Search results for "Primary productivity"
showing 10 items of 17 documents
Evaluation of the MOD16A2 evapotranspiration product in an agricultural area of Argentina, the Pampas region
2021
The Pampas Region is a big plain of approximately 520,000 km2 in Argentina. It is essential to estimate evapotranspiration (ET) in this region since the primary productivity is directly linked to water availability. Information provided by satellite missions allows monitoring the spatial and temporal variability of ET. In the current study, we evaluated the version 006 of MOD16A2 product (MOD16A2.006) of Potential Evapotranspiration (ETp) and Actual Evapotranspiration (ETa) in Argentinian Pampas Region (APR). MOD16A2.006 product was compared with Crop Evapotranspiration (ETc), calculated with local measurements from the Oficina de Riesgo Agropecuario (ORA), and Crop Coefficient (Kc) data (f…
Use of NOAA-AVHRR NDVI data for environmental monitoring and crop forecasting in the Sahel. Preliminary results
1992
Abstract Several studies have shown that the NDVI calculated from NOAA-AVHRR data is related to annual rainfall and primary productivity in Sahelian areas. Such correlations, however, are affected by several environmental factors and have been tested only with data accumulated during rainy seasons, which is not ideal for the prediction of crop yield. In the present study a methodology of NOAA AVHRR data processing is presented which utilizes NDVI computed only in the first part of some rainy seasons and statistically takes into account the geographical variability in land resources and atmospheric conditions. From the first results of the application of the methodology in Niger, its potenti…
Assessment of the Potential Evapotranspiration MODIS Product Using Ground Measurements in the Pampas
2018
Evapotranspiration is the hydrological variable of greatest relevance in the Argentina Pampas Region (APR). The estimation of potential evapotranspiration (PET) in this area becomes essential since primary productivity is directly linked to water availability. In order to evaluate the MOD16_A2 product of evapotranspiration (ET), a comparison with in situ measurements was conducted. We used ET data provided by the Oficina de Riesgo Agropecuario, corresponding to 24 stations placed in the region covering all seasons for the years 2012 to 2014. Results show an overestimation of 86% and 52% in Autumn-Winter and Spring-Summer, respectively. Mean Absolut Error (MAE) range between ±0.9 and ±2.1 mm…
Beyond APAR and NPQ: Factors Coupling and Decoupling SIF and GPP Across Scales
2021
The connection between solar-induced fluorescence (SIF) and vegetation gross primary productivity is being widely investigated across spatial, temporal, and biological scales, including: a) studies at the leaf [1], [2], plant canopy [2]–[4] or satellite pixel scale [5], [6], b) temporally with studies spanning from diurnal [7] to seasonal scales [1], [3], [5], and b) biologically with studies covering various plant functional types (PFTs), e.g., crops [4], [7], deciduous [8] or evergreen forests [1], [3], in response to different sources of stress.
Carbon sequestration potential of Italian orchards and vineyards
2017
From 2004 to 2012 carbon (C) fluxes between the soil-vegetation system and the atmosphere in apple, grape, olive and orange orchards planted in different Italian regions were measured. Above-ground net primary productivity (ANPP) ranged from 4 (olive) to 9 (apple) Mg C ha-1. Alley grass contribution to total ANPP significantly varied among the systems, reaching a maximum of 60% in vineyards. The harvest index ranged from 46% for apple, to 58% for orange, 60% for grape and 41% for olive, while abscised leaves accounted for 30% of ANPP, on average. Soil respiration fluxes ranged from 6 (orange) to 10 (grape) Mg C ha-1. Results indicate the potential of these fruit crop to sequester atmospheri…
Lead contamination affects the primary productivity traits, biosynthesis of macromolecules and distribution of metal in durum wheat (Triticumdurum L.)
2021
Highlights • The growth, biosynthesis of pigments and other macromolecules appeared to be strong predictors in appraisal of Pb tolerance/susceptibility in durum wheat. • Germplasm of CBD59, CBD63 and CBD66 can be exploited for future selection and breeding programs. • The bioaccumulation of metal in grains of some cultivars of durum wheat much below than permissible limits set by FAO/WHO is of great significance owing to its implications for food safety.
Biomass, litterfall and nutrient content in Castanea sativa coppice stands of southern Europe
1996
Les biomasses et les mineralomasses, les retombees de litiere et la restitution au sol de bioelements par leur intermediaire ont ete etudiees dans des peuplements de Castanea sativa Mill en Espagne (province de Salamanque), en Italie (massif de l'Etna) et en France (Cevennes). Les meilleurs correlations et resultats ont ete trouves avec des regressions allometriques de type: Y (biomasse) = aX (diametre tronc a 1,30 m) b . Les parametres des differentes equations de regression sont semblables et tres proches pour les châtaigniers de France et d'Italie. La principale source de differences, au niveau stationnel, resulte de la repartition differente des arbres en fonction des classes de diametr…
The Mid-Cenomanian Event in southeastern France: evidence from palaeontological and clay mineralogical data.
2013
16 pages; International audience; Reconstruction of main palaeoenvironmental conditions across the Mid-Cenomanian Event (MCE I) in the hemipelagic Tethyan section of Blieux (Southeast France, Vocontian Basin) is proposed. Quantitative analyses of calcareous nannofossil, ammonoid and clay mineral assemblages have been made and compared with respect to sea level changes and the carbon cycle perturbations. The nannofossil primary productivity, as recorded by nannofossil fluxes and relative abundances of meso-eutrophic taxa, is low just below and during the MCE Ia, then slightly increases in the interval including the MCE Ib. The clay assemblages mainly consist of illite/smectite mixed-layers w…
Changes of energy fluxes in marine animal forests of the anthropocene: Factors shaping the future seascape
2019
12 pages, 3 figures
Biomasse, productivité et transferts de matière organique dans une séquence altitudinale de peuplements de Castanea sativa Mill de l'Etna
1996
Les differents compartiments et flux caracterisant la repartition de la matiere organique sont etudies dans quatre taillis de Castanea sativa Mill, etages le long d'un gradient altitudinal, dans le massif de l'Etna (Sicile). Les biomasses epigees sont respectivement de 22 et de 24 Mg ha -1 a 7 ans, 83 Mg ha -1 a 12 ans et 100 Mg ha -1 a 22 ans, avec de bonnes correlations : biomasse/âge et biomasse/facteurs climatiques. Le bois represente 95 % et les feuilles 5 % de ces biomasses. Les productions aeriennes perennes s'echelonnent entre 2,4 et 5,4 Mg ha -1 an -1 en relation a la fois avec l'âge des taillis et leur localisation geographique. Les retombees de litiere, observees durant 3 annees …