title: Resource availability and repeated defoliation mediate compensatory growth in trembling aspen (Populus tremuloides) seedlings.
abstract: Plant ecologists have debated the mechanisms used by plants to cope with the impact of herbivore damage. While plant resistance mechanisms have received much attention, plant compensatory growth as a type of plant tolerance mechanisms has been less studied. We conducted a greenhouse experiment to evaluate compensatory growth for trembling aspen (Populus tremuloides) seedlings under varying intensities and frequencies of simulated defoliation, with or without nutrient enriched media. For the purpose of this study, changes in biomass production and non-structural carbohydrate concentrations (NSC) of roots and leaves were considered compensatory responses. All defoliated seedlings showed biomass accumulation under low defoliation intensity and frequency, regardless of resource availability; however, as defoliation intensity and frequency increased, compensatory growth of seedlings was altered depending on resource availability. Seedlings in a resource-rich environment showed complete compensation, in contrast responses ranged from undercompensation to complete compensation in a resource-limited environment. Furthermore, at the highest defoliation intensity and frequency, NSC concentrations in leaves and roots were similar between defoliated and non-defoliated seedlings in a resource-rich environment; in contrast, defoliated seedlings with limited resources sustained the most biomass loss, had lower amounts of stored NSC. Using these results, we developed a new predictive framework incorporating the interactions between frequency and intensity of defoliation and resource availability as modulators of plant compensatory responses.
authors.affiliation: Department of Renewable Resources, University of Alberta , Edmonton, Alberta , Canada.
authors.forename: Nadir
authors.initials: N
authors.lastname: Erbilgin
authors.affiliation: Department of Renewable Resources, University of Alberta , Edmonton, Alberta , Canada.
authors.forename: David A
authors.initials: DA
authors.lastname: Galvez
authors.affiliation: Department of Renewable Resources, University of Alberta , Edmonton, Alberta , Canada.
authors.forename: Bin
authors.initials: B
authors.lastname: Zhang
authors.affiliation: Department of Renewable Resources, University of Alberta , Edmonton, Alberta , Canada.
authors.forename: Ahmed
authors.initials: A
authors.lastname: Najar
keywords: Carbon sink:source relationships; Compensatory responses; Defoliation intensity and frequency; Non-structural carbohydrates; Populus tremuloides; Woody plants
references.citation: J Evol Biol. 2010 Oct;23(10):2185-96
references.pmid: 20796136
references.citation: Trends Ecol Evol. 1999 May;14(5):179-185
references.pmid: 10322530
references.citation: Am Nat. 2007 Apr;169(4):443-54
references.pmid: 17253430
references.citation: New Phytol. 2013 Apr;198(1):139-148
references.pmid: 23347066
references.citation: Ecol Lett. 2007 Mar;10(3):177-87
references.pmid: 17305801
references.citation: Ann Bot. 2013 Aug;112(4):711-20
references.pmid: 23589631
references.citation: Tree Physiol. 2011 Mar;31(3):250-7
references.pmid: 21444372
references.citation: Ann Bot. 2011 Oct;108(5):965-73
references.pmid: 21873259
references.citation: Proc Natl Acad Sci U S A. 2006 Aug 22;103(34):12935-40
references.pmid: 16912118
references.citation: New Phytol. 2006;170(3):423-5
references.pmid: 16626464
references.citation: Ecol Appl. 2010 Oct;20(7):1787-93
references.pmid: 21049868
references.citation: Oecologia. 2003 Jan;134(2):167-75
references.pmid: 12647156
references.citation: Oecologia. 1981 Oct;51(1):14-18
references.pmid: 28310302
references.citation: Ann Bot. 2005 May;95(6):1049-58
references.pmid: 15753116
references.citation: Oecologia. 1984 Mar;61(3):311-318
references.pmid: 28311055
references.citation: Tree Physiol. 2004 Oct;24(10):1129-36
references.pmid: 15294759
references.citation: Am Nat. 2008 Nov;172(5):635-47
references.pmid: 18840070
references.citation: Oecologia. 2012 May;169(1):49-60
references.pmid: 22057898
references.citation: Oecologia. 2005 Dec;146(2):190-9
references.pmid: 16133192
references.citation: Am J Bot. 2003 Feb;90(2):243-9
references.pmid: 21659114
references.citation: Oecologia. 2013 May;172(1):1-10
references.pmid: 23053231
references.citation: Tree Physiol. 2012 Aug;32(8):946-57
references.pmid: 22659460
references.citation: Tree Physiol. 2009 Jun;29(6):753-64
references.pmid: 19324694
references.citation: Science. 1985 Nov 22;230(4728):895-9
references.pmid: 17739203
references.citation: Am J Bot. 2005 Oct;92(10):1632-40
references.pmid: 21646080
references.citation: Evolution. 2000 Jun;54(3):789-97
references.pmid: 10937253
references.citation: Oecologia. 1998 Dec;117(4):460-468
references.pmid: 28307670
references.citation: Tree Physiol. 2012 Jan;32(1):24-35
references.pmid: 22174093
references.citation: New Phytol. 2006;169(3):561-70
references.pmid: 16411958
references.citation: J Environ Sci (China). 2005;17(2):232-6
references.pmid: 16295895
references.citation: J Chem Ecol. 2014 Jan;40(1):21-30
references.pmid: 24363094
references.citation: Am Nat. 2010 Apr;175(4):481-93
references.pmid: 20170370