Day-night and inter-habitat variations in ant assemblages in a mosaic agroforestry landscape

Throughout the Mediterranean basin, the long-term interaction between human activities and natural processes has led to the formation of unique ecosystems whose biodiversity may be higher than that of the “original” systems. This is particularly true in the case of transformations of continuous stretches of closed forest into a complex mosaic of open and closed habitat over the course of centuries. In this study, we assessed the variation in diversity of ant assemblages in a typical patchy landscape, sampling ants in the three most important constituting habitats: olive plantation, harvested forest, and mature forest. In the study we used two different sampling methods—pitfall traps and observation at baits—which provided information on species presence at different temporal scales. The three habitats displayed different species assemblages, and considerable variation in species composition was observed at different times of the day, particularly in the harvested forest. Functional group analysis showed that the olive plantation, although the most artificial habitat, displayed the highest number of functional groups, suggesting a wider spectrum of available ecological niches for ant species within this habitat type. Overall, it was concluded that each of the three habitats contributes to enhance diversity at the landscape scale, which is greater than that expected from a more homogeneous habitat composition

The effects of fire on ant trophic assemblage and sex allocation

Fire plays a key role in ecosystem dynamics worldwide, altering energy flows and species community structure and composition. However, the functional mechanisms underlying these effects are not well understood. Many ground-dwelling animal species can shelter themselves from exposure to heat and therefore rarely suffer direct mortality. However, fire-induced alterations to the environment may change a species' relative trophic level within a food web and its mode of foraging. We assessed how fire could affect ant resource utilization at different scales in a Mediterranean forest. First, we conducted isotopic analyses on entire ant species assemblages and their potential food resources, which included plants and other arthropods, in burned and unburned plots 1 year postfire. Second, we measured the production of males and females by nests of a fire-resilient species, Aphaenogaster gibbosa, and analyzed the differences in isotopic values among workers, males, and females to test whether fire constrained resource allocation. We found that, in spite of major modifications in biotic and abiotic conditions, fire had little impact on the relative trophic position of ant species. The studied assemblage was composed of species with a wide array of diets. They ranged from being mostly herbivorous to completely omnivorous, and a given species' trophic level was the same in burned and unburned plots. In A. gibbosa nests, sexuals had greater δ15N values than workers in both burned and unburned plots, which suggests that the former had a more protein-rich diet than the latter. Fire also appeared to have a major effect on A. gibbosa sex allocation: The proportion of nests that produced male brood was greater on burned zones, as was the mean number of males produced per nest with the same reproductive investment. Our results show that generalist ants with relatively broad diets maintained a constant trophic position, even following a major disturbance like fire. However, the dramatically reduced production of females on burned zones compared to unburned zones 1 year postfire may result in considerably reduced recruitment of new colonies in the mid to long term, which could yield genetic bottlenecks and founder effects. Our study paves the way for future functional analyses of fire-induced modifications in ant populations and communities.This work was funded by MICINN (project CONSOLIDER-MONTES CSD2008-00040), MICINN and FEDER (projects CGL2009-12472 to RB and CGL2009-09690 to XC), the Consejo Superior de Investigaciones Cientıficas (JAE postdoctoral contract to SC), and the National Science Foundation (International Research Fellowship to J.M.C P-D)

Effetti della somministrazione di fiori di Bach sul comportamento del cane in canile

La permanenza del cane in canile è caratterizzata dal progressivo affermarsi di comportamenti anomali, soprattutto ripetitivi (quali le stereotipie e le attività di sostituzione), indicanti un crescente stato di frustrazione e di incertezza indotti dal contesto di restrizione sociale e spaziale. Queste circostanze possono causare un impoverimento del benessere dei cani, che riflette stati emozionali negativi. Scopo del presente lavoro è stato quello di valutare quantitativamente l’effetto del trattamento con una miscela di fiori di Bach sul comportamento spontaneo di cani la cui permanenza nel canile era superiore ai 50 giorni. Il campione oggetto dello studio era costituito da 21 cani trattati e da 6 cani di controllo. Sono state effettuate tre riprese filmate della durata di 10 minuti e tre prelievi ematici con cadenza settimanale. Immediatamente dopo la prima osservazione è stato intrapreso il trattamento. L’analisi dei filmati si è svolta sulla base di un etogramma ed è stata realizzata in cieco. L'analisi dei dati multivariati, effettuata con npMANOVA con disegno two-way a misure ripetute, p<0,05 e SIMPER, e successivamente dei dati univariati rivelano un effetto complessivo della miscela di fiori di Bach nel ridurre la frequenza di comportamenti rigidi e stereotipati, in contrasto con quanto si verifica nel trend comportamentale che caratterizza il gruppo di controllo. Il presente studio rappresenta il primo tentativo di valutazione quantitativa dell’effetto dei fiori di Bach sul comportamento della specie canina. I risultati suggeriscono una precisa collocazione di questo approccio terapeutico nel contesto di interventi di arricchimento ambientale, sociale e cognitivo che stanno progressivamente affermandosi nel campo del benessere animale

The restoration of phytophagous beetles in species-rich chalk grasslands

This study focuses on the restoration of chalk grasslands over a six-year period and tests the efficacy of two management practices, hay spreading and soil disturbance, in promoting this process for phytophagous beetles. Restoration success for the beetles, measured as similarity to target species-rich chalk grassland, was not found to be influenced by either management practice. In contrast, restoration success for the plants did increase in response to hay spreading management. While the presence of suitable host plants was considered to dictate the earliest point at which phytophagous beetles could successfully colonise, few beetle species colonised as soon as their host plants became established. Morphological characteristics and feeding habits of 27 phytophagous beetle species were therefore tested to identify factors that limited their colonisation and persistence. The lag time between host plant establishment and colonisation was greatest for flightless beetles. Beetles with foliage-feeding larvae both colonised at slower rates than seed-, stem- or root-feeding species, and persisted within the swards for shorter periods. While the use of hay spreading may benefit plant communities during chalk grassland restoration it did not directly benefit phytophagous beetles. Without techniques for overcoming colonisation limitation for invertebrate taxa short-term success of restoration may be limited to the plants only