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1.
Environmental and urban forest managers in cities located in highly biodiverse regions may need to balance biodiversity conservation with the provision of ecosystem services to people. However, striking this balance is not easy and many competing factors influence the decision-making process. Set in the Perth Metropolitan Area, located in the global biodiversity hotspot of the Southwestern Australia Floristic Province, this study aimed to understand: (i) the extent to which a benefits-oriented approach is used by local governments to optimise biodiversity and human wellbeing urban forest outcomes, and (ii) what other factors influence the decision-making process shaping urban forest composition. Using a social-ecological framework, we conducted semi-structured interviews with 29 local government practitioners. We found that biodiversity conservation is actively considered in the planning and management of urban forest in natural areas and parks, but rarely in streetscapes. Maximising shade and cooling, and to a lesser extent enhancing sense of place, were the key benefits actively sought in streetscapes. Parks appeared to straddle the middle ground as areas with most flexibility to accommodate multiple biodiversity and human wellbeing benefits. Yet, benefits were only some of a multitude of social-ecological factors influencing the decision-making process shaping urban forest composition. In particular, streetscapes were affected by a large number of social and political factors (e.g., perceived risk and nuisance, ad-hoc decisions by elected members), many of them leading to suboptimal urban forest outcomes. For a benefits-oriented approach to prevail in complex and contested urban spaces it is important that the decision-making process is evidence-informed and capable of handling the challenges and conflicts that are likely to arise. Reactive decision-making results in a conservative, “safe” species palette that over time defines streetscapes by what they do not do (creating disservices) rather than what they do (delivering multiple biodiversity and wellbeing benefits), which ultimately is not a desired outcome in the context of an increasingly urbanized world.  相似文献   

2.
Synergies between biodiversity conservation objectives and ecosystem service management were investigated in the Succulent Karoo biome (83,000 km2) of South Africa, a recognised biodiversity hotspot. Our study complemented a previous biodiversity assessment with an ecosystem service assessment. Stakeholder engagement and expert consultation focussed our investigations on surface water, ground water, grazing and tourism as the key services in this region. The key ecosystem services and service hotspots were modelled and mapped. The congruence between these services, and between biodiversity priorities and ecosystem service priorities, were assessed and considered in relation to known threats. Generally low levels of overlap were found between these ecosystem services, with the exception of surface and ground water which had an 80% overlap. The overlap between ecosystem service hotspots and individual biodiversity priority areas was generally low. Four of the seven priority areas assessed have more than 20% of their areas classified as important for services. In specific cases, particular service levels could be used to justify the management of a specific biodiversity priority area for conservation. Adopting a biome scale hotspot approach to assessing service supply highlighted key management areas. However, it underplayed local level dependence on particular services, not effectively capturing the welfare implications associated with diminishing and limited service provision. We conclude that regional scale (biome level) approaches need to be combined with local level investigations (municipal level). Given the regional heterogeneity and varied nature of the impacts of drivers and threats, diverse approaches are required to steer land management towards sustainable multifunctional landscape strategies.  相似文献   

3.
The rapid expansion of the world’s urban population is a major driver of contemporary landscape change and ecosystem modification. Urbanisation destroys, degrades and fragments native ecosystems, replacing them with a heterogeneous matrix of urban development, parks, roads, and isolated remnant fragments of varying size and quality. This presents a major challenge for biodiversity conservation within urban areas. To make spatially explicit decisions about urban biodiversity conservation actions, urban planners and managers need to be able to separate the relative influence of landscape composition and configuration from patch and local (site)-scale variables for a range of fauna species. We address this problem using a hierarchical landscape approach for native, terrestrial reptiles and small mammals living in a fragmented semi-urban landscape of Brisbane, Australia. Generalised linear modelling and hierarchical partitioning analysis were applied to quantify the relative influence of landscape composition and configuration, patch size and shape, and local habitat composition and structure on the species’ richness of mammal and reptile assemblages. Landscape structure (composition and configuration) and local-scale habitat structure variables were found to be most important for influencing reptile and mammal assemblages, although the relative importance of specific variables differed between reptile and mammal assemblages. These findings highlight the importance of considering landscape composition and configuration in addition to local habitat elements when planning and/or managing for the conservation of native, terrestrial fauna diversity in urban landscapes.  相似文献   

4.
[目的]研究库尔勒香梨园土壤锰的空间分布特征及其有效性与土壤pH之间的关系,为建立库尔勒香梨优质高产的土壤养分管理系统提供科学依据.[方法]在25 a树龄库尔勒香梨园树体冠幅内(离树干1.00 m)、冠幅边缘(离树干2.00 m)、冠幅外(离树干3.25 m)对土壤进行采样,测定分析不同取样点0~60 cm 土层微量元...  相似文献   

5.
Urbanization has caused countless changes in the lives, behaviors, and community structures of wild animals. Habitat loss in urban areas has led to the proliferation of certain species over others; in the case of birds, frugivores and certain predators can be found in abundance in cities. These birds, however, occasionally show novel behaviors that can cause stress within human-wildlife interactions. The black kite, Milvus migrans, for example, has displayed a tendency to attack humans for their food in certain urban areas in Japan. In order to determine how habitat availability and land-use types affected these aggressive tendencies, field observations were combined with GIS analysis of five locations along Sagami Bay in Japan. The following locations were assessed according to the amount of each land-use type present and the aggressive tendencies of each location’s black kite population: Enoshima, Fujisawa; Kamakura Beach, Kamakura; Zushi Beach, Zushi; Oiso Beach, Oiso; and Iwa Beach, Manazuru. The aggression of each population, designated by the log of the aggression index, was found to be significantly affected by the amount of forest area per black kite, the amount of non-rice-paddy agricultural area per black kite, and the season. Thus, aggression was higher amongst populations with less forested or agricultural area within their foraging zones, and aggression increased during spring, which is the breeding season.  相似文献   

6.
Landscape Ecology - Urbanisation is an environmental filter for many species that leads to community homogenisation, with a few species inhabiting isolated patches (e.g. public and private gardens...  相似文献   

7.
Urban forests are increasingly valued for multiple benefits such as amenity, cultural values, native biodiversity, ecosystem services, and carbon sequestration. Urban biodiversity in particular, is the new focus although global homogenisation is undermining regional differentiation. In the northern hemisphere (e.g., Canada and USA) and in the southern hemisphere, particularly in countries like South Africa, Australia, South America and New Zealand, local biodiversity is further impacted by historical colonisation from Europe. After several centuries, urban forests are now composed of synthetic and spontaneous mixtures of native species, and exotic species from around the temperate world (e.g., Europe, North and South America, South Africa, Asia). As far as we are aware no-one has carried out in-depth study of these synthetic forests in any Southern Hemisphere city. Here we describe the composition, structure, and biodiversity conservation imperatives of urban temperate forests at 90 random locations in Christchurch city, New Zealand.We document considerable plant diversity; the total number of species encountered in the 253 sampled urban forest patches was 486. Despite this incredibly variable data set, our ability to explain variation in species richness was surprisingly good and clearly indicates that total species richness was higher in larger patches with greater litter and vegetation cover, and taller canopy height. Species richness was also higher in patches surrounded by higher population densities and closer to very large native forest patches. Native species richness was higher in patches with higher soil pH, lower canopy height, and greater litter cover and in patches closer to very large native forest patches indicating dispersal out of native areas and into gardens. Eight distinct forest communities were identified by Two-Way INdicator SPecies ANalysis (TWINSPAN) using the occurrence of 241 species that occurred in more than two out of all 253 forest patches.Christchurch urban forest canopies were dominated by exotic tree species in parklands and in street tree plantings (linear parkland). Native tree and shrub species were not as common in public spaces but their overall density high in residential gardens. There was some explanatory power in our data, since less deprivation resulted in greater diversity and density, and more native species, which in turn is associated with private ownership. We hypothesise that a number of other factors, which were not well reflected in our measured environmental variables, are responsible for much of the remaining variation in the plant community structure, e.g., advertising, peoples choice. For a more sustainable asset base of native trees in New Zealand cities we need more, longer-lived native species, in large public spaces, including a greater proportion of species that bear fruit and nectar suitable for native wildlife. We may then achieve cities with ecological integrity that present multiple historical dimensions, and sequester carbon in legible landscapes.  相似文献   

8.
9.
Having an aesthetic form is one of the desirable aspects of trees used to create or reforest urban green areas, which is often achieved by procedures that require a great effort. The understanding of factors affecting the architecture of plants in natural conditions may be useful to promote a desirable shape during the growth process. Under the hypothesis that trees in high luminosity conditions have a more aesthetical growth, in this study we explore the relationship between plant shape and photosynthetically active radiation (PAR) in Bursera fagaroides, a characteristic species of the tropical dry forest and xerophytic shrub-lands useful for urban green areas in semiarid environments. To evaluate trees shape we calculate a symmetry index (IS) by using two diameters of the crown, perpendicular to each other, and the total height. Measurements were made over three periods (before, during and after the growth period); and PAR was also measured for each tree. Linear regressions were used to analyze the relationship between the symmetry of trees and PAR received during the growth period. The post-growth symmetry of trees showed a positive relationship with the PAR received by trees during the growth period, suggesting that PAR effects can be harnessed to develop post-germination strategies for the production of trees with a more aesthetical growth in the studied species. Effect of PAR on the shape of plants may represent a practical option to promote aesthetical growth of trees and shrubs with importance for creation and restoration of urban green areas.  相似文献   

10.

Context

Land use and land cover (LULC) change is a major part of environmental change. Understanding its long-term causes is a major issue in landscape ecology.

Objectives

Our aim was to characterise LULC transitions since 1860 and assess the respective and changing effects of biophysical and socioeconomic drivers on forest, arable land and pasture in 1860, 1958 and 2010, and of biophysical, socioeconomic and distance from pre-existing forest on forest recovery for the two time intervals.

Methods

We assessed LULC transitions by superimposing 1860, 1958 and 2010 LULCs using a regular grid of 1 × 1 km points, in a French Mediterranean landscape (195,413 ha). We tested the effects of drivers using logistic regressions, and quantified pure and joint effects by deviance partitioning.

Results

Over the whole period, the three main LULCs were spatially structured according to land accessibility and soil productivity. LULC was driven more by socioeconomic than biophysical drivers in 1860, but the pattern was reversed in 2010. A widespread forest recovery mainly occurred on steeper slopes, far from houses and close to pre-existing forest, due to traditional practice abandonment. Forest recovery was better explained by biophysical than by socioeconomic drivers and was more dependent on distance from pre-existing forest between 1958 and 2010.

Conclusions

Our results showed a shift in drivers of LULC and forest recovery over the last 150 years. Contrary to temperate regions, the set-aside of agricultural practices on difficult land has strengthened the link between biophysical drivers and LULC distribution over the last 150 years.
  相似文献   

11.
We studied the spatial distribution of saplings in the vicinity of other saplings and mature trees in heavily worn urban forests. Our aim was to identify favorable microsites for saplings to regenerate under different levels of wear. We hypothesized that these safe microsites were situated close to tree trunks that might offer shelter from trampling caused by humans and their pet dogs. The distribution of saplings was explored at 0.1–0.6 m to the nearest sapling and 0.1–2 m to the nearest mature tree. Sorbus aucuparia was the most abundant sapling species, followed by Populus tremula, Betula pubescens and Picea abies. These species all tended to cluster with their conspecific saplings and were generally randomly distributed with respect to mature trees. Saplings of S. aucuparia and P. tremula favored growing close to mature P. abies (already at 0.4–0.8 up to 2 m from the trunk base, respectively) and S. aucuparia trees (at 0.2–0.4 m up to 2 m). Betula sp. and Acer platanoides grew close to Pinus sylvestris trees. Furthermore, with increased levels of wear, saplings clustered more likely together and close to tree trunks. The results are contrary to the gap regeneration hypothesis known from rural unworn forests where saplings often grow in canopy gaps. We suggest the idea of a ‘sheltering group’, i.e. tree groups and thickets of densely growing conspecific saplings, for the maintenance of regeneration of saplings and other vegetation in heavily worn recreational forests. Since urban forestry may strongly affect the existence and spatial location of a high variety of microhabitats, small-scale spatial exploration is needed to identify microsites that offer opportunities for natural regeneration under heavy recreational use. To maintain natural regeneration and the survival of saplings in worn urban forests, we recommend microhabitat-level species-specific forest management.  相似文献   

12.
Understanding how different ethno-cultural groups value urban nature is important to understand the role of ethno-cultural diversity in urban ecosystem management. Based on a systematic literature review, this paper summarizes the empirical evidence on how different ethno-cultural groups use, perceive, prefer, and assign meaning to urban nature. I use the urban forest, defined here as all the trees in a city, as a proxy to understand this process. The 31 studies reviewed here differ widely in their lines of inquiry, research methods, urban natural setting, and conceptualizations of ethno-cultural identity. Most studies take place in the US and Europe, where the most common definition of an ethno-culturally diverse group is a person of non-European/non-White background. Most studies focus on what these groups like about a particular urban natural setting, such as an urban park; and whether they like more or less trees in a specific context (e.g. urban park). These groups usually prefer passive and social uses of urban natural areas, and more manicured/functional natural landscapes with less trees. The most common meanings associated with urban natural settings dominated by trees are social interaction and integration. The most common explanations on why these differences occur involve theories on socio-economic marginality, collectivist vs. individualist cultures, urban vs. rural lifestyles, and landscapes of origin. Future research on the topic will benefit by differentiating race from ethnicity, capturing intra-ethnic variation, capturing immigrant identities, exploring the different social, cultural, and economic factors that influence values and/or preferences, and focusing on concrete aspects of urban nature, such as urban forests.  相似文献   

13.
Urban greenspace is vital in fulfilling people's nature needs. Informal urban greenspace (IGS) such as vacant lots, street or railway verges and riverbanks is an often-overlooked part of the natural urban landscape. We lack a formal definition of IGS and a comprehensive review of knowledge about IGS and its role for urban residents. This paper advances a formal definition and typology of IGS that can be applied globally. Based on this definition, a total of 65 peer-reviewed papers in English (57), Japanese (7) and German (1) were reviewed. We analyzed this literature for its temporal trends, spatial patterns, studied IGS types, methods used and key authors, and summarized the individual research papers’ findings concerning IGS. Results show IGS plays an important role for urban residents, but also highlight limitations and problems in realizing IGS’ full potential. Research papers focused on perception, preferences, value and uses of IGS. Residents could distinguish between formal and informal greenspace. They preferred a medium level of human influence in IGS. The analysis of patterns in the literature reveals: a marked increase in publications in the last 20 years; a strong geographical bias towards the USA; and a lack of multi-type IGS studies including all IGS types. Publications outside of scholarly research papers also make valuable contributions to our understanding of IGS. Our results suggest IGS is emerging as an important sub-discipline of urban greening research.  相似文献   

14.

Context

Various species of forest trees are commonly used for ornamental purposes and are therefore frequently found in nonforest ecosystems. They constitute an important component of the so-called trees outside forests (TOF). Not much is known, however, about the drivers of TOF spatial distribution either in urbanized or in agricultural landscapes since they are generally absent from forest inventories.

Objective

The present study focused on the spatial distribution of TOF across agricultural landscapes and their potential role in the dispersal of a forest pest insect, the pine processionary moth, Thaumetopoea pityocampa (PPM).

Methods

All the TOF belonging to the genera Pinus, Cedrus and Pseudotsuga were considered as potential hosts and inventoried within a 22 × 22 km study window. We fitted a nonstationary Poisson process to the empirical data and used the distance to the nearest building as a covariate.

Results

Both empirical and simulated data indicated that TOF associated to human artifacts/urbanized areas constituted the main source of landscape connectivity for the PPM in the open fields under study. Because they do not account for TOF, forest inventories dramatically underestimate landscape connectivity and provide an erroneous picture of the PPM habitat distribution.

Conclusions

We conclude that TOF, especially the ornamental component, must be taken into account when it comes to understanding forest insect landscape dynamics or genetics. The omnipresence of TOF also suggests a potentially huge role in pest dispersal and invasive species expansion.
  相似文献   

15.
Patterns of land ownership and forest cover are related in complex and ecologically significant ways. Using a Geographic Information System and regression analysis, we tested for spatial relationships between the structure of land ownership and forest cover across 66 watersheds in the state of Oregon (USA), Coast Range mountains. We found that in these watersheds (1) forest cover diversity increased with land ownership diversity, (2) size of forest patches increased with size of land ownership patches, and (3) connectivity of forest cover increased with connectivity of land ownership. Land ownership structure explained between 29% and 40% of the variability of forest cover structure across these watersheds. Driving this relationship are unique associations among particular ownership classes and various forest cover classes. The USDA Forest Service and the USDI Bureau of Land Management were associated with mature forest cover; private industry was associated with young forest cover; nonindustrial private forest owners were associated with a wide diversity of cover classes. Watersheds with mixed ownership appear to provide greater forest cover diversity, whereas watersheds with concentrated ownership provide less diverse but more connected forest cover. Results suggest that land ownership patterns are strongly correlated with forest cover patterns. Therefore, understanding landscape structure requires consideration of land ownership institutions, dynamics, and patterns.This revised version was published online in May 2005 with corrections to the Cover Date.  相似文献   

16.
BackgroundRegular physical activity can help prevent noncommunicable diseases, and improve mental health, quality of life, and well-being. ‘Green exercise’ is physical activity performed in natural settings such as parks and open green spaces. It is important to understand whether green exercise can provide additional physiological benefits over and above those of physical activity in urban environments. This pilot study compared the acute effects of a 30-min walk in a green environment to a 30-min walk in urban streets on adults’ heart rate and salivary cortisol.MethodsUsing a 2 × 2 randomised cross-over design, groups of 2–5 adults completed two experimental sessions involving a randomly assigned walk in an urban or a green environment. Heart rate and salivary cortisol were collected at regular intervals before, during, and in the 1.5 h following the walks and were compared within and between participants. Peak height, reactivity, area under the curve with respect to ground (AUCg) and area under the curve with respect to increase (AUCi), were also calculated for heart rate and cortisol and compared between walking conditions.ResultsThe sample included 20 participants (50 % female, mean =24.4 ± 4.0 years). Changes in heart rate (Condition × Time: F[5.8, 103.8]=1.67, p = 0.140) or cortisol (Condition × Time: F[2.6, 49.5]=0.81, p = 0.482) in response to walking were not statistically significantly different between the urban and green walking conditions. There were also no statistically significant differences in heart rate or salivary cortisol for the peak height of the response, reactivity, or AUCi or AUCg between the urban and green walking conditions.ConclusionOur findings suggest that physical exertion is the main driver of the acute physiological response to walking. Notwithstanding psychological benefits reported elsewhere, the acute physiological response to walking was not influenced by the green compared with the urban environment in the current study. Further research is warranted to understand the longer-term effects of regular green exercise.  相似文献   

17.
Our refuge design strategy involves a landscape approach formulated to complement existing management efforts and employ restoration in the heavily degraded Kankakee River watershed in northeastern Indiana and northwestern Illinois. The watershed historically contained an approximately 400,000 ha wetland (Grand Marsh), a diverse riverine system, oak savanna, and prairie. Today only fragments of these habitats remain. The U.S. Fish and Wildlife Service developed a preliminary project proposal (PPP) during the summer of 1996 to protect and restore habitat within the watershed by establishing the Grand Kankakee Marsh National Wildlife Refuge. The Indiana and Illinois Gap Analysis projects provided the resources to move beyond the expert workshop approach to a data-driven method for initial reserve design. Using visual analysis of various Gap Analysis data layers, we established Focus Areas that formed the basis for the Environmental Assessment and the Economic Impact Study required under the National Environmental Policy Act (NEPA). We have initiated Phase II of the reserve design analysis using preliminary results of the Indiana Gap Analysis project and C-Plan software in conjunction with the New South Wales National Parks and Wildlife Service.  相似文献   

18.
Apart from influencing the amount of leaf-deposited particles, tree crown morphology will influence the local distribution of atmospheric particles. Nevertheless, tree crowns are often represented very rudimentary in three-dimensional air quality models. Therefore, the influence of tree crown representation on the local ambient PM10 concentration and resulting leaf-deposited PM10 mass was evaluated, using the three-dimensional computational fluid dynamics (CFD) model ENVI-met® and ground-based LiDAR imaging. The modelled leaf-deposited PM10 mass was compared to gravimetric results within three different particle size fractions (0.2–3, 3–10 and >10 μm), obtained at 20 locations within the tree crown. Modelling of the LiDAR-derived tree crown resulted in altered atmospheric PM10 concentrations in the vicinity of the tree crown. Although this model study was limited to a single tree and model configuration, our results demonstrate that improving tree crown characteristics (shape, dimensions and LAD) affects the resulting local PM10 distribution in ENVI-met. An accurate tree crown representation seems, therefore, of great importance when aiming at modelling the local PM distribution.  相似文献   

19.
Quantitative measurements of structure and morphology of urban trees are hardly exhausted so far, especially in regard to variations caused by altering urban environments. However, structure and functions of trees are heavily interwoven. In fact, knowledge about structural attributes is essential for a better understanding of urban ecosystem functions and services. In order to scrutinize spatially explicit and detailed structural attributes under varying urban environments, we acquired terrestrial laser scans and applied the according methodological approaches to the common urban tree species black locust (Robinia pseudoacacia L.) and small-leaved lime (Tilia cordata Mill.). We analyzed 52 small-leaved limes and 41 black locust trees within the city of Munich (Germany). Species as well as growing location had a significant effect on the height-diameter relation. We also found greater crown volumes for small-leaved lime. Black locust however, displayed more crown projection area and likely more shade efficient crown shapes at similar volumes. Stem inclination of black locust was found to be higher in parks than in street canyons with town squares lying in between. Furthermore, black locust displayed strong crown asymmetry in park areas, likely caused by competition with neighbors. The angles of main branches did not differ significantly between both species nor between the growing location. Branch angles, branch bending, the length of the branches as well as species and growing location had a significant effect on vertical crown center position, i.e. general crown shape. Surface complexity of lime is lower than of black locust, with its lowest manifestation in parks. Fractal-like crown surface structures, increasing surface roughness and complexity, were found to be more pronounced for black locust than for small-leaved lime. Thereby, black locust featured the highest crown surface complexity in parks, the lowest in street canyons. The results suggest that studies on spatially explicit tree structures may contribute to more target oriented tree plantings and thus, more effective exploitation of ecosystem services and benefits.  相似文献   

20.
Due to rapid urbanization and an increase in mental health issues in urban populations, urban green spaces (UGS) design needs to be optimized to meet mental health and well-being promotion goals. However, existing frameworks and tools that aim to address this pressing need are often not adequately validated against health measures. The Contemplative Landscape Model (CLM), developed in 2016, is the first instrument that measures the quality of UGS and informs landscape design with regard to the mental health and well-being of people passively exposed to them. Recent studies with this tool and developments in UGS literature prompted the development and validation of a revised version of CLM presented here. The reliability and validity of CLM were tested with a panel of independent experts and showed better reliability/internal consistency (ω = .893; α = .890) than the original CLM. This time, validity was tested in two ways: (1) against neuropsychological data (electroencephalogram, EEG, and self-reported valence and arousal ratings), acquired during passive exposure to UGS scenes and (2) through factor analysis of experts’ UGS assessments. Validity testing showed that (1) CLM predicts brain activity patterns associated with mindfulness, relaxation, and positive mood, and (2) contemplativeness of landscapes is a valid construct undergird by two parallel factors both predicting beneficial EEG responses. In conclusion, CLM is an effective and robust instrument for assessing the visual quality of UGS predictive of mental health and well-being benefits in urban residents.  相似文献   

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