Search results for "GRI"
showing 10 items of 10209 documents
25S rDNA-based molecular monitoring of glomalean fungi in sewage sludge-treated field plots
2001
Recycling of sewage wastes in agriculture is likely to affect the biological activity of soils through contamination of ecosystems by pathogens and metallic or organic micropollutants. The impact of sewage sludge spreading under field conditions on arbuscular mycorrhiza (AM) formation by a community of glomalean fungi was evaluated using a nested polymerase chain reaction (PCR) and discriminating primers based on 25S rDNA polymorphisms to detect different fungal species within root systems. Medicago truncatula was grown in soil of field plots amended or not with a composted sewage sludge, spiked or not with organic or metallic micropollutants. Overall AM development in roots decreased with …
Distribution and diversity of fish species along the Sudanese Red Sea coast based on three combined trap and gillnet surveys
2021
Abstract On the western shore of the semi-enclosed coral-reef rich Red Sea, the 850 km coastline of the Red Sea State of the Republic of Sudan provides livelihoods to artisanal fishers, but the present state of the living natural resources and the impact of fisheries are poorly known. To provide a baseline on the biodiversity and fish abundance three fisheries research surveys spanning the entire Sudanese coast were carried out in 2012−13 designed around the seven Sudanese fisheries management areas. Baited traps and gillnets were employed to sample the various reef habitats and fish assemblages from inshore to deeper outer reef archipelagos. The highest species richness, functional diversi…
Viscous Synergism in Carrageenans (κ and λ) and Locust Bean Gum Mixtures: Influence of Adding Sodium Carboxymethylcellulose
2001
Se han estudiado las interacciones sinergicas entre la goma de garrofin (LBG) y dos tipos de carragenanos (kappa y lambda). Para cada mezcla se obtuvo el indice de sinergia viscosa, Iy, en funcion de la relacion de concentraciones, z =c'LBG/c'car, y de la velocidad de cizalla. Los valores de estos indices disminuyeron al aumentar la velocidad de cizalla en ambos sistemas binarios. En las mezclas de LBG + K, I, presento un maximo para una relacion de concentraciones z = 60/40, que puede considerarse como la optima proporcion de estas gomas en la mezcla. Sin embargo, en los sistemas LBG + A, I, aumento con z en todo el intervalo considerado, es decir, la mayor sinergia correspondio a las meno…
The relevance of urban agroforestry and urban remnant forest for avian diversity in a densely-populated developing country: the case of Port-au-Princ…
2021
9 pages; International audience; Urban green spaces can contribute to conserve some of the original avian diversity in urbanized landscapes. However, the relative contribution of urban agriculture vs. urban forest remnants to the preservation of the avifauna in large cities, particularly in developing countries in the tropics, remains poorly documented. We assessed bird assemblages in the densely-populated capital city of Port-au-Prince in Haiti, one of the poorest countries in the world. From early January to late April 2018, 10 censuses per site were conducted in 16 urban green sites, consisting of 8 unexploited, private forest patches and 8 agroforestry plantations, embedded within the u…
Defoliation effects on plant and soil properties in an experimental low arctic grassland community – the role of plant community structure
2008
In Northern Fennoscandia, sub-arctic and arctic grasslands are commonly grazed by the semi-domesticated reindeer. Reindeer grazing is known to affect plant production and belowground processes, such as nutrient mineralization in these grasslands, but little is known of the role of plant community structure in the response of plant and soil properties to the defoliation of plants. Using soil and seeds from a low arctic meadow, we established a 23-week greenhouse experiment to test whether communities of different plant species richness (one, two or four species) and composition (three different replicated compositions within each richness level) respond to defoliation in a different way. We …
Downscaling rice yield simulation at sub-field scale using remotely sensed LAI data
2019
Abstract Crop modeling and remote sensing are key tools to gain deeper understanding on cropping system dynamics and, ultimately, to increase the sustainability of agricultural productions. This study presents a system to estimate rice yields at sub-field scale based on the integration of a biophysical model and remotely sensed products. Leaf area index (LAI) data derived from decametric optical imageries (i.e., Landsat-8, Landsat-7 and Sentinel–2A) were assimilated into the WARM rice model via automatic recalibration of crop parameters at a fine spatial resolution (30 m × 30 m), targeting the lowest error between simulated and remotely sensed LAI. The performance of the system was evaluate…
Role of Soil Organisms in the Maintenance of Species-Rich Seminatural Grasslands through Mowing
2009
To preserve species-rich grasslands, management practices such as mowing are often required. Mowing is known to promote aboveground conditions that help to maintain plant species richness, but whether belowground effects are important as well is not known. We hypothesized that if mowing decreases belowground carbon transfer by reducing root mass, this will reduce the abundance and activity of soil decomposers and lead to diminished nutrient availability in soil. In grasslands, this would provide a means to mitigate the negative effects of nitrogen enrichment on plant species richness. We established experimental plots on grassland with one-third of plots growing untouched, one-third mowed o…
Alleviating Soil Acidity: Optimization of Lime and Zinc Use in Maize (Zea mays L.) Grown on Alfisols
2019
ABSTRACTSoil acidity, one of the causes of soil degradation, adversely affects phytoavailability of soil nutrients and crop growth in 50% of arable land of the world. There is a persistent need for...
Root growth and soil carbon turnover in Opuntia ficus-indica as affected by soil volume availability
2019
Abstract The aim of this study was to investigate the effect of soil volume restriction, i.e. root confinement, on below-and-above ground growth of cactus pear (Opuntia ficus-indica (L.) Mill) as well as the effect on root architecture and turnover, and soil carbon turnover. In May 2014, 1- year-old cladodes were planted in five different pots size (50, 33, 18, 9 and 5 L). Soil samples were collected from each pot and dried before SOC and δ13C determination. Roots of each plant were divided visually into three groups depending on their diameter, and then measured and weighed. Results indicated a significant effect of soil volume and sampling dates on total root length, root dry mass and δ13…
Modelling the effects of more selective trawl nets on the productivity of European hake (Merluccius merluccius) and deep-water rose shrimp (Parapenae…
2018
Single-species Gadget models were used to assess the effects of using a sorting grid mounted on the traditional trawl net used by Sicilian trawlers to exploit the deep-water rose shrimp in the Strait of Sicily. The main commercial by-catch species of this fleet is the European hake (Merluccius merluccius), often caught at sizes well below the minimum conservation reference size. Selectivity curves based on the results of an experimental survey carried out in the area using a commercial trawler equipped with an ad hoc-designed sorting grid were incorporated into single-species Gadget models to forecast the effects of changing fishery selectivity on the performance of the two stocks in terms …