Root biomass, root : shoot ratio and belowground carbon stocks in the open savannahs of Roraima, Brazilian Amazonia
Reinaldo Imbrozio Barbosa A C , Jhonson Reginaldo Silva dos Santos B , Mariana Souza da Cunha B , Tania Pena Pimentel A and Philip Martin Fearnside A C
+ Author Affiliations
- Author Affiliations
A National Institute for Research in the Amazon, Department of Environmental Dynamic, Av. André Araújo 2936, CEP 69060-000, Manaus − Amazonas, Brazil.
B Federal University of Roraima, Post-graduate Program in Natural Resources, Campus Paricarana, Av. Cap. Ene Garcez 2413 − Bairro Aeroporto, 69304-000 Boa Vista – Roraima, Brazil.
C Corresponding author. Email: philip.fearnside@gmail.com
Australian Journal of Botany 60(5) 405-416 https://doi.org/10.1071/BT11312
Submitted: 10 December 2011 Accepted: 30 April 2012 Published: 11 July 2012
Abstract
Biomass of roots, the root : shoot ratio (ratio of below- to aboveground biomass) and carbon stocks belowground (to 100-cm depth) were estimated in different open savannah environments in the extreme north of the Brazilian Amazon. Sampling was conducted in permanent plots established in two open savannah areas in the state of Roraima. We identified four phytopedounits in the 27 plots sampled in two areas: four in dry grasslands on Argisol/Ultisol soils (DG-Arg), eight in dry grasslands on Latosol/Oxisol soils (DG-Lts), five in a mosaic of grasslands with savannah-parkland on Latosol/Oxisol soils (GP-Lts) and 10 in seasonally flooded (wet) grasslands on Hydromorphic/Entisol soils (WG-Hyd). Fine roots (<2 mm diameter) dominated the 0–100-cm vertical profile in the four phytopedounits (>92.5%). Biomass of the roots in WG-Hyd (29.52 ± 7.15 Mg ha–1) was significantly higher as compared with the other phytopedounits studied, although the carbon stocks did not differ among the phytopedounits (6.20–7.21 MgC ha–1). The largest concentration of roots was found in the upper three 10-cm sections of the soil profile, ranging from 56.3 to 82.9% in the four environments. The root : shoot ratio based only on living biomass of roots with diameter ≥2 mm (standard Intergovernmental Panel on Climate Change methodology) ranged from 0 for seasonally flooded grasslands to 0.07–0.20 for unflooded grasslands on clay soils. The results indicate that the root : shoot ratio (expansion factor) for belowground biomass in open savannah ecosystems in the northern Amazon are low and differ from the default values used in Brazil’s reference report to the Climate Convention.
References
Abdala GC, Caldas LS, Haridasan M, Eiten G (1998) Above and belowground organic matter and root : shoot ratio in a cerrado in Central Brazil. Brazilian Journal of Ecology 2, 11–23.Araújo ACO, Barbosa RI (2007) Riqueza e diversidade do estrato arbóreo-arbustivo de duas áreas de savanas em Roraima, Amazônia Brasileira. Mens Agitat 2, 11–18.
Asner GP, Elmore AJ, Olander LP, Martin RE, Harris AT (2004) Grazing systems, ecosystem responses, and global change. Annual Review of Environment and Resources 29, 261–299.
| Grazing systems, ecosystem responses, and global change.Crossref | GoogleScholarGoogle Scholar |
Barbosa RI (1997) Distribuição das chuvas em Roraima. In ‘Homem, ambiente e ecologia no estado de Roraima’. (Eds RI Barbosa, EJG Ferreira, EG Castellon) pp. 325–335. (INPA: Manaus, Amazonas, Brazil)
Barbosa RI (2001) Savanas da Amazônia: emissão de gases do efeito estufa e material particulado pela queima e decomposição da biomassa acima do solo, sem a troca do uso da terra, em Roraima, Brasil. PhD Thesis. Ecology, Instituto Nacional de Pesquisas da Amazônia, Universidade do Amazonas, Manaus, Amazonas, Brazil.
Barbosa RI, Campos C (2011) Detection and geographical distribution of clearing areas in the savannas (‘lavrado’) of Roraima using Google Earth web tool. Journal of Geography and Regional Planning 4, 122–136.
Barbosa RI, Fearnside PM (2005a) Fire frequency and area burned in the Roraima savannas of Brazilian Amazonia. Forest Ecology and Management 204, 371–384.
| Fire frequency and area burned in the Roraima savannas of Brazilian Amazonia.Crossref | GoogleScholarGoogle Scholar |
Barbosa RI, Fearnside PM (2005b) Above-ground biomass and the fate of carbon after burning in the savannas of Roraima, Brazilian Amazonia. Forest Ecology and Management 216, 295–316.
| Above-ground biomass and the fate of carbon after burning in the savannas of Roraima, Brazilian Amazonia.Crossref | GoogleScholarGoogle Scholar |
Barbosa RI, Nascimento SP, Amorim PAF, Silva RF (2005) Notas sobre a composição arbóreo-arbustiva de uma fisionomia das savanas de Roraima, Amazônia Brasileira. Acta Botanica Brasilica 19, 323–329.
| Notas sobre a composição arbóreo-arbustiva de uma fisionomia das savanas de Roraima, Amazônia Brasileira.Crossref | GoogleScholarGoogle Scholar |
Barbosa RI, Campos C, Pinto F, Fearnside PM (2007) The ‘Lavrados’ of Roraima: Biodiversity and Conservation of Brazil’s Amazonian Savannas. Functional Ecosystems and Communities 1, 29–41.
Baruch Z (1994) Responses to drought and flooding in tropical forage grasses I. Biomass allocation, leaf growth and mineral nutrients. Plant and Soil 164, 87–96.
| Responses to drought and flooding in tropical forage grasses I. Biomass allocation, leaf growth and mineral nutrients.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK2MXitlyktbw%3D&md5=63cde1286df031e1e2d4d0afc42c2516CAS |
Beard JS (1953) The savanna vegetation of northern tropical America. Ecological Monographs 23, 149–215.
| The savanna vegetation of northern tropical America.Crossref | GoogleScholarGoogle Scholar |
Benedetti UG, Vale JF, Schaefer CEGR, Melo VF, Uchôa SCP (2011) Gênese, química e mineralogia de solos derivados de sedimentos Pliopleistocênicos e de rochas vulcânicas básicas em Roraima, norte amazônico. Revista Brasileira de Ciencia do Solo 35, 299–312.
| Gênese, química e mineralogia de solos derivados de sedimentos Pliopleistocênicos e de rochas vulcânicas básicas em Roraima, norte amazônico.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3MXhsFyhurnF&md5=abddc225dbc00e930bfaec8e09cb0e22CAS |
Brazil MCT (2004) ‘Brazil’s initial national communication to the United Nations Framework Convention on Climate Change.’ (Ministério de Ciência e Tecnologia: Brazil)
Brazil MCT (2010) ‘Segunda comunicação nacional do Brasil à Convenção-Quadro das Nações Unidas sobre mudança do clima. Vol. 1.’ (Ministério de Ciência e Tecnologia: Brazil) Available at http://www.mct.gov.br/upd_blob/0213/213909.pdf [Verified 11 April 2010]
Brazil Projeto RADAMBRASIL (1975) ‘Levantamento dos recursos naturais. Vol. 8.’ (Ministério das Minas e Energia: Rio de Janeiro)
Brazil SNLCS (1996) ‘Levantamento semidetalhado dos solos e aptidão agrícola das terras do campo experimental água boa do CPAF-RR, estado de Roraima.’ (Empresa Brasileira de Pesquisa Agropecuária, Serviço Nacional de Levantamento e Conservação do Solo: Rio de Janeiro)
Castro EA, Kauffman JB (1998) Ecosystem structure in the Brazilian Cerrado: a vegetation gradient of aboveground biomass, root mass and consumption by fire. Journal of Tropical Ecology 14, 263–283.
| Ecosystem structure in the Brazilian Cerrado: a vegetation gradient of aboveground biomass, root mass and consumption by fire.Crossref | GoogleScholarGoogle Scholar |
Castro-Neves BM (2007) Efeito de queimadas em áreas de cerrado strictu sensu e na biomassa de raízes finas. PhD Thesis. Universidade de Brasília, Brazil.
Cattanio JH, Anderson AB, Rombold JS, Nepstad DC (2004) Phenology, litterfall, growth, and root biomass in a tidal floodplain forest in the Amazon estuary. Revista Brasileira de Botânica 27, 703–712.
Chen X, Eamus D, Hutley LB (2004) Seasonal patterns of fine-root productivity and turnover in a tropical savanna of northern Australia. Journal of Tropical Ecology 20, 221–224.
| Seasonal patterns of fine-root productivity and turnover in a tropical savanna of northern Australia.Crossref | GoogleScholarGoogle Scholar |
Delitti WBC, Pausas JG, Burger DM (2001) Belowground biomass seasonal variation in two Neotropical savannahs (Brazilian Cerrados) with different fire histories. Annals of Forest Science 58, 713–721.
| Belowground biomass seasonal variation in two Neotropical savannahs (Brazilian Cerrados) with different fire histories.Crossref | GoogleScholarGoogle Scholar |
Eden M (1970) Savanna vegetation in the northern Rupununi, Guyana. The Journal of Tropical Geography 30, 17–28.
Eiten G (1978) Delimitation of the Cerrado concept. Plant Ecology 36, 169–178.
| Delimitation of the Cerrado concept.Crossref | GoogleScholarGoogle Scholar |
Espeleta JF, Clark DA (2007) Multi-scale variation in fine-root biomass in a tropical rain forest: a seven-year study. Ecological Monographs 77, 377–404.
| Multi-scale variation in fine-root biomass in a tropical rain forest: a seven-year study.Crossref | GoogleScholarGoogle Scholar |
February EC, Higgins SI (2010) The distribution of tree and grass roots in savannas in relation to soil nitrogen and water. South African Journal of Botany 76, 517–523.
| The distribution of tree and grass roots in savannas in relation to soil nitrogen and water.Crossref | GoogleScholarGoogle Scholar |
Fiala K, Herrera R (1988) Living and dead belowground biomass and its distribution in some savanna communities in Cuba. Folia Geobotanica 23, 225–237.
Furley P (1999) The nature and diversity of neotropical savanna vegetation with particular reference to the Brazilian cerrados. Global Ecology and Biogeography 8, 223–241.
Gale MR, Grigal DF (1987) Vertical distributions of northern tree species in relation to successional status. Canadian Journal of Forest Research 17, 829–834.
| Vertical distributions of northern tree species in relation to successional status.Crossref | GoogleScholarGoogle Scholar |
Gill RA, Jackson RB (2000) Global patterns of root turnover for terrestrial ecosystems. New Phytologist 147, 13–31.
| Global patterns of root turnover for terrestrial ecosystems.Crossref | GoogleScholarGoogle Scholar |
(a) IBGE (1992) ‘Manual técnico da vegetação brasileira.’ (Instituto Brasileiro de Geografia e Estatística, Diretoria de Geociências, Departamento de Recursos Naturais e Estudos Ambientais: Rio de Janeiro)
(b) IPCC (2003) ‘2003 IPCC good practice guidance for land use, land-use change and forestry.’ (Eds J Penman, M Gytarsky, T Hiraishi, T Krug, D Kruger, R Pipatti, L Buendia, K Miwa, T Ngara, K Tanabe, F Wagner) (Institute for Global Environmental Strategies for the Intergovernmental Panel on Climate Change: Kanagawa)
IPCC (2006) ‘2006 IPCC guidelines for national greenhouse gas inventories. Prepared by the National Greenhouse Gas Inventories Programme.’ (Eds HS Eggleston, L Buendia, K Miwa, T Ngara, K Tanabe) (Intergovernmental Panel on Climate Change and Institute for Global Environmental Strategies: Kanagawa)
IPCC (2007) Climate change 2007: synthesis report. Intergovernmental Panel on Climate Change Plenary XXVII, Valencia, Spain, 12–17 November 2007’. Working Group contributions to the Fourth Assessment Report. IPCC, Geneva.
Jackson RB, Canadell J, Ehleringer JR, Mooney HA, Sala OE, Schulze ED (1996) A global analysis of root distributions for terrestrial biomes. Oecologia 108, 389–411.
| A global analysis of root distributions for terrestrial biomes.Crossref | GoogleScholarGoogle Scholar |
Jackson RB, Mooney HA, Schulze ED (1997) A global budget for fine root biomass, surface area, and nutrient contents. Ecology 94, 7362–7366.
Jordan CF, Escalante G (1980) Root productivity in an Amazonian rain forest. Ecology 61, 14–18.
| Root productivity in an Amazonian rain forest.Crossref | GoogleScholarGoogle Scholar |
Kellman M, Sanmugadas K (1985) Nutrient retention by savanna ecosystems I. retention in the absence of fire. Journal of Ecology 73, 935–951.
| Nutrient retention by savanna ecosystems I. retention in the absence of fire.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaL28XltVehtA%3D%3D&md5=ce7ad781dc2f4b4096dca56b63b28a1fCAS |
Klinge H (1973) Root mass estimation in lowland tropical rain forests of central Amazonia Brazil. Tropical Ecology 14, 29–38.
Knoop WT, Walker BH (1985) Interactions of woody and herbaceous vegetation in a southern African savanna. Journal of Ecology 73, 235–253.
| Interactions of woody and herbaceous vegetation in a southern African savanna.Crossref | GoogleScholarGoogle Scholar |
Luizão F, Luizão R, Chauvel A (1992) Premiers résultats sur la dynamique des biomasses racinaires et microbiennes dans un latosol d’Amazonie centrale (Brésil) sous forêt et sous pâturage. Cahiers Orstom, serie. Pédologie (Gent) 27, 69–79.
Magnusson WE, Lima AP, Luizão R, Luizão F, Costa FRC, Castilho CV, Kinupp VF (2005) RAPELD: A modification of the Gentry method for biodiversity surveys in long-term ecological research sites. Biota Neotropica 5(2). http://www.biotaneotropica.org.br/v5n2/pt/abstract?point-of-view+bn01005022005
Manlay RJ, Chotte JL, Masse D, Laurent JY, Feller C (2002) Carbon, nitrogen and phosphorus allocation in agro-ecosystems of a West African savanna. III. Plant and soil components under continuous cultivation. Agriculture Ecosystems & Environment 88, 249–269.
| Carbon, nitrogen and phosphorus allocation in agro-ecosystems of a West African savanna. III. Plant and soil components under continuous cultivation.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD38XhvVWgurk%3D&md5=fc2d9d2d3fb10824e03ccd25daeab45fCAS |
McClaugherty CA, Aber JD, Melillo JM (1982) The role of fine roots in the organic matter and nitrogen budgets of two forested ecosystems. Ecology 63, 1481–1490.
| The role of fine roots in the organic matter and nitrogen budgets of two forested ecosystems.Crossref | GoogleScholarGoogle Scholar |
McKell CM, Wilson AM, Jones MB (1961) A flotation method for easy separation of roots from soil samples. Agronomy Journal 53, 56–57.
| A flotation method for easy separation of roots from soil samples.Crossref | GoogleScholarGoogle Scholar |
McNaughton SJ, Banyikwa FF, McNaughton MM (1998) Root biomass and productivity in a grazing ecosystem: the Serengeti. Ecology 79, 587–592.
| Root biomass and productivity in a grazing ecosystem: the Serengeti.Crossref | GoogleScholarGoogle Scholar |
Medina E, Silva JF (1990) Savannas of northern South America: a steady state regulated by water–fire interactions on a background of low nutrient availability. Journal of Biogeography 17, 403–413.
| Savannas of northern South America: a steady state regulated by water–fire interactions on a background of low nutrient availability.Crossref | GoogleScholarGoogle Scholar |
Menaut JC, Cesar J (1979) Structure and primary productivity of Lamto Savannas, Ivory Coast. Ecology 60, 1197–1210.
| Structure and primary productivity of Lamto Savannas, Ivory Coast.Crossref | GoogleScholarGoogle Scholar |
Milchunas DG, Lauenroth WK (1993) Quantitative effects of grazing on vegetation and soils over a global range of environments. Ecological Monographs 63, 327–366.
| Quantitative effects of grazing on vegetation and soils over a global range of environments.Crossref | GoogleScholarGoogle Scholar |
Miranda IS, Absy ML, Rebêlo GH (2002) Community structure of woody plants of Roraima savannahs, Brazil. Plant Ecology 164, 109–123.
| Community structure of woody plants of Roraima savannahs, Brazil.Crossref | GoogleScholarGoogle Scholar |
Mokany K, Raison RJ, Prokushkin AS (2006) Critical analysis of root : shoot ratios in terrestrial biomes. Global Change Biology 12, 84–96.
| Critical analysis of root : shoot ratios in terrestrial biomes.Crossref | GoogleScholarGoogle Scholar |
Nadelhoffer KJ, Raich JW (1992) Fine root production estimates and belowground carbon allocation in forest ecosystems. Ecology 73, 1139–1147.
| Fine root production estimates and belowground carbon allocation in forest ecosystems.Crossref | GoogleScholarGoogle Scholar |
Neill C (1992) Comparison of soil coring and ingrowth methods for measuring belowground production. Ecology 73, 1918–1921.
| Comparison of soil coring and ingrowth methods for measuring belowground production.Crossref | GoogleScholarGoogle Scholar |
Nelson DW, Sommers LE (1996) Total carbon, organic carbon, and organic matter. In ‘Methods of soil analysis: part 3 – chemical methods’. SSSA Book Series No. 5. pp. 961−1010. (SSSA & ASA: Madison, WI)
Nepstad D, Carvalho CR, Davidson EA, Jipp PH, Lefebvre PA, Negreiros GH, Silva ED, Stone TA, Trumbore SA, Vieira S (1994) The role of deep roots in the hydrological and carbon cycles of Amazonian forests and pastures. Nature 372, 666–669.
| The role of deep roots in the hydrological and carbon cycles of Amazonian forests and pastures.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK2MXislant7c%3D&md5=5760aec75f72add174bf3c94f98edca5CAS |
Newman EI (1966) A method of estimating the total length of root in a sample. Journal of Applied Ecology 3, 139–145.
| A method of estimating the total length of root in a sample.Crossref | GoogleScholarGoogle Scholar |
Oliveira RS, Bezerra L, Davidson ED, Pinto F, Klink CA, Nepstad D, Moreira A (2005) Deep root function in soil water dynamics in cerrado savannas of central Brazil. Functional Ecology 19, 574–581.
| Deep root function in soil water dynamics in cerrado savannas of central Brazil.Crossref | GoogleScholarGoogle Scholar |
Paiva OA, Faria GE (2007) Estoque de carbono do solo sob cerrado sensu stricto no Distrito Federal, Brasil. Revista Trópica – Ciências Agrárias e Biológicas 1, 59–65.
Pandey CB, Singh JS (1992) Rainfall and grazing effects on net primary productivity in a tropical savanna, India. Ecology 73, 2007–2021.
| Rainfall and grazing effects on net primary productivity in a tropical savanna, India.Crossref | GoogleScholarGoogle Scholar |
Priess J, Then C, Fölster H (1999) Litter and fine-root production in three types of tropical premontane rain forest in SE Venezuela. Plant Ecology 143, 171–187.
| Litter and fine-root production in three types of tropical premontane rain forest in SE Venezuela.Crossref | GoogleScholarGoogle Scholar |
Rodin P (2004) Distribuição da biomassa subterrânea e dinâmica de raízes finas em ecossistemas nativos e em uma pastagem plantada no Cerrado do Brasil Central. MSc Thesis. Universidade de Brasília, Instituto de Ciências Biológicas, Brazil.
San José JJ, Fariñas MR (1983) Change in tree density and species composition in a protected Trachypogon savanna, Venezuela. Ecology 64, 447–453.
| Change in tree density and species composition in a protected Trachypogon savanna, Venezuela.Crossref | GoogleScholarGoogle Scholar |
San José JJ, Berrade F, Ramirez J (1982) Seasonal changes of growth mortality and disappearance of belowground root biomass in the Trachypogon savanna grass. Acta Oecologica – Oecologia Plantarum 3, 347–352.
San José JJ, Montes RA, Fariñas MR (1998) Carbon stocks and fluxes in a temporal scaling from a savanna to a semi-deciduous forest. Forest Ecology and Management 105, 251–262.
| Carbon stocks and fluxes in a temporal scaling from a savanna to a semi-deciduous forest.Crossref | GoogleScholarGoogle Scholar |
Santos CPF, Valles GF, Sestini MF, Hoffman P, Dousseau SL, Homem de Mello AJ (2007) Mapeamento dos Remanescentes e Ocupação Antrópica no Bioma Amazônia. In ‘Anais do XIII Simpósio Brasileiro de Sensoriamento Remoto (Florianópolis, Brasil, 21–26 abril 2007)’. pp. 6941–6948. (Instituto Nacional de Pesquisas Espaciais: São José dos Campos, Brazil) Available at http://marte.dpi.inpe.br/rep/dpi.inpe.br/sbsr@80/2006/11.18.01.25?mirror=dpi.inpe.br/banon/2003/12.10.19.30.54&metadatarepository=dpi.inpe.br/sbsr@80/2006/11.18.01.25.31 [Verified 8 April 2009]
Sarmiento G (1984) ‘The ecology of neotropical savannas.’ (Harvard University Press: Cambridge, MA)
Sarmiento G, Vera M (1979) Composición, estructura, biomasa y producción primaria de diferentes sabanas en los Llanos occidentales de Venezuela. Boletin de la Sociedad Venezolana de Ciencia Natural 34, 5–41.
Schenk HJ, Jackson RB (2002a) The global biogeography of roots. Ecological Monographs 72, 311–328.
| The global biogeography of roots.Crossref | GoogleScholarGoogle Scholar |
Schenk HJ, Jackson RB (2002b) Rooting depths, lateral root spreads and below-ground/above-ground allometries of plants in water-limited ecosystems. Journal of Ecology 90, 480–494.
| Rooting depths, lateral root spreads and below-ground/above-ground allometries of plants in water-limited ecosystems.Crossref | GoogleScholarGoogle Scholar |
Scholes RJ, Hall DO (1996) The carbon budget of tropical savannas, woodlands and grasslands. In ‘Global change: effects on coniferous forests and grasslands’. SCOPE − Scientific Committee on Problems of the Environment (v. 56). (Eds AI Breymeyer, DO Hall, JM Melillo, GI Agren) pp. 69–100. (Wiley & Sons: Chichester, UK)
Silver WL, Neff J, McGroddy M, Veldkamp E, Keller M, Cosme R (2000) Effects of soil texture on belowground carbon and nutrient storage in a lowland Amazonian forest ecosystem. Ecosystems 3, 193–209.
| Effects of soil texture on belowground carbon and nutrient storage in a lowland Amazonian forest ecosystem.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3cXktFGht78%3D&md5=4b69d1ad4bc5cc181236ea693934f7f4CAS |
Snowdon P, Eamus D, Gibbons P, Khanna P, Keith H, Raison J, Kirschbaum M (2000) Synthesis of allometrics, review of root biomass and design of future woody biomass sampling strategies. Technical Report no. 17. National Carbon Accounting System: Canberra)
Solbrig OT, Medina E, Silva JF (1996) Biodiversity and tropical savanna properties: a global view. In ‘Functional roles of biodiversity: A global perspective’. (Eds HA Mooney, JH Cushman, E Medina, OE Sala, ED Schulze) pp. 185–211. SCOPE − Scientific Committee on Problems of the Environment. (Wiley & Sons: Chichester)
Sombroek WG, Fearnside PM, Cravo M (2000) Geographic assessment of carbon stored in Amazonian terrestrial ecosystems and their soils in particular. In ‘Global climate change and tropical ecosystems. Advances in soil science’. pp. 375–389. (CRC Press: Boca Raton, FL)
Stanton NL (1988) The underground in grasslands. Annual Review of Ecology and Systematics 19, 573–589.
| The underground in grasslands.Crossref | GoogleScholarGoogle Scholar |
Thompson J, Proctor J, Viana V, Milliken W, Ratter JA, Scott DA (1992) Ecological studies on a lowland evergreen rain forest on Maraca Island, Roraima, Brazil. I. Physical environment, forest structure and leaf chemistry. Journal of Ecology 80, 689–703.
| Ecological studies on a lowland evergreen rain forest on Maraca Island, Roraima, Brazil. I. Physical environment, forest structure and leaf chemistry.Crossref | GoogleScholarGoogle Scholar |
Vitousek PM, Sanford RL (1986) Nutrient cycling in moist tropical forest. Annual Review of Ecology and Systematics 17, 137–167.
| Nutrient cycling in moist tropical forest.Crossref | GoogleScholarGoogle Scholar |
Yavitt JB, Wright SJ (2001) Drought and irrigation effects on fine root dynamics in a Tropical Moist Forest, Panama. Biotropica 33, 421–434.
Zar JH (1999) ‘Biostatistical analysis.’ 4th edn. (Prentice-Hall: Englewood Cliffs, NJ)
