Fecha/hora: 03/06/2024 04:05:51

Biblioteca(s): | INIA Treinta y Tres.
Fecha corriente: | 12/09/2014
Fecha de la última actualización: | 27/09/2018
Autoria: | BAEZA, S.; LEZAMA, F.; PIÑEIRO, G.; ALTESOR, A.; PARUELO, J.M.
Afiliación: | FELIPE LEZAMA HUERTA, Instituto Nacional de Investigación Agropecuaria (INIA), Uruguay.
Título: | Spatial variability of above-ground net primary production in Uruguayan grasslands: A remote sensing approach.
Año de publicación: | 2010
Fuente/Imprenta: | Applied Vegetation Science, 2010, v. 13, no. 1 p. 72-85.
ISSN: | 1654-109X
DOI: | 10.1111/j.1654-109X.2009.01051.x
Idioma: | Inglés
Notas: | Article history: Received 4 November 2008;  accepted 16 July 2009. Published in 2010.

Contenido:

Abstract:
Question: How does above-ground net primary production (ANPP) differ (estimated from remotely sensed data) among vegetation units in sub-humid temperate grasslands?
Location: Centre-north Uruguay. 
Methods: A vegetation map of the study area was generated from LANDSAT imagery and the landscape configuration described. The functional heterogeneity of mapping units was analysed in terms of the fraction of photosynthetically active radiation absorbed by green vegetation (fPAR), calculated from the normalized difference vegetation index (NDVI) images provided by the moderate resolution imaging spectroradiometer (MODIS) sensor. Finally, the ANPP of each grassland class was estimated using NDVI and climatic data.
Results: Supervised classification presented a good overall accuracy and moderate to good average accuracy for grassland classes. Meso-xerophytic grasslands
occupied 45% of the area, Meso-hydrophytic grasslands 43% and Lithophytic steppes 6%. The landscape was shaped by a matrix of large, unfragmented patches of Meso-xerophytic and Meso-hydrophytic grasslands. The region presented the lowest anthropic fragmentation degree reported for the Rio de la Plata grasslands. All grassland units showed bimodal annual fPAR seasonality, with spring and autumn peaks. Meso-hydrophytic grasslands showed a radiation interception 10% higher than the other units. On an annual basis, Meso-hydrophytic grasslands produced 3800 kg dry matter (DM) ha 1 yr  1 and Meso-xerophytic grasslands and ithophytic
steppes around 3400 kg  DM ha 1  yr 1 . Mesoxerophytic grasslands had the largest spatial variation during most of the year. The ANPP temporal variation was higher than the fPAR variability.
Conclusions: Our results provide valuable information for grazing management (identifying spatial and temporal variations of ANPP) and grassland conservation (identifying the spatial distribution of vegetation units).

Palabras-Clave: | LAND-COVE CLASSIFICATION; NATIVE GRASS-LANDS; NDVI; NORMALIZED DIFFERENCE VETETATION INDEX (NDVI); RADIATION-USE EFFICIENCY; RIO DE LA PLATA GRASSLANDS.
Thesagro: | ESPECIES; IDENTIFICACION; PASTIZAL NATURAL; SISTEMAS GEOGRAFICOS; URUGUAY.
Categoría del tema: | F70 Taxonomía y geografía de las plantas
Registro original: | INIA Treinta y Tres (TT)
Ejemplares: | TT - (100035-1) - PXI - AP - DD - PP/Lezama/Arb/2010/1 -  -  - DIS