Search results for "Plan"
showing 10 items of 24706 documents
The importance of phytoplankton production for carbon budgets in a semiarid floodplain wetland
2011
Phytoplankton production (PP) in wetlands is not measured as often as that of macrophytes. A three year-study during a period of sustained high flooding was undertaken in a central Spanish floodplain wetland (Las Tablas de Daimiel National Park) to determine net PP, its spatial heterogeneity and controlling factors, and compare it with primary production in macrophyte communities. This enabled us to estimate carbon budgets for each community. All PP variables showed high spatial and temporal variability among sites, resulting in low coherence even when flooding connected all sites. Net PP corresponded to 25- 36% of submerged plant production and 3-10% of helophyte production. Net PP was con…
Ecological and evolutionary impact of diapause on zooplankton
2012
La diapausa es un tipo de dormición que permite a los organismos sobrevivir a periodos ambientales desfavorables y lidiar con la impredicibilidad del hábitat. La producción de huevos diapáusicos es especialmente común en especies de invertebrados acuáticos como ostrácodos, anostráceos, notostráceos, copépodos, cladóceros o rotíferos. La presente tesis profundiza en el estudio de las implicaciones ecológicas y evolutivas de la diapausa tanto a nivel poblacional, como a nivel de comunidad. A nivel poblacional, se estudia el impacto de los bancos de huevos sobre la diferenciación genética poblacional y su relación con el flujo génico, la deriva genética y los efectos fundadores persistentes. L…
Does differential iron supply to algae affect Daphnia life history? : An ionome-wide study
2019
The availability of iron (Fe) varies considerably among diet items, as well as ecosystems. Availability of Fe has also changed due to anthropogenic environmental changes in oceanic as well as inland ecosystems. We know little about its role in the nutrition of ecologically important consumers, particularly in inland ecosystems. Physiological studies in several taxa indicate marked effects of dietary Fe on oogenesis. We predicted that differential Fe supply to algae will impact algal Fe concentration with consequences on the life history of the freshwater grazer, Daphnia magna. We found that algal Fe concentration increased with Fe supply, but did not affect algal growth, indicating that the…
Browning-induced changes in trophic functioning of planktonic food webs in temperate and boreal lakes: insights from fatty acids
2022
AbstractThe effects of lake browning on trophic functioning of planktonic food webs are not fully understood. We studied the effects of browning on the response patterns of polyunsaturated fatty acids and n−3/n−6 ratio in seston and compared them between boreal and temperate lakes. We also compared the regional differences and the effects of lake browning on the reliance of zooplankton on heterotrophic microbial pathways and the mass fractions of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in zooplankton. Lake browning was associated with increasing phytoplankton biomass and concentrations of EPA and DHA in both temperate and boreal lakes, but the seston n−3/n−6 ratio was low…
Relationship between trophic state and plankton community structure in 21 Sicilian dam reservoirs
1994
The relationship between the trophic state of 21 Sicilian dam reservoirs and their taxonomic community structure of phytoplankton (87 taxa) as well as zooplankton (45 taxa) have been examined by means of cluster analysis performed using annual average biomass values. The phytoplankton community structure was closely connected with the trophic state of the reservoirs, whereas the zooplankton community structure was related to hydrological regimes peculiar to the individual water bodies and not to the trophic state. © 1994 Kluwer Academic Publishers.
Modeling multipartite virus evolution: the genome formula facilitates rapid adaptation to heterogeneous environments
2020
Multipartite viruses have two or more genome segments, and package different segments into different particle types. Although multipartition is thought to have a cost for virus transmission, its benefits are not clear. Recent experimental work has shown that the equilibrium frequency of viral genome segments, the setpoint genome formula (SGF), can be unbalanced and host-species dependent. These observations have reinvigorated the hypothesis that changes in genome-segment frequencies can lead to changes in virus-gene expression that might be adaptive. Here we explore this hypothesis by developing models of bipartite virus infection, leading to a threefold contribution. First, we show that th…
Expansión urbana del Área Metropolitana de Valencia en el periodo 1984-2011 a partir de imágenes Landsat TM y ETM+
2015
La expansión urbana acelerada producida en décadas recientes en las grandes áreas metropolitanas como Valencia conlleva importantes impactos ambientales, entre ellos la impermeabilización o "sellado antropogénico" del suelo y la pérdida de espacios naturales de gran valor paisajístico. Este trabajo analiza la evolución de la cobertura artificial en el Área Metropolitana de Valencia (AMV) en el periodo 1984-2011 a partir de imágenes Landsat TM y ETM+, validadas a partir de datos SIOSE de mayor resolución espacial. Los resultados muestran, con una precisión del 71%, un aumento de la superficie artificial en el AMV de 8000 ha en dicho periodo, lo que supone un incremento del 10% del suelo sell…
Educación para la sostenibilidad y educación ambiental
2010
En este trabajo se analizan algunos de los obstáculos que están dificultando la implicación de diferentes sectores sociales en la adopción de las medidas necesarias para hacer frente a la actual situación de emergencia planetaria. En particular, analizamos la supuesta confrontación entre educación ambiental y educación para la sostenibilidad. Intentaremos mostrar que no existen razones para dicho antagonismo, sino que responde a malentendidos que es urgente deshacer, porque entorpecen la necesaria convergencia de esfuerzos para lograr una formación ciudadana que haga comprender la gravedad de la situación y prepare para participar en la toma de decisiones. Dans cet article nous analysons qu…
Una década prodigiosa: los años 60: entre reformas y rupturas
2006
Chemical Composition of the Essential Oil of Bupleurum Fontanesii (Apiaceae) Growing Wild in Sicily and its Activity on Microorganisms Affecting Hist…
2016
Hydrodistillation of the flowers (BpFl) of and fruits (BpFr) of Bupleurum fontanesii Guss. ex Caruel gave two oils that were analyzed by GC and GC-MS. The main components were α-elemol (16.7%), caryophyllene oxide (16.4%) and heptacosane (15.9%) in BpFl, and spathulenol (16.8%), caryophylladienol I (13.2%) and α-elemol (12.8%) in BpFr. A good antimicrobial activity against several microorganisms, including Bacillus subtilis, Staphylococcus aureus, Fusarium oxysporum and Aspergillus niger, all infesting historical art craft, was also determined.