Abstract
Background
Cities are hotter and have poor soil compared to surrounding natural areas, necessitating identification of stress-tolerant species suitable for urban plantings. Species selection based on physiology is highly informative, but also time-consuming, so quick-to-measure proxies are needed. Further, parks may represent relatively less stressful locations where native trees could be included to increase urban biodiversity.
Methods
We examined seasonal physiological responses of leaf hydraulic conductance, turgor loss point (ΨTLP), and gas exchange for 3 Northeastern Ohio species (Acer rubrum, Acer saccharum, and Nyssa sylvatica), one Southeastern United States (US) species (Liquidambar styraciflua), and one East Asian species (Pyrus calleryana) growing at 2 parks in Northeast Ohio. We compared these with published growth, leaf dry matter content (LDMC), and carbon:nitrogen ratio (CN) data for the same trees in our study.
Results
Lakeview soil was most similar to surrounding natural areas, but both parks had higher soil bulk density and sand percentage compared to a nearby forest. At both parks, physiology was related to soil properties. Our seasonal analysis showed that water stress was mitigated via seasonal physiological adjustments at both parks. Pyrus calleryana was not distinguished from Liquidambar styraciflua and Nyssa sylvatica. Principal component analysis showed positive correlations of LDMC with growth and ΨTLP, and CN with carbon sequestration.
Conclusions
Our study demonstrates suitability of Ohio and Southeastern US species for Northeastern Ohio parks, despite the presence of some compacted soil. In addition, we suggest LDMC and CN could be useful physiological proxies for broadscale analysis of tree suitability for urban environments.
