TREE Fund

Tree Research & Education Endowment Fund

2011 General Grant Research Archive Jack Kimmel International Grant 

Effects of root severance by excavation on growth, physiology and uprooting resistance of two urban tree species

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2011 | Dr. Alessio Fini, University of Florence

Damage to tree root often occurs in the urban environment when the soil near the tree is excavated for construction or for the settlement of below ground infrastructures. When roots are damaged, tree health can be negatively affected and stability may be reduced. The purpose of this project is: 1) to evaluate the effect of two different levels of root severing on tree growth, physiology and stability; 2) to evaluate the response to root damage by two species supposed to differ in tolerance to root manipulation; 3) to determine if root severance on one side of the tree affects leaf gas exchange over the whole canopy, or if the effect is restricted to the branches attached at that side of the tree.

Study Results

The experiment found that root severance imposes physiological stress on damaged plants. Also, tree stability is seriously threatened, as the risk of wind throw greatly increases. Therefore, we provide new evidence about the importance of root protection during construction works and trenching activities. These include: the design of a properly sized root protection zone around to the tree or the use of trenchless methods, such as directional drilling. This experiment shows that, if these measures are not adopted, a single trench can remove about 45-47% of the root system, and multiple trenching around the tree can remove as much as 75% of tree roots. Root loss reduces photosynthesis, thus slowing down the assimilation of CO2 and the production of carbohydrates required for growing new roots. Further, root severance may expose damaged trees to severe drought stress, particularly in harsh sites or in dry years. As recovery is very slow, trees are vulnerable to drought spells for several years after the severance (in this case, complete recovery was not achieved during the five year period of the study).

Year: 2011

Funding Duration: 1-3 years

Grant Program: Jack Kimmel International Grant

Grant Title: Effects of root severance by excavation on growth, physiology and uprooting resistance of two urban tree species

Researcher: Dr. Alessio Fini

Key words:

Peer Reviewed Publications from Grant:

  • A. Fini, F. Ferrini, P. Frangi, R. Piatti, G. Amoroso. 2013. Effects of root severance by excavation on growth, physiology and uprooting resistance of two urban tree species. Acta Horticulturae, 990: 487-494.
  • A. Fini. 2013. Excavations, roots and physiological damage: an ongoing search. AboutPlants, http://www.aboutplants.eu/portal/cms/ENG/content-ricerca/419-excavations-roots-and-physiological-damage-an-ongoing-search.html
  • P. Frangi, G. Amoroso, M. Faoro, R. Piatti, A. Fini, F. Ferrini. 2012. Sotto controllo. Acer 4:  35-39
  • A. Fini, F. Ferrini. 2013. Effetti di scavi in prossimità degli apparati radicali sulla crescita e fisiologia degli alberi. Minoprio Informa, 2

General Audience/Trade Publications:

 

Short Discussion Articles/Conference Proceedings:

  • A. Fini, R. Piatti, P. Frangi, G. Amoroso, F. Ferrini. 2012. Effects of root severance by excavation on growth and physiology of two urban species. Proceedings of the 88th ISA Annual Conference and Trade Show

Presentations:

  • “Effects of root severance by excavation on growth, physiology and uprooting resistance of two urban tree species”, presented at the ISHS 2nd International Symposium on woody ornamental of temperate zones (Ghent, Belgium), 2-5 July 2012;
  • “Effects of root severance by excavation on growth, physiology and uprooting resistance of two urban tree species”, presented at the 88th ISA Annual Conference and Trade Show (Portland, OR, USA), 11-15 August 2012
  • “Environmental stresses on urban trees: effects on ecophysiology and biochemistry”, presented at the “Molecular, physiological and morphological aspects of ornamentals response to sub-optimal water resources and ionic stress” workshop (Bolzano, 12-13 September 2013)
  • “Root severance and urban trees: a four years study evaluating growth, physiology and stability”, submitted as oral presentation at the Urban Tree Diversity Conference (Alnarp, Sweden, 16-18 June 2014)
  • “Effects of root severance by excavation on growth, physiology and stability of two urban tree species: results from a 4-year-experiment”, submitted as oral presentation at the 90th ISA Annual Conference and Trade Show.
  • Results of this experiment have been included in lectures of some Master University Degrees and post-Degree classes at the University of Florence and at the Tuscan Horticulture Society

 

 

For more information on this project, contact the researcher via TREE Fund at treefund@treefund.org.