Including Carbon Sequestration Research Articles

Asset management and risk based process safety management approaches to the energy trilemma

The global energy landscape is transforming towards a carbon-neutral future, necessitating strategic and systematic approaches to address the energy trilemma of security, affordability, and sustainability. Two critical elements of this transformation include the large-scale global adoption of hydrogen for energy use and carbon capture, usage, and storage (CCUS), including carbon sequestration. These efforts require effective management from a lifecycle perspective, considering net emissions and economics, including the life-cycle cost of energy systems, and a risk based process safety (RBPS) management approach that ensures public safety. Embracing asset management principles, which encompass lifecycle management, risk management, and performance optimisation, will be key in facilitating this transition. By analysing energy generation, demand patterns, and storage capacity, optimising the use of renewable energy, systematically, and dynamically monitoring asset performance, and process safety assurance metrics, operators can optimise resource allocation, reduce costs, and improve sustainability and public safety. Furthermore, adopting good risk engineering practices, including RBPS management, will manage risks to as low as reasonably practicable, ensuring a tolerable residual public risk level. This article highlights the correlation between the energy trilemma and asset management practices and suggests practical strategies to manage these major changes by implementing principles of asset management and RBPSmanagement, including a supporting case study.

Application of remote sensing methods for monitoring extent, condition and blue carbon storage in salt marshes

Salt marshes are fragile coastal ecosystems that provide a wide range of ecosystem services, including carbon sequestration and storage. Despite the importance of salt marshes for blue carbon sequestration, few studies have been done on blue carbon monitoring using satellite remote sensing techniques. This study arose to fill this knowledge gap, and aimed to determine the amount of blue carbon sequestered in salt marshes by analyzing the particular case of the Pancas salt marsh (Tagus Estuary, Portugal). To achieve this, the extent and condition of the Pancas salt marsh were assessed using remote sensing methods, by establishing a methodology that effectively identified and validated its extent based on Sentinel-2 imagery from 2016 to 2022. This method involves generating a reference salt marsh extent map followed by mapping salt marsh extent through four Vegetation Indices (VI) from Sentinel-2 data to compare and thus validate the salt marsh extent based on the information provided by the satellite. Considering the extent of the salt marsh and the changes it has undergone over the 7 years studied, together with reference values for sequestered carbon in the salt marsh sediments, approximate values for sequestered blue carbon were determined. The results highlighted the validation of Normalised Difference Vegetation Index (NDVI) as the best-performing VI for this study and as a proxy for the condition of the salt marsh in terms of the spatial and temporal distribution of its aboveground biomass. It was also verified that the salt marsh expanded its frontal region by 0.22 km2 between 2016 and 2022, while certain areas of high marsh have suffered dieback. Concerning sequestered carbon, an increase of 508.2 tonnes since 2016 was quantified, corresponding to 66500 tonnes of blue carbon stored for 2022. Our study revealed the intrinsic relationship between the extent of a salt marsh and its carbon sequestration capacity highlighting the importance of future application of more remote sensing techniques, to emphasize the significant role of these ecosystems in carbon sequestration and climate change mitigation.

Escarpments within Mediterranean seagrass Posidonia oceanica meadows increase habitat heterogeneity and structural complexity enhancing fish diversity and biomass

Seagrass meadows provide important ecosystem services including carbon sequestration, coastal protection from erosion, and sustained biodiversity and fisheries thereby improving the wellbeing and livelihoods of coastal communities. The erosion of millenary deposits of intertwined roots and rhizomes of Posidonia results in the formation of three-dimensional structures named escarpments that constitute a biogenic reef habitat. However, the natural history of seagrass escarpments including their formation processes and their role as habitat for reef fauna and flora remains poorly understood. This research located and characterized Posidonia oceanica escarpments in Menorca (Balearic Islands) and compared structural complexity and fish assemblages among seagrass escarpments, seagrass meadows, rocky substrates and bare sand with emphasis on its role as habitat and shelter for typical rocky fish. Fish abundance and biomass were similar between seagrass escarpments and rocky substrates (P > 0.05), but significantly lower in seagrass meadows (P < 0.001). The large number of caves found along seagrass escarpments provide shelter to fish, including species only associated to rocky substrates. Seagrass meadows form a rather homogenous habitat within their canopy, but the presence of seagrass escarpments enhances habitat heterogeneity and structural complexity along with fish abundance and biomass at the seascape level. This study enhances understanding on the ecological importance of seagrass escarpments.

Beyond biomass production: Enhancing biodiversity while capturing carbon in short rotation coppice poplar plantations

Biodiversity is essential for the functioning of ecosystems and the provision of services. In recent years, the role of plantations in mitigating climate change through carbon sequestration has been highlighted. In the Mediterranean area, high-density poplar plantations in short-rotation with resprouting management (SRC) have been established for biomass purposes on mostly irrigated agricultural land, coexisting with rainfed and irrigated agricultural crops. This study aims to assess the contribution of these plantations to this type of agroforest ecosystem in terms of biodiversity. For this purpose, both flora and fauna diversity were evaluated both within and outside of the plantation. Additionally, the accumulated carbon in the biomass, as well as in the accompanying vegetation within the plantation, was assessed. Different indices were used to evaluate both the intrinsic diversity of the forest plantation and the degree of substitution and complementarity between the different communities of the landscape. Our findings reveal distinct biodiversity patterns in the land-use scenarios sampled. Specifically, we observed significantly higher flora-species richness in SRC plantations than in the adjacent agricultural land, whereas fauna richness showed a similar but slightly higher level in the forested area. A moderate level of complementarity between land uses was found for insects and mammals (around 45 %), contrasting with high complementarity for birds (87 %) and flora (90 %). This suggests substantial turnover and replacement among these ecological environments. Our results indicate that a second rotation (4 year) plantation could accumulate a total of 61.6 Mg C ha−1, and even though adventitious flora represents <2 % of the total carbon accumulated, its importance in providing ecosystem services is considerable. Hence, these findings evidence the fact that SRC poplar plantations can enhance biodiversity in Mediterranean agroforest ecosystems and actively contribute to various provisioning ecosystem services, including carbon sequestration, reflecting a multi-objective approach that extends beyond biomass production.

What challenges impede the adoption of agroforestry practices? A global perspective through a systematic literature review

AbstractDespite the extensive amount of evidence in the literature regarding the benefits of agroforestry systems including carbon sequestration, soil erosion reduction, climate change resilience, biodiversity conservation and other ecosystem services, the adoption of agroforestry practices presents several barriers for farmers and other stakeholders, thus requiring comprehensive examination from the scientific community. We performed a systematic literature review following the methodology described in the PRISMA framework, to provide a novel comprehensive and systematic overview of what is present in the literature regarding the obstacles stakeholders perceive with regards to agroforestry adoption, gathered through participatory research methods, which are methodologies that engage stakeholders in the research process. In this work, we highlighted and categorized 31 obstacles that stakeholders around the globe perceive according to the examined literature (n = 90) with regards to agroforestry adoption, pertaining to i) technical-agronomic, ii) socio-economic and iii) policy-legislative aspects. We produced a consultable database of the examined literature presenting the extracted and categorized data including 1) Region of interest; 2) Investigated agroforestry system; 3) Methodologies utilized in the papers; 4) Number, gender ratio and type of stakeholders; 5) Main relevant obstacles found in the paper. We highlighted the five most frequently encountered issues i) the availability or quality of knowledge or experience on technical and agronomic matters, or knowledge diffusion necessary to implement or maintain agroforestry systems ii) the perceived socio-economic issue related to the market, marketing of agroforestry products, supply chain or jobs in agroforestry; iii) issues related to the amount of labor or time necessary to implement or maintain agroforestry systems; iv) issues related to the upfront economic investment necessary to establish an agroforestry system and availability of capital; and v) issues related to the availability of technical support necessary to implement or maintain agroforestry systems.

A global meta-analysis on the effects of organic and inorganic fertilization on grasslands and croplands.

A central role for nature-based solution is to identify optimal management practices to address environmental challenges, including carbon sequestration and biodiversity conservation. Inorganic fertilization increases plant aboveground biomass but often causes a tradeoff with plant diversity loss. It remains unclear, however, whether organic fertilization, as a potential nature-based solution, could alter this tradeoff by increasing aboveground biomass without plant diversity loss. Here we compile data from 537 experiments on organic and inorganic fertilization across grasslands and croplands worldwide to evaluate the responses of aboveground biomass, plant diversity, and soil organic carbon (SOC). Both organic and inorganic fertilization increase aboveground biomass by 56% and 42% relative to ambient, respectively. However, only inorganic fertilization decreases plant diversity, while organic fertilization increases plant diversity in grasslands with greater soil water content. Moreover, organic fertilization increases SOC in grasslands by 19% and 15% relative to ambient and inorganic fertilization, respectively. The positive effect of organic fertilization on SOC increases with increasing mean annual temperature in grasslands, a pattern not observed in croplands. Collectively, our findings highlight organic fertilization as a potential nature-based solution that can increase two ecosystem services of grasslands, forage production, and soil carbon storage, without a tradeoff in plant diversity loss.

Are forest management practices to improve carbon balance compatible with maintaining bird diversity under climate change? A case study in Eastern North America

The combination of climate change and anthropogenic disturbance significantly impacts forest bird assemblages. Assessing the cumulative effects of forest management and climate change on biodiversity and ecosystem services, including carbon sequestration and storage and provisioning of wood products is key to informing forest management and conservation decision making. Specifically, we projected changes in forest composition and structure according to various forest management strategies under a changing climate using LANDIS-II for two case study areas of Quebec (Canada): a hemiboreal (Hereford Forest) and a boreal (Montmorency Forest) area. Then, we assessed projected bird assemblage changes, as well as sensitive and at-risk species. As part of an integrated assessment, we evaluated the best possible management measures aimed at preserving avian diversity and compared them with optimal options for mitigation of carbon emissions to the atmosphere. Forest management and climate change were projected to lead to significant changes in bird assemblages in both types of forest through changes in forest composition. We projected an increase in deciduous vegetation which favored species associated with mixed and deciduous stands to the detriment of species associated with older, coniferous forests. Changes were more pronounced in Hereford Forest than Montmorency Forest. In addition, Hereford’s bird assemblages were mainly affected by climate change, while those in Montmorency Forest were more impacted by forest management. We estimated that 25% of Hereford and 6% of Montmorency species will be sensitive to climate change, with projected abundance changes (positive or negative) exceeding 25%. According to the simulations, a decrease in the level of forest harvesting could benefit bird conservation and contribute to reduction of carbon emissions in the boreal forest area. Conversely, the hemiboreal forest area require trade-offs, as mitigation of carbon emissions is favored by more intensive forest management that stimulates the growth and carbon sequestration of otherwise stagnant stands.

Urban roadside greenery as a carbon sink: Systematic assessment considering understory shrubs and soil respiration

Roadside greenery is an efficient strategy for maximizing ecosystem services, including carbon sequestration in urban settings. However, the quantification of carbon sequestration is not comprehensive because understory shrubs and soil respiration have not been thoroughly considered. We developed an integrated methodology that combined field measurements and greenhouse incubation to comprehensively assess carbon sequestration in roadside greenery systems. The system was defined as an 8 m long section comprising a single tree (Zelkova serrata), 79 shrubs (Euonymus japonicus), and soil. Annual carbon uptake by a tree was estimated using an allometric equation derived from an official government report. For shrubs, carbon uptake was measured in the field by monitoring CO2 concentration change in the chamber enclosing the leaves and stems. Annual carbon uptake by shrubs was estimated by using the regression equation among carbon uptake, air temperature, and photosynthetically active radiation. We also estimated shrub root respiration by combining net primary production (NPP) from the greenhouse incubation and measured pruning effect in the field. This enabled us to differentiate heterotrophic respiration from the total soil respiration. The overall methodology accurately assessed net ecosystem production (NEP) from the roadside greenery system, which is 0.528 kg C m−2 yr−1. If this figure is extended to all roads in the target city, it can offset daily carbon emitted from the total registered passenger vehicles in the target city. Considering that shrubs sequester an amount equivalent to 29.3 % of the carbon sequestered by tree species, the current greenhouse gas inventory should include shrubs as an important carbon sink. As we also revealed that roadside soil has high carbon vulnerability, proper soil management is needed to enhance NEP. Our systematic approach evaluating the carbon balance within the roadside greenery system can be applied to other cities, contributing to enhance global understanding of urban carbon cycle.

Shaping and enhancing resilient forests for a resilient society.

The world is currently facing uncertainty caused by environmental, social, and economic changes and by political shocks. Fostering social-ecological resilience by enhancing forests' ability to provide a range of ecosystem services, including carbon sequestration, habitat provision, and sustainable livelihoods, is key to addressing such uncertainty. However, policy makers and managers currently lack a clear understanding of how to operationalise the shaping of resilience through the combined challenges of climate change, the biodiversity crisis, and changes in societal demand. Based on a scientific literature review, we identified a set of actions related to ecosystem services, biodiversity conservation, and disturbance and pressure impacts that forest managers and policy makers should attend to enhance the resilience of European forest systems. We conclude that the resilience shaping of forests should (1) adopt an operational approach, which is currently lacking, (2) identify and address existing and future trade-offs while reinforcing win-wins and (3) attend to local particularities through an adaptive management approach.

Indices and methods for evaluating gross ecosystem product in sea areas: a case study in Changdao County, China

IntroductionCoastal nations heavily rely on their sea areas to achieve sustainable socioeconomic development. Sea areas offer abundant marine ecosystem products and services that are difficult to substitute with industrial goods. Although considerable research has been performed to evaluate the contribution offrom the marine ecosystems to human well-being, systematic and measurable indices are lacking.MethodsTo address this knowledge gap, ecosystem service theory was used to establish a framework for assessing the gross ecosystem product (GEP) of a sea area, which represents the total monetary value of final ecosystem products directly and indirectly used by people within a specific administrative jurisdiction in one year. To evaluate marine GEP, three primary indices, i.e., material products, regulating products, and cultural products, were employed, and they consist of eight secondary indices. Material products in the sea area include aquatic products and oxygen products; regulating products include carbon sequestration, climate regulation, waste treatment, and coastal protection; and cultural products include leisure and recreation, and seascape-added value. The marine GEP was calculated for the administrative sea areas of Changdao County, which is located in the Yellow Sea-Bohai Sea transitional zone.Results and discussionOur analysis indicated that from 2017 to 2019, the marine GEP in Changdao ranged between 32.59 and 33.35 billion Chinese yuan (CNY). Regulating products contributed two-thirds of this total value. However, over the three-year period, the marine GEP underwent a 5.64% decrease in Changdao. Specifically, the value of material products increased by 38.85% while that of regulating and cultural products decreased by 9.16% and 15.87%, respectively. Notably, the spatial distribution of ecosystem product values in Changdao displayed two prominent trends: (1) higher values along the coastal sea areas of islands and lower values in offshore sea areas; and (2) higher values in coastal areas of southern islands and lower values in coastal areas of northern islands. Marine GEP may serve as a comprehensive indicator for assessing the sustainability of marine ecosystem. Combining the assessment of both marine and terrestrial GEP facilitates an understanding of how marine and terrestrial ecosystems interact in coastal regions. Furthermore, the combined use of marine GEP and GDP helps better evaluate and sort the level of green development of coastal nations and regions.

Effects of an Invasive Bark Beetle Polygraphus proximus Blandf. Outbreak on Carbon Pool Dynamics in West Siberian Dark Coniferous Forests

Invasions of dendrophagous insects pose major threats to forest ecosystems and to the timber industry. The alien species bark beetle Polygraphus proximus Blandf. of Far Eastern origin has caused Siberian fir dieback in vast areas within several regions of Russia. Rapid spread of the pest and its outbreaks raise the issue of preserving the most important functions, including carbon sequestration, by the damaged forests. In this study, monitoring of carbon pool dynamics was carried out during 2012–2023 on four sample plots showing various degrees of damage in the southern taiga zone of Western Siberia in the Larinsky Landscape Reserve. Dynamics of the forest stands’ vitality were reflected in a rapid decline of the number of viable trees and an increase in amounts of deadwood, debris, and soil composition, resulting in a transformation of the natural biological carbon cycle in the native dark coniferous ecosystems.

Plastic Paradox in Blue Carbon Ecosystems.

Plastics are rapidly accumulating in blue carbon ecosystems, i.e., mangrove forests, tidal marshes, and seagrass meadows. Accumulated plastic is diverted from the ocean, but the extent and nature of impacts on blue carbon ecosystem processes, including carbon sequestration, are poorly known. Here, we explore the potential positive and negative consequences of plastic accumulation in blue carbon ecosystems. We highlight the effects of plastic accumulation on organic carbon stocks and sediment biogeochemistry through microbial metabolism. The notion of beneficial plastic accumulation in blue carbon ecosystems is controversial, yet considering the alternative impacts of plastics on oceanic and aboveground environments, this may be the "lesser of evils". Using environmental life cycle impact assessment, we propose a research framework to address the potential positive and negative impacts of plastic accumulation in blue carbon ecosystems. Considering the multifaceted benefits, we prioritize expanding and managing blue carbon ecosystems, which may help with ecosystem conservation, as well as mitigating the negative effects of plastic.

Soil Moisture Conservation through Crop Diversification and Related Ecosystem Services in a Blown-Sand Area with High Drought Hazard.

Soil moisture reserves are a key factor in maintaining soil fertility and all other related ecosystem services (including carbon sequestration, soil biodiversity, and soil erosion control). In semiarid blown-sand areas under aridification, water preservation is a particularly crucial task for agriculture. The international Diverfarming project (2017-2022), within the EU Horizon 2020 Program, focused on the impacts of crop diversification and low-input practices in all pedoclimatic regions of Europe. In this three-year experiment conducted in the Pannonian region, the impact of intercropping asparagus with different herbs on some provisioning and regulating ecosystem services was evaluated in the Kiskunság sand regions. Relying on findings based on a range of measured physical and chemical soil parameters and on crop yields and qualitative properties, advice was formulated for farmers. The message drawn from the experiment is somewhat ambiguous. The local farmers agree that crop diversification improves soil quality, but deny that it would directly influence farm competitiveness, which primarily depends on cultivation costs (such as fertilization, plant protection, and labour). Further analyses are needed to prove the long-term benefits of diversification through enriching soil microbial life and through the possible reduction of fertilizer use, while water demand is kept at a low level and the same crop-quality is ensured.

Biomass recovery along a tropical forest succession: Trends on tree diversity, wood traits and stand structure

Secondary forests recovering after disturbances currently comprise about half of the world′s tropical forests. A better understanding of the recovery of species composition, stand structure, and biomass stocks of these secondary forests is critical for the sustainable management of these ecosystems. The main objective of this research was to develop the successional trends in forest biomass, tree diversity, and species composition recovery. We monitored the changes in tree species composition, stand structural characteristics, and biomass growth in a chronosequence of tropical secondary forests in the Yucatan Peninsula of Southeastern Mexico. We used both linear and non-linear regressions to develop biomass growth models during forest succession. We calculated tree species diversity and similitude indices between forest successional groups (young, medium-aged, and old-growth forests). The aboveground biomass stocks ranged from 5.2 to 121 Mg C ha-1, which increased gradually with forest age. We observed a divergent trend of biomass accumulation between soft- and densewood species during succession. The contribution of densewood species on tree biomass stock increased (from 32 % to 81 %) with the increasing forest ages. However, the tree diversity indices did not change significantly with forest age and were a poor predictor of aboveground biomass growth during succession. Secondary forests (SFs) of advanced age were more similar to old-growth forests (OF) in their species composition compared to young ones, as evidenced by the Chao-Jaccard index. However, it may take more than a century for these secondary forests to recover to OF-level species composition. Furthermore, the structural equation model allowed us to infer the relative importance of forest age, tree diversity, soil properties, and stand structural attributes, including wood density on biomass growth along the forest chronosequence. Forest age-mediated effect of species composition shift and stand structural changes was a better predictor of biomass accumulation than the changes in tree diversity or soil properties during succession. However, the soil properties as a construct (latent variable), had a significant positive covariance with stand structure, indirectly influencing biomass growth. These biomass and species composition recovery models could be useful in forest management for biodiversity conservation, landscape restoration, and ecosystem services, including carbon sequestration.

Unravelling blue landscape fragmentation effects on ecosystem services in urban agglomerations

The blue landscape (BL), which refers to the wetlands, rivers, lakes, and other bodies of water, is of immense importance for a sustainable environment. It provides a variety of ecosystem services, including carbon sequestration, water purification, soil fertility, and habitat for diverse flora and fauna. These services are crucial for sustaining the livelihoods of local communities and maintaining the health of the environment. In megacities like Kolkata, India, the BL is often subjected to fragmentation and degradation due to rapid urbanisation, industrialization, and other human activities. This has serious implications for ecosystem services and the overall health of the environment. This study is intended to value ecosystem service losses over the last 25 years and assess the influence of blue landscape fragmentation on ecosystem services in Kolkata, India. To accomplish this goal, satellite data was collected from 1994 to 2019 for both pre-monsoon and post-monsoon seasons. The results of the study showed that significant losses in ecosystem services were observed over this time period, primarily due to the decline of the East Kolkata Wetland and its conversion for settlement and agricultural purposes. Despite the existence of some policies aimed at protecting the wetland, more robust restrictions and remedial strategies are required to conserve and restore the blue landscape in Kolkata. This work adds to the corpus of research on the value of blue landscapes (BLs) and the environmental services they provide. The findings of this study highlight the need for increased attention to the conservation and management of BLs in India and provide a valuable foundation for future research and policy development. Furthermore, this research introduces the innovative concept of urban BLs as a nature-based framework for understanding urban landscape fragmentation, a novel contribution that fills a gap in the existing literature on this topic.

Assessment of Carbon Sequestration in Private Forests across Two Different Physiographic Regions of Nepal: Implications for Conservation and Climate Change Mitigation

Private forests offer diverse ecosystem services, including carbon sequestration and biodiversity conservation, which are crucial for Nepal. However, there is a notable absence of comprehensive research on these services. Assessing carbon sequestration in private forests can have economic advantages for forest owners by promoting resource conservation and contributing to greenhouse gas reduction. This study aims to estimate and compare carbon stocks in private forests located in two distinct physiographic regions of Nepal while also identifying the factors influencing these carbon stocks. The analysis focuses on 16 private forests (with 0.1 to 0.5 hectares) each from Chitwan district (Terai region) and Kavrepalanchok district (Hilly region). Field data collection involved direct measurements of tree and sapling diameter at breast height (DBH), as well as height and class of trees and poles, utilizing a total enumeration method. These collected values were utilized to calculate aboveground biomass (AGTB), aboveground sapling biomass (AGSB), belowground biomass, and carbon stock. Private forests of Terai region were dominated by Shorea borneensis, Tectona grandis, and Dalbergia sissoo, whereas the Hilly region was dominated by Pinus patula, Alnus nepalensis, Schima wallichii, and Quercus leucotrichophora. The aboveground biomass carbon in the Terai region’s private forests was estimated to be 83.53 t·ha−1, while in the Hilly region, it was 37.32 t·ha−1. The belowground biomass carbon in the Terai region’s private forests was found to be 21.72 t·ha−1, compared to 9.70 t·ha−1 in the Hilly region. Consequently, the estimated total carbon stock in the Terai and Hilly regions’ private forests was 105.25 t·ha−1 (386.26 t·ha−1 CO2-eq) and 47.02 t·ha−1 (172.57 t·ha−1 CO2-eq), respectively. Carbon sequestration in the Terai region’s private forests was discovered to be 2.24 times higher than that in the Hilly region. These findings underscore the significant potential of private forests, which can generate economic benefits through carbon trading and leverage mechanisms such as REDD+/CDM to promote sustainable conservation practices.

The Return of Organic Soft Tissue Preservation Abilities and the “Bog Body” Phenomenon in MLTT Restored Peatlands

Climate change and human manipulation in peatlands threatens peatland health, presaging the loss of instrumental peatland functions including carbon sequestration or the bog body mummification function. In response, peatland ecologists are studying restoration methods to revive degenerating bogs, including the Rochefort Moss Layer Transfer Technique (MLTT). Since the advent of these studies, questions regarding the return of lost peatland functions have arisen. This study employed a qualitative experimental study of mammal soft tissue samples in a controlled incubatory environment mimicking an MLTT restored peatland to discern if the MLTT method induced the return of the bog body mummification function. The findings indicate that the function does appear to return, which crucially implies that restorative efforts in peatland ecology have a valid prospect with promising returns, therefore this field is worthwhile to continue because this study shows that it is possible to save peatlands and their functions, further permitting the archaeological community to save the artifacts found in peatlands.

Transplanted Ginkgo growth rates indicate common Chinese nursery techniques may severely limit urban ecosystem services

China has experienced history's largest rural-to-urban migration. The social, economic, and environmental challenges brought about by urbanization are diverse and complex. Given China's national goal to achieve carbon neutrality by 2060 and commitment to urban sustainability, large cities have focused on urban greening initiatives. Yet, studies seeking to quantify ecosystem services and disservices only assess healthy, mature trees, rather than those with severe damage, declining health, or lack of vitality due to poor management. In this short communication, we conducted a case-study in one of China's major nursery stock-producing cities, Chengdu, on a common street tree, Ginkgo biloba, to assess the long-term impact of one of the most common yet extreme nursery transplant practices on tree growth (traumatic root-cutting of ‘super-large’ nursery stock). We used tree-ring data collected in a typical urban greenspace from 23 Ginkgo trees, including 18 trees transplanted as ‘super-large’ nursery stock and a control group (5 trees) transplanted as small-caliper trees. We found the trees transplanted as ‘super-large’ nursery stock experienced declining tree growth with decades of lost landscape potential likely due to traumatic root-cutting at the time of transplant from nursery to landscape. The control group allowed contrast between the growth patterns of ‘super-large’ transplanted trees with those that remained healthy, being transplanted as smaller-caliper trees. For the ‘super-large’ trees, we found a decrease in carbon sequestration from 7.6 kg C yr−1 on average per tree in 2001 to about 1.5 kg C yr−1 on average per tree in 2021, while no decreasing trends were observed among the control trees. This implies a negative impact on multiple expected ecosystem services including carbon sequestration, shade, canopy coverage, and pollutant mitigation. These results highlight the unrecognized costs of common Chinese nursery and transplant techniques on urban landscape trees, necessitating more research, science-based policies, and better management techniques.

Consumer perceptions of the co-benefits of biosolids and carbon sequestration in a fertiliser aimed at the urban retail market

New markets for biosolids-derived products are urgently required to provide cost-effective solutions for water utilities to address the increasing production of municipal sewage waste. One potential outlet for biosolids is the domestic retail fertiliser market. Biosolids-derived fertilisers could be marketed to consumers by highlighting their environmental benefits, including carbon sequestration potential. This study used a two-part research approach to assess the feasibility of biosolids-derived fertiliser in the current market and to gauge the extent to which retail consumers value carbon sequestration features in fertilisers. First, a hedonic price analysis of existing fertilisers in the market explored consumer preferences and whether they currently pay extra for “sustainable” or “organic-certified” products. Second, a discrete choice experiment was designed to elicit consumers’ willingness-to-pay for biosolids-derived fertilisers and those clearly labelled with their carbon sequestration capability. The hedonic price analysis determined that organic or natural fertilisers sell at similar or slightly higher prices than synthetic alternatives. The choice experiment revealed that consumers would pay 17% more for fertilisers labelled with their carbon capture capacity. Purchasers of organic fertilisers perceived biosolids-derived fertilisers as valuable organic alternatives. In contrast, buyers of synthetic fertilisers were willing to pay slightly less for biosolids-derived alternatives. These findings suggest that some consumers are willing to purchase biosolids-derived fertilisers at prices comparable to current alternatives and place higher value on fertilisers offering environmental benefits, such as carbon sequestration. These results indicate that urban retail markets could be a strategic outlet for biosolids by producing biosolids-derived fertilisers.

Evaluating urban park ecosystem services and modeling improvement scenarios

Three ecosystem services of the 25 public parks in Bangkok, including carbon sequestration, avoided runoff, four air pollutant removals (CO, NO2, PM10, and PM2.5), and the relevant monetary values, were determined using i-Tree Eco software. Two modeling scenarios (MS) including MS1 (no greening improvement) and MS2 (improvement by increasing either green area or tree planting, or both in the parks) with tree annual mortality rates (AMR) of 1 and 3% were developed to forecast the parks' ecosystem services for 50 years after 2020 (2021–2071). The results revealed the synergistic interactions of the different tree planting specifications (MS1 and MS2) and tree mortality rates on the parks' ecosystem services. For MC2 with the assigned 1% AMR, the parks’ optimal ecosystem services were obtained and the average annual monetary value (0.55 million USD) of the total ecosystem services of the 25 parks over the 50-year forecast was 150% higher than that (0.22 million USD) in 2020. Based on MS1 and MS2, tree rotations should be conducted in the parks after 2057 and 2065, respectively, for the low tree AMR (≤1%) but not later than 2041 and 2043, respectively, for the higher tree AMR.