Development of Fine Root Biomass of Two Contrasting Urban Tree Cultivars in Response to Drought Stress

Abstract

Global climate change associated with rapid urbanization is projected to cause a worsening of environmental problems such as extreme heat and drought in cities. Urban trees play an essential role in improving air quality, fixing carbon, mitigating environmental degradation, and providing other ecosystem services. However, limited research has been conducted on belowground processes, which hampers a comprehensive understanding of the effect of climate change and urbanization on urban tree growth. Fine roots (<2-mm diameter) are the primary pathway for water and nutrient uptake by plants, and they considerably contribute to the survival of urban trees under drought stress. In this study, we conducted a controlled experiment on the development of fine roots of Tilia cordata Mill ‘Greenspire’ and Tilia tomentosa Moench ‘Brabant’ in response to drought stress via soil coring. Our results indicate that the two cultivars have different strategies for coping with drought. Tilia tomentosa ‘Brabant’, originating from drier regions, gave allocation to deeper soil parts priority probably to obtain more water. On the other hand, Tilia cordata ‘Greenspire’, which is native in Central Europe, showed a negative response to water shortage and preferred a more horizontal development of fine roots rather than a vertical development. Long-term studies are needed to gain a better understanding of the belowground processes of urban trees to select tree species and cultivars which are appropriate for planting in major cities, particularly with regard to future climate change.

Fine root and root hair morphology of cotton under drought stress revealed with RhizoPot

“…These factors might be related to root water detection and adaptations for alleviating soil moisture stress. Research on fine roots has mostly focused on forest ecosystems (Brunner, Herzog, Galiano, & Gessler, 2019;Zhang, Stratopoulos, Xu, Pretzsch, & Rötzer, 2020), while little is known about morphological changes in cotton fine roots and root hairs. Therefore, the in situ observation of fine roots and root hairs is in urgent need of low-cost research tools that can genuinely reflect root growth in the soil matrix to accurately assess the changes in fine roots and root hairs under drought stress.…”

A single tree model to consistently simulate cooling, shading, and pollution uptake of urban trees

“…Environmental conditions include direct influences of immediate climate and indirect influences, particularly the soil water availability (Livesley et al 2016 ). Increased drought can be expected to affect the plant properties and thus the ecosystem services that are related to water evaporation (cooling) and pollution uptake (Stratópoulos et al 2019 ; Zhang et al 2020 ). Consequently, water availability impacts must be reflected in a model for decision support.…”

Delayed Inhibition of Photosynthetic Performance—Three Linden Species in an Urban Environment

“…Due to those morphological features, and its origin in relatively dry regions, T. tomentosa is thought to be better suited for urban areas compared with other species. However, while T. cordata is widely planted in European cities its suitability, as well as its hybrids is more often perceived [28,29].…”