Influence of drainage status on soil and water chemistry, litter decomposition and soil respiration in central Amazonian forests on sandy soils

  • Fabrício Berton Zanchi Universidade Federal do Amazonas
  • Maarten Johannes Waterloo VU University
  • Albertus Johannes Dolman VU University
  • Margriet Groenendijk VU University
  • Jurgen Kesselmeier Max Planck Institute for Chemistry
  • Bart Kruijt Alterra, Wageningen University and Research
  • Marcos Alexandre Bolson Instituto Nacional de Pesquisa da Amazônia
  • Flávio Jesus Luizão Instituto Nacional de Pesquisa da Amazônia
  • Antônio Ocimar Manzi Instituto Nacional de Pesquisa da Amazônia
Keywords: Amazon rainforest, Drought experiment, Campina, Soil Nutrients, CO2 Efflux

Abstract

Central Amazonian rainforest landscape supports a mosaic of tall terra firme rainforest and ecotone campinarana, riparian and campina forests, reflecting topography-induced variations in soil, nutrient and drainage conditions. Spatial and temporal variations in litter decomposition, soil and groundwater chemistry and soil CO2 respiration were studied in forests on sandy soils, whereas drought sensitivity of poorly-drained valley soils was investigated in an artificial drainage experiment. Slightly changes in litter decomposition or water chemistry were observed as a consequence of artificial drainage. Riparian plots did experience higher litter decomposition rates than campina forest. In response to a permanent lowering of the groundwater level from 0.1 m to 0.3 m depth in the drainage plot, topsoil carbon and nitrogen contents decreased substantially. Soil CO2 respiration decreased from 3.7±0.6 µmol m-2 s-1 before drainage to 2.5±0.2 and 0.8±0.1 µmol m-2 s-1 eight and 11 months after drainage, respectively. Soil respiration in the control plot remained constant at 3.7±0.6 µmol m-2 s-1. The above suggests that more frequent droughts may affect topsoil carbon and nitrogen content and soil respiration rates in the riparian ecosystem, and may induce a transition to less diverse campinarana or short-statured campina forest that covers areas with strongly-leached sandy soil.

Author Biographies

Fabrício Berton Zanchi, Universidade Federal do Amazonas
Instituto Agricultura em Ambiente - IAA, possui os Cursos de Engenharia Ambiental e Agronomia que fornece conhecimento para a regiao sul do Estado do amazonas.
Maarten Johannes Waterloo, VU University
Department of Hydrology and Geo-environmental Science, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands.
Albertus Johannes Dolman, VU University
Department of Hydrology and Geo-environmental Science, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands.
Margriet Groenendijk, VU University
Department of Hydrology and Geo-environmental Science, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands.
Jurgen Kesselmeier, Max Planck Institute for Chemistry
Biogeochemistry Department, Joh.-J.-Becher-Weg 27, 55128 Mainz, Germany.
Bart Kruijt, Alterra, Wageningen University and Research
Wageningen University and Research, P.O. Box 47, 6700AA, Wageningen, The Netherlands.
Marcos Alexandre Bolson, Instituto Nacional de Pesquisa da Amazônia
Instituto Nacional de Pesquisa da Amazônia - INPA, Av. André Araújo 2936, Campus 2, CEP: 69060-020, Manaus-AM, Brazil.
Flávio Jesus Luizão, Instituto Nacional de Pesquisa da Amazônia
Instituto Nacional de Pesquisa da Amazônia - INPA, Av. André Araújo 2936, Campus 2, CEP: 69060-020, Manaus-AM, Brazil.
Antônio Ocimar Manzi, Instituto Nacional de Pesquisa da Amazônia
Instituto Nacional de Pesquisa da Amazônia - INPA, Av. André Araújo 2936, Campus 2, CEP: 69060-020, Manaus-AM, Brazil.
Published
28/04/2011
Section
Papers