Interpatch movements in spatially structured populations: a literature review

We used published data of individuals moving among habitat patches to answer questions pertaining to frequency of interpatch movements and subsequent effects on population dynamics. A review of 415 published articles produced data for 89 species-system combinations where movements were recorded in sufficient detail to include in our analysis. The percentage of individuals in a population that moved among habitat patches ranged from 0.00 to 93.00%, with a mean of 16.84%. Scaling this statistic by generation time yielded a mean movement rate of 15.45 ± 3.27% per generation. The relatively low movement rates suggest that subpopulations, except those of invertebrates, should not be highly integrated. Less than half of the empirical studies reported on the population effects of interpatch movement. Of these, thirty-three studies yielded population effects on 34 individual species in 45 species-systems. They reported movement having a positive effect 28 times, a negative effect twice and a neutral effect 14 times. Despite its importance, relatively few studies document rates of interpatch movement and far fewer determine population level consequences of these movements. This deficiency limits our ability to understand the dynamics of spatially structured populations and apply that knowledge to conservation efforts.This revised version was published online in May 2005 with corrections to the Cover Date.     

Dispersal of annual plants in hierarchically structured landscapes

The scale at which plants utilize spatially distributed resources may be determined by their ability to locate sites that can sustain population growth. We developed a spatially-explicit model of the dispersal of annual plants in landscapes which were hierarchically structured, i.e., the spatial pattern of suitable sites was nested and scale-dependent. Results show that colonizing ability and extinction probability are most sensitive to the mean dispersal distance of the species. Dispersal out of the parental site, but within the immediate neighborhood, was the most efficient means for population expansion. When landscape patterns change with scale then dispersal distances determine the spatial scales of habitat utilization. As a complicating factor, the type of statistical distribution of dispersal distances also influences the colonizing ability. However, the importance of dispersal distance mean and distribution decreased as the number and connectance of suitable sites increased. The results suggest that landscape models which consider the interaction between scale dependent changes in landscape pattern and species dispersal and establishment characteristics are relevant to many issues in community ecology, invasion biology, and conservation biology.     

Non-native plants and illegitimate interactions are highly relevant for supporting hummingbird pollinators in the urban environment

Urbanization leads to the restructuring of plant-animal interactions due to environmental changes and introduction of non-native species that become part of local ecological processes. The conservation of pollinators in urban areas has received increasing attention. However, detailed quantification of available floral resources and their use by pollinators are rarely conducted. Here, we characterized the interaction network between hummingbirds and native and non-native plants, the behavior of resource use by pollinators and the temporal availability of nectar resources in an extensive urban green area from Brazil. We found that more than half of the interactions between hummingbirds and plants were illegitimate, which do not constitute potential pollination. The interaction network was generalized, indicating low level of niche partitioning, which is usual for urban environments. Inclusion of non-pollination interactions increased specialization. Although native and non-native plants provide a similar amount of nectar when considering each plant species for a given month, the latter contributed most to the total nectar availability owed to their higher abundance and longer flowering phenologies. Importantly, non-native plants provided resources when native flowers were scarce. Our results show how non-native plants may sometimes have relevant contributions for maintenance of pollinators in cities throughout the year, supporting them during periods of resource shortage. At the same time, urban pollinator-plant communities may be characterized by high prevalence of illegitimate interactions, which highlights the opportunistic use of resources by animals. In conclusion, our study suggests that biodiversity-friendly urban planning should consider the relevant role played by non-native species and that pollinator support may require different types of interactions with flowers.     

Effects of urban parks on the local urban thermal environment

Air temperatures in and outside of 60 parks in Taipei city were surveyed to study the effect of different urban parks on their surrounding thermal gradients. Results suggest that the factors governing the temperature of park surroundings are not identical to those of park interiors. Air-temperature gradients surrounding urban parks are influenced by both the horizontal transport of cool or warm air mass above parks and the evapotranspirative air-parcels from trees, creating a cool island larger than the boundaries of cool-island parks, a heat-island larger than the boundaries of strong heat-island parks, and a cool-ring outside weak heat-island parks. Such horizontal air movement is not easily detected using remotely sensed data. During daytime, the thermal environment within a park is dominated by the amount of solar input absorbed by unshaded paved area, which, when strong, can overflow to increase the temperatures of park surroundings; at night, despite park trees causing a warming effect inside parks, park surroundings are cooled by horizontal flow of evapotranspirative air-parcels from park trees. In business and other districts used mostly during daytime, it is recommended that parks and other open spaces be designed with less than 50% paved area and at least 30% trees, shrubs, and other shadings. In residential districts that are used mostly during nighttime, parks and other open spaces are recommended to be designed with more trees. Night irrigation, a measure commonly recommended for the conservation of water, is also recommended to further enhance this nighttime cooling.     

园艺植物在居室环境中的运用

居室环境是指人们生活、工作和休憩的室外庭院和室内环境。随着工业化的发展,大量使用人造建材进行美化和装饰工作、生活环境,使人们的居室环境污染也成为值得关注的重要议题。尤其对城市居民来讲,每天平均大约80%～90%以上的时间是在各种室内环境中度过的,居室环境成为直接影响人们生活的关键。园艺植物在居室中的各种运用,不仅美化居室环境、净化空气、减轻污染、改善居室理化条件,还能使生活环境增添生命的气息,增进身心健康。     

试论城市绿化中乡土植物与外来植物的互补性

在对城市绿化建设中的乡土植物与外来植物选用的观点论述或实际操作中,往往偏执其一.本文在客观论述乡土植物与外来植物各自特点的基础上,系统明确地对两者在城市绿化中有机结合(优势互补)的必要性及可行性方面进行了论述.     

Modeling the invasive emerald ash borer risk of spread using a spatially explicit cellular model

The emerald ash borer (EAB, Agrilus planipennis) is decimating native ashes (Fraxinus sp.) throughout midwestern North America, killing millions of trees over the years. With plenty of ash available throughout the continent, the spread of this destructive insect is likely to continue. We estimate that the insect has been moving along a “front” at about 20 km/year since about 1998, but more alarming is its long-range dispersal into new locations facilitated by human activities. We describe a spatially explicit cell-based model used to calculate risk of spread in Ohio, by combining the insect’s flight and short-range dispersal (“insect flight”) with human-facilitated, long-range dispersal (“insect ride”). This hybrid model requires estimates of EAB abundance, ash abundance, major roads and traffic density, campground size and usage, distance from the core infested zone, wood products industry size and type of wood usage, and human population density. With the “insect flight” model, probability of movement is dependent on EAB abundance in the source cells, the quantity of ash in the target cells, and the distances between them. With the “insect-ride” model, we modify the value related to ash abundance based on factors related to potential human-assisted movements of EAB-infested ash wood or just hitchhiking insects. We attempt to show the advantage of our model compared to statistical approaches and to justify its practical value to field managers working with imperfect knowledge. We stress the importance of the road network in distributing insects to new geographically dispersed sites in Ohio, where 84% were within 1 km of a major highway.     

Global patterns in urban green space are strongly linked to human development and population density

Urban green space is important for alleviating high temperatures, pollution, and flooding in cities. Furthermore, it is becoming increasingly clear that urban green space is important for the mental and physical health of humans residing in cities and that urban green space may harbor unique biodiversity. Understanding the extent and drivers of urban green space is thus important. While urban green space has been mapped and studied at local to national scales, the global patterns and drivers of urban green space remain unknown, potentially hampering effective planning and allocation of resources toward reaching sustainable development goals. Here, we quantified the effect of environmental and socio-economic drivers (temperature, precipitation, human development, and population density) on urban green space globally by focusing on national capital cities. We used satellite imagery to map urban green space using two measures: the Normalized Difference Vegetation Index (NDVI), and the fractional cover of “green” land cover classes. NDVI is useful as it includes all vegetated surfaces, also small ones like gardens. However, land cover classes allow the exclusion of certain classes such as sports fields or cropland. We used boosted regression trees to show that climatic variables accounted for 75 % of the relative influence in urban green space, with a positive effect of precipitation and a negative effect of temperature. Importantly, socioeconomic variables accounted for 25 % of the influence on global urban green space, with a positive effect of human development index (HDI) and a negative effect of population density. HDI in relation to urban green space has not previously been tested globally, and our study shows that significantly affects urban greenspace. The results demonstrate that cities where development status is low and population densities are high, typically in the Global South, have less urban green space than the climate would predict. The results therefore suggest that human wellbeing does not only benefit directly from increasing human development and decreasing population densities in urban areas, but that these effects may be compounded by also improving nature’s contribution to people.     

榆林市城市绿地景观植物与配置设计

通过对榆林市绿地景观中常用植物资源的分析,探讨了城市绿地植物配置设计原则,应根据植物的生物学特性科学地、有机地、合理地搭配应用,以期优化榆林市绿地景观植物与配置设计。     

彩叶植物在南宁道路绿化中的应用调查

对南宁市22条主要城市道路绿化中的彩叶植物进行调查,结果表明,南宁市现有道路绿地主要应用的彩叶植物共有16科、31种,其中乔木4科、9种;灌木9科、12种;草本6科、10种.根据色彩在叶面上的分布可将其分成单色叶类、双色叶类、斑叶及花叶类、镶边类和彩脉类.文章在研究结果基础上,针对目前南宁市道路绿化彩叶植物应用存在的问题,提出相应的建议与对策.     

Landscape influence on biophony in an urban environment in the European Alps

Landscape Ecology - Biophony is the acoustic manifestation of biodiversity, and humans interact with biophony in many ways. However, quantifying biophony across urban landscapes has proven...     

3种入侵植物乙醇提取物对椰子木蛾的杀虫活性研究

以椰子木蛾(Opisina arenosella Walker)3龄幼虫为靶标,测定了3种入侵植物乙醇提取物的杀虫活性。结果表明:同一浓度下的马缨丹(Lantana camara)、薇甘菊(Mikania micrantha)和假臭草(Eupatorium catarium)3种入侵植物乙醇提取物,随着时间增加校正死亡率均不断提高;72 h时,浓度为40 mg/m L的3种植物乙醇提取物的杀虫活性均超过50%;3种植物乙醇提取物对椰子木蛾3龄幼虫的LC50最小的是马缨丹,其次是薇甘菊和假臭草,说明椰子木蛾对马缨丹最为敏感;采用气相色谱-质谱(GC-MS)联用法分析鉴定了马缨丹提取物中的17种化学成分。     

Dependence of urban park visits on thermal environment and air quality

Activities in urban parks contribute to greater socialization and a more active lifestyle, yet such health benefits could be mingled with health concerns – e.g., extreme thermal events or hazardous air quality, which received much less attention than the benefits. Particularly, there is a lack of empirical studies on behavioral changes under different thermal and air-quality conditions. To address the research gap, this study quantitatively measured the impact of thermal environmental parameters (air temperature, humidity, wind scale) and air quality parameters (PM_2.5, PM₁₀, NO₂, SO₂, O₃, integrated air quality index (AQI)) on the daily attendance at Haidian Park – a neighborhood park – and Chaoyang Park – an urban recreational park – in Beijing covering consecutive days from April 1, 2020 to March 31, 2021. The analysis revealed the degrees to which urban park visits were influenced by temperature and air quality. Temperature had the greatest impact on the attendance, while the impact was asymmetric: The effect of low temperature showed more elasticity than that of high temperature. The influence of air quality was not as significant as that of the air temperature. The analysis also showed that such impacts of thermal and air-quality conditions on park visits were mediated by type of activities (the everyday-recreational continuum), days (weekday/weekend), and seasons. The findings provide useful implications for tackling the wicked problem of promoting outdoor activities in parks while controlling adverse effects of thermal and air-quality conditions.     

The re-emergence of indigenous forest in an urban environment, Christchurch, New Zealand

Christchurch, the second largest city in New Zealand is a planned city on a coastal plain on the east coast of the South Island. The birth of the city and the subsequent century of development was characterised by colonial values and tree and garden planting with familiar European species along with those from Australia, North America, and eventually all other continents. The image of an “English garden city” with classical parks of oaks and willow-lined rivers became the accepted norm and the way in which the city has been promoted to potential tourists. Gardening is one of the top two recreational activities and exotic species greatly outnumber native species in the flora and in gardens. This has had serious consequences for the highly fragmented and degraded indigenous vegetation and its co-adapted wildlife. A few hardy indigenous species continued to regenerate through this period, but since the 1970s, there has been a progressive change of attitude and interest in reclaiming the natural heritage of the city, manifest in widespread private and public planting of indigenous species and active habitat restoration. In this article we examine the indigenous and exotic shrub and tree components of the Christchurch flora as planted street trees, in domestic gardens, and in parks. We also present data on shrub and tree regeneration in parks and domestic gardens in the city. Indications are that the more sensitive, less intrusive management of urban environments, combined with the greater density of indigenous seed sources, has allowed regeneration of a wide range of indigenous species across a broad spectrum of habitats – from neglected gardens to pavement cracks to exotic plantations. This is despite the competition from the prodigious seed banks and density of exotic trees, shrubs, and ground covers and albeit minimal impacts of introduced browsing and seed eating mammals. If the present trends continue through appropriate management and facilitation, these tentative signs of native forest regeneration should eventually proliferate into a sustainable mixed origin urban forest that resurrects and preserves the natural character of the region.     

Building shade affects light environment and urban greenery in high-density residential estates in Singapore

Urban green spaces are an important component of the urban ecosystem of cities as they provide a range of ecosystem services that contribute to sustainability and livability of urban areas. The extent to which such services are provided is influenced by limitations on biological processes that underpin such ecosystem services. A poorly understood limitation in the urban environment is the effects of shade created by buildings on the adequacy of photosynthetically active radiation (PAR) for plant growth. We examined the effects of building shade in high-density, high-rise residential estates in Singapore on the level and distribution of PAR, and how PAR might in turn be correlated with growth of plants in community green spaces nested within these estates. Our estimates showed that high-rise and high-density buildings reduced daily PAR by almost 50% when compared to fully exposed conditions. The reduced PAR levels were correlated with lower vegetative and reproductive growth of several species of shrubs, and increased slenderness of two tree species. The shade environment created by buildings was differentiated from shade under vegetation canopies by longer periods of high instantaneous PAR during a diurnal cycle. There was also evidence of higher red to far-red ratio in the spectral composition of PAR. We suggest that an understanding of the spatial and temporal characteristics of PAR is necessary for appropriate selection of plants, particularly to match daily PAR received on site to daily light integral requirements of plants for improved delivery of ecosystem services.     

Airborne multispectral imagery and deep learning for biosecurity surveillance of invasive forest pests in urban landscapes

Urban and peri-urban trees in major cities provide a gateway for exotic pests and diseases (hereafter “pests”) to establish and spread into new countries. Consequently, they can be used as sentinels for early detection of exotic pests that could threaten commercial, environmental and amenity forests. Biosecurity surveillance for exotic forest pests relies on monitoring of host trees — or sentinel trees — around high-risk sites, such as airports and seaports. There are few publicly available spatial databases of urban street and park trees, so locating and mapping host trees is conducted via ground surveys. This is time-consuming and resource-intensive, and generally does not provide complete coverage. Advances in remote sensing technologies and machine learning provide an opportunity for semi-automation of tree species mapping to assist in biosecurity surveillance. In this study, we obtained high resolution (≥12 cm), 10-band, multispectral imagery using the ArborCam™ system mounted to a fixed-wing aircraft over Sydney, Australia. We mapped 630 Pinus trees and 439 Platanus trees on-foot, validating their exact location on the airborne imagery using an in-field mapping app. Using a machine learning, convolutional neural network workflow, we were able to classify the two target genera with a high level of accuracy in a complex urban landscape. Overall accuracy was 92.1% for Pinus and 95.2% for Platanus, precision (user’s accuracy) ranged from 61.3% to 77.6%, sensitivity (producer’s accuracy) ranged from 92.7% to 95.2%, and F1-score ranged from 74.6% to 84.4%. Our study validates the potential for using multispectral imagery and machine learning to increase efficiencies in tree biosecurity surveillance. We encourage biosecurity agencies to consider greater use of this technology.     

Effects of street landscape planting and urban public parks on dwelling environment evaluation in Japan

In this paper, we use data from 12 metropolitan cities in Japan to investigate the effects of street landscape planting and urban park areas on land prices, and estimate the magnitude and saturation levels of these effects, as well as examining the current level of planting and park areas in these cities. The empirical results imply that increasing the street landscape planting ratio improves the dwelling environment, in terms of both the magnitude and saturation level of the planting ratio, while increasing the amount of urban park area does not.     

Growth responses of some greenhouse plants to environment. I. Experimental techniques

A system for continuous measurement of net photosynthesis of small stands of greenhouse plants in an almost air-tight cabinet is described. The accuracy of control of the CO₂ concentration in the cabinet is within ± 1% of the desired value. The control of air temperature is within ± 0.2°C and the relative humidity within ± 2% from the adjusted value. The amount of CO₂ used in photosynthesis is measured by the number of injections of controlled volumes of CO₂ in a specific time interval.A system for soil temperature regulation is described. In the range from 5 to 35°C, the accuracy of control of the soil temperature is usually within ± 0.5°C from the desired value. At high solar irradiance, however, the temperature may rise about 2°C at the lower, and somewhat less at the higher, soil temperatures.Results from preliminary experiments with roses and chrysanthemums are presented.     

The assessment of mulch sheets to inhibit competitive vegetation in tree plantations in urban and natural environment

Weed control is often crucial for successful tree establishment. Removal or suppression of competitive vegetation has most often been done by either mowing or the use of herbicides. The Institute of Forestry and Game Management in Flanders (Belgium) has been conducting a three-year experiment (as part of a five-year programme) to assess 18 treatments for newly planted deciduous trees established on ex-agricultural sites. On grass-covered sites mortality of English oak(Quercus roburL.) decreased significantly when mulch sheets were applied. Mulch sheets increased growth of all species in a pasture. An unequivocal relation was found between the diameter of the weed-free area around the tree and the Relative Growth Rate of Common alder (Alnus glutinosa (L.) Gaertn.). Rigid sheets, such as those made of polypropylene could severely damage the trunk of the trees. Bark mulch decreased growth of English oak in the first year, but increased it significantly after 3 years. The application of bark mulch was time-consuming compared to the other treatments. Usage of herbicides on a clay soil was nefarious to both survival and growth of the treated trees. Mowing, often used by the Flemish Forestry Service, had no significant effect on the growth of the trees.     

A ground-based comparison of nutrient delivery technologies originally developed for growing plants in the spaceflight environment

A ground-based comparison of plant nutrient delivery systems that have been developed for microgravity application was conducted for dwarf wheat (Triticum aestivum L. 'Yecora Rojo') and rapid-cycling brassica (Brassica rapa L. CrGC#1-33) plants. These experiments offer insight into nutrient and oxygen delivery concerns for greenhouse crop production systems. The experiments were completed over a 12-day period to simulate a typical space shuttle-based spaceflight experiment. The plant materials, grown either using the porous-tube nutrient delivery system, the phenolic foam support system, or a solidified agar nutrient medium, were compared by plant-growth analysis, root zone morphological measurements, elemental composition analysis, and alcohol dehydrogenase enzyme activity assay. The results of these analyses indicate that the porous tube plant nutrient delivery and the phenolic foam systems maintain plant growth at a higher level than the solidified agar gel medium system. Root zone oxygenation problems associated with the agar system were manifested through biochemical and morphological responses. The porous tube nutrient delivery system outperformed the other two systems on the basis of plant growth analysis parameters and physiological indicators of root zone aeration. This information is applicable to the current crop production techniques used in greenhouse-controlled environments.