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Soil Nutrient Depletion and Tree Functional Composition Shift Following Repeated Clearing in Secondary Forests of the Congo Basin


The Congo Basin's rapidly growing population still largely depends on shifting cultivation for both energy and food security. This nexus of population growth and ecological impact will continue to exacerbate landscape degradation in the coming decades. To quantify the effects of land-use intensity on soil nutrient stocks and the functional composition of young regrowth forest in the Congo Basin, we used fallows of different ages that had been subjected to a varying number of clearing cycles. We show that repeated clearing substantially affected soil cation stocks, reducing total K, Mg and Ca in the upper 20 cm of soil by roughly 20% per clearing cycle. Additionally, we show that plant-available nitrogen (ammonium and nitrate) and phosphorus decline in the topsoil with increasing land-use intensity. Furthermore, the tree functional composition of young fallows changed after repeated clearing cycles: we observed a decrease in abundance of pioneer species and an increase in nitrogen fixing species early in succession. Variation in soil total nutrient stocks was decoupled from changes in vegetation, and soil plant-available nutrients only marginally explained tree functional composition changes. We conclude that land-use intensity substantially affects both soil total and plant-available nutrients in a shifting cultivation system, as well as the functional composition of the regenerating vegetation. However, compositional changes of the tree community are only partly driven by land-use intensity effects on soil plant-available nutrients.

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  • Adams, M. A., T. L. Turnbull, J. I. Sprent, and N. Buchmann. 2016. Legumes are different: Leaf nitrogen, photosynthesis, and water use efficiency. Proceedings of the National Academy of Sciences of the United States of America 113:4098–4103.

  • Asner, G. P., C. B. Anderson, R. E. Martin, R. Tupayachi, D. E. Knapp, and F. Sinca. 2015. Landscape biogeochemistry reflected in shifting distributions of chemical traits in the Amazon forest canopy. Nature Geoscience 8:567–573.

  • Bartholomew, W. V., J. Meyer, and H. Laudelout. 1953. Mineral nutrien immobilization under forest and grass fallow in the Yangambi. Publications de l’institut national pour l’étude agronomique du Congo Belge 57.

  • Batterman, S. a, L. O. Hedin, M. van Breugel, J. Ransijn, D. J. Craven, and J. S. Hall. 2013. Key role of symbiotic dinitrogen fixation in tropical forest secondary succession. Nature 502:224–7.

  • Baumann, P. (unpublished). simplerspec: Soil and plant spectroscopic model building and prediction. Packages R CRAN.

  • Bauters, M., E. Ampoorter, D. Huygens, E. Kearsley, T. De Haulleville, G. Sellan, H. Verbeeck, P. Boeckx, K. Verheyen, T. De Aulleville, G. Sellan, H. Verbeeck, P. Boeckx, K. Verheyen, T. De Haulleville, G. Sellan, H. Verbeeck, P. Boeckx, and K. Verheyen. 2015. Functional identity explains carbon sequestration in a 77-year-old experimental tropical plantation. Ecosphere 6:1–11.

  • Bauters, M., N. Mapenzi, E. Kearsley, B. Vanlauwe, and P. Boeckx. 2016. Facultative nitrogen fixation by legumes in the central Congo basin is downregulated during late successional stages. Biotropica 48:281–284.

  • Bauters, M., O. Vercleyen, B. Vanlauwe, J. Six, B. Bonyoma, H. Badjoko, W. Hubau, A. Hoyt, M. Boudin, H. Verbeeck, and P. Boeckx. 2019. Long-term recovery of the functional community assembly and carbon pools in an African tropical forest succession. Biotropica 51:319–329.

  • Becknell, J. M., and J. S. Powers. 2014. Stand age and soils as drivers of plant functional traits and aboveground biomass in secondary tropical dry forest. Canadian Journal of Forest Research 44:604–613.

  • Bonnier, C. 1958. Symbiose Rhizobium-Légumineuses en région équatoriale. Publications de l’Institut National pour l’étude Agronomique du Congo Belge 72.

  • Bürkner, P. C. 2017. brms: An R package for Bayesian multilevel models using Stan. Journal of Statistical Software.

  • Carpenter, B., A. Gelman, M. D. Hoffman, D. Lee, B. Goodrich, M. Betancourt, M. A. Brubaker, J. Guo, P. Li, and A. Riddell. 2017. Stan: A probabilistic programming language. Journal of Statistical Software.

  • Carreno-Rocabado, G., M. Pena-Claros, F. Bongers, S. Diaz, F. Quétier, J. Chuvina, and L. Poorter. 2012. Land-use intensification effects on functional properties in tropical plant communities. Ecological Applications 33:81–87.

  • Carrière, S. M., P. Letourmy, and D. B. McKey. 2002. Effects of remnant trees in fallows on diversity and structure of forest regrowth in a slash-and-burn agricultural system in southern Cameroon. Journal of Tropical Ecology 18:375–396.

  • Chadwick OA, Derry LA, Vitousek PM, Huebert BJ, Hedin LO. 1999. Changing sources of nutrients during four million years of ecosystem development. Nature 397:491–7.

  • Curtis, P. G., C. M. Slay, N. L. Harris, A. Tyukavina, and M. C. Hansen. 2018. Classifying drivers of global forest loss. Science 1111:1108–1111.

  • D’Angelo, E., Crutchfield, J., and M. Vandiviere. 2001. Rapid, sensitive, microscale determination of phosphate in water and soil. Journal of Environmental Quality 30:2206–2209.

  • Dalle, S. P., and S. de Blois. 2006. Shorter Fallow Cycles Affect the Availability of Noncrop Plant Resources in a Shifting Cultivation System. Ecology and Society 11.

  • Das, R., D. Lawrence, P. D’Odorico, and M. DeLonge. 2011. Impact of land use change on atmospheric P inputs in a tropical dry forest. Journal of Geophysical Research-Biogeosciences 116:G01027–G01027.

  • Douh, C., K. Daïnou, J. Joël Loumeto, J. M. Moutsambote, A. Fayolle, F. Tosso, E. Forni, S. Gourlet-Fleury, and J. L. Doucet. 2018. Soil seed bank characteristics in two central African forest types and implications for forest restoration. Forest Ecology and Management 409:766–776.

  • Ewel, J. J., M. J. Mazzarino, and C. W. Berish. 1991. Tropical Soil Fertility Changes Under Monocultures and Successional Communities of Different Structure. Ecological Applications 1:289–302.

  • Gerland, P., N. Li, D. Gu, T. Spoorenberg, L. Alkema, B. K. Fosdick, J. Chunn, N. Lalic, G. Bay, and T. Buettner. 2014. World population stabilization unlikely this century. Science 346.

  • Hall SJ, Huang W. 2017. Iron reduction: a mechanism for dynamic cycling of occluded cations in tropical forest soils? Biogeochemistry 136:91–102.

  • Hansen, M. C., P. V. Potapov, R. Moore, M. Hancher, S. A. Turubanova, A. Tyukavina, D. Thau, S. V. Stehman, S. J. Goetz, T. R. Loveland, A. Kommareddy, A. Egorov, L. Chini, C. O. Justice, and J. R. G. Townshend. 2013. High-Resolution Global Maps of. Science 850.

  • Hattori, D., T. Kenzo, T. Shirahama, Y. Harada, J. J. Kendawang, I. Ninomiya, and K. Sakurai. 2019. Degradation of soil nutrients and slow recovery of biomass following shifting cultivation in the heath forests of Sarawak, Malaysia. Forest Ecology and Management 432:467–477.

  • Hood-Nowotny, R., Umana, N. H., Inselbacher, E., Lachouani, P. O., and W. Wanek. 2010. Alternative Methods for Measuring Inorganic, Organic, and Total Dissolved Nitrogen in Soil. SSSAJ 74:1018–1027.

  • Jakovac, C. C., M. Peña-Claros, T. W. Kuyper, and F. Bongers. 2015. Loss of secondary-forest resilience by land-use intensification in the Amazon. Journal of Ecology 103:67–77.

  • Jakovac, C. C., F. Bongers, T. W. Kuyper, R. C. G. Mesquita, and M. Peña-Claros. 2016. Land use as a filter for species composition in Amazonian secondary forests. Journal of Vegetation Science 27:1104–1116.

  • Kaspari, M., M. N. Garcia, K. E. Harms, M. Santana, S. J. Wright, and J. B. Yavitt. 2008. Multiple nutrients limit litterfall and decomposition in a tropical forest. Ecology Letters 11:35–43.

  • Kleinman, P. J. A., R. B. Bryant, and D. Pimentel. 1996. Assessing ecological sustainability of slash-and-burn agriculture through soil fertility indicators. Agronomy Journal 88:122–127.

  • Kuhn, M., and and T. H. Contributions from Jed Wing, Steve Weston, Andre Williams, Chris Keefer, Allan Engelhardt, Tony Cooper, Zachary Mayer, Brenton Kenkel, the R Core Team, Michael Benesty, Reynald Lescarbeau, Andrew Ziem, Luca Scrucca, Yuan Tang, Can Candan. 2018. caret: Classification and Regression Training. R package version 6.0-79.

  • Laliberté, E., and P. Legendre. 2010. A distance-based framework for measuring functional diversity from multiple traits. Ecology 91:299–305.

  • Lambers H, Raven JA, Shaver GR, Smith SE. 2008. Plant nutrient-acquisition strategies change with soil age. Trends in ecology & evolution 23:95–103.

  • Landeweert, R., E. Hoffland, R. D. Finlay, T. W. Kuyper, and N. van Breemen. 2001. Linking plants to rocks: ectomycorrhizal fungi mobilize nutrients from minerals. Trends in ecology & evolution 16:248–254.

  • Lawrence, D., and W. H. Schlesinger. 2001. Changes in Soil Phosphorus during 200 Years of Shifting Cultivation in Indonesia. Ecology 82:2769–2780.

  • Lawrence, D., V. Suma, and J. P. Mogea. 2005. Change in species composition with repeated shifting cultivation: Limited role of soil nutrients. Ecological Applications 15:1952–1967.

  • Lawrence, D., P. D’Odorico, L. Diekmann, M. DeLonge, R. Das, and J. Eaton. 2007. Ecological feedbacks following deforestation create the potential for a catastrophic ecosystem shift in tropical dry forest. Proceedings of the National Academy of Sciences 104:20696–20701.

  • Lawrence, D., C. Radel, K. Tully, B. Schmook, and L. Schneider. 2010. Untangling a Decline in Tropical Forest Resilience: Constraints on the Sustainability of Shifting Cultivation across the Globe. Biotropica 42:21–30.

  • Lohbeck, M., L. Poorter, H. Paz, L. Pla, M. van Breugel, M. Martínez-Ramos, and F. Bongers. 2012. Functional diversity changes during tropical forest succession. Perspectives in Plant Ecology, Evolution and Systematics 14:89–96.

  • Lohbeck, M., L. Poorter, E. Lebrija-Trejos, M. Martinez-Ramos, J. A. Meave, H. Paz, E. A. Perez-Garcia, I. E. Romero-Perez, A. Taura, and F. Bongers. 2013. Successional changes in functional composition contrast for dry and wet tropical forest. Ecology 94:1211–1216.

  • Mertz, O. 2002. The relationship between length of fallow and crop yields in shifting cultivation: A rethinking. Agroforestry Systems 55:149–159.

  • Mevik, B.-H., R. Wehrens, and K. H. Liland. 2019. Partial Least Squares and Principal Component Regression. Packages R CRAN.

  • Molinario, G., M. Hansen, P. Potapov, A. Tyukavina, and S. Stehman. 2020. Contextualizing Landscape-Scale Forest Cover Loss in. Land 2.

  • Moonen, P. C. J., B. Verbist, J. Schaepherders, M. Bwama Meyi, A. Van Rompaey, and B. Muys. 2016. Actor-based identification of deforestation drivers paves the road to effective REDD+ in DR Congo. Land Use Policy 58:123–132.

  • Moonen, P. C. J., B. Verbist, F. Boyemba Bosela, L. Norgrove, S. Dondeyne, K. Van Meerbeek, E. Kearsley, H. Verbeeck, P. Vermeir, P. Boeckx, and B. Muys. 2019. Disentangling how management affects biomass stock and productivity of tropical secondary forests fallows. Science of the Total Environment 659:101–114.

  • Mukul, S. A., and J. Herbohn. 2016. The impacts of shifting cultivation on secondary forests dynamics in tropics: A synthesis of the key findings and spatio temporal distribution of research. Environmental Science and Policy 55:167–177.

  • Nye, P. H., and D. J. Greenland. 1964. Changes in the soil after clearing tropical forest. Plant and Soil.

  • Oksanen, J., F. G. Blanchet, R. Kindt, P. Legendre, P. R. Minchin, R. B. O’Hara, G. L. Simpson, P. Solymos, M. H. H. Stevens, and H. Wagner. 2013. Package ‘vegan.’ R package ver. 2.0–8:254.

  • Piironen, J., and A. Vehtari. 2017. Sparsity information and regularization in the horseshoe and other shrinkage priors. Electronic Journal of Statistics 11:5018–5051.

  • Quesada C a., Phillips OL, Schwarz M, Czimczik CI, Baker TR, Patiño S, Fyllas NM, Hodnett MG, Herrera R, Almeida S, Alvarez Dávila E, Arneth a., Arroyo L, Chao KJ, Dezzeo N, Erwin T, di Fiore a., Higuchi N, Honorio Coronado E, Jimenez EM, Killeen T, Lezama a. T, Lloyd G, López-González G, Luizão FJ, Malhi Y, Monteagudo a., Neill D a., Núñez Vargas P, Paiva R, Peacock J, Peñuela MC, Peña Cruz a., Pitman N, Priante Filho N, Prieto a., Ramírez H, Rudas a., Salomão R, Santos a. JB, Schmerler J, Silva N, Silveira M, Vásquez R, Vieira I, Terborgh J, Lloyd J. 2012. Basin-wide variations in Amazon forest structure and function are mediated by both soils and climate. Biogeosciences 9:2203–46. Last accessed 17/02/2013

  • R Development Core Team. 2018. R: A language and environment for statistical computing. Vienna, Austria,

  • Roder, W., S. Phengchanh, and B. Keoboulapha. 1995. Relationships between soil, fallow period, weeds and rice yield in slash-and-burn systems of Laos. Plant and Soil 176:27–36.

  • Rosenstock NP, Stendahl J, Van Der Heijden G, Lundin L, McGivney E, Bishop K, Löfgren S. 2019. Base cations in the soil bank: Non-exchangeable pools may sustain centuries of net loss to forestry and leaching. Soil 5:351–66.

  • Sanchez, P. A., J. H. Villachica, and D. E. Bandy. 1983. Soil Fertility Dynamics after Clearing a Tropical Rainforest in Peru1. Soil Science Society of America Journal 47:1171.

  • Sanchez, P. A., K. D. Shepherd, M. J. Soule, F. M. Place, R. J. Buresh, A.-M. N. Izac, A. Uzo Mokwunye, F. R. Kwesiga, C. G. Ndiritu, and P. L. Woomer. 1997. Soil Fertility Replenishment in Africa: An Investment in Natural Resource Capital. Page in R. J. Buresh, P. A. Sanchez, and F. Calhoun, editors. Replenishing Soil Fertility in Africa. WI: SSSA, Madison.

  • Tiessen, H., I. H. Salcedo, and E. V. S. B. Sampaio. 1992. Nutrient and soil organic matter dynamics under shifting cultivation in semi-arid northeastern Brazil. Agriculture, Ecosystems and Environment 38:139–151.

  • Vitousek, P. M., and R. W. Howarth. 1991. Nitrogen Limitation on Land and in the Sea: How Can It Occur? Biogeochemis 13:8–115.

  • Vitousek, P. M., and R. L. Sanford. 1986. Nutrient Cycling in Moist Tropical Forest. Annual Review of Ecology and Systematics 17:137–167.

  • Vliet, N. Van, O. Mertz, A. Heinimann, T. Langanke, U. Pascual, B. Schmook, C. Adams, D. Schmidt-vogt, P. Messerli, S. Leisz, J. Castella, L. Jørgensen, T. Birch-thomsen, C. Hett, T. Bech-bruun, A. Ickowitz, K. Chi, K. Yasuyuki, J. Fox, C. Padoch, W. Dressler, and A. D. Ziegler. 2012. Trends, drivers and impacts of changes in swidden cultivation in tropical forest-agriculture frontiers: A global assessment. Global Environmental Change 22:418–429.

  • Walker, T. W., and J. K. Syers. 1976. The fate of phosphorus during pedogenesis. Geoderma 15:1–19.

  • Wood, S. L. R., J. M. Rhemtulla, and O. T. Coomes. 2017. Cropping history trumps fallow duration in long-term soil and vegetation dynamics of shifting cultivation systems: Ecological Applications 27:519–531.

  • WRB. 2006. World reference base for soil resources 2006.

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We gratefully acknowledge the local communities for granting access to their forest and for contributing to the study by sharing their knowledge and helping with data collection. M.B. is funded as a postdoctoral fellow of the research Foundation – Flanders (FWO). We thank two anonymous reviewers and the subject-matter editor, Dr. Peter Vitousek, for their valuable comments on earlier versions of this manuscript.

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Correspondence to Marijn Bauters.

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MB and PM designed the study; MB, PM, LS, DW and MG analyzed samples and data; MB, SD and LM contributed to the methods in the paper; MB, FMM, CE, FB coordinated the fieldwork and helped set up the study design; all authors helped in interpreting the data and writing the paper.

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Bauters, M., Moonen, P., Summerauer, L. et al. Soil Nutrient Depletion and Tree Functional Composition Shift Following Repeated Clearing in Secondary Forests of the Congo Basin. Ecosystems 24, 1422–1435 (2021).

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  • Secondary forests
  • Forest recovery
  • Congo basin
  • Slash-and-burn
  • Shifting agriculture
  • Swidden agriculture
  • Tropical forest