Assessing the carbon capture potential of a reforestation project

Abstract

The number of reforestation projects worldwide is increasing. In many cases funding is obtained through the claimed carbon capture of the trees, presented as immediate and durable, whereas reforested plots need time and maintenance to realise their carbon capture potential. Further, claims usually overlook the environmental costs of natural or anthropogenic disturbances during the forest’s lifetime, and greenhouse gas (GHG) emissions associated with the reforestation are not allowed for. This study uses life cycle assessment to quantify the carbon footprint of setting up a reforestation plot in the Peruvian Amazon. In parallel, we combine a soil carbon model with an above- and below-ground plant carbon model to predict the increase in carbon stocks after planting. We compare our results with the carbon capture claims made by a reforestation platform. Our results show major errors in carbon accounting in reforestation projects if they (1) ignore the time needed for trees to reach their carbon capture potential; (2) ignore the GHG emissions involved in setting up a plot; (3) report the carbon capture potential per tree planted, thereby ignoring limitations at the forest ecosystem level; or (4) under-estimate tree losses due to inevitable human and climatic disturbances. Further, we show that applications of biochar during reforestation can partially compensate for project emissions.

Spatiotemporal Variations of Soil Reactive Nitrogen Oxide Fluxes across the Anthropogenic Landscape

“…We also identified lower relative abundance of microbes associated with ammonia oxidation in soils from locations with high human populations. AOA and AOB have been found to be affected by increased heavy metal pollution, including Cd, Cu, and Pb, which were found in this study to be significantly positively correlated with the human population …”

“…In this data set, we found that grass-dominated soils tended to be a “middle ground” in terms of the measured variables, suggesting grassland to be a buffered soil type, capable of withstanding pressures from chemical and physical disturbances. The prevailing mindset is that regeneration of woodlands is one of the most effective ways to combat increasing greenhouse gas (GHG) emissions; however, more recently, it has been suggested that many reforestation projects do not take into account the GHGs produced by the creation of woodlands and from the woodlands once they are established . This study and those such as Dass et al agree that, if conversion of land to woodland comes at the expense of losing grassland habitats, this is also a loss of important GHG sinks …”

Forest tree species distribution for Europe 2000–2020: mapping potential and realized distributions using spatiotemporal machine learning

“…Reforestation and forest restoration are considered key strategies for tackling climate change by enhancing CO 2 sequestration ( Lefebvre et al, 2021 ; Domke et al, 2020 ; Nave et al, 2019 ). Under the European Green Deal and the European biodiversity strategy for 2030, the European Union has committed to plant at least three billion additional trees by 2030 ( European Commission, 2021 ).…”

A global meta-analysis of woody plant responses to elevated CO2: implications on biomass, growth, leaf N content, photosynthesis and water relations

“…Understanding how these plants respond to eCO 2 may guide scientists and decision-makers in deriving climatesmart mitigation strategies (Hu et al 2018). Amongst other disciplines, forestry plays a pivotal role in climate change mitigation by increasing C sinks through afforestation/reforestation (Lefebvre et al 2021). For this reason, woody plant responses to eCO 2 require a special scientific assessment (Wang and Wang 2021a).…”