Biological and chemical factors controlling the patchy distribution of soil water repellency among plant species in a Mediterranean semiarid forest

Natural soil water repellency is a property that has already been observed in forest soils and is characterized by its patchy distribution. There are many factors involved in its development. In this work, we have studied a large number of chemical and biological factors under the influence of different plant species (. Pinus halepensis, Quercus rotundifolia, Cistus albidus and Rosmarinus officinalis) to learn which has the greatest responsibility for its presence and persistence in the top-soil layer. We observed strong and significant correlations between ergosterol, glomalin related soil protein (GRSP), extractable lipids, soil organic matter (SOM) content and water repellency (WR). Our results suggested lipid fraction as the principal factor. Moreover, apart from Pinus, fungal biomass seems to be also related to the SOM content. Soil WR found under Pinus appears to be the most influenced by fungi. Quality of SOM, to be precise, lipid fraction could be responsible for WR and its relationship with fungal activity.Ministerio de Economía y Competitividad CGL2010- 21670-C02-01, CGL2012-38655-C04-0

The burn severity and plant recovery relationship affect the biological and chemical soil properties of Pinus halepensis Mill. stands in the short and midterms after wildfire

In the Mediterranean Basin, changes in climate and fire regime (increased recurrence and severity) reduce ecosystem services after wildfires by increasing soil degradation and losses in plant diversity. Our study was a biological approach to relate soil properties to vegetation recovery and burn severity. We focused our study on the natural recovery of the soil-plant interphase in Pinus halepensis Mill. forests located in the SE of Iberian Peninsula, a semiarid climate. We included some chemical properties 3 years after fire (available phosphorus (P) and soil organic carbon (Corg), among others), and biological soil indicators 3 and 5 years after fire (i.e. basal soil respiration (BSR), microbial biomass carbon (Cmic), carbon mineralization coefficient (Cmineral), metabolic quotient (qCO2) and microbial quotient (Cmic:Corg)). We analyzed the activity of three different enzymes: urease (UR), phosphatase (PHP) and β-glucosidase (GLU). The changes in most chemical properties were ephemeral, but P and Corg showed higher values in burned areas, and the highest were found for low-moderate severity. Plant recovery was the triggering factor for the recovery of Corg and biological soil function. Burn severity and time after fire influenced Cmic and the Cmic:Corg, which were higher for moderate-high severity 3 years later, but were below the unburned values 5 years after fire. The microbial activities of GLU and UR were recovered in burned areas 5 years after fire. The PHP values lowered according to higher burn severity and time after fire. The soil ecological trends obtained by a principal component analysis revealed a relationship linking GLU, BSR and qCO2 that explained soil response to burn severity. PHP, Cmic and Cmic:Corg explained most of the variability related to time after fire. Our results provide insights into how burn severity, in Mediterranean fire-prone Aleppo pine stands, modulated the natural plant recovery linked to soil biochemical and microbiological response to fire. High burn severity limited natural vegetation recovery, and both reduced biological soil functionality. This knowledge can be implemented in post-fire planning to apply post-fire management (for mitigation and restoration) in which the “no intervention” tool should be contemplated. These findings provide information to be applied in adaptive forest management to improve the resilience of vulnerable ecosystems and to reduce burn severity in future fire events.This study was supported by a research award provided by the Instituto Estudios Albacetenses (IEA2016-Daniel Moya) and funds provided to the Forest Ecology Research Group by the University Castilla-La Mancha.The authors also thank the Spanish Institute for Agricultural and Food Research and Technology (INIA) for the funding awarded through National Research Projects GEPRIF (RTA2014-00011-C06), POSTFIRE_CARE (CGL2016-75178-C2-1-R) financed by the Spanish Research Agency (AIE), and the European Union for European Funding for Regional Development (FEDER)

Influencia de la nialamida sobre algunos parámetros metabólicos

Se estudia en ratas el metabolismo proteico bajo la influencia de la Nialamida (20, mg/100 g de dieta), inhibidor de la monoaminooxidasa. Los estudios confirman que la Nialamida produce un aumento en el catabolismo proteico que aunque no se hizo patente a nivel sérico, sin embargo a nivel urinario presenta un marcado aumento en los valores medios de aclaramiento de urea, ácido úrico y aún más notable de creatinina. No se ha encontrado efecto de la Nialamida sobre el metabolismo lipídico y glucídico en suero.The effets of Nialamide, a mono a inooxidase inhibitor, administration (20 mg/100 g in the diet) on protein metabolism, studied. The results obtained show that Nialamide increases protein catabolismo This fact, although it is not evident in the serum parameters measured, is deduced from the data of urea, uric acid and ICreatinine clearance. Effets of Nialamide on lipidic and glucidic metabolism have not been detected in serum

Importancia de la alimentación controlada a la par (Pair Fed) en algunos parámetros del metabolismo proteico y niveles séricos de triglicéridos y colesterol

Se estudia en ratas la necesidad de utilizar una alimentación controlada a la par (pair fed) para eliminar el factor ingesta cuando se investigan otras variables. Se determinan algunos parámetros del metabolismo protéico y niveles séricos de triglicéridos y colesterol. La alimentación controlada a la par (pair fed), frente "ad libitum" implica una reducción el absorción de nitrógeno, pero no afecta significativamente su retención. No aparecen diferencias en el contenido de nitrógeno en diferentes órganos. En relación a los parámetros bioquímicos experimentados, tanto en suero como en orina, se ha encontrado un incremento de proteinas, triglicéridos y colesterol en suero y una mayor excreción unrinaria de ácido úrico cuando la dieta es suministrada "ad libitum".The necessity to use a feeding at par (pair fed) to eliminate the factor intake when others variables are investigated, like in the case of influence of drug, has been studied in rats. Several parameters of the protein metabolism and serum levels of triglycerides and cholesterol, have been determined. The feeding at par (pair fed), front to lOad libitum" implies a reduction in the nitro gen absorption, and unsignificantly effect on its retention. No differences appear in nitrogen content into different organs. In relation the experimented biochemistry parameters. as serum as urine. its is found an increment of proteins, triglycerides and cholesterol in serum and a bigger urinary excretion of uric acid when the diet is suministrated lOad libitum"

Importancia de la alimentación controlada a la par (Pair Fed) en algunos parámetros del metabolismo proteico y niveles séricos de triglicéridos y colesterol

The necessity to use a feeding at par (pair fed) to eliminate the factor intake when others variables are investigated, like in the case of influence of drug, has been studied in rats. Several parameters of the protein metabolism and serum levels of triglycerides and cholesterol, have been determined. The feeding at par (pair fed), front to "ad libitum" implies a reduction in the nitro gen absorption, and unsignificantly effect on its retention. No differences appear in nitrogen content into different organs. In relation the experimented biochemistry parameters as serum as urine its is found an increment of proteins, triglycerides and cholesterol in serum and a bigger urinary excretion of uric acid when the diet is suministrated "ad libitum" .Se estudia en ratas la necesidad de utilizar una alimentación controlada a la par (pair fed) para eliminar el factor ingesta cuando se investigan otras variables. Se determinan algunos parámetros del metabolismo protéico y niveles séricos de triglicéridos y colesterol. La alimentación controlada a la par (pair fed), frente "ad libitum" implica una reducción el absorción de nitrógeno, pero no afecta significativamente su retención. No aparecen diferencias en el contenido de nitrógeno en diferentes órganos. En relación a los parámetros bioquímicos experimentados, tanto en suero como en orina, se ha encontrado un incremento de proteinas, triglicéridos y colesterol en suero y una mayor excreción unrinaria de ácido úrico cuando la dieta es suministrada "ad libitum"

Importancia de la alimentación controlada a la par (Pair Fed) en algunos parámetros del metabolismo proteico y niveles séricos de triglicéridos y colesterol

The necessity to use a feeding at par (pair fed) to eliminate the factor intake when others variables are investigated, like in the case of influence of drug, has been studied in rats. Several parameters of the protein metabolism and serum levels of triglycerides and cholesterol, have been determined. The feeding at par (pair fed), front to "ad libitum" implies a reduction in the nitro gen absorption, and unsignificantly effect on its retention. No differences appear in nitrogen content into different organs. In relation the experimented biochemistry parameters as serum as urine  its is found an increment of proteins, triglycerides and cholesterol in serum and a bigger urinary excretion of uric acid when the diet is suministrated "ad libitum" .Se estudia en ratas la necesidad de utilizar una alimentación controlada a la par (pair fed) para eliminar el factor ingesta cuando se investigan otras variables. Se determinan algunos parámetros del metabolismo protéico y niveles séricos de triglicéridos y colesterol. La alimentación controlada a la par (pair fed), frente ªad libitum" implica una reducción el absorción de nitrógeno, pero no afecta significativamente su retención. No aparecen diferencias en el contenido de nitrógeno en diferentes órganos. En relación a los parámetros bioquímicos experimentados, tanto en suero como en orina, se ha encontrado un incremento de proteinas, triglicéridos y colesterol en suero y una mayor excreción unrinaria de ácido úrico cuando la dieta es suministrada "ad libitum"

Effect of Particle Size on Droplet Infiltration into Hydrophobic Porous Media As a Model of Water Repellent Soil

The wettability of soil is of great importance for plants and soil biota, and in determining the risk for preferential flow, surface runoff, flooding,and soil erosion. The molarity of ethanol droplet (MED) test is widely used for quantifying the severity of water repellency in soils that show reduced wettability and is assumed to be independent of soil particle size. The minimum ethanol concentration at which droplet penetration occurs within a short time (≤10 s) provides an estimate of the initial advancing contact angle at which spontaneous wetting is expected. In this study, we test the assumption of particle size independence using a simple model of soil, represented by layers of small (0.2–2 mm) diameter beads that predict the effect of changing bead radius in the top layer on capillary driven imbibition. Experimental results using a three-layer bead system show broad agreement with the model and demonstrate a dependence of the MED test on particle size. The results show that the critical initial advancing contact angle for penetration can be considerably less than 90° and varies with particle size, demonstrating that a key assumption currently used in the MED testing of soil is not necessarily valid

Estudio detallado de los efectos del acetato de hidrocortisona durante la gestación sobre el número de fetos y abortos en la rata

Se estudia la evolución del efecto de la administración de acetato de hidrocortisona (4mg/100 g. peso/día) a ratas sobre el número de fetos y abortos de la camada en los días 6, 9, 12, 14, 16, 18 y 21 de gestación. Se observa que el acetato de hidrocortisona disminuye el número de fetos vivos a partir del día 17 de tratamiento siendo la disminución más acusada en el día 21, en el que la diferencia respecto al grupo control es de un 25%. El acetato de hidrocortisona incrementa el porcentaje de ratas que presentan abortos en cualquiera de los periodos estudiados. Además en el día 14 el 22,2% de ratas inyectadas con acetato de hidrocortisona presentan abortos de la totalidad de sus fetos, hecho que nunca sucede en las ratas control. En el día 21 es más acusado el efecto de la hormona ya que mientras que las ratas testigo mantienen todos los fetos vivos, un 66% de ratas tratadas con cortisona siguen presentando abortos.The evolution of the effect of the administration of hydrocortisone aceta te (HA) (4mg/l00g weightlday) to the pregnant rat on the number of viable and nonviable fetuses was studied on days 6, 9, 12, 14, 16, 18 and 21 of gesta tion . . The administration of HA to pregnant rats reduced the number of live fe tuses starting on day 17 of treatment representing a loss of approximately 25% of the fetuses when they are compared with the control rats. High doses of cortisone acetate were seen to increase the percentage of rats whose uterus contained dead fetuses at any given period of study. On day 14 more over the entire litter was found to have died in utero in 22,2% of all cortisol injected rats, a finding which never occurred in controls. The effects of cortisol were most in evidence on day 21, when all fetuses were viable in controls as opposed to hormone-treated rats, 66% of which were found to contain nonviable fetuses