle.

Methods

We developed a comprehensive approach for carbon accounting in buildings. This framework captures spatiotemporal carbon emission patterns across various building types, considering material, energy, and waste flows. It also identifies potential mitigation strategies within the urban building landscape.

Results

Applying this framework to a case study in Shenzhen, we observed a fluctuating increase in total carbon emissions, peaking at 201.5 Mt in 2016 and subsequently declining. Embodied emissions dominated before the twenty-first century, while operational emissions became significant afterward. Spatially, emissions hotspots concentrated in central urban districts, expanding outward, with residential buildings contributing the most. Scenario analysis revealed that extending building lifetimes is a key strategy for mitigating embodied carbon, while improving energy efficiency and adopting clean energy work well together to reduce operational carbon.

Conclusions

Mapping the spatiotemporal patterns of carbon emissions throughout a building’s lifespan can assist urban planners and policymakers in formulating targeted strategies for carbon reduction, thereby enhancing urban sustainability.