13 research outputs found
Children’s Opinions about the Loss of Nature
A survey was conducted among approximately 400 Dutch schoolchildren (age: 8–16 years) in order to test their feelings about deterioration of the environment and the extinction of species. The majority of pupils answered that they regret the extinction of species more or less, especially popular ones. For a minority it does not matter at all. The proportion of pupils who expressed indifference to the pollution of air, water and soil was 7%, 10% and 13%, respectively.Dying of the forest was taken very seriously by approximately 60% of the pupils; this percen tage increased after a slide of a dead forest was shown. A similar result was obtained in respect to the assumed extinction of a common plant species: it was taken more seriously after some information was given.More than half of the pupils predicted a bad future for the Netherlands. However, this pessimistic view can be changed into a more optimistic one by stimulating activities to improve the environment. The fact that most pupils judged their own future positive may indicate that they feel to have some control on the quality of their own life
The role of non-foraging nests in polydomous wood ant colonies
A colony of red wood ants can inhabit more than one spatially separated nest, in a strategy called polydomy. Some nests within these polydomous colonies have no foraging trails to aphid colonies in the canopy. In this study we identify and investigate the possible roles of non-foraging nests in polydomous colonies of the wood ant Formica lugubris. To investigate the role of non-foraging nests we: (i) monitored colonies for three years; (ii) observed the resources being transported between non-foraging nests and the rest of the colony; (iii) measured the amount of extra-nest activity around non-foraging and foraging nests. We used these datasets to investigate the extent to which non-foraging nests within polydomous colonies are acting as: part of the colony expansion process; hunting and scavenging specialists; brood-development specialists; seasonal foragers; or a selfish strategy exploiting the foraging effort of the rest of the colony. We found that, rather than having a specialised role, non-foraging nests are part of the process of colony expansion. Polydomous colonies expand by founding new nests in the area surrounding the existing nests. Nests founded near food begin foraging and become part of the colony; other nests are not founded near food sources and do not initially forage. Some of these non-foraging nests eventually begin foraging; others do not and are abandoned. This is a method of colony growth not available to colonies inhabiting a single nest, and may be an important advantage of the polydomous nesting strategy, allowing the colony to expand into profitable areas
Spatio-Temporal Dynamics of Foraging Networks in the Grass-Cutting Ant Atta bisphaerica Forel, 1908 (Formicidae, Attini)
International audienceForaging networks are a key element for ant colonies because they facilitate the flow of resources from the environment to the nest and they allow the sharing of information among individuals. Here we report the results of an 8-month survey, extending from November 2009 to June 2010, of the foraging networks of four mature colonies of Atta bisphaerica, a species of grass-cutting ant which is considered as a pest in Brazil. We found that the distribution of foraging effort was strongly influenced by the landscape features around the nests, in particular by the permanently wet parts of the pasture in which the nests were located. The foraging networks consisted of underground tunnels which opened on average at 21.5m from the nests and of above-ground physical trails that reached on average 4.70m in length. The use of the foraging networks was highly dynamic, with few sections of the networks used for long periods of time. Three different phases, which could be linked to the seasonal change in the local rainfall regime, could be identified in the construction and use of the foraging networks. The first phase corresponded to the beginning of the rainy season and was characterized by a low foraging activity, as well as a low excavation and physical trail construction effort. The second phase, which began in February and extended up to the end of the humid season at the end of March, was characterized by an intense excavation and trail construction effort, resulting in an expansion of the foraging networks. Finally, in the third phase, which corresponded to the beginning of the dry season, the excavation and trail construction effort leveled off or decreased while foraging activity kept increasing. Our hypothesis is that ants could benefit from the underground tunnels and physical trails built during the humid season to maintain their foraging activity at a high level
Urban areas as hot-spots for introduced and shelters for native isopod species
Isopod assemblages were studied in Budapest, capital of Hungary.
The analyses of literary and field data revealed a high species
richness (28 species), compared to the total species number (57)
in Hungary. Habitats characteristics for the city were
categorized as native forests, urban forests, gardens of Buda,
gardens of Pest, public parks, densely built-up areas and
botanical gardens. We hypothesized that isolated and diverse
habitat patches in the city matrix of Budapest support the
introduction and establishment of exotic species and the
survival of native ones. The composition of assemblages varied
among sampling sites, but were characteristic for the biotope
categories. We concluded that forests, parks and gardens play an
important role in the survival of native isopod populations.
Species numbers were highest in the gardens of Buda and in the
botanical gardens (both 17 species). The overall presence of
cosmopolitan and disturbance-tolerant species indicates an
ongoing homogenization process.
Key-words: soil fauna, woodlice, urban biodiversity, species
introduction, taxonomic uniformit
Genetic structure of the Black Bog Ant (Formica picea Nylander) in the United Kingdom
Social Hymenoptera have been relatively little studied in terms of conservation genetics even though their sociality and omplementary sex determination potentially influence the interaction of genetics with extinction risk. Using microsatellite markers, we investigated the social and genetic structure of nests and populations of the Black Bog Ant Formica picea at four sites in the UK, where this habitat specialist has a localized and fragmented range. Nests were weakly polygynous (effective queen number, 4–27 per nest) with low orker relatedness. Isolation by distance tended to be present within sites, indicating limited dispersal, but inbreeding was rare. The four study sites fell into three main populations (two in South Wales, one in southern England). We conclude that, although UK F. picea populations are not at immediate risk from genetic factors, their limited dispersal abilities at both within- and between-site scales should inform conservation management decisions
The role of wood ants (Formica rufa group) in carbon and nutrient dynamics of a boreal Norway spruce forest ecosystem
Wood ants (Formica rufa group) are regarded as keystone species in boreal and mountain forests of Europe and Asia by their effect on ecosystem carbon (C) and nutrient pools and fluxes. To quantify the impact of their activity on boreal forest ecosystems, C, nitrogen (N), phosphorus (P), potassium (K) and calcium (Ca) pools and fluxes in wood ant nests (WAN), and soil were assessed along a 5-, 30-, 60-, and 100-year-old Norway spruce (Picea abies L. Karsten) dominated successional gradient in eastern Finland. Amounts of C and nutrients in WAN increased with stand age, but contained less than 1% of total C and nutrient pools in these stands. The CO2-efflux from nests was also insignificant, as compared to CO2-efflux from the forest floor. Annually, the amount of C brought by wood ants into their nests as honeydew, prey and nest-building materials ranged from 2. 7 to 49. 3 kg ha-1 C, but this is only 0. 1-0. 7% of the combined net primary production of trees and understorey in boreal forests. The difference between wood ant nest C inputs and outputs was very small in the younger-aged stands, and increased in the older stands. Carbon accumulation rates in nests over a 100 year period are estimated to be less than 10 kg ha-1 a-1. In contrast to C, annual inputs of N, P, and K are larger compared to wood ant nest nutrient pool size, ranging from 3 to 6% of the annual tree stand and understorey uptake. This indicates a more rapid turnover and transport of N, P, and K out of WAN, and suggests that wood ants increase the cycling rate of these nutrients in boreal forests. © 2012 Springer Science+Business Media New York