Modeling Ecosystem Services for Park Trees: Sensitivity of i-Tree Eco Simulations to Light Exposure and Tree Species Classification

Abstract

Ecosystem modeling can help decision making regarding planting of urban trees for climate change mitigation and air pollution reduction. Algorithms and models that link the properties of plant functional types, species groups, or single species to their impact on specific ecosystem services have been developed. However, these models require a considerable effort for initialization that is inherently related to uncertainties originating from the high diversity of plant species in urban areas. We therefore suggest a new automated method to be used with the i-Tree Eco model to derive light competition for individual trees and investigate the importance of this property. Since competition depends also on the species, which is difficult to determine from increasingly used remote sensing methodologies, we also investigate the impact of uncertain tree species classification on the ecosystem services by comparing a species-specific inventory determined by field observation with a genus-specific categorization and a model initialization for the dominant deciduous and evergreen species only. Our results show how the simulation of competition affects the determination of carbon sequestration, leaf area, and related ecosystem services and that the proposed method provides a tool for improving estimations. Misclassifications of tree species can lead to large deviations in estimates of ecosystem impacts, particularly concerning biogenic volatile compound emissions. In our test case, monoterpene emissions almost doubled and isoprene emissions decreased to less than 10% when species were estimated to belong only to either two groups instead of being determined by species or genus. It is discussed that this uncertainty of emission estimates propagates further uncertainty in the estimation of potential ozone formation. Overall, we show the importance of using an individual light competition approach and explicitly parameterizing all ecosystem functions at the species-specific level.

Deposition and Resuspension Mechanisms Into and From Tree Canopies: A Study Modeling Particle Removal of Conifers and Broadleaves in Different Cities

“…In particular, parameters could be selected specifically by tree type or species that are not currently differentiated (i.e., species-specific deposition velocities, resuspension, and washing threshold according to leaf characteristics). The importance of this issue, the connected uncertainty, as well as the potentially large impacts have been demonstrated before (Pace et al, 2018). For the most sensitive parameter which is PMdeposition velocity, it is important to distinguish at least between deciduous, broadleaf evergreen, and conifer trees (Khan and Perlinger, 2017).…”

Adaptive co-management of urban forests: monitoring reforestation programs in Mexico City

“…The participation of diverse non-expert actors is essential for adequate urban forest management due to the fact that it can yield large amounts of data remotely; for example, online tools have been broadly used to generate urban forest inventories and to collect other types of information (see i-tree and other platforms; e.g. Hirabayashi & Kroll, 2017;Nowak, Maco, & Binkley, 2018;Pace, Biber, Pretzsch, & Grote, 2018). Environmental management literature refers to this active interaction of a diverse group of actors towards a common goal as adaptive co-management.…”

“…It implicates mixed actors cooperating across scales and through institutional and formal/informal channels (horizontally and vertically) to undertake actions and learn through feedback (Armitage et al, 2009). ACM has been implemented in several cities to improve and expand the participatory monitoring of trees and the urban forest in general (Baird et al, 2016;Pace et al, 2018;Van der Jagt et al, 2019). Mexico City is an illustrative example of ACM applied for monitoring urban trees because of two reasons.…”

Assessment and Mapping Green Areas Ecosystem Services and Socio-Demographic Characteristics in Turin Neighborhoods (Italy)

“…In this paper, the combination of services offered by land uses, and the urban tree component is particularly and likewise important.The lack of wealth of information on the current state of specific resources, such as an accurate tree inventory and an assessment of the current state of the urban forest, is probably the basis for specifically planning urban development [35].In addition, the analyses carried out on the tree bark to monitor air quality, which reflect a long-term and multi-year average air contaminant load [36], were interesting, indicating that plants are also excellent indicators. However, plants tolerate air pollution levels differently [37], showing different growth rates in high-polluted areas [38] retaining pollutants according to the size of trees with particular reference to the canopy cover [39,40] and becoming a relevant aspect in future city planning activities [41].In Italy, a national urban green strategy was proposed in 2018 [42], based on three essential elements: moving from square meters to hectares, reducing asphalted areas, and adopting urban forests as a structural and functional reference for urban greening. The aim is to achieve the goals of sustainable growth and the environment, set out in the Conference of the Parties [43] in 2015, in particular concerning the containment of emissions and the adaptation to climate change.…”

“…In addition, the analyses carried out on the tree bark to monitor air quality, which reflect a long-term and multi-year average air contaminant load [36], were interesting, indicating that plants are also excellent indicators. However, plants tolerate air pollution levels differently [37], showing different growth rates in high-polluted areas [38] retaining pollutants according to the size of trees with particular reference to the canopy cover [39,40] and becoming a relevant aspect in future city planning activities [41].…”