ABSTRACT
Interactions between plants and herbivores are central in most ecosystems, but their strength is highly variable. The amount of variability within a system is thought to influence most aspects of plant-herbivore biology, from ecological stability to plant defense evolution. Our understanding of what influences variability, however, is limited by sparse data. We collected standardized surveys of herbivory for 503 plant species at 790 sites across 116° of latitude. With these data, we show that within-population variability in herbivory increases with latitude, decreases with plant size, and is phylogenetically structured. Differences in the magnitude of variability are thus central to how plant-herbivore biology varies across macroscale gradients. We argue that increased focus on interaction variability will advance understanding of patterns of life on Earth.
Subject(s)
Biological Variation, Population , Herbivory , Plant Defense Against Herbivory , Plants , Ecosystem , Phylogeny , Animals , Biological EvolutionABSTRACT
Gall inducers use these structures as shelters and sources of nutrition. Consequently, they cause multiple physiological changes in host plants. We studied the impact caused by seed coat galls of a braconid wasp on the performance of fruits, seeds and seedlings of tree Inga laurina. We tested whether these seed galls are 'nutrient sinks' with respect to the fruit/seed of host plant, and so constrain the reproductive ability and reduce seedling longevity. We measured the influence of such galls on the secondary compounds, fruit and seed parameters, seed viability and germination and seedling performance. Inga laurina has indehiscent legumes with polyembryonic seeds surrounded by a fleshy sarcotesta rich in sugars. The galls formed inside the seed coat and galled tissues presented higher phenol concentrations, around 7-fold that of ungalled tissues. Galls caused a significant reduction in parameters such as fruit and seed size, seed weight and the number of embryos. Fluctuating asymmetry (a stress indicator) was 31% higher in leaves of galled seed plants in comparison to ungalled seed plants. However, the negative effects on fruit and seed parameters were not sufficient to reduce seed germination (except the synchronization index) or seedling performance (except leaf area and chlorophyll content). We attributed these results to the ability of I. laurina to tolerate gall attack on seeds without a marked influence on seedling performance. Moreover, because of the intensity of seed galling on host plant, we suggest that polyembryony may play a role in I. laurina reproduction increasing tolerance to seed damage.
Subject(s)
Fabaceae/physiology , Wasps/physiology , Animals , Fabaceae/cytology , Fabaceae/parasitology , Fruit/cytology , Fruit/parasitology , Fruit/physiology , Germination , Plant Leaves/cytology , Plant Leaves/parasitology , Plant Leaves/physiology , Seedlings/cytology , Seedlings/parasitology , Seedlings/physiology , Seeds/cytology , Seeds/parasitology , Seeds/physiology , TreesABSTRACT
En los últimos años parecen haber aumentado los casos de agresiones de pacientes a trabajadores sanitarios. En Españano existen estudios científicos que hayan abordado esta cuestión. Hemos analizado los datos de una encuesta sobre agresionesen el lugar de trabajo en una muestra estratificada de 1826 profesionales de la salud procedentes de 3 hospitales y 22 centrosde Atención Primaria rurales y urbanos localizados en el noreste y este de España. Encontramos que un 11% de los trabajadoressanitarios han sido víctimas de una agresión física, 5% en más de una ocasión, mientras que un 64% se han vistoexpuestos a comportamientos amenazantes, intimidación o insultos. Alrededor de un 34% han sufrido amenazas e intimidaciónen al menos una ocasión, y 23,8% de forma repetida. En torno al 35% han sido insultados en al menos una ocasión,y 24,3% repetidamente. En general la incidencia era mayor en los hospitales grandes, con niveles muy altos en servicios como accidentes, emergencias y psiquiatría(AU)
In recent years instances of aggression by patients towards health workers appear to have become more frequent. InSpain, no scientific studies appears to have been performed so far on this question. We analyzed questionnaires on workplaceaggression from a stratified sample of 1826 health professionals at 3 hospitals and 22 rural and urban Primary Care facilitieslocated in the Northeast and East of Spain. We found 11% of health workers had been a victim of physical aggression,5% on more than one occasion, while 64% had been exposed to threatening behaviour, intimidation or insults. About34% had suffered threats and intimidation on at least one occasion, and 23.8% repeatedly. Over 35% had been subjectedto insults on at least one occasion, and 24.3% repeatedly. In general the incidence was higher in large hospitals, with veryhigh levels in services such as Accident and Emergency and Psychiatry(AU)
