Changes in Soil Carbon Sequestration during Woody Plant Encroachment in Arid Ecosystems

P V Naikwade

doi:10.32439/ps.v4i5.266-276

Authors

P V Naikwade

DOI:

https://doi.org/10.32439/ps.v4i5.266-276

Keywords:

Carbon sequestration, Climate change, Ecosystem, Woody encroachment

Abstract

Carbon sequestration is one of the most important and highly recommended measures for mitigating climate change. Soil organic carbon (SOC) has potential to sequester the largest amount of carbon (C) for the longest time period in the midst of the organic C sinks in terrestrial ecosystems of the earth. In recent years, apprehension of the role of soils as sink for carbon on a wide-ranging scale has become dynamic. From last 150 years, encroachment of trees and shrubs into grasslands and the ‘thicketization’ of savannas have been reported and is a global phenomenon. One possibly beneficial effect could be that the shrub and tree-dominated ecosystems will sequester more carbon and will be a buffer for elevated atmospheric carbon dioxide (CO₂) levels. The question of what is impact of woody encroachment on soil carbon balance of an ecosystem has proved difficult to answer, and the results remain debatable. The magnitude and pattern of changes in the SOC with woody encroachment are exceedingly abstruse and varies from significant increases, to significant decreases to no net change in SOC. Impact of wood plant encroachment on carbon sequestration is discussed in this paper considering various studies with different results so it will lead to better understanding of the complex phenomenon. SOC sequestration is effective greenhouse gas mitigation strategy and a vital ecosystem service. Increasing SOC may helpful to mitigate negative effects of growing concentration of CO₂ in atmosphere and may be advantageous in decelerating or reversal in global climate change rate.

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Abdallah, M.A.B., Mata-González, R., Noller, J.S., and Ochoa, C.G. (2020). Ecosystem carbon in relation to woody plant encroachment and control: Juniper systems in Oregon, USA. Agriculture, Ecosystems and Environment, 290, 106762. DOI: https://doi.org/10.1016/j.agee.2019.106762

Aber, J.D. and Melillo, J.M., (2001). Terrestrial Ecosystems, second ed. Harcourt Academic Press, CA.

Amundson, R. (2001). The carbon budget in soils. Annu Rev Earth Pl Sc 29:535–562. DOI: https://doi.org/10.1146/annurev.earth.29.1.535

Archer, S. (1994). Woody plant encroachment into southwestern grasslands and savannas: rates, patterns and proximate causes. In: Vavra M, Laycock WA, Pieper RD (eds) Ecological implications of livestock herbivory in the West. Soc Range Manag, Denver, CO, pp 13–68.

Archer, S., Boutton, T., Hibbard, K. (2001). Trees in grasslands: biogeochemical consequences of woody plant expansion. In: Global Biogeochemical Cycles in the Climate System (eds Schultz, E., Harrison, S., Heiman, M., Holland, E., Lloyd, J., Prentic, I., Schimel, D.), Academic Press, San Diego.,pp. 115–137. DOI: https://doi.org/10.1016/B978-012631260-7/50011-X

Archer, S., Schimel, D.S. and Holland. E.A. (1995). Mechanism of shrubland expansion: land use, climate or CO2? Clim. Change 29:91–99. DOI: https://doi.org/10.1007/BF01091640

Archer, S.R., Andersen, E.M., Predick, K.I., Schwinning, S., Steidl, R.J., Woods, S.R., (2017). Woody plant encroachment: causes and consequences. In: Briske, D.D. (Ed.), Rangeland Systems: Processes, Management and Challenges. Springer International Publishing, Cham, Switzerland, pp. 25–84. DOI: https://doi.org/10.1007/978-3-319-46709-2_2

Archer, S.R., Scifres, C., Bassham, D., Maggio, R. (1988). Autogenic succession in a subtropical savanna: conversion of grassland to thorn woodland. Ecological Monographs, 58:111–127. DOI: https://doi.org/10.2307/1942463

Asner, G., and Archer, S. (2010). Livestock and the global carbon cycle, in Livestock in a Changing Landscape: Drivers Consequences and Responses, edited by H. Steinfeld et al., Island Press, Washington, D. C.

Bailey, R.G. (1998). Ecoregions: The Ecosystem Geography of the Oceans and Continents. Springer, New York. DOI: https://doi.org/10.1007/978-1-4612-2200-2_3

Barger, N.N., Archer, S.R. Campbell, J.L. Huang, C.Y., Morton, J. A. and Knapp, A. K.(2011). Woody plant proliferation in North American drylands: a synthesis of impacts on ecosystem carbon balance. J. Geophys. Res. Biogeosci. 116:07. DOI: https://doi.org/10.1029/2010JG001506

Barron-Gafford, G.A., Scott, R.L., Jenerette, G.D., Hamerlynck, E.P., Huxman, T.E. (2012). Temperature and precipitation controls over leaf- and ecosystem-level CO2 flux along a woody plant encroachment gradient. Global Change Biology, 18, 1389–1400. DOI: https://doi.org/10.1111/j.1365-2486.2011.02599.x

Bates, J.D., Svejcar, T.J. and Miller R.F. (2002). Effects of juniper cutting on nitrogen mineralization, J. Arid Environ., 51(2):221–234. DOI: https://doi.org/10.1006/jare.2001.0948

Biedenbender, S.H., McClaran, M.P., Quade, J. and. Weltz, M.A. (2004). Landscape patterns of vegetation change indicated by soil carbon isotope composition. Geoderma 119: 69–81. DOI: https://doi.org/10.1016/S0016-7061(03)00234-9

Biggs, T.H., Quade, J., and Webb, R.H. (2002). delta13 C values of soil organic matter in semiarid grassland with mesquite (Prosopis) encroachment in southeastern Arizona. Geoderma 110: 109–130. DOI: https://doi.org/10.1016/S0016-7061(02)00227-6

Blaser Wilma, J., Shanungu Griffin, K., Edwards Peter, J. and Venterink Harry O. (2014). Woody encroachment reduces nutrient limitation and promotes soil carbon sequestration, Ecology and Evolution, 1423-1438. DOI: https://doi.org/10.1002/ece3.1024

Blaser, W. J. (2013). Impact of woody encroachment on soil-plant-herbivore interactions in the Kafue Flats floodplain ecosystem. [Ph.D. thesis], Swiss Federal Institute of Technology, ETH Zurich, Switzerland.

Bond, W. J., Midgley, G.F. and Woodward, F.I. (2003). The importance of low atmospheric CO2 and fire in promoting the spread of grasslands and savannas. Glob. Change Biol. 9:973–982. DOI: https://doi.org/10.1046/j.1365-2486.2003.00577.x

Boutton, T.W., Archer, S.R. Midwood, A.J. Zitzer, S.F. and Bol, R. (1998). Delta C‐13 values of soil organic carbon and their use in documenting vegetation change in a subtropical savanna ecosystem, Geoderma, 82(1–3):5–41. DOI: https://doi.org/10.1016/S0016-7061(97)00095-5

Boutton, T.W., Liao, J.D., Filley, T.R. and Archer, S.R. (2009). Belowground Carbon Storage and Dynamics Accompanying Woody Plant Encroachment in a Subtropical Savanna in book Soil Carbon Sequestration and the Greenhouse Effect, Second edition, Soil Science Society of America Publication, Madison, USA.

Bradley, B.A., Houghton, R.A., Mustard, J.F., Hamburg, S.P. (2006). Invasive grass reduces aboveground carbon stocks in shrublands of the Western US. Glob. Change Biol. 12: 1815-1822. DOI: https://doi.org/10.1111/j.1365-2486.2006.01232.x

Briggs, J.M., Knapp, A.K., Blair, J.M., Heisler, J.L., Hoch, G.A., Lett, M.S., McCarron, K. (2005). An ecosystem in transition: woody plant expansion into mesic grassland. BioScience, 55:24. DOI: https://doi.org/10.1641/0006-3568(2005)055[0243:AEITCA]2.0.CO;2

Brovkin, V., Sitch, S., von Bloh, W., Claussen, M., Bauer, E. and Cramer, W. (2004). Role of land cover changes for atmospheric CO2 increase and climate change during the last 150 years Glob. Change Biol. 10:1253–66. DOI: https://doi.org/10.1111/j.1365-2486.2004.00812.x

Bucher, E.H. (1987). Herbivory in arid and semi-arid regions of Argentina. Rev. Chil. Hist. Nat.60:265-273.

Buitenwerf, R., Bond, W. J. Stevens, N. and Trollope, W.S.W. (2012). Increased tree densities in South African savannas: > 50 years of data suggests CO2 as a driver. Glob. Change Biol. 18:675–684. DOI: https://doi.org/10.1111/j.1365-2486.2011.02561.x

Cech, P. G., Venterink, H. Olde and Edwards, P.J. (2010). N and P cycling in Tanzanian Humid Savanna: influence of herbivores, fire, and N2-fixation. Ecosystems 13: 1079– 1096. DOI: https://doi.org/10.1007/s10021-010-9375-9

Chiti, T., Mihindou, V., Jeffery, K.J., Malhi, Y., De Oliveira, F.L., White, L.J. and Valentini, R. (2017). Impact of woody encroachment on soil organic carbon storage in the Lopé National Park, Gabon. Biotropica, 49:9-13. DOI: https://doi.org/10.1111/btp.12369

Ciais, P., Sabine, C., Bala, G., Bopp, L., Brovkin, V., Canadell, J., Chhabra, A., DeFries, R., Galloway, J., Heimann, M., Jones, C., Le Quere, C., Myneni, R.B., Piao, S., Thornton, P., (2013). Carbon and other biogeochemical cycles. In: Stocker, T.F., Qin, D., Plattner, G.-K., Tignor, M., Allen, S.K., Boschung, J., Nauels, A., Xia, Y., Bex, V., Midgley, P.M. (2013). Climate Change: the Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA.

Coetsee, C., Gray, E.F., Wakeling, J., Wigley, B.J., Bond, W.J. (2013). Low gains in ecosystem carbon with woody plant encroachment in a South African savanna. J. Trop. Ecol. 29:49–60. DOI: https://doi.org/10.1017/S0266467412000697

Connin, S.L., Virginia, R.A., Chamberlain (1997). Carbon isotopes reveal soil organic matter dynamics following arid land shrub expansion. Oecologia, 110:374–386. DOI: https://doi.org/10.1007/s004420050172

Ding Leilei, Puchang Wang, Wen Zhang, Yu Zhang, Shige Li, Xin Wei, Xi Chen, Yujun Zhang, Fuli Yang (2020). Soil stoichiometry modulates effects of shrub encroachment on soil carbon concentration and stock in a subalpine grassland, iForest - Biogeosciences and Forestry, 13(1):65-72. DOI: https://doi.org/10.3832/ifor3091-012

Eldridge David J. and Ding Jingyi (2021). Remove or retain: ecosystem effects of woody encroachment and removal are linked to plant structural and functional traits, New Phytologist, (5): 2637-2646. DOI: https://doi.org/10.1111/nph.17045

Eldridge, D. J., Bowker, M. A., Maestre, F. T., Roger, E., Reynolds, J. F., Whitford, W. G., (2011). Impacts of shrub encroachment on ecosystem structure and functioning: towards a global synthesis. Ecology Letters 14:709–722. DOI: https://doi.org/10.1111/j.1461-0248.2011.01630.x

Emmerich, W. (2007). Ecosystem water use efficiency in a semiarid shrubland and grassland community. Rangeland Ecology and Management 60, 464–470. DOI: https://doi.org/10.2111/1551-5028(2007)60[464:EWUEIA]2.0.CO;2

Field, C.B., Behrenfeld, M.J., Randerson, J.T. et al. (1998). Primary production of the biosphere: integrating terrestrial and oceanic components. Science, 281:237–240. DOI: https://doi.org/10.1126/science.281.5374.237

Field, C.B., Jackson, R.B. and Mooney, H.A. (1995). Stomatal responses to increased CO2: Implications from the plant to the global scale. Plant, Cell and Environment. 18:1214-1225 DOI: https://doi.org/10.1111/j.1365-3040.1995.tb00630.x

Geesing, D., Felker, P., Bingham, R.L. (2000). Influence of mesquite (Prosopis glandulosa) on soil nitrogen and carbon development: implications for global carbon sequestration. Journal of Arid Environments, 46:157–180. DOI: https://doi.org/10.1006/jare.2000.0661

Gifford, R. M. and Howden, M. (2001). Vegetation thickening in an ecological perspective: significance to national greenhouse gas inventories. Environmental Science and Policy 4: 59–72. DOI: https://doi.org/10.1016/S1462-9011(00)00109-X

Gill, R.A., Burke, I.C. (1999). Ecosystem consequences of plant life form changes at three sites in the semiarid United States. Oecologia, 121:551–563. DOI: https://doi.org/10.1007/s004420050962

GLP, (2005). Global land project-science plan and implementation strategy. International Geosphere Biosphere Program report No. 53/International Human Dimensions Programme Report No. 19, Stockholm.

Gonzalez-Roglich, M., Swenson, J.J., Jobbagy, E.G., Jackson, R.B., (2014). Shifting carbon pools along a plant cover gradient in woody encroached savannas of central Argentina. Forest Ecol. Manag. 331, 71–78. DOI: https://doi.org/10.1016/j.foreco.2014.07.035

Hallinger, M., Manthey, M. and Wilmking M. (2010). Establishing a missing link: Warm summers and winter snow cover promote shrub expansion into alpine tundra in Scandinavia, New Phytol., 186(4):890–899. DOI: https://doi.org/10.1111/j.1469-8137.2010.03223.x

Hibbard, K.A., Archer, S., Schimel, D.S., Valentine, D.W. (2001). Biogeochemical changes accompanying woody plant encroachment in a subtropical savanna. Ecology, 82 (7):1999–2011 DOI: https://doi.org/10.1890/0012-9658(2001)082[1999:BCAWPE]2.0.CO;2

Hicke, J.A., Sherriff, R.L., Veblen, T.T. and Asner G.P. (2004). Carbon accumulation in Colorado ponderosa pine stands, Can. J. For. Res., 34(6):1283–1295. DOI: https://doi.org/10.1139/x04-011

Hoobs, R.J and Mooney H.A. (1986). Community changes following shrub invasion of grassland. Oecologia (Berl.)70:508-513. DOI: https://doi.org/10.1007/BF00379896

Houghton, R.A. (2003). Revised estimates of the annual net flux of carbon to the atmosphere from changes in land use and land management 1850–2000, Tellus, Ser. B, 55(2):378–390. DOI: https://doi.org/10.1034/j.1600-0889.2003.01450.x

Houghton, R.A., Hackler, J.L. and Lawrence K.T. (1999). The U.S. carbon budget: Contributions from land‐use change, Science, 285(5427):574–578. DOI: https://doi.org/10.1126/science.285.5427.574

House, J.I., Archer, S., Breshears, D.D. et al. (2002). Conundrums in mixed woody-herbaceous plant systems. Journal of Biogeography, 30:1763–1777. DOI: https://doi.org/10.1046/j.1365-2699.2003.00873.x

Hughes, R. F., Archer, S. R. Asner, G. P. Wessman, C. A. McMurtry, C. Nelson, J. and Ansley, R. J. (2006). Changes in aboveground primary production and carbon and nitrogen pools accompanying woody plant encroachment in a temperate savanna, Global Change Biol., 12(9):1733–1747. DOI: https://doi.org/10.1111/j.1365-2486.2006.01210.x

Hurtt, G.C., Pacala, S.W., Moorcroft, P.R., Caspersen, J., Shevliakova, E., Houghton, R. A. and Moore B. (2002). Projecting the future of the U.S. carbon sink, Proc. Natl. Acad. Sci. U. S. A., 99(3):1389–1394. DOI: https://doi.org/10.1073/pnas.012249999

Jackson, R.B., Banner, J.L., Jobba´gy E.G. et al. (2002). Ecosystem carbon loss with woody plant invasion of grasslands. Nature, 418, 623–626. DOI: https://doi.org/10.1038/nature00910

Johnson H.B., Polley, H.W. Mayeux, H.S. (1993). Increasing CO2 and plant–plant interactions: effects on natural vegetation Vegetation, 104-105:157–170. DOI: https://doi.org/10.1007/BF00048151

Kauppi, P.E., Mielikainen, K. Kuusela K. (1992). Biomass and carbon budget of European forests, 1971 to 1990 Science, 256:70–74. DOI: https://doi.org/10.1126/science.256.5053.70

Knapp, A.K., Briggs, J.M., Collins, S.L., Archer, S.R., Bret-Harte, M.S. and Ewers, B.E. et al. (2008). Shrub encroachment in North American grasslands: shifts in growth form dominance rapidly alters control of ecosystem carbon inputs. Glob. Change Biol. 14:615–623. DOI: https://doi.org/10.1111/j.1365-2486.2007.01512.x

Lal, R. (2004). Carbon sequestration in dryland ecosystems. Environ Manag 33:528–544. DOI: https://doi.org/10.1007/s00267-003-9110-9

Lambers, H., Chapin III, F.S. and Pons, T.L. (2008). Plant physiological ecology, 2nd edition. New York,NY: Springer, 610 p DOI: https://doi.org/10.1007/978-0-387-78341-3

Liao, J.D., Boutton, T.W. and Jastrow, J. D. (2006). Storage and dynamics of carbon and nitrogen in soil physical fractions following woody plant invasion of grassland. Soil Biology and Biochemistry 38:3184–3196. DOI: https://doi.org/10.1016/j.soilbio.2006.04.003

Lugo, A.E., Brown, S. (1986). Steady state terrestrial ecosystems and the global carbon budget Vegetatio, 68:83–90. DOI: https://doi.org/10.1007/BF00045058

Malhi, Y., Higuchi, N., Nobre, A., Grace, J., Pereira, M., Ribeiro, R.J., (1997). Direct measurement of a carbon sink in an area of tropical rainforest. Proceedings of the Fifth International Carbon Dioxide Conference Extended Abstracts, Cairns, Queensland, Australia, 8–12 September 1997, p. 260

Mbaabu, P.R., Olago, D., Gichaba, M. et al. (2020). Restoration of degraded grasslands, but not invasion by Prosopis juliflora, avoids trade-offs between climate change mitigation and other ecosystem services. Sci Rep 10:20391. DOI: https://doi.org/10.1038/s41598-020-77126-7

McCarron, J.K., Knapp, A.K., Blair, J.M. (2003). Soil C and N responses to woody plant expansion in a mesic grassland. Plant Soil 257:183–192. DOI: https://doi.org/10.1023/A:1026255214393

McCulley, R.L., Archer, S.R., Boutton, T.W. et al. (2004). Soil respiration and nutrient cycling in wooded communities developing in grassland. Ecology, 85, 2804–2817. DOI: https://doi.org/10.1890/03-0645

McKinley, D.C. Morris. M.D., Blair, J.M., Johnson L.C. (2008). Altered ecosystem processes as a consequence of Juniperus virginiana L. encroachment into North American tallgrass prairie O.W. Van Auken (Ed.), Western North American Juniperus Communities: A Dynamic Vegetation Type, Springer, New York, pp. 170–187. DOI: https://doi.org/10.1007/978-0-387-34003-6_9

McKinley, D.C., Blair, J.M. (2008). Woody plant encroachment by Juniperus virginiana in a mesic native grassland promotes rapid carbon and nitrogen accrual. Ecosystems 11:454–468. DOI: https://doi.org/10.1007/s10021-008-9133-4

Meena Archana, Bidalia Ankita, Hanief M., Dinakaran J. and Rao K. S. (2019). Assessment of above- and belowground carbon pools in a semi-arid forest ecosystem of Delhi, India, Ecological Processes, 8:1-11. DOI: https://doi.org/10.1186/s13717-019-0163-y

Mooney, H.A., B.G. Drake, R.J. Luxmore, W.C. Oechel, and L.F Pitelka. (1991). Predicting ecosystem responses to elevated CO2 concentrations. BioScience. 41:96-104. DOI: https://doi.org/10.2307/1311562

Mureva Admore, Chivenge Pauline and Ward David, (2021). Soil organic carbon and nitrogen in soil physical fractions in woody encroached grassland in South African savannas, Soil Research – https://doi.org/10.1071/SR20245 DOI: https://doi.org/10.1071/SR20245

Mureva, A., Ward, D., Pillay, T. Chivenge P. and Cramer M. (2018). Soil Organic Carbon Increases in Semi-Arid Regions while it Decreases in Humid Regions Due to Woody-Plant Encroachment of Grasslands in South Africa. Sci Rep 8:15506. DOI: https://doi.org/10.1038/s41598-018-33701-7

Naikwade, P.V. (2013). Basic and applied research in soil organic matter. Journal of Today’s biological Sciences: Research and Review, 1 (1):138-147.

Naikwade, P.V. (2014). Evaluation of leaf litter compost and vermicompost on yield and nutrient uptake of Trigonella, Indian Journal of Applied Research, 4 (2):1-3. DOI: https://doi.org/10.15373/2249555X/FEB2014/14

Naikwade, P.V. (2017). Impact of climate change on agricultural production in India: effect on rice productivity, Bioscience Discovery, 8(4):897-914.

Naikwade, P.V. (2019). Soil organic carbon sequestration by long-term application of manures prepared from Trianthema portulacastrurm Linn. Communications in Soil Science and Plant Analysis 50(20):2579-2592. DOI: https://doi.org/10.1080/00103624.2019.1671442

Naikwade, P.V. (2020a). Effect of climate change on growth and productivity of cotton: Global Scenario, The International journal of analytical and experimental modal analysis, 12(4):64-80.

Naikwade, P.V. (2020b). Impact of Climate Change on Potato Production and Mitigation Measures, Our heritage Journal, 68 (38):1296-1305.

Naikwade, P.V., Bansode, R.P., Jadhav, S. Tatkare, M., Karande, M. (2017). Estimation of carbon sequestrated in ASP College campus, Devrukh, Dist. Ratnagiri, Maharashtra, India, Bioinfolet, 14(4a): 366-367.

Noble, I., (1997). The contribution of ‘vegetation thickening’ to Australia's greenhouse gas inventory. A Report for the Australian Department of the Environment, Sport & Territories, Canberra, 14.

Ochoa, C.G., Caruso, P., Ray, G., Deboodt, T., Jarvis, W.T., Guldan, S.J. (2018). Ecohydrologic connections in semiarid watershed systems of central Oregon USA. Water. 10, 181. DOI: https://doi.org/10.3390/w10020181

Oelofse, M., Birch-Thomsen, T., Magid, J., de Neergaard, A., van Deventer, R., Bruun, S. and Hill, T. (2016). The impact of black wattle encroachment of indigenous grasslands on soil carbon, Eastern Cape, South Africa. Biological invasions, 18:445–456. DOI: https://doi.org/10.1007/s10530-015-1017-x

Phillips, O.L. Malhi, Y. Higuchi, N. Laurance, W.F., Nunez, P.V. Vasquez, R.M., Laurance, S.G., Ferreira, L.V., Stern, M., Brown, S., Grace J. (1998). Changes in the carbon balance of tropical forests: Evidence from long term plots Science, 282:439–442. DOI: https://doi.org/10.1126/science.282.5388.439

Polley, H.W., Johnson, H.B., Mayeux H.S. (1992). Carbon dioxide and water fluxes of C3 annuals and C3 and C4 perennials at subambient CO2 concentrations Func. Ecol., 6: 693–703. DOI: https://doi.org/10.2307/2389966

Poulter, B., Frank, D., Ciais, P., Myneni, R. B., Andela, N., Bi, J., Broquet, G., Canadell, J. G., Chevallier, F., Liu, Y. Y., Running, S. W., Sitch, S., van der Werf, G. R., (2014). Contribution of semi-arid ecosystems to interannual variability of the global carbon cycle. Nature 509, 600–604. DOI: https://doi.org/10.1038/nature13376

Pyne, S.J., (1991). Burning Bush: A Fire History of Australia. Henry Holt and Company, New York, 520 pp.

Rau, B.M., Johnson, D.W., Blank, R.R., Tausch, R.J., Roundy, B.A., Miller, R.F., Caldwell, T.G., Luccesi, A., (2011). Woodland expansion’s influence on belowground carbon and nitrogen in the Great Basin US. J. Arid Environ. 75, 827–835. DOI: https://doi.org/10.1016/j.jaridenv.2011.04.005

Reynolds, J.F., Smith, D.M.S., Lambin, E.F., Turner II B.L. (2007). Global desertification: building a science for dryland development Science, 316:847–851. DOI: https://doi.org/10.1126/science.1131634

Reynolds, J.F., Virginia, R.A., Kemp, P.R., de Soyza, A.G., Tremmel, D.C. (1999). Impact of drought on desert shrubs: effects of seasonality and degree of resource island development. Ecol Monogr 69(1):69–106. DOI: https://doi.org/10.1890/0012-9615(1999)069[0069:IODODS]2.0.CO;2

Scharenbroch, B.C., Flores‐Mangual, M. L., Lepore, B., Bockheim, J. G. and Lowery B. (2010). Tree encroachment impacts carbon dynamics in a sand prairie in Wisconsin, Soil Sci. Soc. Am. J., 74(3):956–968. DOI: https://doi.org/10.2136/sssaj2009.0223

Schimel, D. et al (2000). Contribution of increasing CO2 and climate to carbon storage by ecosystems in the United States. Science 287: 2004–2006. DOI: https://doi.org/10.1126/science.287.5460.2004

Schlesinger, W.H. (1997). Biogeochemistry: An Analysis of Global Change, 2nd ed., Academic, New York.

Scholes, R.J. and Hall D.O. (1996). The carbon budget of tropical savannas, wodlands and grasslands A.I. Breymeyer, D.O. Hall, J.M. Melillo, G.I. Agren (Eds.), Global Change: Effects on Coniferous Forestes and Grasslands (SCOPE 56), Wiley, Chichester pp. 69–100.

Singh J.S. and Joshi (1979). Ecology of the semi arid regions of India with emphasis on land use. Pages 243-273 in B.H. Walker, ed. Management of semi arid ecosystems. Elsevier, Amsterdam. DOI: https://doi.org/10.1016/B978-0-444-41759-6.50012-8

Sitters, J., Edwards, P. J. and Venterink, H. Olde. (2013). Increases of soil C, N, and P pools along an Acacia tree density gradient and their effects on trees and grasses. Ecosystems 16: 347– 357. DOI: https://doi.org/10.1007/s10021-012-9621-4

Smith, D. and Johnson, L. (2004). Vegetation-mediated changes in microclimate reduce soil respiration as woodlands expand into grasslands. Ecology, 85:3348–3361. DOI: https://doi.org/10.1890/03-0576

Soliveres, S., Maestre, F.T., Eldridge, D.J., Delgado-Baquerizo, M., Luis Quero, J., Bowker, M.A., Gallardo, A. (2014). Plant diversity and ecosystem multifunctionality peak at intermediate levels of woody cover in global drylands. Global Ecology and Biogeography 23 (12):1408-1416. DOI: https://doi.org/10.1111/geb.12215

Solomon, N., Pabi, O., Annang, T. et al. (2018). The effects of land cover change on carbon stock dynamics in a dry Afromontane forest in northern Ethiopia. Carbon Balance Manage, 13, 14. DOI: https://doi.org/10.1186/s13021-018-0103-7

Springsteen, A., W. Loya, M. Liebig, and J. Hendrickson (2010). Soil carbon and nitrogen across a chronosequence of woody plant expansion in North Dakota, Plant Soil, 328(1): 369–379. DOI: https://doi.org/10.1007/s11104-009-0117-8

Steffen, Will, Jäger Jill, Carson David J., Bradshaw Clare (2002). Challenges of a Changing Earth Eds, published by Springer Science and Business Media, NewYork First edition, Oct 2002. DOI: https://doi.org/10.1007/978-3-642-19016-2

Stow, D. A., et al. (2004). Remote sensing of vegetation and land‐cover change in Arctic Tundra Ecosystems, Remote Sens. Environ., 89(3):281–308. DOI: https://doi.org/10.1016/j.rse.2003.10.018

Strain, B.R. and Bazzaz. F.A. (1983). Terrestrial plant communities, In: E.R. Lemon [ed.], CO2 and plants: The response of plants to rising levels of atmospheric carbon dioxide. Boulder, CO: Westview Press: 177-222. DOI: https://doi.org/10.1201/9780429046308-7

Strand, E.K., Vierling, L.A., Smith, A.M.S. and Bunting S.C. (2008). Net changes in aboveground woody carbon stock in western juniper woodlands, 1946–1998, J. Geophys. Res., 113, G01013. DOI: https://doi.org/10.1029/2007JG000544

Tape, K., Sturm, M. and Racine, C. (2006). The evidence for shrub expansion in Northern Alaska and the Pan‐Arctic, Global Change Biol., 12(4):686–702. DOI: https://doi.org/10.1111/j.1365-2486.2006.01128.x

Throop, H.L. and Lajtha, K. (2018). Spatial and temporal changes in ecosystem carbon pools following juniper encroachment and removal. Biogeochemistry. 140:373–388. DOI: https://doi.org/10.1007/s10533-018-0498-y

Tiedemann, A.R., Klemmedson, J.O. (2004). Response of desert grassland vegetation to mesquite removal and regrowth. Journal of Range Management, 57:455–465. DOI: https://doi.org/10.2111/1551-5028(2004)057[0455:RODGVT]2.0.CO;2

Tsegay, G., and Meng, X. Z. (2021). Impact of Ex-Closure in above and below Ground Carbon Stock Biomass. Forests 12, 130. DOI: https://doi.org/10.3390/f12020130

Van Auken, O. W. (2009). Causes and consequences of woody plant encroachment into western North American grasslands. J. Environ. Manage. 90:2931–2942. DOI: https://doi.org/10.1016/j.jenvman.2009.04.023

Van Auken, O.W. (2000). Shrub invasions of North American semiarid grasslands. Annu. Rev. Ecol. Syst. 31:197–215. DOI: https://doi.org/10.1146/annurev.ecolsys.31.1.197

Van Vegten, J.A. (1983). Thornbush invasion in a savanna ecosystem in eastern Botswana. Vegetatio 56:3-7. DOI: https://doi.org/10.1007/BF00036129

Virginia, R. A. (1986). Soil development under legume tree canopies. Forest Ecology and Management 16: 69–79. DOI: https://doi.org/10.1016/0378-1127(86)90009-5

Walker, J. and Gillison, A.N. (1982). Australian savannas. Pages 5-24 in B.J. Huntley and B.H. Walker, eds Ecology of tropical savannas. Springer-Verlag, New York. DOI: https://doi.org/10.1007/978-3-642-68786-0_2

Wang, D., Wu, G. L., Zhu, Y. J. and Shi, Z. H. (2014). Grazing exclusion effects on above‐ and below‐ground C and N pools of typical grassland on the Loess Plateau (China). Catena 123:113–120. DOI: https://doi.org/10.1016/j.catena.2014.07.018

Wessman, C.A., Archer, S.A., Johnson, L.C., Asner, G.P. (2004). Woodland expansion in U.S. grasslands. In: Land Change Science (eds GutmanG et al.), pp. 185–208. Kluwer Academic Press, the Netherlands. DOI: https://doi.org/10.1007/978-1-4020-2562-4_11

Wheeler Megan M., Dipman Madison M., Adams Tessa A., Ruina Annemieke V., Robins Colin R., Meyer Wallace M. (2016). Carbon and nitrogen storage in California sage scrub and non-native grassland habitats. Journal of Arid Environments 129:119-125. DOI: https://doi.org/10.1016/j.jaridenv.2016.02.013

Wheeler, C.W., Archer, S.R., Asner, G.P. and McMurtry C.R. (2007). Climatic/edaphic controls on soil carbon/nitrogen response to shrub encroachment in desert grassland, Ecol. Appl., 17(7):1911–1928. DOI: https://doi.org/10.1890/06-1580.1

Wigley, Benjamin J., Augustine, David J., Coetsee, Corli, Ratnam, Jayashree and Sankaran Mahesh, (2020). Grasses continue to trump trees at soil carbon sequestration following herbivore exclusion in a semiarid African savanna, Ecology, 101(5):1-10. DOI: https://doi.org/10.1002/ecy.3008

Williams, R.J., Carter, J., Duff, G.A., Woinarski, J.CZ., Cook, G.D., and Farrer, S.L. (2005). Carbon accounting, land management, science and policy uncertainty in Australian savanna landscapes: introduction and overview. Australian Journal of Botany (Special Issue) 53:583–588. DOI: https://doi.org/10.1071/BT05181

Wu, X., Li, Z., Fu, B., Zhou, W., Liu, H., and Liu, G. (2014). Restoration of ecosystem carbon and nitrogen storage and microbial biomass after grazing exclusion in semi‐arid grasslands of Inner Mongolia. Ecol. Eng. DOI: https://doi.org/10.1016/j.ecoleng.2014.09.077

Zavaleta, E.S., Kettley, L.S. (2006). Ecosystem change along a woody invasion chronosequence in a California grassland. J Arid Environ 66:290–306. DOI: https://doi.org/10.1016/j.jaridenv.2005.11.008

Zhou, Y., Boutton, T.W. and Wu, X.B. (2017). Soil carbon response to woody plant encroachment: importance of spatial heterogeneity and deep soil storage. Journal of Ecology 105, 1738–1749 DOI: https://doi.org/10.1111/1365-2745.12770