Hierarchical feedbacks of vegetation and soil carbon pools to climate constraints in Brazilian ecosystems

Souza, Ivan Francisco de; Gomes, Lucas de Carvalho; Fernandes Filho, Elpídio Inácio; Silva, Ivo Ribeiro da

doi:10.36783/18069657rbcs20210079

Ivan Francisco de Souza ^**Corresponding author: E-mail: ivanfrsouza@gmail.com ; ivan.souza@ufv.br

Universidade Federal de Viçosa, Departamento de Solos, Programa de Pós-Graduação em Solos e Nutrição de Plantas, Viçosa, Minas Gerais, Brasil.

http://orcid.org/0000-0001-5240-0303

Lucas de Carvalho Gomes

Universidade Federal de Viçosa, Departamento de Solos, Programa de Pós-Graduação em Solos e Nutrição de Plantas, Viçosa, Minas Gerais, Brasil.

http://orcid.org/0000-0002-2105-2470

Elpídio Inácio Fernandes Filho

Universidade Federal de Viçosa, Departamento de Solos, Viçosa, Minas Gerais, Brasil.

http://orcid.org/0000-0002-9484-1411

Ivo Ribeiro da Silva

Universidade Federal de Viçosa, Departamento de Solos, Viçosa, Minas Gerais, Brasil.

http://orcid.org/0000-0002-6730-1487

*Corresponding author: E-mail: ivanfrsouza@gmail.com ; ivan.souza@ufv.br

Editors: José Miguel Reichert orcid.org/0000-0001-9943-2898 and Yuri Jacques Agra Bezerra da Silva orcid.org/0000-0001-6865-7146.

AUTHOR CONTRIBUTIONS

Conceptualization: orcid.org/0000-0001-5240-0303 Ivan Francisco de Souza (lead), orcid.org/0000-0002-6730-1487 Ivo Ribeiro da Silva (lead) and orcid.org/0000-0002-2105-2470 Lucas de Carvalho Gomes (lead).

Data curation: orcid.org/0000-0002-9484-1411 Elpídio Inácio Fernandes Filho (equal), orcid.org/0000-0001-5240-0303 Ivan Francisco de Souza (equal) and orcid.org/0000-0002-2105-2470 Lucas de Carvalho Gomes (lead).

Formal analysis: orcid.org/0000-0002-9484-1411 Elpídio Inácio Fernandes Filho (equal), orcid.org/0000-0001-5240-0303 Ivan Francisco de Souza (equal) and orcid.org/0000-0002-2105-2470 Lucas de Carvalho Gomes (lead).

Investigation: orcid.org/0000-0001-5240-0303 Ivan Francisco de Souza (equal) and orcid.org/0000-0002-2105-2470 Lucas de Carvalho Gomes (lead).

Methodology: orcid.org/0000-0001-5240-0303 Ivan Francisco de Souza (equal) and orcid.org/0000-0002-2105-2470 Lucas de Carvalho Gomes (lead).

Resources: orcid.org/0000-0002-9484-1411 Elpídio Inácio Fernandes Filho (lead) and orcid.org/0000-0002-2105-2470 Lucas de Carvalho Gomes (equal).

Software: orcid.org/0000-0002-9484-1411 Elpídio Inácio Fernandes Filho (lead) and orcid.org/0000-0002-2105-2470 Lucas de Carvalho Gomes (equal).

Supervision: orcid.org/0000-0002-9484-1411 Elpídio Inácio Fernandes Filho (equal) and orcid.org/0000-0002-6730-1487 Ivo Ribeiro da Silva (lead).

Validation: orcid.org/0000-0002-9484-1411 Elpídio Inácio Fernandes Filho (equal) and orcid.org/0000-0002-6730-1487 Ivo Ribeiro da Silva (equal).

Visualization: orcid.org/0000-0001-5240-0303 Ivan Francisco de Souza (equal), orcid.org/0000-0002-6730-1487 Ivo Ribeiro da Silva (equal) and orcid.org/0000-0002-2105-2470 Lucas de Carvalho Gomes (equal).

Writing – original draft: orcid.org/0000-0001-5240-0303 Ivan Francisco de Souza (equal) and orcid.org/0000-0002-2105-2470 Lucas de Carvalho Gomes (equal).

Figures (4)
Tables (2)

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Figure 1
Distribution of frequency for mean annual precipitation (MAP) and mean annual temperature (MAT) across the six major Brazilian biomes, namely Amazon, Caatinga, Cerrado, Atlantic Forest, Pampa and Pantanal.

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Figure 2
Spatial distribution of annual and seasonal ecosystem effective moisture (EEM), i.e., the difference between mean annual precipitation and potential evapotranspiration ( Kramer and Chadwick, 2018Kramer MG, Chadwick OA. Climate-driven thresholds in reactive mineral retention of soil carbon at the global scale. Nat Clim Chang. 2018;8:1104-8. https://doi.org/10.1038/s41558-018-0341-4
https://doi.org/10.1038/s41558-018-0341-... ) across the Brazilian territory. Summer: December–February; Autumn: March–May; Winter: June–August; and Spring: September–November.

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Figure 3
Spatial distribution of vegetation and soil C pools, and their sum to yield the ecosystem C pool in Brazil. The spatial distribution of vegetation C pools has been published by Englund et al. (2017)Englund O, Sparovek G, Berndes G, Freitas F, Ometto JP, Oliveira PVDCE, Costa C, Lapola D. A new high-resolution nationwide aboveground carbon map for Brazil. Geo Geogr Environ. 2017;4:e00045. https://doi.org/10.1002/geo2.45
https://doi.org/10.1002/geo2.45... . Soil C pools included observations from more than 8,200 soil profiles as described elsewhere by Gomes et al. (2019)Gomes LC, Faria RM, Souza E, Veloso GV, Schaefer CEGR, Fernades Filho EI. Modelling and mapping soil organic carbon stocks in Brazil. Geoderma. 2019;340:337-50. https://doi.org/10.1016/j.geoderma.2019.01.007
https://doi.org/10.1016/j.geoderma.2019.... .

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Figure 4
Conceptual model to describe the control of temperature and precipitation on ecosystem effective moisture (EEM), which in turn determines the partition of C and vegetation and soils across the six major Brazilian biomes: Amazon, Cerrado, Pantanal, Caatinga, Pampa and Atlantic Forest.

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Table 1
Pearson’s correlation coefficients ( r ) for the spatial distribution of mean annual precipitation (MAP), temperature (MAT), ecosystem effective moisture (EEM), plant and soil C pools across the six Brazilian biomes and the whole country

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Table 2
Major climate constraints (temperature and precipitation) on ecosystem effective moisture (EEM) and their impacts on ecosystem C pools (vegetation and soils) across the major Brazilian biomes and supporting evidence from the literature consulted

Biome	Variables	MAT	EEM	Plant C pools	Soil C pools	Ecosystem C pools
Amazon	MAP	0.20	0.99	0.40	0.50	0.50
	MAT		0.20	0.10	-0.10	0.10
	EEM			0.40	0.50	0.50
	Plant C pools				0.20	0.99
	Soil C pools					0.50
Atlantic Forest	MAP	-0.50	0.90	0.20	0.50	0.40
	MAT		-0.70	-0.20	-0.80	-0.60
	EEM			0.20	0.70	0.60
	Plant C pools				0.20	0.80
	Soil C pools					0.70
Caatinga	MAP	0.30	0.80	0.20	0.30	0.30
	MAT		0.00	-0.10	-0.60	-0.50
	EEM			0.20	0.50	0.50
	Plant C pools				0.30	0.70
	Soil C pools					0.80
Cerrado	MAP	0.20	0.90	0.00	0.10	0.10
	MAT		-0.10	0.20	-0.60	-0.20
	EEM			-0.10	0.20	0.10
	Plant C pools				-0.20	0.70
	Soil C pools					0.60
Pampa	MAP	0.50	0.80	0.00	-0.10	-0.10
	MAT		0.30	-0.10	-0.20	-0.30
	EEM			0.00	-0.20	-0.20
	Plant C pools				0.10	0.70
	Soil C pools					0.80
Pantanal	MAP	-0.20	0.90	-0.30	-0.10	-0.30
	MAT		0.00	0.20	-0.30	0.00
	EEM			-0.20	0.00	-0.10
	Plant C pools				0.20	0.90
	Soil C pools					0.60
Brazil	MAP	0.40	0.99	0.70	0.30	0.80
	MAT		0.20	0.40	-0.50	0.20
	EEM			0.70	0.40	0.80
	Plant C pools				0.10	0.90
	Soil C pools					0.40

Precipitation and temperature constraints on ecosystem effective moisture	Impact on ecosystem C pools	Occurrence	Supporting evidence from the literature
High moisture availability due to the control of precipitation on EEM, regardless of temperature	Carbon pools can be much higher in vegetation than in soils, which C sink strength is reduced; Transport of C by water percolating through the soil profile could contribute significantly for mineral-organic associations in subsoil horizons; Ecosystem C pools are determined by the vegetation.	Predominantly humid forests across the Amazon domain	Plants invest C in organs with long time span ( Herrera et al., 1978Herrera R, Merida T, Stark N, Jordan CF. Direct phosphorus transfer from leaf litter to roots. Naturwissenschaften. 1978;65:208-9. https://doi.org/10.1007/BF00450594 https://doi.org/10.1007/BF00450594... ; Aerts, 1995Aerts R. The advantages of being evergreen. Trends Ecol Evol. 1995;10:402-7. https://doi.org/10.1016/S0169-5347(00)89156-9 https://doi.org/10.1016/S0169-5347(00)89... ; Wardle et al., 2004Wardle DA, Bardgett RD, Klironomos JN, Setälä H, van der Putten WH, Wall DH. Ecological linkages between aboveground and belowground biota. Science. 2004;304:1629-33. https://doi.org/10.1126/science.1094875 https://doi.org/10.1126/science.1094875... ; Körner, 2017Körner C. A matter of tree longevity. Science. 2017;355:130-1. https://doi.org/10.1126/science.aal2449 https://doi.org/10.1126/science.aal2449... );
			High resorption rates of nutrients in senescing leaves, especially P ( Vitousek and Sanford, 1986Vitousek PM, Sanford RL. Nutrient cycling in moist tropical forest. Annu Rev Ecol Syst. 1986;17:137-67. https://doi.org/10.1146/annurev.es.17.110186.001033 https://doi.org/10.1146/annurev.es.17.11... ; Cleveland and Liptzin, 2007Cleveland CC, Liptzin D. C:N:P stoichiometry in soil: Is there a “Redfield ratio” for the microbial biomass? Biogeochemistry. 2007;85:235-52. https://doi.org/10.1007/s10533-007-9132-0 https://doi.org/10.1007/s10533-007-9132-... ; Vergütz et al., 2012Vergütz L, Manzoni S, Porporato A, Novais RF, Jackson RB. Global resorption efficiencies and concentrations of carbon and nutrients in leaves of terrestrial plants. Ecol Monogr. 2012;82:205-20. https://doi.org/10.1890/11-0416.1 https://doi.org/10.1890/11-0416.1... );
			Wide C-to-nutrient ratios reduce microbial C use efficiency during litter decay in the soil ( Cleveland et al., 2002Cleveland CC, Townsend AR, Schmidt SK. Phosphorus limitation of microbial processes in moist tropical forests: Evidence from short-term laboratory incubations and field studies. Ecosystems. 2002;5:680-91. https://doi.org/10.1007/s10021-002-0202-9 https://doi.org/10.1007/s10021-002-0202-... ; Manzoni et al., 2010Manzoni S, Trofymow JA, Jackson RB, Porporato A. Stoichiometric controls on carbon, nitrogen, and phosphorus dynamics in decomposing litter. Ecol Monogr. 2010;80:89-106. https://doi.org/10.1890/09-0179.1 https://doi.org/10.1890/09-0179.1... ; Schneider et al., 2012Schneider T, Keiblinger KM, Schmid E, Sterflinger-Gleixner K, Ellersdorfer G, Roschitzki B, Richter A, Eberl L, Zechmeister-Boltenstern S, Riedel K. Who is who in litter decomposition? Metaproteomics reveals major microbial players and their biogeochemical functions. ISME J. 2012;6:1749-62. https://doi.org/10.1038/ismej.2012.11. https://doi.org/10.1038/ismej.2012.11... ; Zechmeister-Boltenstern et al., 2015Zechmeister-Boltenstern S, Keiblinger KM, Mooshammer M, Peñuelas J, Richter A, Sardans J, Wanek W. The application of ecological stoichiometry to plant-microbial-soil organic matter transformations. Ecol Monogr. 2015;85:133-55. https://doi.org/10.1890/14-0777.1 https://doi.org/10.1890/14-0777.1... ; Camenzind et al., 2018Camenzind T, Hättenschwiler S, Treseder KK, Lehmann A, Rillig MC. Nutrient limitation of soil microbial processes in tropical forests. Ecol Monogr. 2018;88:4-21. https://doi.org/10.1002/ecm.1279 https://doi.org/10.1002/ecm.1279... );
			Microbial succession during the decay of plant litter alleviates nutrient stoichiometric constraints, but respiration rates increase ( Kaiser et al., 2014Kaiser C, Franklin O, Dieckmann U, Richter A. Microbial community dynamics alleviate stoichiometric constraints during litter decay. Ecol Lett. 2014;17:680-90. https://doi.org/10.1111/ele.12269 https://doi.org/10.1111/ele.12269... ; Maynard et al., 2017Maynard DS, Crowther TW, Bradford MA. Fungal interactions reduce carbon use efficiency. Ecol Lett. 2017;20:1034-42. https://doi.org/10.1111/ele.12801 https://doi.org/10.1111/ele.12801... );
			Carbon use efficiency by soil microbes is low under high temperatures ( Manzoni et al., 2012Manzoni S, Taylor P, Richter A, Porporato A, Ågren GI. Environmental and stoichiometric controls on microbial carbon-use efficiency in soils. New Phytol. 2012;196:79-91. https://doi.org/10.1111/j.1469-8137.2012.04225.x https://doi.org/10.1111/j.1469-8137.2012... ; Frey et al., 2013Frey SD, Lee J, Melillo JM, Six J. The temperature response of soil microbial efficiency and its feedback to climate. Nat Clim Chang. 2013;3:395-8. https://doi.org/10.1038/nclimate1796 https://doi.org/10.1038/nclimate1796... ; Qiao et al., 2019Qiao Y, Wang J, Liang G, Du Z, Zhou J, Zhu C, Huang K, Zhou X, Luo Y, Yan L, Xia J. Global variation of soil microbial carbon-use efficiency in relation to growth temperature and substrate supply. Sci Rep. 2019;9:5621. https://doi.org/10.1038/s41598-019-42145-6 https://doi.org/10.1038/s41598-019-42145... );
			High denitrification rates (“open” N cycle) are linked to wide N:P ratios ( Martinelli et al., 1999Martinelli LA, Piccolo MC, Townsend AR, Vitousek PM, Cuevas E, McDowell W, Robertson GP, Santos OC, Treseder K. Nitrogen stable isotopic composition of leaves and soil: Tropical versus temperate forests. Biogeochemistry. 1999;46:45-65. https://doi.org/10.1023/A:1006100128782 https://doi.org/10.1023/A:1006100128782... ; Breuer et al., 2002Breuer L, Kiese R, Butterbach-Bahl K. Temperature and moisture effects on nitrification rates in tropical rain-forest soils. Soil Sci Soc Am J. 2002;66:834-44. https://doi.org/10.2136/sssaj2002.8340 https://doi.org/10.2136/sssaj2002.8340... ; Davidson et al., 2007Davidson EA, Carvalho CJR, Figueira AM, Ishida FY, Ometto JPHB, Nardoto GB, Sabá RT, Hayashi SN, Leal EC, Vieira ICG, Martinelli LA. Recuperation of nitrogen cycling in Amazonian forests following agricultural abandonment. Nature. 2007;447:995-8. https://doi.org/10.1038/nature05900 https://doi.org/10.1038/nature05900... );
			In permanent or temporarily water-saturated soils, nitrate can be used as an alternative electron acceptor to oxygen, keeping soil C mineralization at high rates ( Bollmann and Conrad, 1998Bollmann A, Conrad R. Influence of O2availability on NO and N2O release by nitrification and denitrification in soils. Glob Chang Biol. 1998;4:387-96. https://doi.org/10.1046/j.1365-2486.1998.00161.x https://doi.org/10.1046/j.1365-2486.1998... ; Houlton et al., 2006Houlton BZ, Sigman DM, Hedin LO. Isotopic evidence for large gaseous nitrogen losses from tropical rainforests. Proc Natl Acad Sci. 2006;103:8745-50. https://doi.org/10.1073/pnas.0510185103 https://doi.org/10.1073/pnas.0510185103... ; Butterbach-Bahl et al., 2013Butterbach-Bahl K, Baggs EM, Dannenmann M, Kiese R, Zechmeister-Boltenstern S. Nitrous oxide emissions from soils: how well do we understand the processes and their controls? Phil Trans R Soc B. 2013;368:20130122. https://doi.org/10.1098/rstb.2013.0122 https://doi.org/10.1098/rstb.2013.0122... ; Keiluweit et al., 2016Keiluweit M, Nico PS, Kleber M, Fendorf S. Are oxygen limitations under recognized regulators of organic carbon turnover in upland soils? Biogeochemistry. 2016;127:157-71. https://doi.org/10.1007/s10533-015-0180-6 https://doi.org/10.1007/s10533-015-0180-... );
			Shallow root mats optimize nutrient recycling at or close to the soil surface ( Stark and Jordan, 1978Stark NM, Jordan CF. Nutrient retention by the root mat of an Amazonian rain forest. Ecology. 1978;59:434-7. https://doi.org/10.2307/1936571 https://doi.org/10.2307/1936571... ; Jordan and Escalante, 1980Jordan CF, Escalante G. Root productivity in an amazonian rain forest. Ecology. 1980;61:14-8. https://doi.org/10.2307/1937148 https://doi.org/10.2307/1937148... ; Kingsbury and Kellman, 1997Kingsbury N, Kellman M. Root mat depths and surface soil chemistry in Southeastern Venezuela. J Trop Ecol. 1997;13:475-9. https://doi.org/10.1017/S0266467400010646 https://doi.org/10.1017/S026646740001064... ).
Moderate to high restrictions in moisture availability with high temperatures controlling EEM owing to seasonal and/or low precipitation levels	Carbon inputs to soils may be limited by low primary productivity; Vegetation C sink strength is weakened, and plants contribute little for total ecosystem C pools.	Dry forests (Caatinga), grasslands (Pampa), Brazilian savanna (Cerrado), mixed vegetation in the Pantanal and deciduous forests of the Atlantic Forest and Cerrado domains	Soil C pools may be limited by shallow soil profiles ( Corrêa et al., 2019Corrêa ACB, Tavares BAC, Lira DR, Mutzenberg DS, Cavalcanti LCS. The semi-arid domain of the Northeast of Brazil. In: Salgado AAR, Santos LJC, Paisani JC, editors. The physical geography of Brazil. Geography of the physical environment. Cham: Springer International Publishing; 2019. p. 119-50. https://doi.org/10.1007/978-3-030-04333-9_7 https://doi.org/10.1007/978-3-030-04333-... );
			Vegetation C pools may be limited by seasonal precipitation and/or low primary productivity ( Bond and Keeley, 2005Bond WJ, Keeley JE. Fire as a global “herbivore”: The ecology and evolution of flammable ecosystems. Trends Ecol Evol. 2005;20:387-94. https://doi.org/10.1016/j.tree.2005.04.025 https://doi.org/10.1016/j.tree.2005.04.0... ; Dexter et al., 2018Dexter KG, Pennington RT, Oliveira-Filho AT, Bueno ML, Miranda PLS, Neves DM. Inserting tropical dry forests into the discussion on biome transitions in the tropics. Front Ecol Evol. 2018;6:104. https://doi.org/10.3389/fevo.2018.00104 https://doi.org/10.3389/fevo.2018.00104... );
			Part of the biomass produced during the humid season may dry out once precipitation declines under high temperatures ( Coutinho, 1990Coutinho LM. Fire in the ecology of the Brazilian Cerrado. In: Goldammer JG, editor. Fire in the Tropical Biota. Ecological Studies (Analysis and Synthesis). Heidelberg: Springer; 1990. p. 82-105. ; Sarmiento, 1992Sarmiento G. Adaptive strategies of perennial grasses in South American savannas. J Veg Sci. 1992;3:325-36. https://doi.org/10.2307/3235757 https://doi.org/10.2307/3235757... ; Moritz et al., 2005Moritz MA, Morais ME, Summerell LA, Carlson JM, Doyle J. Wildfires, complexity, and highly optimized tolerance. Proc Natl Acad Sci. 2005;102:17912-7. https://doi.org/10.1073/pnas.0508985102 https://doi.org/10.1073/pnas.0508985102... );
			Dried biomass may be burnt upon ignition events depending on the amount of combustible available ( Bond and Keeley, 2005Bond WJ, Keeley JE. Fire as a global “herbivore”: The ecology and evolution of flammable ecosystems. Trends Ecol Evol. 2005;20:387-94. https://doi.org/10.1016/j.tree.2005.04.025 https://doi.org/10.1016/j.tree.2005.04.0... );
			Fire events trigger biomass mineralization and can favor nutrient volatilization and/or transport of particles by wind, particularly N and S, but not only these elements ( Pivello and Coutinho, 1992Pivello VR, Coutinho LM. Transfer of macro-nutrients to the atmosphere during experimental burnings in an open cerrado (Brazilian savanna). J Trop Ecol. 1992;8:487-7. https://doi.org/10.1017/S0266467400006829 https://doi.org/10.1017/S026646740000682... ; Pivello et al., 2010Pivello VR, Oliveras I, Miranda HS, Haridasan M, Sato MN, Meirelles ST. Effect of fires on soil nutrient availability in an open savanna in Central Brazil. Plant Soil. 2010;337:111-23. https://doi.org/10.1007/s11104-010-0508-x https://doi.org/10.1007/s11104-010-0508-... );
			Frequent burning of aboveground biomass, increases the relative importance of belowground C inputs to soils ( Hoffmann and Franco, 2003Hoffmann WA, Franco AC. Comparative growth analysis of tropical forest and savanna woody plants using phylogenetically independent contrasts. J Ecol. 2003;91:475-84. https://doi.org/10.1046/j.1365-2745.2003.00777.x https://doi.org/10.1046/j.1365-2745.2003... );
			Nutrients can be stored in roots or other belowground organs with long timespan ( Hoffmann and Franco, 2003Hoffmann WA, Franco AC. Comparative growth analysis of tropical forest and savanna woody plants using phylogenetically independent contrasts. J Ecol. 2003;91:475-84. https://doi.org/10.1046/j.1365-2745.2003.00777.x https://doi.org/10.1046/j.1365-2745.2003... ; Appezzato-da-Glória et al., 2008Appezzato-da-Glória B, Cury G, Soares MKM, Rocha R, Hayashi AH. Underground systems of Asteraceae species from the Brazilian Cerrado. J Torrey Bot Soc. 2008;135:103-13. https://doi.org/10.3159/07-RA-043.1 https://doi.org/10.3159/07-RA-043.1... ; Simon and Pennington, 2012Simon MF, Pennington T. Evidence for adaptation to fire regimes in the tropical savannas of the Brazilian Cerrado. Int J Plant Sci. 2012;173:711-23. https://doi.org/10.1086/665973 https://doi.org/10.1086/665973... );
			High nutrient resorption favors graminoids under frequent fire ( Aerts, 1996Aerts R. Nutrient resorption from senescing leaves of perennials: Are there general patterns? J Ecol. 1996;84:597-608. https://doi.org/10.2307/2261481 https://doi.org/10.2307/2261481... ).
Moderate restrictions in moisture availability with reducing precipitation levels coincident with decreasing temperatures limiting evapotranspiration	Soil C sink strength is greater than that of the vegetation; Deep rooting should contribute more for mineral-organic associations than transport by percolating water to form subsoil C pools; Vegetation may account for a significant fraction of the whole ecosystem C pool.	Predominantly across the semideciduous and mixed forests of the Atlantic Forest domain	Plants that keep their leaves during the dry season should increase C allocation into roots ( Markesteijn et al., 2010Markesteijn L, Iraipi J, Bongers F, Poorter L. Seasonal variation in soil and plant water potentials in a Bolivian tropical moist and dry forest. J Trop Ecol. 2010;26:497-508. https://doi.org/10.1017/S0266467410000271 https://doi.org/10.1017/S026646741000027... );
			Leaf-shedding plants represent between 25 and 50 % of the vegetation ( Arruda et al., 2018Arruda DM, Schaefer CEGR, Fonseca RS, Solar RRC, Fernandes Filho EI. Vegetation cover of Brazil in the last 21 ka: New insights into the Amazonian refugia and Pleistocenic arc hypotheses. Glob Ecol Biogeogr. 2018;27:47-56. https://doi.org/10.1111/geb.12646 https://doi.org/10.1111/geb.12646... );
			Leaf-shedding may be followed by root senescence ( Kummerow et al., 1990Kummerow J, Castillanos J, Maas M, Larigauderie A. Production of fine roots and the seasonality of their growth in a Mexican deciduous dry forest. Vegetatio. 1990;90:73-80. https://doi.org/10.1007/BF00045590 https://doi.org/10.1007/BF00045590... ; Eissenstat and Yanai, 1997Eissenstat DM, Yanai RD. The ecology of root lifespan. Adv Ecol Res. 1997;27:1-60. https://doi.org/10.1016/s0065-2504(08)60005-7 https://doi.org/10.1016/s0065-2504(08)60... ; Campo et al., 1998Campo J, Jaramillo VJ, Maass JM. Pulses of soil phosphorus availability in a Mexican tropical dry forest: Effects of seasonality and level of wetting. Oecologia. 1998;115:167-72. https://doi.org/10.1007/s004420050504 https://doi.org/10.1007/s004420050504... ; Brunner et al., 2015Brunner I, Herzog C, Dawes MA, Arend M, Sperisen C. How tree roots respond to drought. Front Plant Sci. 2015;6:547. https://doi.org/10.3389/fpls.2015.00547 https://doi.org/10.3389/fpls.2015.00547... );
			Plants that keep their leaves under reduced moisture availability may invest C in deep rooting ( Markesteijn and Poorter, 2009Markesteijn L, Poorter L. Seedling root morphology and biomass allocation of 62 tropical tree species in relation to drought- and shade-tolerance. J Ecol. 2009;97:311-25. https://doi.org/10.1111/j.1365-2745.2008.01466.x https://doi.org/10.1111/j.1365-2745.2008... ; Brunner et al., 2015Brunner I, Herzog C, Dawes MA, Arend M, Sperisen C. How tree roots respond to drought. Front Plant Sci. 2015;6:547. https://doi.org/10.3389/fpls.2015.00547 https://doi.org/10.3389/fpls.2015.00547... );
			Aboveground C inputs are added to the soil surface when the potential for fast mineralization rates is low ( Sayer et al., 2006Sayer EJ, Tanner EVJ, Cheesman AW. Increased litterfall changes fine root distribution in a moist tropical forest. Plant Soil. 2006;281:5-13. https://doi.org/10.1007/s11104-005-6334-x https://doi.org/10.1007/s11104-005-6334-... );
			Reduced evapotranspiration under cool temperatures during the dry season limits the risk of fire ( Duff et al., 2018Duff TJ, Cawson JG, Harris S. Dryness thresholds for fire occurrence vary by forest type along an aridity gradient: evidence from Southern Australia. Landsc Ecol. 2018;33:1369-83. https://doi.org/10.1007/s10980-018-0655-7 https://doi.org/10.1007/s10980-018-0655-... );
			Soil C pools are favored by deep rooting ( Jobbágy and Jackson, 2000Jobbágy E, Jackson R. The vertical distribution of soil organic carbon and its relation to climate and vegetation. Ecol Appl. 2000;10:423-36. https://doi.org/10.1890/1051-0761(2000)010%255B0423:TVDOSO%255D2.0.CO%253B2 https://doi.org/10.1890/1051-0761(2000)0... ; Markesteijn et al., 2010Markesteijn L, Iraipi J, Bongers F, Poorter L. Seasonal variation in soil and plant water potentials in a Bolivian tropical moist and dry forest. J Trop Ecol. 2010;26:497-508. https://doi.org/10.1017/S0266467410000271 https://doi.org/10.1017/S026646741000027... ; Brunner et al., 2015Brunner I, Herzog C, Dawes MA, Arend M, Sperisen C. How tree roots respond to drought. Front Plant Sci. 2015;6:547. https://doi.org/10.3389/fpls.2015.00547 https://doi.org/10.3389/fpls.2015.00547... );
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[1] *Corresponding author: E-mail: ivanfrsouza@gmail.com ; ivan.souza@ufv.br

Brasil

Brasil

Hierarchical feedbacks of vegetation and soil carbon pools to climate constraints in Brazilian ecosystems

ABSTRACT: