19 research outputs found

    Impact of Forest Seral Stage on use of Ant Communities for Rapid Assessment of Terrestrial Ecosystem Health

    Get PDF
    Bioassessment evaluates ecosystem health by using the responses of a community of organisms that integrate all aspects of the ecosystem. A variety of bioassessment methods have been applied to aquatic ecosystems; however, terrestrial methods are less advanced. The objective of this study was to examine baseline differences in ant communities at different seral stages from clear cut to mature pine plantation as a precursor to developing a broader terrestrial bioassessment protocol. Comparative sampling was conducted at nine sites having four seral stages: clearcut, 5 year recovery, 15 year recovery, and mature stands. Soil and vegetation data were also collected at each site. Ants were identified to genus. Analysis of the ant data indicated that ants respond strongly to habitat changes that accompany ecological succession in managed pine forests, and both individual genera and ant community structure can be used as indicators of successional change. Ants exhibited relatively high diversity in both early and mature seral stages. High ant diversity in mature seral stages was likely related to conditions on the forest floor favoring litter dwelling and cold climate specialists. While ants may be very useful in identifying environmental stress in managed pine forests, adjustments must be made for seral stage when comparing impacted and unimpacted forests

    Biodiversity on Broadway - Enigmatic Diversity of the Societies of Ants (Formicidae) on the Streets of New York City

    Get PDF
    Each year, a larger proportion of the Earth's surface is urbanized, and a larger proportion of the people on Earth lives in those urban areas. The everyday nature, however, that humans encounter in cities remains poorly understood. Here, we consider perhaps the most urban green habitat, street medians. We sampled ants from forty-four medians along three boulevards in New York City and examined how median properties affect the abundance and species richness of native and introduced ants found on them. Ant species richness varied among streets and increased with area but was independent of the other median attributes measured. Ant assemblages were highly nested, with three numerically dominant species present at all medians and additional species present at a subset of medians. The most common ant species were the introduced Pavement ant (Tetramorium caespitum) and the native Thief ant (Solenopsis molesta) and Cornfield ant (Lasius neoniger). The common introduced species on the medians responded differently to natural and disturbed elements of medians. Tetramorium caespitum was most abundant in small medians, with the greatest edge/area ratio, particularly if those medians had few trees, whereas Nylanderia flavipes was most abundant in the largest medians, particularly if they had more trees. Many of the species encountered in Manhattan were similar to those found in other large North American cities, such that a relatively small subset of ant species probably represent most of the encounters humans have with ants in North America

    Influence of fire prevention management strategies on the diversity of butterfly fauna in the eastern Pyrenees

    Get PDF
    Fire prevention management is becoming a necessity in many Mediterranean locations to regulate fire of natural or human origin. However, very few studies have determined the real effects of the strategies adopted on local fauna. Butterflies are sensitive to local changes and they can thus serve as indicators of environmental changes. Three different types of fire prevention management approaches in three different localities in the Eastern Pyrenees (France) were performed and the butterfly community composition was investigated. We show that of the 80 species of butterflies observed, 36 % can be considered as biological markers. An original objective treatment of data using hierarchical distance analysis combined with a neural network analysis (Self-Organizing Maps) was applied in this study. Our conclusions are that the overall number of species is maintained independently of the fire prevention type but that some important changes are observed among butterfly communities, with a clear reduction of the numbers of endemic/specialized species in favour of generalist ones for the two most drastic fire prevention management approaches studied here. The influence of such approaches is discussed on the basis of the conservation of Mediterranean species of Lepidoptera

    Impact of hydropower dam development on agriculturally based livelihoods of resettled communities: A case study of Duong Hoa Commune in central Vietnam

    No full text
    Dam development is widespread in central Vietnam. Interviews were conducted with households that had been resettled and those that had not to determine the type of agricultural livelihoods that were re-established nine years after resettlement due to the Ta Trach reservoir project. Results showed that resettled households, despite having more forest land, were economically worse off compared with households that were not moved. This discrepancy between households was attributed to less arable land allocated to resettled households. The provision of good-quality land, able to grow crops and food trees, was essential if households were to re-establish a comparable agriculturally based livelihood

    The importance of farmers' perceptions of salinity and adaptation strategies for ensuring food security: Evidence from the coastal rice growing areas of Bangladesh

    No full text
    Coastal salinity causes substantial adverse impacts on agricultural productivity and food security. Farmers' choice of salinity adaptation strategies might depend on how they perceive the problem. This research examined rice farmers' perceptions of salinity, adaptation strategies, and its implications for policy initiatives to sustain rice production in the affected coastal areas of Bangladesh. Boro rice growers (n = 109) randomly selected from two coastal sub-districts were interviewed using a semi-structured survey. Awareness of salinity and its increase over the past 20 yearswaswidespread among rice farmers. A high proportion of farmers (90%) perceived the reproductive (e.g. booting, heading, and flowering) stages of the rice plant as the most sensitive to salinity problems. Salinity (ECe) was measured in the farmers' fields and were categorized according to farmers' perceptions and scientific interpretation (e.g. high or low). Farmers perceived a field affected by high salinity at a lower EC reading than the scientific interpretation of the salinity level. Most of the farmers (67%) were undertaking early transplanting and applying irrigation in order to adapt to salinity problems which occur later in rice crop growth during Boro season. Thus, farmers' actions demonstrated that their perceptions of salinity and adaptation responses were pre-emptive of when salinity was most likely to have an impact on the rice crop. Farmers' perceptions of salinization and measures to manage salinity need to be considered in research prioritization and policy formulation by the government. This action could potentially secure rice production and thus contribute to the achievement of Sustainable Development Goals (SDG-1, 2 and 3)
    corecore