Submitted to: Ecological Society of America Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: August 9, 2001
Publication Date: August 9, 2001
Citation: RUSSELL, A.E., CAMBARDELLA, C.A. SPECIES AND MANAGEMENT EFFECTS ON SOIL CARBON DYNAMICS IN EXPERIMENTAL TROPICAL ECOSYSTEMS. ECOLOGICAL SOCIETY OF AMERICA PROCEEDINGS. 2001. Paper No. RUS-9803-58467.
Our objective was to quantify the effects of species composition, species richness and rotation length on soil organic matter (SOM) dynamics in a humid-lowland site in Costa Rica. We evaluated potential mechanisms of species' influence: the quantity and quality of detrital inputs. The experimental design consisted of: 3 tree species in monoculture (Cedrela odorata, Cordia alliodora, Hyeronima alchorneoides) x 3 rotation lengths (1-yr, 4-yr and long-term) x 3 blocks x 4 sampling times. In the long- term rotation, each species was grown also in polyculture with Euterpe oleracea and Heliconia imbricata. In years 9-10 of the experiment, we measured total SOM, particulate organic matter (POM an index of soil fertility), root growth, litterfall, and tissue quality of roots and senesced leaves of the five species. Total soil organic C (3610-4080 g/m2 over all treatments) did not differ significantly among treatments. However, POM amounts did vary significantly, from 0.66 to 3.42 g C/kg soil, with individual species differing in their response to rotation length. POM correlated significantly with quality of detrital inputs (leaf and root C:N ratio), but not with quantity of litterfall or root growth. We conclude that tropical tree species do differ in their effects on SOM dynamics, and that species' effects may be largely driven by phytochemistry, rather than production. Our results provide insights for restoration of soil fertility in the humid tropics, design of sustainable agroecosystems, and carbon sequestration.