Quantifying multiple ecosystem services for adaptive management of green infrastructure

Sustaining ex-mining lake-converted constructed wetlands as nature-based solutions: A comprehensive assessment of the carbon-water nexus in Paya Indah Wetlands, Malaysia

Water and carbon, essential for Earth's well-being, face imminent threats from human activities that fuel climate change. This study investigates nature-based solutions, focusing on the carbon-water nexus of ex-mining lake-converted constructed wetlands, specifically in Malaysia's Paya Indah Wetlands (PIW). Addressing research gaps, it assesses the ecosystem services of these wetlands, emphasising integrated evaluations for informed land management and employing a top-down conservation approach. Methodologically, spatial assessments, soil and water sampling, carbon quantification, water quality index calculations, land cover classification and stakeholder surveys were conducted. Results underscore the significant carbon sequestration and water quality improvement potential of constructed wetlands, with soil and sediment carbon accumulation reaching 1553.11 Mg C ha-1 (equivalent to 5700 Mg CO2 ha-1), translating to an annual sequestration capacity of 67.5 Mg C ha-1 year-1. Water quality index values ranged from 58 to 81 (Classes II to III). PIW's establishment led to a reduction of over 90% in barren land, with increases in water bodies (36%) and vegetation-covered land (38%), boosting wildlife populations by 30%. Spatial variations in organic carbon density and water quality underscore the complexity of the carbon-water nexus and its impacts on ecosystem health and water security. Despite land use changes, PIW demonstrates resilience, contributing to climate change mitigation. Stakeholder perceptions vary, emphasising the need for adaptive strategies. The study proposes transdisciplinary conservation initiatives and adaptive plans, stressing the pivotal role of ex-mining lake-converted constructed wetlands in enhancing climate resilience.

The integration of nature values and services in the nature-based solution assessment framework of constructed wetlands for carbon-water nexus in carbon sequestration and water security

As the climate change impacts are expected to become increasingly disruptive, affecting water security, environmental health and ecosystem, constructed wetlands receive attention for their functions in delivering various life-sustaining services to human and environmental systems. In this article, a systematic review was conducted through the Preferred Reporting Items for Systematic Reviews and Meta-Analyses standard to identify the current research on constructed wetlands' nature values and services from 2011 to 2020 of two databases, namely Scopus and Web of Science. The criteria of assessment focus on holistic deliberation of subject matters, namely carbon sequestration and water security as regulating and provisioning services, as well as nature values of constructed wetlands, namely instrumental and intrinsic values. As a result, 38 articles were selected and comprehensively examined. As the lack of an interdisciplinary approach makes data and information integration difficult, this study derived an integrated classification of constructed wetlands' services and mapped with its nature values, guided by the Millennium Ecosystem Assessment framework. Besides, mechanisms and factors affecting carbon sequestration and water security were also discussed. The carbon-water nexus was then conceptualised as interlinkages between engineered and natural physicochemical processes at the interface between carbon and water cycles. To fill the gaps, based on the carbon-water nexus concept, a new framework was synthesised at the end of the deliberation for constructed wetlands in regulating local climate through carbon sequestration and ensuring water security through water treatment and purification as well as influencing socio-cultural values, which needs an integrated approach that is the novelty of this work. The framework integrates the dichotomy of the instrumental-intrinsic nature values of constructed wetlands to evaluate the importance and benefit of the carbon-water nexus. The framework that reveals the vitality of nature values provided by constructed wetlands can help improve the decision-making to prioritise ecosystem services and conservation efforts, particularly in the sustainable management of constructed wetlands.

Phased and polarized development of ecological quality in the rapidly-urbanized Pearl River Delta, China

Urbanization is one of the most significant human activities in the Anthropocene, with profound impacts on environmental quality. The lack of an understanding about the relationship between urbanization and ecological quality limits the effectiveness of urban planning and ecological policies in alleviating urban ecological problems. Based on the integrated ecological index RSEI (remote sensing ecological index), this study attempts to clarify the spatio-temporal characteristics of ecological quality in an urbanization process through an empirical study in China's Pearl River Delta (PRD) and explores the relationship between urbanization and ecological quality. Our results show that the ecological development of the PRD in the period of 1986 to 2019 was a phased and polarized process. Two periods are distinguished, based on RSEI dispersion: the period of 1986 to 2003, with slight dispersion, and the period of 2004 to 2019, with higher dispersion. Plain areas show evidence of ecological degradation, whereas a considerable improvement was observed in hilly areas. Industrialization and consummation of legal system were the driving factors behind the phased development of ecological quality, while the differences in landform and land management were the fundamental reasons for the spatial differentiation of ecological quality. The findings of this study provide experience and enlightenment for ecological management and sustainable development strategies in regions seeking rapid growth in their prosperity.

Assessing Ecological Infrastructure Investments-A Case Study of Water Rights Trading in Lu'an City, Anhui Province, China

Investment in ecological infrastructure construction alters behaviors and quantities of the ecosystem service (ES) provided, and market-clearing can learn the value and scale of ES. We integrated ecological and economic methods to put forward the idea of realizing the aquatic ecological products’ value by investing in water-saving irrigation infrastructure. Firstly, the demand for aquatic ecological products was calculated by a Cobb–Douglas production function, and then the supply of aquatic ecological products was estimated by InVEST and water-saving potential models; Finally, the scale of ecological infrastructure investment and the aquatic ecological products’ value are illustrated by cost-benefit analysis and market equilibrium theory. Research indicates that, (1) industrial water efficiency is high, and the ecological infrastructure construction provides a considerable number of ecological products; (2) implementing water-saving irrigation project is at least 30% more profitable than maintaining the status quo; (3) the market-clearing results showed that the market equilibrium price is about 0.256 USD/m³, and the transaction volume is about 1.667 billion m³. The output value of industrial enterprises after buying water can reach about 1.37 times of the current stage, reflecting the aquatic ecological products’ value. Investment in water-saving irrigation infrastructure has huge economic, social and ecological benefits, and provides reference for decision-making.

Urban Green Infrastructure and Sustainable Development: A Review

Urban green infrastructure (UGI) can alleviate many of the problems that the growing urban population is facing. This study performed a literature review about UGI and sustainable development (SD) using the Web of Science (WoS) and the software VOSviewer. Of 195 papers selected, 89 are qualitative, focusing on theoretical approaches and design; equally, 89 are quantitative, dealing with metrics and spatial analysis and 17 combined both approaches. A high connectivity between “green infrastructure”, “ecosystem services”, “urban planning” and “sustainable development” was observed. Only 39 of the documents embrace environmental, social and economic aspects. Most of the papers are related to Sustainable Development Goal (SDG) 11, “to make cities inclusive, safe, resilient and sustainable” and SDG 15, “protect, restore and promote sustainable use of terrestrial ecosystems”. Further research integrating the three pillars of sustainability and relating UGI to all the SDGs is recommended.

Scale effects on the relationships between land characteristics and ecosystem services- a case study in Taihu Lake Basin, China

It is generally recognized that marginal changes in landscape characteristics can influence multiple ecosystem services, but the causal relationships involved are still very unclear due to lack of knowledge and data gaps. Planners and managers need spatial information and evidence on these causal relationships for systematic and sound land planning. This study evaluated the effects of landscape characteristics on seven types of ecosystem services and the trade-offs among the ecosystem services by combining statistical data and the InVEST model with correlation analysis across Taihu Lake Basin, China. We found that all ecosystem services except food production increased from 2005 to 2015 in the whole basin. We also found that correlations between landscape characteristic metrics and ecosystem services indicators changed over time for different types of ecosystem service indicators at the county scale, and between county and pixel scale. The results demonstrated the effects of landscape characteristic metrics on multiple ecosystem services indicators and the tradeoffs among these ecosystem services indicators, and also revealed scale effects on correlations and tradeoffs. Therefore planners and managers need to consider both landscape characteristic metrics and scale effects for effective landscape management to improve ecosystem services and reduce unwanted tradeoffs.