Ecology of City Trees

Dr. Somidh Saha (ITAS)

Organisation: The module will take place in the third block of the winter semester and involves both theory and practical work with urban trees outside, meaning that students should be prepared to work open air as well.

Scoring: a written exam of 90 min will give 50% of the scores. In addition, the students will organise themselves into teams of 4 people max and select a practical research topic and write a short report (10 pages max), which will give the remaining 50% of the scores.

Teaching language: English

Topic: Urban trees are pivotal to the well-being of us humans and also the non-human life forms living in cities. To sustain and develop urban trees is crucial to prepare our cities for the challenges of climate change. This requires an interdisciplinary approach combining knowledge on plant stress, ecology with social, psychological and political aspects. The module will highlight different aspects of city trees, introduce into important methodology, and also integrate student activities in ongoing projects on urban trees in Karlsruhe.

Methodology: Students will learn how to assess tree health, ecological role, and environmental challenges using both monitoring techniques such as field tree inventories or microhabitat assessment, as well as analytical methods, such as WinRhizo scanning of fine roots, sonic tomography for internal trunk damage assessment, hand-held X-ray spetrometry to measure heavy-metal pollution.

Concepts: Stress ecology (such as impact of drought on city trees), dendroecology (tree ring analysis and climate), ecophysiology (transpiration, photosynthesis, sap flow), growth pattern of city trees depending on urban factors, such as sealing and compaction of soils or pollution. Experimental design of field studies, perception of urban trees by the society, also in the international and intercultural context. Life cycles of city tress. Crown morphology and size allometry of city trees and their variations between growing habitats. Productivity and stress ecology of city trees (light, water, and nutrients use efficiency, supply, and uptake with emphasis on drought). Root ecology of city trees. City trees as toxicological bioindicators with a focus on fruit and nut trees in cities Microhabitat and biodiversity values of city trees. Provisioning, regulating, supporting and cultural ecosystem services of trees