The influence of feral horses dung piles on surrounding vegetation

The effect of grazing by large herbivores on grassland communities has been extensively studied, however less is known about changes associated with sites of high-intensity activity, such as dust bowls, tracks, urine patches and dung piles, that might induce disproportionate impacts to the directly affected areas and the surrounding vegetation. This paper explores the changes associated with exotic feral horse dung piles in relicts of natural grasslands in Argentine Pampas. We expected greater changes in the composition of plant communities and a greater facilitation effect on the establishment of invasive alien plants adjacent to the dung piles. Characteristics of the vegetation surrounding dung piles were recorded in 10025 cm plots located 0–1.5 m from the edge of the piles. We compared the immediate surroundings with reference plots at 5 m. The diversity of plant species increased as distance from the edge increased from 0–1.5 m; however, species richness was significantly higher in the first meter next to dung piles than 5 m away. Percentage cover of bare ground decreased further from the dung piles at both scales. Percentage cover of woody plants was greater at greater distances from the manure, whereas percentage cover of exotic plants was significantly higher next to the dung piles. The reported changes could be related to concentration gradients of nutrients liberated from the manure and/or to behaviour patterns of the horses, which may avoid grazing in the immediate surroundings of dung piles. These changes result in invasion windows facilitating the establishment and subsequent dispersal of exotic plant species in grasslands.Fil: Zalba, Sergio Martin. Universidad Nacional del Sur. Departamento de Biologia, Bioquimica y Farmacia. Grupo de Estudios En Conservacion y Manejo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Loydi, Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida(i); Argentin

Vegetation change in response to grazing exclusion in montane grasslands, Argentina

Background and aims – Natural montane grasslands in the Southern Pampas of Argentina are expected to show a high potential for recovery after heavy grazing due to their evolutionary history in the presence of large herbivores and their high productivity. The objective of this work is to compare plant diversity, bare soil percentage, biomass and botanical composition between grazed and non-grazed areas at different times following grazing exclusion. Methods – Vegetation was assessed on exclosures established in 2006 and on nearby areas open to grazing by feral horses in December 2006, 2007, 2008 and 2009. In 2009 we added 15 year old exclosures to the analysis. Key results – Species richness declined 24 months after grazing exclusion, mainly due to a decrease in the abundance of forb species. Bare soil percentage was significantly reduced 12 months after exclosures were built. Above-ground biomass showed a 3-fold increase 12 months after grazing exclusion. After three years, species richness and biomass were similar to those corresponding to older exclosures (15-years old). The composition of plant communities also changed following horse exclusion, with three and 15-years old exclosures dominated by perennial grasses typical of late seral stages. Conclusions – Our results support the hypothesis that natural montane grasslands in the Southern Pampas of Argentina may recover fast from grazing by large herbivores without application of specific restoration techniques.Fil: Loydi, Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiarida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiarida; ArgentinaFil: Zalba, Sergio Martin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Ciencias Biológicas y Biomédicas del Sur. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Instituto de Ciencias Biológicas y Biomédicas del Sur; ArgentinaFil: Distel, Roberto Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiarida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiarida; Argentin

Biological aspects of Acacia longifolia, an exotic species potentially invasive in sandy dunes vegetation

Las dunas costeras de la Pampa Austral constituyen un ambiente importante por mantener valiosas funciones ecosistémicas y conservar una alta biodiversidad. Acacia longifolia (aromo) es un árbol exótico establecido-invasor en regiones costeras de nuestro país. Este trabajo describe un núcleo poblacional de la especie que crece sobre dunas litorales de Monte Hermoso (Buenos Aires) y evalúa aspectos de la biología de sus semillas, incluyendo su peso y tamaño, tasa de germinación e intensidad de remoción por predadores. El núcleo exhibe una densidad media de 510 (ES=192,8) individuos/ha, una cobertura del dosel promedio de 42,85 % (ES=6,2) y una variación de 6,4-14,8 cm en el diámetro de sus troncos. Las semillas promedian 3,8±0,07 mm de largo y 2,4±0,04 mm de ancho, con un peso de 16,08±0,4 mg. El porcentaje de germinación resulta máximo previa escarificación química o física de las semillas (90±2,98 % y 84±5,62 %, respectivamente). La tasa de remoción de las semillas resulta del 27 % (ES=8,3). Los resultados obtenidos aportan información sobre la ecología de esta leñosa exótica presente en pastizales pampeanos. Sus antecedentes invasores en otros ambientes similares postulan a la especie como riesgosa, resultando prioritario monitorear su estado y evitar que traspase la barrera de dispersión.Fil: Lecanda, Julieta. Universidad Nacional del Sur. Departamento de Biologia, Bioquimica y Farmacia. Grupo de Estudios En Conservacion y Manejo; ArgentinaFil: Cuevas, Yannina Andrea. Universidad Nacional del Sur. Departamento de Biologia, Bioquimica y Farmacia. Grupo de Estudios En Conservacion y Manejo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Zalba, Sergio Martin. Universidad Nacional del Sur. Departamento de Biologia, Bioquimica y Farmacia. Grupo de Estudios En Conservacion y Manejo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Reproductive pattern in the southernmost populations of South American redbelly toads

Anurans can be classified as explosive or prolonged breeders. In species with short breeding periods, intensive competition for females is expected. We analyse the temporal breeding pattern of Melanophryniscus aff. montevidensis, a bufonid inhabiting grasslands of Argentina, whose breeding is concentrated in events of short duration. Males are active during more than one breeding event per season, whereas most females take part in a single event per season. Active males outnumbered females by up to 14 times at one event, operational sex ratio (OSR) ranged from 0.07 to 0.75 and intensity of sexual selection (I s) from 0.69 to 24. We found a negative association between I s and OSR, but no correlation between number of active males per event and OSR or I s. The OSR is the key that regulates the intensity of sexual selection, nevertheless, and in spite of being explosive breeders, females would potentially have chances to select their mate.Fil: Cairo, Samanta Lis. Universidad Nacional del Sur. Departamento de Biologia, Bioquimica y Farmacia. Grupo de Estudios En Conservacion y Manejo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahia Blanca; ArgentinaFil: Zalba, Sergio Martin. Universidad Nacional del Sur. Departamento de Biologia, Bioquimica y Farmacia. Grupo de Estudios En Conservacion y Manejo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahia Blanca; ArgentinaFil: Úbeda, Carmen A.. Universidad Nacional del Comahue. Centro Reg.universidad Bariloche. Departamento de Zoologia. Catedra de Vertebrados; Argentin

Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat

Correction to: Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

The original version of this article unfortunately contained a mistake

Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat

Site-specific reproductive performance of an invasive fleshy-fruited tree in remnant grasslands of the Argentinean Pampas

Prunus mahaleb (Saint Lucie´s cherry) is a fleshy-fruited small rosaceous tree, native to the Mediterranean region that has been extensively used as a rootstock species for commercial orchard trees. It has been widely introduced in several countries, becoming invasive in many regions, including the Pampas region of southern Argentina. We studied the reproductive performance of trees spontaneously growing in natural grasslands inside a protected area, estimating age at first reproduction and analysing changes in fruit production, age, canopy volume and basal stem diameter associated with different soil types: rock crevices on hillsides, deep soils in valleys and deep soils in stream-side habitats. Fruit production starts at the age of 3?6 years, and it can be abundant, even for young plants. We found evidence that fecundity is related to plant size, and that the age at which individuals reach a particular size and begin fruiting differs depending on the soil type where they grow. Trees in the study area show an order of magnitude increase in fruit production on reaching ages from 7 to 10 years for plants growing in deep soils at stream-side habitats and 13?16 years for plants growing in rock crevices. Invasive trees should be felled before they reach a basal stem diameter of c. 9 cm to avoid this increase in propagule pressure. Considering that the age at which this stage is reached depends on soil type, the streams could act as dispersal corridors for the spread and invasion of this species.Fil: Zalba, Sergio Martin. Universidad Nacional del Sur. Departamento de Biologia, Bioquimica y Farmacia. Grupo de Estudios en Conservacion y Manejo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Amodeo, Martín Raúl. Universidad Nacional del Sur. Departamento de Biologia, Bioquimica y Farmacia. Grupo de Estudios en Conservacion y Manejo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Wild cherries invading natural grasslands: unraveling colonization history from population structure and spatial patterns

Invasive success of many fleshy-fruited plants has been linked to opportunistic interactions with generalist frugivores. Prunus mahaleb is a small tree, producing large quantities of little, bright black, sugary drupes that are consumed by vertebrates. It is native to the Mediterranean region but has become invasive in several countries. This study was carried out at a nature reserve including remnant mountain grasslands of high conservation value in the southern Argentine Pampas. Our aim is to reconstruct the colonization history of invading populations proposing a generalized model to describe the invasion process: colonization events result in the establishment of a founder tree followed by a lag phase until it reaches massive seed production and enables an increase in local recruitment and plant density. To test this hypothesis, we analyzed population age structures and contrasted them with those predicted using a Leslie matrix growth model. We found that matrix model predictions fit well to actual age structures. Our results reveal the existence of an 8-18-year lag period between the establishment of the founder tree and local effective recruitment. The end of this lag coincides with an abrupt increase in individual fruit production that may have a strong effect on bird attraction and successful seed dispersal. This lag phase represents an opportunity for preventing further spread of P. mahaleb. Early detection and rapid eradication of new invasion focuses should be targeted as a principal aim of an effective control strategy.Fil: Amodeo, Martín Raúl. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional del Sur. Departamento de Biologia, Bioquimica y Farmacia. Grupo de Estudios en Conservacion y Manejo; ArgentinaFil: Zalba, Sergio Martin. Universidad Nacional del Sur. Departamento de Biologia, Bioquimica y Farmacia. Grupo de Estudios en Conservacion y Manejo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin