How green is an urban tree? The impact of species selection in reducing the carbon footprint of park trees in Swedish cities

Abstract

IntroductionPlanting trees in urban areas can mitigate some of the emissions generated in cities by carbon sequestration (annual uptake of CO2 through the process of photosynthesis) and carbon storage (amount of carbon stored in the tree's biomass throughout its lifespan). The aim of this study was to calculate the carbon footprint from nursery production to final establishment of different tree species grown for planting in urban parks in a northern European context.Material and methodsThe analysis included a cradle-to-gate approach and investigated the amount of carbon the adult trees needed to sequester in order to compensate for initial carbon emissions and which temporal perspectives are of concern. Greenhouse gas emissions were estimated based on an inventory of consumption of fuels, energy, materials and other production inputs during cultivation, delivery, planting and establishment of three different tree species in three different locations in Sweden. The tree species considered in the analysis (Salix alba, Quercus rubra, Pinus sylvestris) were selected due to significant differences in their growth rates. Salix alba is a competitive strategist in resource-rich habitats, and is proficient at converting these resources into vigorous growth. Pinus sylvestris is a pronounced stress strategist with good ability to handle resource-limited habitats, and invests in traits accordingly, resulting in significantly slower development. Quercus rubra has its main distribution in cool and moderately resource-rich habitats, but has relatively high stress tolerance and can be considered intermediate between the other two species in terms of growth rate.Results and discussionThe results showed that within 16 years of planting, all species in all three cities, except Pinus sylvestris planted in Umeå, compensated for initial carbon emissions, i.e. showed net absorption of CO2 after emissions from cultivation, delivery, planting and establishment of the trees had been deducted. There was a clear link between the time by which compensation of initial carbon emissions was achieved and growth rate of the different species, with the fast-growing Salix alba showing the best results. The single largest source of emissions among all activities carried out during cultivation, delivery and planting of all species, regardless of the city in which they were planted, was fuel consumption during tree planting.

Empirical Assessment of the Efficiency of Poland’s Energy Transition Process in the Context of Implementing the European Union’s Energy Policy

“…This achievement can be attributed, in part, to the composition of its energy production and consumption, with renewable energy sources (RESs) comprising the largest share of total consumption. Moreover, Sweden's extensive tree planting initiatives contribute significantly to diminishing carbon dioxide emissions into the atmosphere [78]. Furthermore, the country has set forth ambitious objectives aimed at achieving complete climate neutrality by 2045 [79].…”

Improving Tree Seedling Quality Using Humates Combined with Bacteria to Address Decarbonization Challenges through Forest Restoration

“…The present investigation studied the possibility of their use in combination with rhizosphere microorganisms as a means of improving the quality of tree seedlings for forest restoration and solving the problem of decarbonization. It is widely accepted that increasing greenhouse gas emissions are causing global warming and associated climate disruptions, such as frequent droughts and other adverse weather events and natural disasters, triggering increased interest in finding ways to reduce the concentration of carbon dioxide in the atmosphere [4,5]. Growing trees absorb carbon dioxide through photosynthesis and store carbon in their biomass and soils; therefore, large-scale tree planting is seen as an effective way to decrease the buildup of carbon dioxide in the Plants 2024, 13, 1452 2 of 14 atmosphere [6].…”

“…Growing trees absorb carbon dioxide through photosynthesis and store carbon in their biomass and soils; therefore, large-scale tree planting is seen as an effective way to decrease the buildup of carbon dioxide in the Plants 2024, 13, 1452 2 of 14 atmosphere [6]. To reduce the concentration of carbon dioxide in the atmosphere, it is important to plant trees not only in forests, but also in urban areas; according to some data, urban areas account for more than half of carbon dioxide emissions [4]. At the same time, according to American researchers, large-scale achievement of global reforestation goals, aiming to mitigate the effects of climate change, will require an increase in the number of tree seedlings by 2-3 times, compared with their number in existing nurseries [7].…”

Is ward-level calculation of urban green space availability important?—A case study on Vellore city, India, using the histogram-based spectral discrimination approach

“…Urban green space (UGS), which is popularly known in literature, is defined as the area which is covered by vegetation that normally includes trees, crop lands, and shrubs and these spaces are considered as the last vestiges of nature in urban areas (Sathyakumar et al, 2020;Sun et al, 2022). The presence of a sufficient quantity of UGS in cities is important from an environmental and ecological point of view as UGS helps to reduce urban heat island (UHI) effects, improve the air and water quality, prevent soil erosion, reduce the risk of flooding, and improve the biodiversity (Kowe et al, 2021;Kefale et al, 2023;Lind et al, 2023). In addition to many environmental and ecological benefits, UGS also offers many social advantages.…”