Interacting effects of soil degradation and precipitation on plant productivity in NE Patagonia,Argentina

Our objective was to examine the effects of inter-annual variation of precipitation on productivity of two dominant species (Chuquiraga avellanedae, an evergreen shrub, and Nassella tenuis, a perennial grass) in two communities of contrasting soil degradation: a herbaceous steppe with shrubs (HSS) and a degraded shrub steppe (SS). Data were collected during two consecutive years with different annual precipitation. Aboveground productivity was determined nondestructively using a double sampling approach. The number of inflorescences per plant was recorded too. Perennial grass productivity was lower in SS than in HSS in both years, while shrub productivity was lower in SS only during the year of below average precipitation. With rising precipitation the perennial grass increased the number of inflorescences while the evergreen shrub augmented vegetative biomass. In summary, the effects of precipitation on plant productivity are community dependent; abiotic factors, such as superficial and sub-superficial soil characteristics, and biotic factors, such as leaf area index (LAI) or tussock sizes, may interact to influence the responses of species to precipitation. Our results suggest that if precipitation increased, this would favor the dominance of shrubs over grasses.     

A survey of Lolium rigidum populations in citrus orchards: Factors explaining infestation levels

The presence of herbicide‐resistant Lolium rigidum in Mediterranean (Spanish) citrus orchards was reported in 2005 and it poses a serious threat to crop management. The main objective of this research was to investigate which components could be responsible for the persistence of annual ryegrass populations in Mediterranean mandarin and orange orchards. This is the first study regarding L. rigidum populations in Mediterranean citrus orchards. Surveys were conducted in 55 commercial citrus orchards in eastern Spain in 2013 by interviewing technicians who were working in cooperatives about crop management. The level of infestation by L. rigidum and the presence of harvester ants (Messor barbarus) then were estimated in the same orchards. The variables were subjected to a two‐dimensional analysis and both univariate and multivariate logistic regression models were fitted for each of the three L. rigidum density levels that had been established. The multivariate models showed the significant factors that were associated with various L. rigidum densities: (i) at a low density, the herbicides that were applied, the number of applications in 2013 and the type of irrigation (flood or drip); (ii) at a medium density, the presence of harvester ants; and (iii) at a high density, the herbicides that were applied in 2013. The results indicated that drip irrigation and one application of glyphosate mixed with other herbicides (or herbicides other than glyphosate) were associated with a lower L. rigidum density. The alternative management options that are presented here should help farmers to reduce weed problems in Mediterranean citrus orchards. Future research is required to better understand the presence of herbicide‐resistant populations, as well as the possible beneficial presence of granivorous ant species.     

Evidence-based culling of a facultative predator: Efficacy and efficiency components

Human activities have greatly modified predator-prey dynamics within seabird communities by favouring a rapid increase in density of large predatory gulls. To counteract such a subsidized growth, conservation agencies perform massive random culling programs, which generally fail to restore the original predator-prey relationship. We used long-term individual-based information to evaluate the effects of a selective culling of a top seabird predator, the yellow-legged gull (Larus michahellis), on the predatory pressure, survival and reproductive success probabilities of a secondary prey, the vulnerable European storm-petrel (Hydrobates pelagicus). The selective removal of only 16 gulls in 3 years led to a reduction of ca. 65% in the number of petrels killed, and to a relative increase in their survival and breeding success probabilities of 16% and 23%, respectively. Our results show that only a few specialised predators were responsible for the bulk of the impact on a secondary prey and that the removal of those specialised individuals was an effective and efficient way to improve prey demographic parameters.     

Prospective use of collected fog water in the restoration of degraded burned areas under dry Mediterranean conditions

A mountainous plot located in the interior of the Valencia region (east coast of the Iberian Peninsula) was identified for reforestation using the fog-water collection potential prevailing in the area. Fog data were obtained by means of an instrument ensemble consisting of a passive cylindrical fog-water collector, a rain gauge, a wind direction and velocity sensor and a temperature and humidity probe. Preliminary results gave rise to the additional deployment of a low-cost 18-m² flat-panel collector connected to three 1000-l tanks for larger scale fog-water collection and storage. The 2007 annual rate of fog water that could be derived from the instrument ensemble amounted to 3.3 l/m²/day, which turn out to fill up the storage tanks completely in only 5 months, even though the flat-panel collector could not be operative 100% of the time. The study made use of the in situ stored water and a micro-irrigation network to irrigate a plot of reforestation seedlings through small water pulses localized deep in the planting hole during the summer dry period. Until the present, this forest location had always shown a difficult self-recovery due to the high level of land degradation resulting from recurrent forest fires in the past. Results indicate that survival rates and seedling performance of the two species planted, Pinus pinaster and Quercus ilex, improved with the use of small timely waterings and additional treatments with composted biosolid.     

Comparison of Oil,Shortening, and a Structured Shortening on Wheat Dough Rheology and Starch Pasting Properties

Monoacylglycerol‐stabilized oil in water emulsion (MAG gel) is an alternate shortening that is free of trans fatty acids, and low in saturated fatty acids. However, the behavior of MAG gels in comparison to other lipids has not been studied. This study investigated effects of structured MAG gel, a mixture of MAG gel unstructured components (Mixture), canola oil (Oil), or interesterified soy shortening (IE Soy) at different levels (6–24%) on hard or soft wheat dough properties. Doughs were prepared with different lipid types at equivalent lipid contents. Dough mixing and water absorption parameters were evaluated using a farinograph; gluten behavior was measured using a gluten peak tester (GPT); and pasting characteristics were measured using a micro‐viscoamylograph (MVAG). Water absorption values decreased with increasing lipid content. Dough development times were similar between the MAG gel and IE Soy, but farinogram curve characteristics during mixing were similar between MAG gel, Mixture, and Oil. The trend for peak max time in GPT was similar between MAG gel and IE Soy exhibiting delayed gluten aggregation; whereas Mixture and Oil exhibited earlier gluten aggregation. In MVAG, starch interaction with monoglyceride component of MAG gel and Mixture appeared to be the dominating factor resulting in increased pasting temperature and a second viscosity peak during cooling at higher levels of lipid addition.     

Obstetric and fetal outcomes in dystocic and eutocic sows to an injection of exogenous oxytocin during farrowing

Sixty hybrid Yorkshire-Landrace penned sows, 30 with eutocic farrowing and 30 experiencing a dystocic parturition, were studied to evaluate the obstetric and neonatal outcomes to low doses of oxytocin administered at advanced stages of parturition. Animals in each group were randomly subdivided into 2 subgroups: 15 eutocic and 15 dystocic sows received oxytocin 0.083 IU/kg (equivalent to 1 IU/12 kg body weight), administered intramuscularly after the delivery of the 5th piglet; the other 15 eutocic and 15 dystocic sows received saline solution intramuscularly at the same time. Oxytocin decreased the number of intrapartum deaths by approximately 50% (P = 0.002). No piglet was born dead from the saline- and oxytocin-treated eutocic sows. The highest viability score was observed among piglets born to eutocic sows treated with oxytocin. In summary, this dose schedule would help to decrease the number of stillbirths in both eutocic and dystocic farrowing sows.