Biomass production and carbon balance in two hybrid poplar (Populus euramericana) plantations raised with and without agriculture in southern France

Abstract

Poplar is useful in different climates for bioenergy production and carbon sequestration when planted as a single species or in agroforestry. Europe has large areas potentially suitable for poplar forestry and a bioenergy policy that would encourage poplar forestry. In this study I estimated biomass production and carbon sequestration in poplar monoculture plantation and poplar-wheat agroforestry, in the Mediterranean region of France. A single-tree harvesting method was used to estimate biomass and an empirical conversion factor was adopted to calculate sequestered carbon. Total biomass was higher in agroforestry trees (1223 kg tree⁻¹) than in monoculture plantation trees (1102 kg tree⁻¹). Aboveground and belowground biomass distributions were similar in both cases (89 and 88% aboveground, and 11 and 12% belowground, respectively in agroforestry and monoculture). The partitioning of total biomass in an agroforestry tree in leaves, branch, and trunk (aboveground), and fine roots, medium roots, coarse roots and underground stem (belowground) was 1, 22, and 77, and 6, 9, 44 and 40%, respectively. Except for branch and trunk, all other compartments were similarly distributed in a monoculture tree. Storage of C was higher in agroforestry trees (612 kg tree⁻¹) than in monoculture trees (512 kg tree⁻¹). In contrast, C storage on a per hectare basis was lower in agroforestry (85 Mg ha⁻¹) than in monoculture (105 Mg ha⁻¹) due to the lower density of trees per hectare in agroforestry (139 trees in agroforestry vs 204 trees in monoculture). On a per hectare basis, soil C stocks pattern were similar to per tree stocking: They were higher in agroforestry at 330 Mg ha⁻¹ than in monoculture 304 Mg ha⁻¹. Higher C accumulation by agroforestry has a direct management implication in the sense that expanding agroforestry into agriculture production areas with short rotation and fast growing trees like poplar would encourage quicker and greater C sequestration. This could simultaneously fulfil the requirement of bioenergy plantation in Europe.

Keywords

Populus euramericana / Wood volume and density / Root: shoot ratio / Vegetation and soil carbon / System efficiency

References

[1] Ahmad A, Nizami SM. Carbon stock of different land uses in the Kumrat valley, Hindu Kush Region of Pakistan. J For Res, 2015, 26(1): 57-64.

[2] Ajit, Das DK, Chaturvedi OP, Jabeen N, Dhyani SK. Predictive models for dry weight estimation of above and below ground biomass components of Populus deltoides in India: development and comparative diagnosis. Biomass Bioenergy, 2011, 35: 1145-1152.

[3] Alías JC, García M, Sosa T, Valares C, Chaves N. Carbon storage in the different compartments of two systems of shrubs of the southwestern Iberian Peninsula. Agrofor Syst, 2015, 89(4): 575-585.

[4] Anderson F. Ecological studies in a Scanian woodland and meadow area, southern Sweden II. Plant biomass, primary production, and turnover of organic matter. Bot Notiser, 1970, 123: 8-51.

[5] Anonymous. Intercropping: marrying forests and agriculture, 1991, Ottawa: Natural Resource Canada, Canadian Forest Service.

[6] Arevalo CBM, Bhatti JS, Chang SX, Sidders D. Ecosystem carbon stocks and distribution under different land-uses in north central Alberta, Canada. For Ecol Manag, 2009, 257: 1776-1785.

[7] Arora G, Chaturvedi S, Kaushal R, Nain A, Tewari S, Alam NM, Chaturvedi OP. Growth, biomass, carbon stocks, and sequestration in an age series of Populus deltoides plantations in Tarai region of central Himalaya. Turk J Agric For, 2014, 38: 550-560.

[8] Arraiolos A (2006) Etude d’un peuplier preleve sur une parcelle agroforestiere de Vezenobre dans l’objectif de caliber un model de culture agroforestiere. UMR-SYSTEM. Master thesis, Montpellier, p 23

[9] Balatinecz J, Kretschmann D. Dickmann D, Isebrands J, Eckenwalder J, Richardson J. Properties and utilization of poplar wood. Poplar culture in North America, 2001, Ottawa: National Research Council of Canada 277 290

[10] Banerjee H, Dhara PK, Mazumdar D. Bamboo (Bambusa spp.) based agroforestry systems under rainfed upland ecosystem. J Crop Weed, 2009, 5(1): 286-290.

[11] Barrio-Anta M, Sixto-Blanco H, Canellas-Rey DVI, Castedo-Dorado F. Dynamic growth model for I-214 poplar plantations in the northern and central plateaux in Spain. For Ecol Manag, 2008, 255: 1167-1178.

[12] Basuki TM, van Laake PE, Skidmore AK, Hussin YA. Allometric equations for estimating the above-ground biomass in tropical lowland Dipterocarp forests. For Ecol Manag, 2009, 257: 1684-1694.

[13] Block RMA, Van Rees KCJ, Knight JD. A review of fine root dynamics in Populus plantations. Agrofor Syst, 2006, 67: 73-84.

[14] Bungart R, Huttl R. Growth dynamics and biomass accumulation of 8-year-old hybrid poplar clones in a short-rotation plantation on a clayey-sandy mining substrate with respect to plant nutrition and water budget. Eur J For Res, 2004, 123: 105-115.

[15] Cagelli L, Lefèvre F. The conservation of Populus nigra and gene flow with cultivated poplars in Europe. For Genet, 1995, 2: 135-144.

[16] Calfapietra C, Gielen B, Karnosky D, Ceulemans R, Scarascia Mugnozza G. Response and potential of agroforestry crops under global change. Environ Pollut, 2010, 158: 1095-1104.

[17] Ceulemens R, Scarassia-Mugnozza G, Wiard BM, Braatne GH, Hinckley TM, Stettler RF, Isebrands JG, Heilman PE. Production, physiology and morphology of Populus species and their hybrids grown under short rotation. I. Clonal comparison of 4-year growth and phonology. Can J For Res, 1992, 22: 1937-1948.

[18] Chambers JQ, dos Santos J, Rebeiro RJ, Higuchi N. Tree damage, allometric relationships, and aboveground net primary production in central Amazon forest. For Ecol Manag, 2001, 152: 73-84.

[19] Chauhan SK, Gupta N, Walia R, Yadav S, Chauhan R, Mangat PS. Biomass and carbon sequestration potential of poplar-wheat inter-cropping system in irrigated agro-ecosystem in India. J Agric Sci Technol, 2011, A1: 575-586.

[20] Chen W, Zhang Q, Cihlar J, Bauhus J, Price DY. Estimating fine-root biomass and production of boreal and cool temperate forests using aboveground measurements: a new approach. Plant Soil, 2004, 265: 31-46.

[21] Cooper CF. Carbon storage in managed forests. Can J For Res, 1983, 13: 155-166.

[22] Dainese M, Luna DI, Sitzia T, Marini L. Testing scale-dependent effects of seminatural habitats on farmland biodiversity. Ecol Appl, 2015, 25(6): 1681-1690.

[23] Das DK, Chaturvedi OP. Structure and function of Populus deltoides agroforestry systems in eastern India: I. Dry matter dynamics. Agrofor Syst, 2005, 65: 215-221.

[24] Don A, Osborne B, Hastings A, Skiba U, Carter MS, Drewer J, Flessa H, Freibauer A, Hyvonen N, Jones MB, Lanigan GJ, Mander U, Monti A, Djomo SN, Valentine J, Walte RK, Zegadalizarazu W, Zenone T. Land-use change to bioenergy production in Europe: implications for the greenhouse gas balance and soil carbon. GCB Bioenergy, 2012, 4: 372-391. 10.1111/j.1757-1707.2011.01116.x

[25] Dowell RC, Gibbins D, Rhoads JL, Pallardy SG. Biomass production physiology and soil carbon dynamics in short-rotation-grown Populus deltoides and P. deltoides x P. nigra hybrids. For Ecol Manag, 2009, 257: 134-142.

[26] Dupraz C, Liagre F. Agroforesterie: Des arbres et des cultures, 2008, Paris: Editions France Agricole.

[27] Fang S, Xu X, Lu S, Tang L. Growth dynamics and biomass production in short-rotation poplar plantations: 6-year results for three clones at four spacings. Biomass Bioenergy, 1999, 17: 415-425.

[28] Fang S, Xue J, Tang L. Biomass production and carbon sequestration potential in poplar plantations with different management patterns. J Environ Manag, 2007, 85: 672-679.

[29] Fang S, Xie B, Liu J. Soil nutrient availability, poplar growth and biomass production on degraded agricultural soil under fresh grass mulch. For Ecol Manag, 2008, 255: 1802-1809.

[30] Fontaine S, Bordeaux G, Abbadie L, Mariotti A. Carbon input to soil may decrease soil carbon content. Ecol Lett, 2004, 7: 314-320.

[31] Fontaine S, Barot S, Barre P, Bdioui N, Mary B, Rumpel C. Stability of organic carbon in deep soil layers controlled by fresh carbon supply. Nature, 2007, 450(7167): 277-288.

[32] Fortier J, Gagnon D, Truax B, Lambert F. Biomass and volume yield after 6 years in multiclonal hybrid poplar riparian buffer strips. Biomass Bioenergy, 2010, 34: 1028-1040.

[33] Fortier J, Gagnon D, Truax B, Lambert F. Nutrient accumulation and carbon sequestration in 6-year-old hybrid poplars in multiclonal agricultural riparian buffer strips. Agric Ecosyst Environ, 2010, 137: 276-287.

[34] Fortier J, Truax B, Gagnon D, Lambert F. Biomass carbon, nitrogen and phosphorus stocks in hybrid poplar buffers, herbaceous buffers and natural woodlots in the riparian zone on agricultural land. J Environ Manag, 2015, 154: 333-345.

[35] Fossati T, Grassi F, Sala F, Castiglione S. Molecular analysis of natural populations of Populus nigra L. intermingled with cultivated hybrids. Mol Ecol, 2003, 12(8): 2033-2043.

[36] Gao Y, Cheng J, Ma Z, Zhao Y, Su J. Carbon storage in biomass, litter and soil of different plantations in a semiarid temperate region of northwest China. Ann For Sci, 2014, 71: 427-435.

[37] Gasol CM, Martinez S, Rigola M, Rieradevall J, Anton A, Carrasco J, Ciria P, Gabarrell X. Feasibility assessment of poplar bioenergy systems in the southern Europe. Renew Sustain Energy Rev, 2009, 13: 801-812.

[38] Gower ST, Krankina O, Olson RJ, Apps M, Linder S, Wang C. Net primary production and carbon allocation patterns of boreal forest ecosystems. Ecol Appl, 2001, 11: 1395-1411.

[39] Graefe S, Hertel D, Leuschner C. Fine root dynamics along a 2,000-m elevation transect in South Ecuadorian mountain rainforests. Plant Soil, 2008, 313: 155-166.

[40] Graves AR, Burgess PJ, Palma JHN, Herzog F, Moreno G, Bertomeu M, Dupraz C, Liagre F, Keesman K, Werf WV, Nooy AK, Briel JP. Development and application of bio-economic modelling to compare silvoarable, arable and forestry systems in three European countries. Ecol Eng, 2007, 29: 434-449.

[41] Gucinski H, Vance E, Reiners WA. Smith WK, Hinckley TM. Potential effects of global climate change. Ecophysiology of coniferous forests, 1995, New York: Academic Press 309 331

[42] Guo LB, Gifford RM. Soil carbon stocks and land use change: a meta analysis. Glob Change Biol, 2002, 8: 345-360.

[43] Gupta N, Kukal SS, Bawa SS, Dhaliwal GS. Soil organic carbon and aggregation under poplar based agroforestry system in relation to tree age and soil type. Agrofor Syst, 2009, 76: 27-35.

[44] Hegazy S, Aref I, Al-Mefarrej H, El-Juhany LI. Effect of spacing on the biomass production and allocation in Conocarpus erectus L. trees grown in Riyadh, Saudi Arabia. Saudi J Biol Sci, 2008, 15: 315-322.

[45] Heilmen PE, Ekuan G, Foggle D. Above and below ground biomass and fine roots of 4-year old hybrids of Populus trichocarpa x Populus deltoides and parental species in short rotation culture. Can J For Res, 1994, 24: 1186-1192.

[46] IPCC. Noble IR, Bolin B, Ravindranath NH, Verardo DJ, Dokken DJ. Land, land-use change, and forestry: a special report of the intergovernmental panel on climate change. Watson RT, 2000, Cambridge: Cambridge University Press 25 51

[47] Jha KK. Poplar (Populus deltoides) farming, 1999, Lucknow: International Book Distributing Company.

[48] Jha KK. Carbon storage and sequestration rate assessment and allometric model development in young teak plantations of tropical moist deciduous forest, India. J For Res, 2015, 26(3): 589-604.

[49] Jha KK, Gupta C. Intercropping of medicinal plants with poplar and their phenology. Indian For, 1991, 117: 335-544.

[50] Kang K, Zhang S, Mansfield S. The effects of initial spacing on wood density, fibre and pulp properties in jack pine (Pinus banksiana lamb.). Holzforschung, 2004, 58: 455-463.

[51] Kanime N, Kaushal R, Tewari SK, Raverkar KP, Chaturvedi S, Chaturvedi OP. Biomass production and carbon sequestration in different tree-based systems of Central Himalayan Tarai region. For Trees Livelihoods, 2013, 22: 38-50.

[52] Kirby KR, Potvin C. Variation in carbon storage among tree species: implications for the management of a small-scale carbon sink project. For Ecol Manag, 2007, 246: 208-221.

[53] Koerper G, Richardson C. Biomass and net annual primary production regression for Populus grandidentata on three sites in northern lower Michigan. Can J For Res, 1980, 10: 92-101.

[54] Kort J, Turnock R. Carbon reservoir and biomass in Canadian prairie shelterbelts. Agrofor Syst, 1998, 44: 175-186.

[55] Kunhamu T, Kumar BM, Samuel S. Does tree management affect above ground and soil carbon sequestration in Acacia mangium wild in the humid tropics of India. World congress of agroforestry: agroforestry-the future of global landuse, 2009, Nairobi: World Agroforestry Centre.

[56] Laclau P. Biomass and carbon sequestration of ponderosa pine plantation and native cypress forests in northwestern Potagonia. For Ecol Manag, 2003, 180: 317-333.

[57] Lal R. Sequestering carbon in soils of agro-ecosystems. Food Policy, 2011, 36(1): S33-S39.

[58] Lamlom S, Savidge R. Carbon content variation in boles of mature sugar maple and giant sequoia. Tree Physiol, 2006, 26: 459-468.

[59] Lasco R, Pulhin F. Carbon sequestration of small holder tree farms and agroforestry farms in The Philippines. World congress of agroforestry: agroforestry-the future of global landuse, 2009, Nairobi: World Agroforestry Centre.

[60] Levin DA, Francisco-Ortega JAV, Jansen RK. Hybridization and the extinction of rare plant species. Conserv Biol, 1996, 10: 10-16.

[61] Lodhiyal L, Lodhiyal N. Variation in biomass and net primary productivity in short rotation high density central Himalayan poplar plantations. For Ecol Manag, 1997, 98: 167-179.

[62] Lodhiyal LS, Singh RP, Singh SP. Structure and function of an age series of poplar plantations in Central Himalaya: dry matter dynamics. Ann Bot, 1995, 76: 191-199.

[63] Lu M, Nygren P, Perttunen J, Pallardy SG, Larsen DR. Application of functional-structural tree model LIGNUM to growth simulation of short-rotation eastern cottonwood. Silva Fennica, 2011, 45(3): 431-474.

[64] Maia SMF, Xavier FAS, Oliviera TS, Mendonca ES, Filho JAA. Organic carbon pools in a Luvisol under agroforestry and conventional farming systems in the semi-arid region of Ceará, Brazil. Agrofor Syst, 2007, 71: 127-138.

[65] Mallik A, Hossain MK, Lamb E. Species and spacing effects of northern conifers on forest productivity and soil chemistry in a 50-year-old common garden experiment. J For, 2008, 3: 83-90.

[66] Mulia R (2005) Modelisation tri-dimensionelle de la croissance du systeme racinaire des plantes en milieu heterogene avec l’approche de l’automate voxellaire. Ph.D. thesis, Universite de Montpellier II, p 86

[67] Mulia R, Dupraz C. Unusual fine root distributions of two deciduous tree species in southern France: what consequences for modelling of tree root dynamics?. Plant Soil, 2006, 281: 71-85.

[68] Nair PKR, Nair VD, Kumar BM, Haile SG. Soil carbon sequestration in tropical agroforestry systems: a feasibility appraisal. Environ Sci Policy, 2009, 12(8): 1099-1111.

[69] Nakane K. Soil carbon cycling in a Japanese cedar (Cryptomaria japonica) plantation. For Ecol Manag, 1995, 72: 185-197.

[70] Nasso NNOD, Guidi W, Ragaglini G, Tozzini C, Bonari E. Biomass production and energy balance of a 12-year-old short-rotation coppice poplar stand under different cutting cycles. Glob Change Biol Bioenergy, 2010, 2: 89-97.

[71] Nerlich K, Graeff-Hönninger S, Claupein W. Agroforestry in Europe: a review of the disappearance of traditional systems and development of modern agroforestry practices, with emphasis on experiences in Germany. Agrofor Syst, 2013, 87(2): 475-492.

[72] Nogueira EM, Fearnside PM, Nelson BW, Franc MB. Wood density in forests of Brazil’s arc of deforestation: implications for biomass and flux of carbon from land-use change in Amazonia. For Ecol Manag, 2007, 248: 119-135.

[73] Nowak DJ, Crane DE. Carbon storage and sequestration by urban trees in the USA. Environ Pollut, 2002, 116: 381-389.

[74] Oelbermann M, Voroney RP, Gordon AM. Carbon sequestration in tropical and temperate agroforestry systems: a review with examples from Costa Rica and southern Canada. Agriculture Ecosystem Environment, 2004, 104: 359-377.

[75] Oelbermann M, Voroney RP, Thevathasan NV, Gordon AM, Kass DCL, Schlonvoigt AM. Soil carbon dynamics and residue stabilization in a Costa Rican and southern Canadian alley cropping system. Agrofor Syst, 2006, 68: 27-36.

[76] Ostadhashemi R, Shahraji TR, Roehle H, Limaei SM. Estimation of biomass and carbon storage of tree plantations in northern Iran. J For Sci, 2014, 60(9): 363-371.

[77] Paladinic E, Vuletic D, Martinic I, Marjanovic H, Indir K, Benko M, Novotny V. Forest biomass and sequestered carbon estimation according to main tree components on the forest stand scale. Periodicum Biol, 2009, 111(4): 459-466.

[78] Pallardy SG, Gibbins DE, Rhoads JL. Biomass production by two-year-old poplar clones on floodplain sites in the lower Midwest, USA. Agrofor Syst, 2003, 59: 21-26.

[79] Peichl M, Thevathasan NV, Gordon AM, Huss J, Abohassan RA. Carbon sequestration potentials in temperate tree-based intercropping systems, southern Ontario, Canada. Agrofor Syst, 2006, 66: 243-257.

[80] Pibumrung P, Gajaseni N, Popan A. Profiles of carbon stockin forest, reforestation and agricultural land, Norther Thailand. J For Res, 2008, 19(1): 11-18.

[81] Pingale B, Bana OPS, Banga A, Chaturvedi S, Kaushal R, Tewari S, Neema S. Accounting biomass and carbon dynamics in Populus deltoides plantation under varying density in Tarai of central Himalaya. J Tree Sci, 2014, 33(2): 1-6.

[82] Post WM, Pengh TH, Emanuel W, King AW, Dale VH, Delnglis DL. The global carbon cycle. Am Sci, 1990, 78: 310-326.

[83] Puri S, Singh V, Bhushan B, Singh S. Biomass production and distribution of roots in three stands of Populus deltoides. For Ecol Manag, 1994, 65: 135-147.

[84] Quinkenstein A, Wollecke J, Bohm C, Grunewald H, Freese D, Schneider BU, Huttl RF. Ecological benefits of alley cropping agroforestry system in sensitive regions of Europe. Environ Sci Policy, 2009, 12: 1112-1121.

[85] Raizada A, Srivastava M. Biomass yield and biomass equations for Populus deltoides Marsh. Indian J For, 1989, 12: 56-61.

[86] Reisner Y, Filippi R, Herzog F, Palma J. Target regions for silvoarable agroforestry in Europe. Ecol Eng, 2007, 29: 401-408.

[87] Rizvi RH, Dhyani SK, Yadav RS, Singh R. Biomass production and carbon stock of poplar agroforestry systems in Yamunanagar and Saharanpur districts of northwestern India. Curr Sci, 2011, 100(5): 736-742.

[88] Rurak G, Bokheim J. Biomass, net primary production and nutrient distribution for an age sequence of Populus tremuloides ecosystems. Can J For Res, 1988, 18: 435-443.

[89] Rytter RM. The potential of willow and poplar plantations as carbon sinks in Sweden. Biomass Bioenergy, 2012, 36: 86-95.

[90] Sartori F, Lal R, Ebinger MH, Eaton JA. Changes in soil carbon and nutrient pools along a chronosequence of poplar plantations in the Columbia Plateau, Oregon, USA. Agric Ecosyst Environ, 2007, 122: 325-339.

[91] Satoo T. Reichle DE. A synthesis of studies by the harvest method: primary production relations in the temperate deciduous forests of Japan. Analysis of temperate forest ecosystem, 1970, New York: Springer 55 72

[92] Scarascia-Mugnozza GE, Ceulemans R, Heilman PE, Isebrands JG, Stettler RF, Hinckley TM. Production physiology and morphology of Populus species and their hybrids grown under short rotation. II. Biomass components and harvest index of hybrid and parental species clones. Can J For Res, 1997, 27: 285-294.

[93] Schoeneberger M. Agroforestry: working trees for sequestering carbon on agricultural lands. Agrofor Syst, 2009, 75: 27-37.

[94] Sedjo RA. From foraging to cropping: the transition to plantation forestry, and implications for wood supply and demand. Unasylva, 2001, 52: 24-27.

[95] Sharma S, Singh B, Sikka R. Soil organic carbon and nitrogen pools in a chronosequence of poplar (Populus deltoides) plantations in alluvial soil of Punjab, India. Agrofor Syst, 2015, 89(6): 1049-1063.

[96] Shelton M, Switzer G, Nelson L, Baker J, Mueller C. The development of cottonwood plantations in alluvial soils. Missisippi State Univ Tech Bull, 1982, 113: 1-45.

[97] Sierra M, Martínez FJ, Verde R, Martín FJ, Macías F. Soil-carbon sequestration and soil-carbon fractions, comparison between poplar plantations and corn crops in south-eastern Spain. Soil Till Res, 2013, 130: 1-6.

[98] Singh B (1989) A study of silvicultural practices, biomass, productivity and nutrient cycling (NPK) in poplar plantations of sub Himalayan tract of UP state. Ph.D. thesis, Kumaun University, Nainital, India

[99] Singh B. Biomass production and nutrient dynamics in three clones of Populus deltoides planted on Indogangetic plains. Plant Soil, 1998, 203: 15-26.

[100] Singh P, Lodhiyal LS. Biomass and carbon allocation in 8-year-old poplar (Populus deltoides Marsh) plantation in Tarai agroforestry systems of central Himalaya, India. New York Sci J, 2009, 2: 49-53.

[101] Singh G, Singh NT, Dagar JC, Singh H, Sharma VP. An evaluation of agriculture, forestry and agroforestry practices in a moderately alkali soil in northwestern India. Agrofor Syst, 1997, 37: 279-295.

[102] Sitzia T, Trentanovi G, Marini L, Cattaneo D, Semenzato P. Assessment of hedge stand types as determinants of woody species richness in rural field margins. iFor Biogeosci For, 2013 6 4 201

[103] Sitzia T, Pizzeghello D, Dainese M, Ertani A, Carletti P, Semenzato P, Nardi S, Cattaneo D. Topsoil organic matter properties in contrasted hedgerow vegetation types. Plant Soil, 2014, 383(1–2): 337-348.

[104] Smith D. Estimation of tree root lengths using fractal branching rule: a comparison with soil coring for Grevillea robusta. Plant Soil, 2001, 229: 295-304.

[105] Smulders MJM, Beringen R, Volosyanchuk R, Vanden Broeck A, van der Schoot J, Arens P, Vosman B. Natural hybridisation between Populus nigra L. and P. X canadensis Moench. Hybrid offspring competes for niches along the Rhine river in the Netherlands. Tree Genet Genomes, 2008, 4: 663-675.

[106] Sobachkin R, Sobachkin D, Buzykin A (2005) The influence of stand density on growth of three conifer species. In: Binkley D, Menyailo O (eds) Tree species effects on soils: implications for global change. Springer, New York, pp 247–255

[107] Specht A, West PW. Estimation of biomass and sequestered carbon on farm forest plantations in northern New South Wales, Australia. Biomass Bioenergy, 2003, 25: 363-379.

[108] Strong T, Hansen E. Hybrid poplar spacing/productivity relations in short rotation intensive culture plantations. Biomass Bioenergy, 1993, 4: 255-261.

[109] Swamy SL, Puri S. Biomass production and C-sequestration of Gmelina arborea in plantation and agroforestry system in India. Agrofor Syst, 2005, 64: 181-195.

[110] Swamy SL, Mishra A, Puri S. Comparison of growth, biomass and nutrient distribution in five promising clones of Populus deltoides under an agrisilviculture system. Biores Technol, 2006, 97: 57-68.

[111] Takimoto A, Nair PKR, Nair VD. Carbon stock and sequestration potential of traditional and improved agroforestry systems in the West African Sahel. Agric Ecosyst Environ, 2008, 125: 159-166.

[112] Takimoto A, Nair VD, Nair PKR. Contribution of trees to soil carbon sequestration under agroforestry systems in the West African Sahel. Agrofor Syst, 2009, 76: 11-25.

[113] Terakunpisut J, Gajaseni N, Ruankawe N. Carbon sequestration potential in aboveground biomass of Thong Pha Phum national forest, Thailand. Appl Ecol Environ Res, 2007, 5: 93-102.

[114] Thevathasan N, Gordon A. Ecology of tree intercropping systems in the North temperate region: experiences from southern Ontario, Canada. Agrofor Syst, 2004, 61: 257-268.

[115] Tobias K, Pontus O, Oleh C, Matthias B, Katarzyna O, Kurtis EW, Richard AH, Patrick H, William SK, Volker CR. Post Soviet farmland abandonment, forest recovery, and carbon sequestration in western Ukraine. Glob Change Biol, 2011, 17: 1335-1339.

[116] Truax B, Gagnon D, Fortier J, Lambert F. Yield in 8 year-old hybrid poplar plantations on abandoned farmland along climatic and soil fertility gradients. For Ecol Manag, 2012, 267: 228-239.

[117] Updegraff K, Baughman MJ, Taff SJ. Environmental benefits of cropland conversion to hybrid poplar: economic and policy considerations. Biomass Bioenergy, 2004, 27: 411-428.

[118] Wang Y, Hu C, Dong W, Li X, Zhang Y, Qin S, Oenema O. Carbon budget of a winter-wheat and summer-maize rotation cropland in the North China Plain. Agric Ecosyst Environ, 2015, 206: 33-45.

[119] Winfield MO, Arnold GM, Cooper F, LeRay M, White J, Carp A, Edwards KJ. A study of genetic diversity in Populus nigra subsp. betulifolia in the Upper Severn area of the UK using AFLP markers. Mol Ecol, 1998, 7: 3-10.

[120] Yadava AK. Biomass production and carbon sequestration in different Agroforestry systems in tarai region of central Himalaya. Indian For, 2010, 136(2): 234-244.

[121] Yemshanov D, McKinney D. Fast growing poplar plantations as a bioenergy supply source for Canada. Biomass Bioenergy, 2008, 32: 185-197.

[122] Zabek L, Prescott C. Biomass equations and carbon content of aboveground leafless biomass of hybrid poplar in Coastal British Columbia. For Ecol Manag, 2006, 223: 291-302.

[123] Zhang J, Sun Q, Zhou J, Shan Q, Wu L. Biomass production of poplar plantation ecosystem in Yangtze River beach land energy and power. Engineering, 2009, 2009: 81-84.