Effect of pH extraction buffer on antioxidant enzymes activities in water lily’s leaves and petioles

Water lily (Nymphaea antares) is one of the most valuable aquatic ornamental plants which has bright potential in the floriculture industry. It may be useful as an urban ecosystem and as a source of medicinal compounds. Due to its potential to become a new value-added product in the food industry, water lily (N. antares) was investigated in this study. Therefore, the goal of this study was to determine the nutritional content and antioxidant activity in water lily leaves and petioles with different pH extraction buffers. Water lily extract was obtained using three different pH extraction buffers, Tris buffer at pH 6.8, pH 7.1 and pH 7.8. The heat capacity of the extract was analysed using differential scanning calorimetry (DSC) and different functional groups were identified using Fourier transform infrared spectroscopy (FTIR). Thermal denaturation of the leaves sample was detected at 81.84°C. The antioxidant enzymes activities including catalase (CAT), peroxidase (POX), polyphenol oxidase (PPO), and superoxide dismutase (SOD) were determined in the leaves and petioles of water lily. In leaves, PPO activity was found to be higher in samples with pH 7.1 of the extraction buffer while there were no significant differences for activities of CAT, POX and SOD in all samples. In petioles, PPO and POX activity were found to be higher in samples with pH 7.8 and 7.1 of extraction buffer, respectively. Thus, the study found that a pH range of 7 to 9 extraction buffers did not greatly affect most of the analysis performed.

A method of linking functional and structural connectivity analysis in urban green infrastructure network construction

Accelerated urbanization and population growth lead to the fragmentation of urban green space and loss of biodiversity. There are few studies on the integration of structural and functional connectivity to solve this problem. Our study aims to draw up a methodology to synthesize two methods of connectivity evaluation, accordingly, to construct an urban green infrastructure (UGI) network which is of great significance to maintain the stability of the urban ecosystem. Taking Beijing as a study area, we first used Morphological Spatial Pattern Analysis (MSPA) to identify the source patches, then combined with the graph theory-based landscape metrics to discuss the effect of different diffusion distances on the regional landscape connectivity and classify the importance level of the source patches. Finally, we used both least-cost path (LCP) and circuit theory to construct network and identify pinch areas in corridors for network optimization. The results show that (1) the landscape connectivity of the study area is obviously polarized. Source patches in mountain and hilly areas have good ecological bases and large areas, and the density of corridors is relatively high, which makes a large contribution to the overall landscape connectivity; Source patches in plain areas are severely fragmented, and there are only a small number of potential corridors connecting urban areas and suburban areas. (2) The UGI network is composed of 70 source patches and 148 potential corridors. The diffusion distance that is most beneficial to improve landscape connectivity is 20–25 km. (3) 6 pinch areas that are of great significance for improving the connectivity of the landscape present the coexistence of high migration resistance and large optimization potential, and urgently need to be restored first. This study provides a method to combine the structural and the functional analysis to construct a UGI network and formulate more scientifical protection strategies for planning departments.

Native Trees as a Provider of Vital Urban Ecosystem Services in Urbanizing New Zealand: Status Quo, Challenges and Prospects

In New Zealand, over 87% of the population currently resides in cities. Urban trees can face a myriad of complex challenges including loss of green space, public health issues, and harm to the existence of urban dwellers and trees, along with domestic greenhouse gas (GHG) and air pollutant emissions. Despite New Zealand being a biodiversity hotspot in terms of natural environments, there is a lack of knowledge about native tree species’ regulating service (i.e., tree development and eco-physiological responses to low air quality, GHG, rising air temperatures, and drought) and how they grow in built-up environments such as cities. Therefore, we argue for the value of these native species in terms of ecosystem services and insist that they need to be viewed in relation to how they will respond to urban abiotic extremes and climate change. We propose to diversify planted forests for several reasons: (1) to improve awareness of the benefits of diverse planted urban forests; (2) to foster native tree research in urban environments, finding new keystone species; and (3) to improve the evidence of urban ecosystem resilience based on New Zealand native trees’ regulating services. This article aims to re-evaluate our understanding of whether New Zealand’s native trees can deal with environmental stress conditions similarly to more commonly planted alien species.

Urban Forest Ecosystem Services Vary with Land Use and Species: A Case Study of Kyoto City

The demand for urban ecosystem services increases with the rapid growth of the urban population. The urban forest is a crucial ecosystem services provider in cities. To achieve a better estimation of urban ecosystem services, an understanding of the link between heterogeneity and ecosystem services within cities is needed. Other than street trees and forest remnants, the contribution of dispersed green spaces should also be considered. In this study, a ground-based sample quadrat investigation of trees across a sequence of land types in Kyoto City was applied. The ecosystem services and monetary values of trees were further calculated using a customized i-Tree Eco tool. The ecosystem services calculated include carbon storage and sequestration, air pollutants removal, and runoff reduction. Ecosystem services of different land use classes were compared at both quadrat and single-tree levels. We found no significant difference across land use for all the ecosystem services at the quadrat level. However, ecosystem services were different across land use at the single-tree level. We performed a species-specific analysis and found that the pattern of ecosystem services at the single-tree level across land use varies with both the service tested and species. Our study suggests that the heterogeneity within a city should be considered when estimating urban ecosystem services. The results also provide insight into the urban green space management of Kyoto City.

Systematic Review on Urban Ecosystem Services in South-East Asia: Asean Countries

Urban ecosystem services refer to all the benefits of nature especially to the urban community and economy for maintaining human well-being. This concept links to the economic, community and environmental aspects and shows how nature conservation is important for human and economic principles. However, the view of urban ecosystem services assessment based on essential categories with current urban development is provided. So, this paper reviews the aim to analyze the types and assessing the categories of urban ecosystem services and the methodological used in ASEAN countries. Furthermore, understanding studies about urban ecosystem services are important in long-term studies for monitoring purpose. As a result, 8 out of 10 ASEAN countries excluding Laos and Brunei have studied urban ecosystem services. In this context, the result also shows the most studies specify the significance of the ecosystem services given by the urban as regulating (waste absorption, climate regulation, water purification, flood regulation, and disease control) and followed by cultural (tranquility, social relations, and recreation). Thus, exploring urban ecosystem interaction in current ASEAN countries may have added benefits in terms of improving the urban ecosystem services to streamline the urban area planning. Finally, we conclude that all the ASEAN countries should play an important role to make sure the countries maintain sustainable and more livable with the right policies and guidelines like can fit in Paris Agreement especially in Climate Strategies and plans.

Smart Planning for Healthy Cities (Urban Space Is Not Just a Place)

Cities are constantly increasing their importance, from any point of view: population, energy, food, transport. Healthy cities aim at wellbeing for all by creating urban spaces capable of inclusive community prosperity. Place is the combined tangible and intangible context of a location. It includes the integrated urban ecosystem: the constructed, environmental, social, economic, and cultural status. It is a human, natural, and artificial habitat whose combined conditions are able to upgrade or harm health and wellbeing. Its significant impact on people's life happens through a variety of ways, positive or negative, physical or mental. There are several urban determinants that affect the health indicators, which help us measure this impact. This process is named health impact assessment. It is conducted via specific tools, and till now it showed us that the urban environment affects public health much more than the medical system. On the other side, only vigorous communities are able to ensure thriving culture and economy, urban and regional sustainability and development.

A Bibliometric and Visual Analysis of Global Urban Resilience Research in 2011–2020: Development and Hotspots

Urban resilience (UR), which promotes the implementation of resilient cities, has received widespread attention. The purpose of this study is to visualize the knowledge background, research status, and knowledge structure of relevant literatures by using a Citespace based scientometrics survey. The results show that UR is an increasingly popular topic, with 2629 articles published during the study period. (1) The most prolific publications and journals involved in the flourishment of UR research were identified by co-citation. The United States was the most productive contributor, with numerous publications and active institutions. Journal of Cleaner Production, Sustainability, International Journal of Disaster Risk Reduction were the three most cited journals. (2) Co-occurrence analysis was employed to determine the highly productive keywords, and subject categories in the UR domain, including “environmental science & ecology”, “environmental sciences, “science & technology”, “environmental studies”, “green & sustainable science & technology”, and “water resources”. (3) The diversity of highly cited authors in different countries and regions confirmed the evolution of UR studies. (4) Furthermore, the classification of UR knowledge was performed in the form of clusters and knowledge structure to achieve ten distinct sub-domains (e.g., Urban floods and stormwater management, Urban ecosystem services, Urban landscapes, and Trauma). This study provides an overview of UR research and research topics so that future researchers can identify their research topics and partners.

A Novel Approach for the Assessment of Cities through Ecosystem Integrity

To tackle urban heterogeneity and complexity, several indices have been proposed, commonly aiming to provide information for decision-makers. In this study, we propose a novel and customizable procedure for quantifying urban ecosystem integrity. Based on a citywide approach, we developed an easy-to-use index that contrasts physical and biological variables of urban ecosystems with a given reference system. The Urban Ecosystem Integrity Index (UEII) is the sum of the averages from the variables that make up its intensity of urbanization and biological components. We applied the UEII in a Mexican tropical city using land surface temperature, built cover, and the richness of native plants and birds. The overall ecosystem integrity of the city, having montane cloud, tropical dry, and temperate forests as reference systems, was low (−0.34 ± SD 0.32), showing that, beyond its biodiverse greenspace network, the built-up structure highly differs from the ecosystems of reference. The UEII showed to be a flexible and easy-to-calculate tool to evaluate ecosystem integrity for cities, allowing for comparisons between or among cities, as well as the sectors/regions within cities. If used properly, the index could become a useful tool for decision making and resource allocation at a city level.