Effects of defoliation on current-year stem growth and fine root dynamics in Fraxinus mandschurica and Larix gmelinii seedlings

doi:10.3724/SP.J.1258.2014.00102

Abstract

Abstract:

Aims Defoliation by insects leads to significant changes in tree growth and physiological metabolism. However, how fine root dynamics would respond to defoliation is still poorly understood. The objectives of this study were to: 1) compare the responses of height and stem collar diameter to defoliation in manchurian ash (Fraxinus mandschurica) and Dahurian larch (Larix gmelinii) seedlings; 2) quantify the effects of defoliation on the seasonal dynamics of fine root production and mortality in the two species.
Methods Manchurian ash and Dahurian larch seedlings, with different biomass allocation and height growth strategy, were used to investigate the effects of different levels of artificial defoliation (0% (control), 40% and 80% leaf area removal) on the growth of aboveground (height and stem collar diameter) and belowground (production and mortality of fine roots (diameter ≤ 2 mm)). Minirhizotron approach was employed to determine the seasonal dynamics of fine roots, and seedling height and stem collar diameter were measured concurrently.
Important findings The results showed that: 1) defoliation reduced the growth of seedling height (but statistically not significant) and stem collar diameter in both species, with a stronger effect on the stem collar diameter. Effects on aboveground growth by defoliation were enhanced by increasing defoliation intensity in both species. Compared with the control seedlings, the height and collar diameter of ash were reduced by 3.3% to 12.1% and 5.7% to 23.1%, respectively, while the height and collar diameter of larch were only slightly reduced (< 12%). 2) Defoliation significantly reduced live fine roots in both species (p< 0.001), with the reduction in relative growth rate of fine roots being enhanced with defoliation intensity. 3) Defoliation significantly reduced fine root production in both species (p< 0.05), had not apparent effect on fine root mortality. We conclude that defoliation imposes significant effects on aboveground growth (especially stem collar diameter) in ash and belowground growth (particularly root production) in larch. Our findings provide some insights into the inter-specific difference in the response of fine root dynamics to canopy carbon supply.

Key words: fine root dynamic, fine root longevity, Fraxinus mandschurica, Larix gmelinii, minirhizotron

LI Jun-Nan, WANG Wen-Na, XIE Ling-Zhi, WANG Zheng-Quan, GU Jia-Cun. Effects of defoliation on current-year stem growth and fine root dynamics in Fraxinus mandschurica and Larix gmelinii seedlings[J]. Chin J Plant Ecol, 2014, 38(10): 1082-1092.

Add to citation manager EndNote|Ris|BibTeX

URL: https://www.plant-ecology.com/EN/10.3724/SP.J.1258.2014.00102

https://www.plant-ecology.com/EN/Y2014/V38/I10/1082

Figures/Tables 5

Fig. 1 Dynamics of the height and stem collar diameter in Fraxinus mandschurica (A, C) and Larix gmelinii (B, D) seedlings (mean + SE). Different lowercase letters indicate significant differences among treatments on the same sampling dates (p < 0.05); * indicates the date of defoliation.

Fig. 2 Dynamics of fine root standing crops in Fraxinus mandschurica (A) and Larix gmelinii (B) seedlings (mean + SE). Different lowercase letters indicate significant differences among treatments on the same sampling dates (p < 0.05); * indicates the date of defoliation.

Table 1 Summary of the two-way ANOVA testing the effects of defoliation and sampling time on fine root standing crop, production and mortality in Fraxinus mandschurica and Larix gmelinii seedlings

变异来源 Source of variation	df	水曲柳 Fraxinus mandschurica				落叶松 Larix gmelinii
变异来源 Source of variation	df	现存量 Standing crop	生产量 Production	死亡量^a Mortality^a	死亡量^b Mortality^b	现存量 Standing crop	生产量Production	死亡量^a Mortality^a	死亡量^b Mortality^b
去叶 Defoliation	2	<0.001	<0.001	0.814	0.934	<0.001	0.042	0.230	0.318
取样时间 Sampling time	6	<0.001	<0.001	<0.001	0.013	<0.001	<0.001	<0.001	<0.001
去叶×取样时间 Defoliation × sampling time	12	0.113	0.020	0.636	0.338	0.868	0.211	0.804	0.512

Fig. 3 Dynamics of fine root production in Fraxinus mandschurica (A) and Larix gmelinii (B) seedlings (mean + SE). Different lowercase letters indicate significant differences among treatments on the same sampling dates (p < 0.05).

Fig. 4 Percentage of mortality during each sampling period of fine roots initiated in 2012 and 2013 in Fraxinus mandschurica and Larix gemelinii seedlings (mean + SE). A, roots initiated in 2012 in Fraxinus mandschurica. B, roots initiated in 2012 in Larix gmelinii. C, roots initiated in 2013 in Fraxinus mandschurica. D, roots initiated in 2013 in Larix gmelinii. * indicates the date of defoliation.

References 47

[1]	Alcorn PJ, Bauhus J, Smith RGB, Thomas D, James R, Nicotra A (2008). Growth response following green crown pruning in plantation-grown Eucalyptus pilularis and Eucalyptus cloeziana. Canadian Journal of Forest Research, 38,770-781.
[2]	Anderson LJ, Comas LH, Lakso AN, Eissenstat DM (2003). Multiple risk factors in root survivorship: a 4-year study in Concord grape. New Phytologist, 158,489-501.
[3]	Anttonen S, Piispanen R, Ovaska J, Mutikainen P, Saranpää P, Vapaavuori E (2002). Effects of defoliation on growth, biomass allocation, and wood properties of Betula pendula clones grown at different nutrient levels. Canadian Journal of Forest Research, 32,498-508.
[4]	Barry KM, Quentin A, Eyles A, Pinkard EA (2011). Consequences of resource limitation for recovery from repeated defoliation in Eucalyptus globulus Labilladière. Tree Physiology, 32,24-35.
[5]	Bassman JH, Zwier JC (1993). Effect of partial defoliation on growth and carbon exchange of two clones of young Populus trichocarpa Torr & Gray. Forest Science, 39,419-431.
[6]	Beyer F, Hertel D, Jung K, Fender A, Leuschner C (2013). Competition effects on fine root survival of Fagus sylvatica and Fraxinus excelsior. Forest Ecology and Management, 302,14-22.
[7]	Bloomfield J, Vogt K, Wargo PM (1996). Tree root turnover and senescence. In: Waisel Y, Eshel A, Kafkaki U eds. Plant Roots, the Hidden Half. Marcel Dekker, New York. 363-382.
[8]	Coleman MD, Dickson RE, Isebrands JG (2000). Contrasting fine-root production, survival and soil CO₂efflux in pine and poplar plantations. Plant and Soil, 225,129-139.
[9]	Collett NG, Neumann FG (2002). Effects of simulated chronic defoliation in summer on growth and survival of blue gum (Eucalyptus globulus Labill) within young plantations in northern Victoria. Australian Forestry, 65,99-106.
[10]	Craine J, Tremmel D (1995). Improvements to the minirhizo- tron system. Bulletin of the Ecological Society of America, 76,234-235.
[11]	Crocker TL, Hendrick RL, Ruess RW, Pregitzer KS, Burton AJ, Allen MF, Shan JP, Morris LA (2003). Substituting root numbers for length: improving the use of minirhizo- trons to study fine root dynamics. Applied Soil Ecology, 23,127-135.
[12]	Dietze MC, Sala A, Carbone MS, Czimczik CI, Mantooth JA, Richardson AD, Vargas R (2014). Nonstructural carbon in woody plants. The Annual Review of Plant Biology, 65,667-687. DOI URL PMID
[13]	Eissenstat DM, Duncan LW (1992). Root growth and carbohydrate responses in bearing citrus trees following partial canopy removal. Tree Physiology, 10,245-257. URL PMID
[14]	Eissenstat DM, Yanai RD (1997). The ecology of root lifespan. Advances in Ecological Research, 27,1-60.
[15]	Elek JA (1997). Assessing the impact of leaf beetles in eucalypt plantations and exploring options for their management. Forestry Tasmania, 9,139-154.
[16]	Eyles A, Pinkard EA, Mohammed C (2009). Shifts in biomass and resource allocation patterns following defoliation in Eucalyptus globulus growing with varying water and nutrient supplies. Tree Physiology, 29,753-764. URL PMID
[17]	Gieger T, Thomas FM (2002). Effects of defoliation and drought stress on biomass partitioning and water relations of Quercus robur and Quercus petraea. Basic and Applied Ecology, 3,171-181.
[18]	Gill RA, Jackson RB (2000). Global patterns of root turnover for terrestrial ecosystems. New Phytologist, 147,13-31.
[19]	Handa IT, Körner C, Hättenschwiler S (2005). A test of the treeline carbon limitation hypothesis by in situ CO₂ enrichment and defoliation. Ecology, 86,1288-1300.
[20]	Hendrick RL, Pregitzer KS (1992). The demography of fine roots in a northern hardwood forest. Ecology, 73,1094-1104.
[21]	Hoogesteger J, Karlsson PS (1992). Effects of defoliation on radial stem growth and photosynthesis in the mountain birch (Betula pubescens ssp. tortuosa). Functional Ecology, 6,317-323.
[22]	Jacquet JS, Bosc A, O’Grady A, Jactel H (2014). Combined effects of defoliation and water stress on pine growth and non-structural carbohydrates. Tree Physiology, 34,367-376. DOI URL PMID
[23]	Johnson MG, Tingey DT, Phillips DL, Storm MJ (2001). Advancing fine root research with minirhizotrons. Environmental and Experimental Botany, 45,263-289. DOI URL PMID
[24]	Kosola KR, Dickmann DI, Paul EA, Parry D (2001). Repeated insect defoliation effects on growth, nitrogen acquisition, carbohydrates, and root demography of poplars. Oecologia, 129,65-74. DOI URL PMID
[25]	Kosola KR, Gross KL (1999). Resource competition and suppression of plants colonizing early successional old fields. Oecologia, 118,69-75. DOI URL PMID
[26]	Kramer P, Kozlowski TT (1979). Physiology of Woody Plants. Academic Press, New York.
[27]	Krause SC, Raffa KF (1996). Differential growth and recovery rates following defoliation in related deciduous and evergreen trees. Trees, 10,308-316.
[28]	Landhäusser SM, Lieffers VJ (2003). Seasonal changes in carbohydrate reserves in mature northern Populus tremuloides clones. Trees, 17,471-476.
[29]	Li MH, Hoch G, Körner C (2002). Source/sink removal affects mobile carbohydrates in Pinus cembra at the Swiss treeline. Trees, 16,331-337.
[30]	McCormack ML, Adams TS, Smithwick EAH, Eissenstat DM (2012). Predicting fine root lifespan from plant functional traits in temperate trees. New Phytologist, 195,823-831.
[31]	Mainiero R, Kazda M, Schmid I (2010). Fine root dynamics in 60-year-old stands of Fagus sylvatica and Picea abies growing on haplic luvisol soil. European Journal of Forest Research, 129,1001-1009.
[32]	Mei L (2006). Fine Root Turnover and Carbon Allocation in Manchurian Ash and Dahurian Larch Plantations. PhD dissertation, Northeast Forestry University, Harbin. 25-28. (in Chinese with English abstract)
	[ 梅莉 (2006). 水曲柳落叶松人工林细根周转与碳分配. 博士学位论文, 东北林业大学, 哈尔滨. 25-28.]
[33]	Mei L, Zhang ZW, Gu JC, Quan XK, Yang LJ, Huang D (2009). Carbon and nitrogen storages and allocation in tree layers of Fraxinus mandschurica and Larix gmelinii plantations. Chinese Journal of Applied Ecology, 20,1791-1796. (in Chinese with English abstract) URL PMID
	[ 梅莉, 张卓文, 谷加存, 全先奎, 杨丽君, 黄冬 (2009). 水曲柳和落叶松人工林乔木层碳、氮储量及分配. 应用生态学报, 20,1791-1796.] PMID
[34]	Palacio S, Hester AJ, Maestro M, Millard P (2008). Browsed Betula pubescens trees are not carbon-limited. Functional Ecology, 22,808-815.
[35]	Pinkard EA, Beadle CL (1998). Effects of green pruning on growth and stem shape of Eucalyptus nitens (Deane and Maiden) Maiden. New Forests, 15,107-126.
[36]	Ponti F, Minotta G, Cantoni L, Bagnaresi U (2004). Fine root dynamics of pedunculate oak and narrow-leaved ash in a mixed-hardwood plantation in clay soils. Plant and Soil, 259,39-49.
[37]	Qiu J, Gu JC, Jiang HY, Wang ZQ (2010). Factors influencing fine root longevity of plantation-grown Pinus sylvestris var. mongolica. Chinese Journal of Plant Ecology, 34,1066-1074. (in Chinese with English abstract)
	[ 邱俊, 谷加存, 姜红英, 王政权 (2010). 樟子松人工林细根寿命估计及影响因子研究. 植物生态学报, 34,1066-1074.]
[38]	Ruess RW, Hendrick RL, Bryant JP (1998). Regulation of fine root dynamics by mammalian browsers in early successional Alaskan taiga forests. Ecology, 79,2706-2720.
[39]	Schowalter TD, Hargrove W, Crossley Jr DA (1986). Herbivory in forested ecosystems. Annual Review of Entomology, 31,177-196.
[40]	Shen GF, Zhai MP (2011). Silviculture. 2nd edn. China Forestry Publishing House, Beijing. (in Chinese)
	[ 沈国舫, 翟明普 (2011). 森林培育学. 第二版. 中国林业出版社, 北京.]
[41]	Shi JW, Wang ZQ, Yu SQ, Quan XK, Sun Y, Jia SX, Mei L (2007). Estimating fine root production, mortality and turnover with minirhizotrons in Larix gmelinii and Fraxinus mandschurica plantations. Journal of Plant Ecology (Chinese Version), 31,333-342. (in Chinese with English abstract)
	[ 史建伟, 王政权, 于水强, 全先奎, 孙玥, 贾淑霞, 梅莉 (2007). 落叶松和水曲柳人工林细根生长、死亡和周转. 植物生态学报, 31,333-342.]
[42]	Song S, Gu JC, Quan XK, Guo DL, Wang ZQ (2008). Fine-root decomposition of Fraxinus mandschurica and Larix gmelinii plantations. Journal of Plant Ecology (Chinese Version), 32,1227-1237. (in Chinese with English abstract)
	[ 宋森, 谷加存, 全先奎, 郭大立, 王政权 (2008). 水曲柳和兴安落叶松人工林细根分解研究. 植物生态学报, 32,1227-1237.]
[43]	Tschaplinski TJ, Blake TJ (1994). Carbohydrate mobilization following shoot defoliation and decapitation in hybrid poplar. Tree Physiology, 14,141-151. URL PMID
[44]	Waring RH, Schlesinger WH (1985). Forest Ecosystems: Concepts and Management. Academic Press, Orlando.
[45]	Withington JM, Reich PB, Oleksyn J, Eissenstat DM (2006). Comparisons of structure and life span in roots and leaves among temperate trees. Ecological Monographs, 76,381-397.
[46]	Yu SQ, Wang ZQ, Shi JW, Quan XK, Mei L, Sun Y, Jia SX, Yu LZ (2007). Estimating fine-root longevity of Fraxinus mandschurica and Larix gmelinii using minirhizotrons. Journal of Plant Ecology (Chinese Version), 31,102-109. (in Chinese with English abstract)
	[ 于水强, 王政权, 史建伟, 全先奎, 梅莉, 孙玥, 贾淑霞, 于立忠 (2007). 水曲柳和落叶松细根寿命的估计. 植物生态学报, 31,102-109.]
[47]	Zhou R, Quebedeaux B (2003). Changes in photosynthesis and carbohydrate metabolism in mature apple leaves in response to whole plant source-sink manipulation. Journal of the American Society for Horticultural Science, 128,113-119.