Net primary productivity (NPP) dynamics and associated urbanization driving forces in metropolitan areas: a case study in Beijing City,China

Context

Eco-environmental effects of urbanization are a focus in landscape ecology.

Objective

The influences of population, economic and spatial development during the urbanization process in Beijing City, China on net primary productivity (NPP) were analyzed. The responding mechanism of NPP in different urbanization stages was also examined to develop advice about eco-environmental sustainability of urban development.

Methods

Using the Carnegie Ames Stanford Approach model, we estimated NPP. Using linear regression and polynomial regression analysis, we analyzed NPP responses to stages of urbanization.

Results

High NPP areas were located in northeast Yanqing, northwest Miyun, northern Huairou and Pinggu. The distribution of NPP generally occurred in the following order from high NPP to low NPP: outer suburbs, inner suburbs, encircled city center, and inner city. Because of the heat island effect in winter, the estimated NPP in the encircled city center and inner city was higher in 2009 than in 2001. There was a negative correlation between NPP and both economic and spatial urbanization, but an increase in population did not necessarily lead to an immediate decrease in NPP. An analysis of NPP dynamics in five kinds of urban development zones showed that urbanization resulted in a lasting and observable loss of NPP over time and space, although there was some promotion of NPP in highly urbanized zones.

Conclusion

There are three stages in the response of NPP to urbanization: damage stage, antagonistic stage, and coordination stage. The stage threshold depends on local eco-environmental management and urban planning interventions.

     

Distribution of invasive plants in urban environment is strongly spatially structured

Context

Urban environments create a wide range of habitats that harbour a great diversity of plant species, many of which are of alien origin. For future urban planning and management of the green areas within the city, understanding of the spatial distribution of invasive alien species is of great importance.

Objectives

Our main aim was to assess how availability of different ecosystem types within a city area, as well as several parameters describing urban structure interact in determining the cover and identity of invasive alien species.

Methods

We studied the distribution of chosen invasive plant species in a mid-sized city in the Czech Republic, central Europe, on a gradient of equal sized cells from the city centre to its outskirts.

Results

A great amount of variation was explained by spatial predictors but not shared with any measured variables. The species cover of invasive species decreased with increasing proportion of urban greenery and distance from the city centre, but increased with habitat richness; road margins, ruderal sites, and railway sites were richest in invasive species. In contrast, the total number of invasive species in cells significantly decreased with increasing distance from the city centre, but increased with habitat richness.

Conclusions

Our results suggest that different invasive species prefer habitats in the vicinity of the city centre and at its periphery and the spatial structure and habitat quality of the urban landscape needs to be taken into account, in efforts to manage alien plant species invasions in urban environments.

     

Urban ecology principles: are urban ecology and natural area ecology really different?

Context

To understand, even improve, the land of shrinking nature and spreading urbanization, a science applicable from remote natural areas to cities is needed.

Objective

Today’s scientific principles of urban ecology are articulated and compared with ecology based primarily on natural ecosystems; we either robustly merge the trajectories or watch them diverge.

Methods

A literature review emphasizes that the field of ecology emerged from late 19th century and early 20th century research mostly in semi-natural environments, whereas urban ecology mainly developed from studying plants, habitat types, and ecosystem nutrient flows in late 20th century city environments.

Results

Ninety urban ecology principles are identified and succinctly stated. Underlying the principles, 18 distinctive types of urban attributes are recognized in four major groups: land uses; built objects; permeating anthropogenic flows; human decisions/activities. The attributes or objects studied in “natural area” ecology and urban ecology differ sharply, as do the primary objects present in late 19th century and late 20th century cities. None of the 90 basic principles would have emerged from research on natural areas, and all are readily usable for improving urban and urbanizing areas.

Conclusion

Incorporating urban ecology science into ecology’s body of principles and theory now should catapult the field of ecology to the next level, and noticeably increase its usefulness for society.

     

A hierarchical analysis of the relationship between urban impervious surfaces and land surface temperatures: spatial scale dependence,temporal variations,and bioclimatic modulation

Context

Understanding how urban impervious surfaces (UIS) affect land surface temperatures (LST) on different scales in space and time is important for urban ecology and sustainability.

Objectives

We examined how spatial scales, seasonal and diurnal variations, and bioclimatic settings affected the UIS–LST relationship in mainland China.

Methods

We took a hierarchical approach explicitly considering three scales: the ecoregion, urban cluster, and urban core. The UIS–LST relationship was quantified with Pearson correlation using multiple remote sensing datasets.

Results

In general, UIS and LST were positively correlated in summer daytime/nighttime and winter nighttime, but negatively in winter daytime. The strength of correlation increased from broad to fine scales. The mean R² of winter nights at the urban core scale (0.262) was 4.03 times as high as that at the ecoregion scale (0.065). The relationship showed large seasonal and diurnal variations: generally stronger in summer than in winter and stronger in nighttime than in daytime. At the urban core scale, the mean R² of summer daytime (0.208) was 3.25 times as high as that of winter daytime (0.064), and the mean R² of winter nighttime (0.262) was 4.10 times as high as that of winter daytime (0.064). Vegetation and climate substantially modified the relationship during summer daytime on the ecoregion scale.

Conclusions

Our study provides new evidence that the UIS–LST relationship varies with spatial scales, diurnal/seasonal cycles, and bioclimatic context, with new insight into the cross-scale properties of the relationship. These findings have implications for mitigating urban heat island effects across scales in China and beyond.

     

Spatial and temporal heterogeneity of the crop mosaic influences carabid beetles in agricultural landscapes

Context

Landscape spatio-temporal heterogeneity is regarded as an important driver of biodiversity. In agricultural landscapes, the composition and configuration of cultivated fields and their multi-year dynamics should be considered. But the habitat-matrix paradigm in landscape ecology has resulted in little consideration of cropped areas.

Objectives

The main objective of our study was to determine the influences of spatial and multi-year temporal heterogeneity of the crop mosaic on carabid beetle assemblages of agricultural landscapes.

Methods

Carabids were sampled in 40 cereal fields in western France, and their species richness, total abundance and abundance of species groups with different dispersal abilities were measured. For each sampling site, we computed different metrics that characterized crop mosaic spatial and temporal heterogeneity. We quantified relationships between carabid assemblages and heterogeneity metrics and tested their significance.

Results

Total carabid abundance increased with increase in temporal heterogeneity of the crop mosaic. However, all species were not influenced in the same way by spatial and temporal heterogeneity metrics. Some species with high dispersal power such as Trechus quadristriatus were more abundant in landscapes with high spatial heterogeneity, whereas the abundance of less mobile species such as Poecilus cupreus were only positively influenced by temporal crop dynamics.

Conclusions

Our results suggest that both the spatial and temporal heterogeneity of the crop mosaic affects farmland biodiversity, at least for species that use crops during their life cycle or disperse through fields. We highlight the importance of taking this heterogeneity into account in further ecological studies on biodiversity in agricultural landscapes.

     

How many principles of urban ecology are there?

Context

The nature of urban ecology theory is controversial. Issues include whether urban theory is distinct, whether it has principles, and whether those principles differ from those for non-urban systems. Recently, Richard Forman enumerated urban ecology principles, while we have previously articulated different urban ecology principles. This raises the question of whether there are legitimately different sets of principles.

Objectives

Recognizing the legitimacy of Forman’s principles, we wish to determine whether different methodological assumptions can lead to different sets of urban ecology principles.

Methods

We contrast Forman’s 90 urban ecology principles with our much smaller set to determine why they differ in detail, empirical motivation, and generality. We identify the approaches that generate each set of principles, and seek an inclusive framework to integrate them.

Results

The alternative sets represent contrasting approaches to identifying principles: Forman’s approach is more inductive, generating principles from a body of empirical cases, while our concise roster is more deductive, focusing on general ideas from which the details of specific cases can be derived. Both are legitimate.

Conclusions

Principles of urban ecology can arise from inductive empirical generalization within specified ecological, cultural, and historical contexts, as shown by Forman. However, urban ecology principles can also emerge from a more general, synthetic impulse as we have shown. Neither approach is necessarily better. Both can contribute to a comprehensive theoretical hierarchy that can advance urban ecology.

     

Activating landscape ecology: a governance framework for design-in-science

Context

In response to predominantly local and private approaches to landscape change, landscape ecologists should critically assess the multiscalar influences on landscape design.

Objectives

This study develops a governance framework for Nassauer and Opdam’s “Design-in-Science” model. Its objective is to create an approach for examining hierarchical constraints on landscape design in order to investigate linkages among urban greening initiatives, patterns of landscape change, and the broader societal values driving those changes. It aims to provide an integrative and actionable approach for landscape sustainability science.

Methods

This framework is examined through an ethnographic study of public policy processes surrounding the urban tree initiatives in Boston, MA; Philadelphia, PA; and Baltimore, MD.

Results

These initiatives demonstrate the impact of political and economic decentralization on urban landscape patterns. Their collaborative governance approach incorporates diverse resources to implement programming at a fine-scale. The predominant tree giveaway program fragments the urban and regional forest.

Conclusion

Spatial and temporal fragmentation undermines the long-term security of urban greening programs, and it suggests reconsideration of the role of state regimes in driving broad scale spatial planning.

     

Species richness and composition differ in response to landscape and biogeography

Context

Understanding how landscape patterns affect species diversity is of great importance in the fields of biogeography, landscape ecology and conservation planning, but despite the rapid advance in biodiversity analysis, investigations of spatial effects on biodiversity are still largely focused on species richness.

Objectives

We wanted to know if and how species richness and species composition are differentially driven by the spatial measures dominating studies in landscape ecology and biogeography. As both measures require the same limited presence/absence information, it is important to choose an appropriate diversity measure, as differing results could have important consequences for interpreting ecological processes.

Methods

We recorded plant occurrences on 112 islands in the Baltic archipelago. Species richness and composition were calculated for each island, and the explanatory power of island area and habitat heterogeneity, distance to mainland and structural connectivity at three different landscape sizes were examined.

Results

A total of 354 different plant species were recorded. The influence of landscape variables differed depending on which diversity measure was used. Island area and structural connectivity determined plant species richness, while species composition revealed a more complex pattern, being influenced by island area, habitat heterogeneity and structural connectivity.

Conclusions

Although both measures require the same basic input data, species composition can reveal more about the ecological processes affecting plant communities in fragmented landscapes than species richness alone. Therefore, we recommend that species community composition should be used as an additional standard measure of diversity for biogeography, landscape ecology and conservation planning.

     

The heterogeneity of wooded-agricultural landscape mosaics influences woodland bird community assemblages

Context

Landscape heterogeneity (the composition and configuration of different landcover types) plays a key role in shaping woodland bird assemblages in wooded-agricultural mosaics. Understanding how species respond to landscape factors could contribute to preventing further decline of woodland bird populations.

Objective

To investigate how woodland birds with different species traits respond to landscape heterogeneity, and to identify whether specific landcover types are important for maintaining diverse populations in wooded-agricultural environments.

Methods

Birds were sampled from woodlands in 58 2 × 2 km tetrads across southern Britain. Landscape heterogeneity was quantified for each tetrad. Bird assemblage response was determined using redundancy analysis combined with variation partitioning and response trait analyses.

Results

For woodland bird assemblages, the independent explanatory importance of landscape composition and landscape configuration variables were closely interrelated. When considered simultaneously during variation partitioning, the community response was better represented by compositional variables. Different species responded to different landscape features and this could be explained by traits relating to woodland association, foraging strata and nest location. Ubiquitous, generalist species, many of which were hole-nesters or ground foragers, correlated positively with urban landcover while specialists of broadleaved woodland avoided landscapes containing urban areas. Species typical of coniferous woodland correlated with large conifer plantations.

Conclusions

At the 2 × 2 km scale, there was evidence that the availability of resources provided by proximate landcover types was highly important for shaping woodland bird assemblages. Further research to disentangle the effects of composition and configuration at different spatial scales is advocated.

     

Ecological contributions to human health in cities

Context

Ecological research, from organismal to global scales and spanning terrestrial, hydrologic, and atmospheric domains, can contribute more to reducing health vulnerabilities. At the same, ecological research directed to health vulnerabilities provides a problem-based unifying framework for urban ecologists.

Objective

Provide a framework for expanding ecological research to address human health vulnerabilities in cities.

Methods

I pose an urban ecology of human health framework that considers how the ecological contributions to health risks and benefits are driven by interacting influences of the environment, active management, and historical legacies in the context of ecological self-organization. The ecology of health framework is explored for contrasting examples including heat, vector borne diseases, pollution, and accessible greenspace both individually and in a multifunctional landscape perspective.

Results

Urban ecological processes affect human health vulnerability through contributions to multiple hazard and well-being pathways. The resulting multifunctional landscape of health vulnerability features prominent hotspots and regional injustices. A path forward to increase knowledge of the ecological contributions to health vulnerabilities includes increased participation in in interdisciplinary teams and applications of high resolution environmental sensing and modeling.

Conclusions

Research and management from a systems and landscape perspective of ecological processes is poised to help reduce urban health vulnerability and provide a better understanding of ecological dynamics in the Anthropocene.

     

Behavioral and social mechanisms behind pattern formation: an experimental study of animal movement

Context

Although animal movement behaviors are influenced by spatial heterogeneity, such behaviors can also generate spatial heterogeneity via interactions with the emergent spatial structure and other individuals (i.e., the social landscape).

Objective

Elucidate the behavioral and ecological mechanisms of pattern formation in a homogeneous resource landscape.

Methods

We analyzed the movement pathways and space-use patterns of the lesser grain borer (Rhyzopertha dominica) within homogeneous resource landscapes (wheat kernels). Experimental trials consisted of individual beetles foraging alone or paired with a member of the same or different sex.

Results

We identified two sources of pattern formation: (1) beetles were attracted to areas where they or another beetle had previously fed, leading to increased patchiness via positive reinforcement; and (2) the presence of conspecifics affected whether and at what scales patchiness occurred. Solitary males had lower rates of movement and less tortuous pathways than solitary females, but both sexes generated fine-scale patchiness in the resource distribution. Patchy resource landscapes were also generated by male–female pairs, but not by same-sex pairings. Paired females in particular exhibited significantly greater daily net displacements and more random space use than solitary females.

Conclusions

Pattern formation is a complex process, even in a relatively simple, homogeneous resource landscape. In particular, patterns created by individuals when foraging alone versus in pairs underscores how social interactions can fundamentally alter the resultant pattern of heterogeneity that emerges in resource landscapes.

     

Environmental drivers of community diversity in a neotropical urban landscape: a multi-scale analysis

Context

Many aquatic communities are linked by the aerial dispersal of multiple, interacting species and are thus structured by processes occurring in both the aquatic and terrestrial compartments of the ecosystem.

Objectives

To evaluate the environmental factors shaping the aquatic macroinvertebrate communities associated with tank bromeliads in an urban landscape.

Methods

Thirty-two bromeliads were georeferenced to assess the spatial distribution of the aquatic meta-habitat in one city. The relative influence of the aquatic and terrestrial habitats on the structure of macroinvertebrate communities was analyzed at four spatial scales (radius = 10, 30, 50, and 70 m) using redundancy analyses.

Results

We sorted 18,352 aquatic macroinvertebrates into 29 taxa. Water volume and the amount of organic matter explained a significant part of the taxa variance, regardless of spatial scale. The remaining variance was explained by the meta-habitat size (i.e., the water volume for all of the bromeliads within a given surface area), the distance to the nearest building at small scales, and the surface area of buildings plus ground cover at larger scales. At small scales, the meta-habitat size influenced the two most frequent mosquito species in opposite ways, suggesting spatial competition and coexistence. Greater vegetation cover favored the presence of a top predator.

Conclusions

The size of the meta-habitat and urban landscape characteristics influence the structure of aquatic communities in tank bromeliads, including mosquito larval abundance. Modifications to this landscape will affect both the terrestrial and aquatic compartments of the urban ecosystem, offering prospects for mosquito management during urban planning.

     

Does the response of bird assemblages to fire mosaic properties vary among spatial scales and foraging guilds?

Context

An increasing number of studies have investigated the impact of environmental heterogeneity on faunal assemblages when measured at multiple spatial scales. Few studies, however, have considered how the effects of heterogeneity on fauna vary with the spatial scale at which the response variable is characterised.

Objectives

We investigated the relationship between landscape properties in a region characterised by diverse fire mosaics, and the structure and composition of avian assemblages measured at both the site- (1 ha) and landscape-scale (100 ha).

Methods

We surveyed birds and calculated spatial landscape properties in sub-tropical woodlands of central Queensland, Australia.

Results

Environmental heterogeneity, as measured by topographic complexity, was consistently important for bird species richness and composition. However, the explanatory power of topographic complexity varied depending on the spatial scale and the component of diversity under investigation. We found different correlates of richness within particular foraging guilds depending on the scale at which richness was measured. Extent of long-unburnt habitat (>10 years since fire) was the most important variable for the landscape-scale richness of frugivores, insectivores and canopy feeders, whereas environmental heterogeneity in the surrounding landscape was more important for site-scale richness of these foraging guilds.

Conclusions

The response of species richness to landscape characteristics varies among scales, and among components of diversity. Thus, depending on the scale at which a biodiversity conservation goal is conceptualised—maximising richness at a site, or across a landscape—different landscape management approaches may be preferred.

     

Quantifying landscape pattern and ecosystem service value changes in four rapidly urbanizing hill stations of Southeast Asia

Context

Hill stations are known for their favorable cool climate and natural environments which generate valuable ecosystem services that benefit the local population, tourists and visitors. However, rapid urbanization threatens the sustainability of these highly valued fragile landscapes.

Objectives

We aim to characterize and quantify the changes in the landscape patterns and ecosystem service values (ESVs) of Baguio (Philippines), Bogor (Indonesia), Dalat (Vietnam), and Pyin Oo Lwin (Myanmar), and discuss their implications to landscape sustainability.

Methods

We used remote sensing imagery to map land-use/cover (2001 and 2014), and spatial metrics and gradient analysis to characterize the changes in landscape pattern. We employed a benefit transfer method to estimate the changes in ESV and human-to-ESV ratio. A land-change model was used to simulate different scenarios of future built-up expansions (2014–2030).

Results

The landscapes of Dalat and Pyin Oo Lwin are becoming more fragmented, while those of Baguio and Bogor are getting more aggregated. Dalat had the highest decrease (absolute change) in ESV and H-ESV ratio, while Bogor had the highest percentage decrease (2001–2014).

Conclusions

Rapid urbanization has been a major factor in the landscape transformation of Baguio, Bogor, Dalat and Pyin Oo Lwin. If the current built-up expansion rate will speed up, the decline in future ESV and H-ESV ratio (2014–2030) will be higher than if the rate will continue or slow down. Unless the concept of landscape sustainability is taken seriously in landscape and urban planning, the respective ‘values’ of these precious hill stations will become less and less.

     

Incorporating soil ecosystem services into urban planning: status,challenges and opportunities

Context

Traditionally soils have not received much attention in urban planning. For this, tools are needed that can both be understood both by soil scientists and urban planners.

Purpose

The purpose of this paper is to enhance the role of soil knowledge in urban planning practice, through the following objectives: (1) identifying the role soil plays in recent urban plans; (2) analysing the ecosystem services and indicators used in soil science in an urban context; and (3) inferring the main challenges and opportunities to integrate soil into urban planning.

Methods

Seven urban plans and reports of world cities that include sustainability goals were analysed using text-mining and qualitative analysis, with a critical view on the inclusion of soil-related concepts. Secondly, the contribution of soil science to urban planning was assessed with an overview of case studies in the past decade that focus on soil-related ecosystem services in urban context.

Results

The results show an overall weak attention to soil and soil-related ecosystem services in the implementation and monitoring phases of urban plans. The majority of soil science case studies uses a haphazard approach to measure ecosystem service indicators which may not capture the ecosystem services appropriately and hence lack relevance for urban planning.

Conclusions

Even though the most urban plans assessed recognize soil as a key resource, most of them fail to integrate indicators to measure or monitor soil-related functions. There is a need to develop soil-related ecosystem services that can be easily integrated and understood by other fields.

     

Walkability in urban landscapes: a comparative study of four large cities in China

Context

Walkability is an important element for assessing the sustainability of urban landscapes. There are increased concerns that as the world becomes more urbanized, cities become less walkable.

Objectives

We aim to develop a composite walkability index to evaluate the spatio-temporal pattern of the walkability of cities. By using the index to evaluate four major cities China, we also aim to provide policy implications.

Methods

A comprehensive walkability index is developed to integrate five aspects of the urban built environment: dwelling density, street connectivity, land-use mix, access to public transit, and flatness. Shanghai, Hangzhou, Chongqing, and Lanzhou are chosen as case studies to evaluate the spatio-temporal patterns and changes of walkability in the context of rapid urban expansion.

Results

Great variations exist among the four cities in terms of speed, scale, and locations of changes of walkability. During 2000–2010, the inner cities of Hangzhou, Chongqing, and Lanzhou and the entire cities of Shanghai and Chongqing increased their walkability index, whereas the inner city of Shanghai had decreased walkability. Furthermore, while inner cities of Shanghai and Hangzhou experienced decreased or stable walkability, the inner cities of Lanzhou and Chongqing enjoyed moderate to high increases in walkability. For inner cities, Shanghai had the highest average walkability index, whereas Lanzhou held the lowest in 2010.

Conclusions

The spatiotemporal changes in walkability seem to be closely associated with governmental policies and planning. The walkability index method can be widely implemented for any urban landscape because of its comprehensiveness, simplicity, and flexibility.

     

People and pines 1555<Emphasis Type="Bold">–</Emphasis>1910: integrating ecology,history and archaeology to assess long-term resource use in northern Fennoscandia

Context

Past human land use has received increasing attention as an important driver of ecosystem change also in seemingly natural landscapes. Quantification of historical land use is therefore critical for assessing the degree of human impact and requires integration of ecology, history and archaeology.

Objective

This study aims to assess and compare levels of resource use by different actors during 355 years across a large landscape of northern Sweden.

Method

Data on resource use derived from case studies were extrapolated using demographic data to estimate harvested resources at the landscape scale. Here, we examined the use of the key-specie Scots pine by native Sami peoples and farmers and through commercial logging, and reconstructed historical forest conditions in order to interpret harvest levels and sustainability.

Results

We show that (1) the pre-industrial use of Scots pine resources in Pite Lappmark was sustainable from a landscape perspective, and (2) that the early commercial logging, in contrast, was not sustainable. Large and old Scots pine trees were logged at a very high rate, reaching up to 300 % of the annual ingrowth.

Conclusion

We suggest that historical landscape studies should incorporate analysis at different spatial scales, as such an approach can mirror the overall use of resources. Only then can land use data be applied across larger spatial scales, function as reference values and be compared to those of other regions, time-periods and types of human impact.

     

Quantifying spatiotemporal drivers of environmental heterogeneity in Kruger National Park,South Africa

Context

Environmental heterogeneity is considered an important mechanism of biodiversity. How environmental heterogeneity is characterised by the compositional, structural and functional variation of biotic and abiotic components is a central research theme in conservation.

Objectives

We explore how environmental heterogeneity relates to the underlying physical landscape template and how that relationship changes over space and time. We examine how, in some areas, environmental heterogeneity may also be driven by dynamic ecological processes, and how this relates to patterns of plant species richness.

Method

We use local geographically weighted regression to spatially partition environmental heterogeneity, measured as Landsat spectral variance, into the portion explained by stable physical landscape properties (R²) and the portion unexplained (1?R²) which we term landscape complexity. We explore how this relationship varies spatially and temporally as a function of dynamic ecological processes such as rainfall and season in Kruger National Park, as well as plant species richness at landscape scales.

Results

The significance and direction of relationships varied over space and time and as a function of rainfall and season. R² values generally decreased in higher rainfall summer months and revealed patterns describing the importance of known stable factors relative to unknown dynamic factors. Landscape complexity (1?R²) explained over 70 % of variation in species richness.

Conclusions

Rainfall and seasonality are important drivers of environmental heterogeneity. The spatial arrangement and magnitude of model agreement helped disentangle the relative influence of the physical landscape template on environmental heterogeneity. Given the high correlation with species richness, landscape complexity provides complementary guidance to biodiversity research and monitoring prioritization.