Estimation of fine root production, mortality and turnover with Minirhizotron in and plantations

Abstract

Fine root turnover is a major pathway for carbon and nutrient cycling in forest ecosystems. However, to estimate fine root turnover, it is important to first understand the fine root dynamic processes associated with soil resource availability and climate factors. The objectives of this study were: (1) to examine patterns of fine root production and mortality in different seasons and soil depths in the Larix gmelinii and Fraxinus mandshurica plantations, (2) to analyze the correlation of fine root production and mortality with environmental factors such as air temperature, precipitation, soil temperature and available nitrogen, and (3) to estimate fine root turnover. We installed 36 Minirhizotron tubes in six mono-specific plots of each species in September 2003 in the Mao’ershan Experimental Forest Station. Minirhizotron sampling was conducted every two weeks from April 2004 to April 2005. We calculated the average fine root length, annual fine root length production and mortality using image data of Minirhizotrons, and estimated fine root turnover using three approaches. Results show that the average growth rate and mortality rate in L. melinii were markedly smaller than in F. mandshurica, and were highest in the surface soil and lowest at the bottom among all the four soil layers. The annual fine root production and mortality in F. mandshurica were significantly higher than in L. gmelinii. The fine root production in spring and summer accounted for 41.7% and 39.7% of the total annual production in F. mandshurica and 24.0% and 51.2% in L. gmelinii. The majority of fine root mortality occurred in spring and summer for F. mandshurica and in summer and autumn for L. gmelinii. The turnover rate was 3.1 a^-1 for L. gmelinii and 2.7 a^-1 for F. mandshurica. Multiple regression analysis indicates that climate and soil resource factors together could explain 80% of the variations of the fine root seasonal growth and 95% of the seasonal mortality. In conclusion, fine root production and mortality in L. gmelinii and F. mandshurica have different patterns in different seasons and at different soil depths. Air temperature, precipitation, soil temperature and soil available nitrogen integratively control the dynamics of fine root production, mortality and turnover in both species.

References

1. Anderson L J, Comas L H, Lakso A N, Eissenstat D M (2003). Multiple risk factors in root survivorship: a 4-yearstudy in Concord grape. New phytologist, 158: 489–501. doi:10.1046/j.1469-8137.2003.00757.x
2. Bloomfield J, Vogt K A, Wargo P M (1996). Tree root turnover and senescence. In: : Wiasel Y, BshelA, Kafkafi U, eds. Plant Roots: The Hidden Half (second edition, revisedand expanded) . New York: Marcel Dekker, Inc., 363–381
3. Burke M K, Raynal D J (1994). Fineroot growth phonology, production, and turnover in a northern hardwoodforest ecosystems. Plant and Soil, 162: 135–146. doi:10.1007/BF01416099
4. Burton A J, Pregitzer K S, Hendrick R L (2000). Relationships between fine root dynamicsand nitrogen availability in Michigan northern hardwood forest. Oecologia, 125(3): 389–399. doi:10.1007/s004420000455
5. Canadell J, Jackson R B, Ehleringer J B, Mooney H A, Sala O E, Schulze E D (1996). Maximum rooting depth of vegetation types at the globalscale. Oecologia, 108(4): 583–593. doi:10.1007/BF00329030
6. Cheng Y H, Han Y Z, Wang Q C, Wang Z Q (2005). Seasonal dynamics of fine root biomass, root length density, specificroot length and soil resource availability in a larix gmelini plantation. ActaPhytoecologica Sinica, 29: 403–410 (in Chinese)
7. Craine J, Tremmel D (1995). Improvementsto the minirhizotron system. Bulletin ofthe Ecological Society of America, 76: 234–235
8. Eissenstat D M, Yanai R D (1997). The ecologyof root lifespan. Advances in EcologicalResearch, 27: 1–60. doi:10.1016/S0065-2504(08)60005-7
9. Eissenstat D M, Yanai R D (2002). RootLifespan, efficiency, and turnover. In: : Waisel Y, Eshel A, Kafkafi U, eds. Plant Roots: TheHidden Half . 3rd Edition .New York: Marcel Dekker, Inc., 221–238
10. Fahey T J, Hughes J W (1994). Fineroot dynamics in a northern hardwood forest ecosystem, Hubbard BrookExperimental Forest. Journal of Ecology, 82: 533–548. doi:10.2307/2261262
11. Farrar J F, Jones D L (2000). The controlof carbon acquisition by roots. New Phytologist, 147: 43–53. doi:10.1046/j.1469-8137.2000.00688.x
12. Fogel R (1985). Roots as primary producers in below-ground ecosystems. In: : Fitter A H, Atkinson D, Read D J, Usher M B, eds. Ecological interactions in soil: Ecological interactions in soil:plants, microbes and animals. Oxford (UK): Blackwell, 23–36
13. Gill R A, Jackson R B (2000). Globalpatterns of root turnover for terrestrial ecosystems. New phytologist, 147: 13–31. doi:10.1046/j.1469-8137.2000.00681.x
14. Hendrick R L, Pregitzer K S (1992). The demographyof fine roots in a northern hardwood forest. Ecology, 73: 1094–1104. doi:10.2307/1940183
15. Hendrick R L, Pregitzer K S (1993). The dynamicsof fine root, length, biomass, and nitrogen content in two northernhardwood ecosystems. Canadian Journal ofForest Research, 23: 2507–2520. doi:10.1139/x93-312
16. Hendrick R L, Pregitzer K S (1996). Applicationsof minirhizotrons to understand root function in forests and othernatural ecosystems. Plant and Soil, 185: 293–304. doi:10.1007/BF02257535
17. Huang J H, Han X G, Chen L Z (1999). Advances in the research of (fine)root biomass in forest ecosystems. ActaEcologica Sinica, 19: 270–277 (in Chinese)
18. Jackson R B, Reynolds H L (1996). Nitrogenand ammonium uptake for single- and mixed-species communities grownat elevated CO₂. Oecologia, 105(1): 74–80. doi:10.1007/BF00328793
19. Johnson M G, Tingey D T, Phillips D L, Storm M J (2001). Advancing fine root research with minirhizotrons. Environmental and Experimental Botany, 45(3): 263–289. doi:10.1016/S0098-8472(01)00077-6
20. Joslin J D, Henderson G S (1987). Organicmatter and nutrients associated with fine root turnover in a whiteoak stand. Forest Science, 33: 330–346
21. Li P Z, Fan S H, Wang L H, Xu S M (2001). Productivity and turnover of fine roots in poplar tree and grassroots. Chinese Journal of Applied Ecology, 12: 829–832 (in Chinese)
22. Majdi H (1996). Root sampling methods–applications and limitationsof minirhizotron technique. Plant and Soil, 185: 255–258. doi:10.1007/BF02257530
23. Matamala R, Gonzèlez-Meler M A, Jastrow J D, Norby R J, Schlesinger W H (2003). Impactsof Fine Root Turnover on Forest NPP and Soil C Sequestration Potential. Science, 302(5649): 1385–1387. doi:10.1126/science.1089543
24. Mei L, Han Y Z,Yu S Q, Shi J W, Wang Z Q (2006). Impact Factors onFine Roots Seasonal Dynamics in Manchurian ash Plantation. Scientia Silvae Sinicae (in Chinese), (in press)
25. Mei L, Wang Z Q, Cheng Y H, Guo D L (2004). A review: factors influencing fine root longevity in forest ecosystem. Acta Phytoecologica Sinica, 28(5): 704–710 (in Chinese)
26. Norby R J, Jackson R B (2000). Rootdynamics and global change: seeking an ecosystem perspective. New Phytologist, 147: 3–12. doi:10.1046/j.1469-8137.2000.00676.x
27. Powell S W, Day F P Jr (1991). Rootproduction in four communities in the Great Dismal Swamp. American Journal of Botany, 78(2): 288–297. doi:10.2307/2445251
28. Pregitzer K S (2003). Woody plants, carbon allocation and fine roots. New Phytologist, 158(3): 421–423. doi:10.1046/j.1469-8137.2003.00766.x
29. Pregitzer K S, Zak D R, Maziasz J, DeForest J, Curtis P S, Lussenhop J (2000). Fine root growth, mortality, andmorphology in a factorial elevated atmospheric CO₂ × soil N availability experiment. Ecological Applications, 10: 18–33
30. Raich J W, Nadelhoffer K J (1989). Belowgroundcarbon allocation in forest ecosystems: Global trends. Ecology, 70: 1346–1354. doi:10.2307/1938194
31. Schenk H J, Jackson R B (2002). The globalbiogeography of roots. Ecological Monographs, 72(3): 311–328
32. Shan J P, Tao D L, Wang M, Zhao S D (1993). Fine roots turnover in a broadleaved Korean pine forest of ChangbaiMountain. Chinese Journal of Applied Ecology, 4: 241–245 (in Chinese)
33. Shi J W, Yu S Q, Yu L Z, Han Y Z, Wang Z Q, Guo D L (2006). Application of Minirhizotron in Fine Root Studies. Chinese Journal of Applied Ecology (in Chinese) (in press)
34. Steele S J, Gower S T, Vogel J G, Norman J M, (1997). Root mass, net primary production and turnover in aspen, jack pineand black spruce forests in Saskatchewan and Manitoba, Canada. Tree Physiology, 17(8–9): 577–587
35. Tierney G L, Fahey T J (2001). Evaluationof minirhizotron estimates of fine root longevity in the forest floorof a temperate broadleaf forest. Plantand Soil, 229: 167–176. doi:10.1023/A:1004829423160
36. Vogt K A, Gxier C C, Vogt D J (1986). Production, turnover and nutrientdynamics of above-and belowground detritus of world forests. Advances in Ecological Research, 15: 303–377. doi:10.1016/S0065-2504(08)60122-1
37. Vogt K A, Vogt D J, Palmiotto P A, Boon P, O'Hara J, Asbjornsen H (1996). Review of root dynamics in forest ecosystems groupedby climate, climatic forest type and species. Plant and soil, 187(2): 159–219. doi:10.1007/BF00017088
38. Wells C E, Glenn D M, Eissenstat D M (2002). Soil insects alter fine root demographyin peach (Prunus persica). Plant, Cell and Environment, 25(3): 431–439. doi:10.1046/j.1365-3040.2002.00793.x
39. Zhang X Q, Wu K H (2001). Fineroot production and turnover for forest ecosystem. Scientia Silvae Sinicae, 37(3): 126–138 (in Chinese)
40. Zhang X Q, Wu K H, Murach D (2000). A review of methods for fine-rootproduction and turnover of trees. ActaEcologica Sinica, 20(5): 875–883