by JR Sanders, JC Grabosky
Resource Type: Website
Source: Urban Forestry and Urban Greening (2014) 13:295-303
Grades: Middle School and High School
Urban living is tough on trees – the cramped conditions and limited soil access take a serious toll on their growth. This study put that urban stress to the test, comparing the size and canopy development of five common tree species planted in parking lots 20 years ago. The results were eye-opening – the less soil available to the tree, the smaller and scrubbier its growth became.
Phenomena:
Competition for resources
Anthropogenic change
Plant growth
Human impacts on environment
DCIs:
LS1.B: Growth and development of organisms
LS2.A: Interdependent relationships in ecosystems
ESS3.C: Human impacts on earth’s systems
Notes:
- A straightforward experiment comparing the sizes of 20-year-old trees planted in different types of planting spaces with different “soil openings.”
- Results are clear.
- Many cities have rules requiring a certain amount of shade over parking lots. One goal of this paper was to show that mature trees might not achieve the size needed to provide the required amount of shade if their growth is restrained by insufficient soil.
- A lot of the article is spent demonstrating that trunk diameter (dbh) can predict canopy radius because dbh is the most common recorded measurement.
Driving questions:
- How do local conditions (here, available soil) affect plant growth?
- What resources are limited in the smaller planting spaces?
- What can we do to minimize the impacts of urbanization?
Topics: growth and soil quality
Features: charts and regression lines