Abstract:The provision of ecosystem services by urban trees is not yet routinely integrated in city administrations' planting scenarios because the quantification of these services is often time-consuming and expensive. Accounting for these welfare functions can enhance life quality for city dwellers. We present innovative approaches that may appeal to the numerous city administrations that keep tree inventory or cadastre databases of all trees growing on city property for civil law liability reasons. Mining these ubiquitous data can be a feasible alternative to field surveys and improve cost-benefit ratios for ecosystem service assessment. We present methods showing how data gaps (in particular tree height and crown light exposure) in the cadastre data can be filled to estimate ecosystem services with i-Tree Eco. Furthermore, we used the i-Tree Eco output for a noval approach which focus on predicting energy reduction as a proxy for cooling benefits provided by trees. The results for the total publicly owned and managed street trees in our study site of Duisburg (Germany) show that the most important ecosystem services are the removal of particulate matter by 16% of the city emissions and the reduction of 58% of the direct and thermal radiation in the effective range of the trees in the cadastre.

This paper explores the influence of shopping companions in retail sales conversations and the necessity of designing more comprehensive sales training programs. In particular, the characteristics and behaviors of shopping companions and their subsequent effects on accompanied shoppers, the salesperson and the sales conversation are examined. Shopping companions have not played a role in adaptive selling research and most practical trainings for salespeople so far, although they can significantly affect shopper behavior and decision-making, and require distinct approaches by salespeople. Systematizing in-depth interviews with salespeople and qualitative content analysis reveal a variety of different character traits and behaviors of shopping companions that can lead to positive and negative outcomes from a salesperson's perspective. The interactions that take place between customers and salespeople are the core element of customer-oriented service in retailing. When a holistic customer-oriented service is part of their value proposition, retailers should consider redesigning training programs for salespeople and include the influence of shopping companions. In doing so, salespeople's customer orientation can be increased by augmenting their capabilities and enabling them to make use of adaptive selling techniques specifically designed for co-shopping situations.

<p>Forests are important ecosystems for mitigating CO<sub>2</sub>. However, droughts affect the vitality of forests and alter CO<sub>2</sub> uptake. In worst cases, forest ecosystems can even turn from a carbon sink to a source in consequence of water shortage. Forest stands in urban areas are more prone to droughts because of elevated temperatures in comparison to rural land and unfavorable growth conditions such as limited rooting depth and low soil carbon content.</p><p>The drought years 2018 and 2019 in the Ruhr Metropolitan Region (Germany) were characterized by a 0.6 K higher mean annual temperature as normal and only 75 % of the normal annual precipitation. During this period, we investigated the CO<sub>2</sub> balance of urban forest ecosystems, considering annual changes in carbon stocks of tree biomass and litterfall and annual CO<sub>2</sub> effluxes from soil respiration, at eleven monitoring sites across the Ruhr Metropolitan Region by combining measuring and modelling approaches. The chosen sites represent the different urban forest types found here: old-grown semi-natural forests (beech, oak, maple), autochthon non-managed succession forests of birch, poplar or willow on brownfields and allochthone mixed forest stands planted in urban parcs and on heaps (urban greening forests).</p><p>Tree growth, leaf expansion, and CO<sub>2 </sub>efflux decreased at nearly all sites in 2019 in comparison to 2018 in consequence of the ongoing drought. While the semi-natural forests were able to increase CO<sub>2</sub> uptake by 11 % in 2019, the urban greening forests decreased their CO<sub>2</sub> uptake by 62.9 %. The succession forests were CO<sub>2</sub> sources in both years but increased the CO<sub>2 </sub>release in the second year by 85 % in comparison to the first year. Two sites turned from carbon sinks in 2018 to carbon sources in 2019. Correlation analyses showed that the soil hydraulic properties such as depth of the rooting zone, soil carbon content, and plant available water were the main influencing factors describing the decrease in tree growth and leaf development. Overall, the results indicate that, semi-natural forests on mesophilic sites are more resilient against droughts due to unlimited rooting zone, high soil carbon content, which favor the amount and accessibility of plant available water, while urban greening and succession forests are more vulnerable to droughts due to limiting rooting zone, low soil carbon content, and low plant available water. More vulnerable to droughts are also semi-natural forests on more extreme sites, like an examined Stellario-Carpinetum, which turned from a carbon sink in 2018 to a source in 2019. Furthermore, two patterns of seasonal changes in soil respiration were found in reaction to the drought. i) those of elevated soil respiration associated to elevated temperature in 2018 and decrease of soil respiration in 2019 in consequence of thermal denaturation of the microbial community, and one ii) those where, the mineralization activity was shifted to winter when the upper soil layer was rewetted, leading to larger soil respiration during the cold season.</p><p>Urban planners should ensure a deep rooting zone and carbon rich soils by establishing new urban forest stands to tackle drought periods.</p>