Skip to Main content Skip to Navigation
Master Thesis

Évaluation de la biomasse et de la productivité souterraines du caféier dans un système agroforestier au Costa Rica

Abstract : Net primary productivity is a critical component for understanding functioning, productivity and carbon allocation of ecosystem. In Costa Rica, an ongoing study on aboveground NPP has been conducted on arabica coffee cultivated agroforestry system, under the canopy of Erythrina. Allocation of NPP to different above-ground compartments of the coffee tree (leaves, fruits, and branches) was already known and quantified. Our study focuses on belowground NPP: we distinguished perennial coffee roots (tap root, coarse roots and medium roots) from fine coffee roots (Φ < 2 mm). The challenge was to evaluate the belowground productivity of this coppice, rooted down to 450 cm (several plants by location and periodic pruning of resprouts). We developed allometric relationships between coffee root biomass and the basal area of coffee for a depth of 150 cm, extrapolated at 450 cm. Fine root turnover, a component of NPP, has been estimated by sequential soil coring (30 cm deep). Biomass of fine roots was compared using two methods: Voronoï trench (150 cm) and sequential coring (measured for 30 cm, extrapolated at 450 cm). We extrapolated belowground biomass and NPP to the plot scale from an available inventory. We estimated root biomass at 42,tMS.ha-1 with Voronoï trench, around 30% of the whole plant biomass NPP was 1.45 tDM.ha-1.an-1 for perennials roots and from 0.83 at 1.27 tDM ha-1.an-1 for fine roots. Neither fine roots NPP nor biomass depended on the distance to shade trees. Belowground NPP contributed to 11% of the whole plant NPP.
Document type :
Master Thesis
Complete list of metadata

Cited literature [34 references]  Display  Hide  Download

https://dumas.ccsd.cnrs.fr/dumas-00782273
Contributor : Agrocampus Ouest <>
Submitted on : Wednesday, January 30, 2013 - 8:49:05 AM
Last modification on : Monday, July 6, 2020 - 3:38:21 PM
Long-term archiving on: : Monday, June 17, 2013 - 5:12:31 PM

Identifiers

  • HAL Id : dumas-00782273, version 1

Collections

Citation

Elsa Defrenet. Évaluation de la biomasse et de la productivité souterraines du caféier dans un système agroforestier au Costa Rica. Sciences agricoles. 2012. ⟨dumas-00782273⟩

Share

Metrics

Record views

6742

Files downloads

6144