Informations et ressources scientifiques
sur le développement des zones arides et semi-arides

Accueil du site → Doctorat → Argentine → Estimación de la productividad primaria mediante el modelo de eficiencias y sensores remotos

Universidad de Buenos Aires (2010)

Estimación de la productividad primaria mediante el modelo de eficiencias y sensores remotos

Cristiano, Piedad María

Titre : Estimación de la productividad primaria mediante el modelo de eficiencias y sensores remotos

Primary productivity estimation by efficiency model and remote sensing

Auteur : Cristiano, Piedad María

Université de soutenance : Universidad de Buenos Aires

Grade : Doctor de la Universidad de Buenos Aires en el área de Ciencias Biológicas 2010

Résumé
One of the most commonly models used to estimate net primary productivity (NPP) at regional level is that of Kumar and Monteith efficiencies that allows the inclusion of satellite information. One of the key parameters is the radiation use efficiency (RUE), affected by different stresses. The aim was to improve regional estimates of NPP in grasslands under different stress conditions suggesting a thematic mapping of RUE for the Pampas region, taking into account the prevailing factors of stress (water and nutrition). Through manipulative experiments, changes in the EUR were identified in 4 grasses and a multispecies pasture where the effect of grazing was included. To regionalize these results, we generated a thematic mapping of water and nutritional conditions of the region. To validate this map, the monthly and annual aerial NPP (ANPP) was estimated using MODIS images. Data were compared with ANPP from field data and the results of two other commonly used models. In monospecific experiments, RUE ranged from 2.3-5.2 g/MJ under optimal growth conditions and between 1.02-1.75 g/MJ in plants under stress. In the multispecies experiment, the RUE varied between 0.63-1.94 g/MJ. The estimated annual PPNA presented the lowest values in the southwestern region (minor than 5800 kg/ha.year) and was increasing towards the northeast to reach values of 14,500 kg/ha.year. The validation results indicate that our variable RUE model presents adjustment higher than the fixed RUE model.

Mots clés : PRODUCTIVIDAD PRIMARIA NETA ; FPAR ; EFICIENCIA EN EL USO DE LA RADIACION ; SENSORES REMOTOS ; PASTIZALES ; fPAR ; NET PRIMARY PRODUCTIVITY ; FPAR ; RADIATION USE EFFICIENCY ; REMOTE SENSING ; GRASSLAND

Présentation (Biblioteca Digital)

Version intégrale

Page publiée le 8 mars 2016, mise à jour le 3 juillet 2017