The impact of land-use change on floristic diversity at regional scale in southern Sweden 600 BC-AD 2008

International audienceThis study explores the relationship between landuse and floristic diversity between 600BC and AD2008 in the uplands of southern Sweden. We use fossil pollen assemblages and the Regional Estimates of Vegetation Abundance from Large Sites (REVEALS) model to quantitatively reconstruct land cover at a regional scale. Floristic richness and evenness are estimated using palynological richness and REVEALS-based evenness, respectively. We focus on the period AD350 to 750 to investigate the impact of an inferred, short-lived (<200 yr) period of land-use expansion and subsequent land abandonment on vegetation composition and floristic diversity. The observed vegetation response is compared to that recorded during the transition from traditional to modern land-use management at the end of the 19th century. Our results suggest that agricultural land use was most widespread between AD350 and 1850, which correlates broadly with high values of palynological richness. REVEALS-based evenness was highest between AD500 and 1600 which indicates a more equal cover among taxa during this time interval. Palynological richness increased during the inferred land-use expansion after AD350 and decreased during the subsequent regression AD550-750, while REVEALS-based evenness increased throughout this period. The values of palynological richness during the last few decades are within the range observed during the last 1650 yr. However, REVEALS-based evenness shows much lower values during the last century compared to the previous ca. 2600 yr, which indicates that the composition of presentday vegetation is unusual in a millennial perspective. Our results show that regional scale changes in land use have had clear impacts on floristic diversity in southern Sweden, with a vegetation response time of less than 20 to 50 yr. We show the importance of traditional land use to attain high biodiversity and suggest that ecosystem management should include a regional landscape perspective

Floristic diversity in the transition from traditional to modern land-use in southern Sweden A.D. 1800-2008

International audienceWe aim to provide a long-term ecological analysis of land-use and floristic diversity in the transition from traditional to modern land-use management in the time A.D. 1800-2008 in southern Sweden. We use the Regional Estimates of Vegetation Abundance from Large Sites (REVEALS) model to quantify land-cover changes on a regional scale at 20-year intervals, based on the fossil pollen record. Floristic richness and evenness are estimated using palynological richness and the Shannon index applied to the REVEALS output, respectively. We identified a transition period of 60 years between 1880 and 1940 when the total tree cover increased and the tree composition changed from deciduous to coniferous dominance. Within the shrinking area of open land, arable land taxa expanded, while the number and coverage of herbs in the remaining grasslands decreased. The succession from open grasslands to more tree-covered habitats initially favoured palynological richness, which reached its highest values during the first 40 years of the transition period. The highest REVEALS-based evenness was recorded in the time of traditional land-use and at the beginning of the transition period, reflecting higher habitat diversity at these time intervals. Our results support a more dynamic ecosystem management that changes between traditional land-use and phases of succession (\40 years) to promote floristic diversity. We have developed and applied a palaeoecological methodology that contributes realistic estimates to be used in ecosystem management

Testing the effect of site selection and parameter setting on REVEALS-model estimates of plant abundance using th Czech Quaternary Palynological database

International audiencetypes, PFTs) is used in the LANDCLIM project to assess the effect of human-induced land-cover change on past climate in NW Europe. Using the Czech Quaternary Pollen Database, this case study evaluates the extent to which selection of data and input parameters for the REVEALS model applications would affect reconstruction outcomes. The REVEALS estimates of PFTs (grid-cell based REVEALS PFT estimates, GB REVEALS PFT-s) are calculated for five time windows of the Holocene using fossil pollen records available in each 1°×1°grid cell of the Czech Republic. The input data and parameters selected for testing are: basin type and size, number of 14C dates used to establish the chronology of the pollen records, number of taxa, and pollen productivity estimates (PPE). We used the Spearman correlation coefficient to test the hypothesis that there is no association between GB REVEALS PFT-s using different data and parameter inputs. The results show that differences in the basin size and type, number of dates, number and type of taxa (entomophilous included or not), and PPE dataset do not affect the rank orders of the GB REVEALS PFT-s significantly, except for the cases when entomophilous taxa are included. It implies that, given careful selection of data and parameter and interpretation of results, REVEALS applications can use pollen records from lakes and bogs of different sizes together for reconstruction of past land cover at the regional to sub-continental spatial scales for purposes such as the study of past land cover-climate interactions. Our study also provides useful criteria to set up protocols for data compilation REVEALS applications of this kind

Sleep hygiene behaviours in Iranian adolescents: an application of the Theory of Planned Behavior

Poor sleep quality and inadequate sleep in adolescents are a rising trend globally. The Theory of Planned Behaviour (TPB)—which centres on an individual’s attitude toward performing the behaviour, subjective norms and perceived behavioural control—has been applied to examine sleep hygiene behaviours in young adults. We expanded on prior works by using a longitudinal design to examine the effects of TPB factors, together with sleep hygiene knowledge and planning constructs, on sleep hygiene behaviours and on sleep quality and health in a group of Iranian adolescents. A total of 1822 healthy adolescents (mean age = 13.97) from 25 high schools in Qazvin, Iran, completed a selfreported survey at baseline and 6 months later. Structural equation modelling (SEM) was used to delineate the pathway from adolescents’ sleep hygiene knowledge, TPB constructs of their behavioural intentions and sleep hygiene behaviours and their sleep quality and self-reported health. The SEM model demonstrated that although behavioural intention, coping planning and action planning predicted the sleep hygiene behaviours positively 6 months later with acceptable model fit [comparative fit index (CFI) = 0.936; Tucker–Lewis index (TLI) = 0.902; root mean square error of approximation (RMSEA) = 0.080; standardized root mean square residual (SRMR) = 0.044], sleep hygiene knowledge did not predict behavioural intentions significantly. Sleep hygiene behaviours were associated with sleep quality and psychiatric wellbeing. Thus, the TPB, combined with coping and action planning, is useful in understanding the sleep hygiene behaviours of adolescents. Health-care providers may want to emphasize TPB constructs and coping and action planning to improve adolescents’ sleep hygiene behaviours, rather than rely solely upon increasing adolescents’ sleep hygiene knowledge

Signals of tree volume and temperature in a high-resolution record of pollen accumulation rates in northern Finland

International audiencePollen accumulation rates (PARs) provide a potential proxy for quantitative tree volume (m3 ha 1) reconstruction with reliable absolute pollen productivity estimates (APPEs). We obtained APPEs for pine, spruce and birch at their range limits in northern Finland under two temperature periods ('warm' and 'cold') based on long-term pollen trap and tree volume records within a 14-km radius of each trap. APPEs (mean SE; 108 grains m 3 a 1) tend to be higher for the 'warm' periods (pine 123.8 24.4, birch 528.0 398.4, spruce 434.3 113.7) compared with the 'cold' periods (pine 95.5 37.3, birch 317.3 282.6, spruce 119.6 37.6), although the difference is only significant for spruce. Using an independent temperature record and the APPEs obtained, we reconstruct a low-frequency record of pine volume changes over the last 1000 years at Palomaa mire, where a high-resolution record of Pinus PARs is available. Five phases are distinguished in the reconstruction: moderate pine volume, AD 1080-1170; high volume, AD 1170-1340; low volume, AD 1340-1630; very low volume, AD 1630-1810; and rising pine volume, AD 1810- 1950. These phases do not coincide with periods of high or low June-July-August temperatures, and thus appear to reflect regional variations in tree volume, while high-frequency changes within each time-period block show variations in PARs in response to temperatur

Two hundred years of land-use change in the South Swedish Uplands : comparison of historical map-based estimates with a pollen-based reconstruction using the landscape reconstruction algorithm

International audienceLong-term records of environmental history at decadal to millennial timescales enable an assessment of ecosystem variability and responses to past anthropogenic disturbances and are fundamental for the development of environmental management strategies. This study examines the local variability of land-use history in the South Swedish Uplands over the last 200 years based on pollen records from three lake-sediment successions. Temporal changes in the proportional cover of 14 plant taxa were quantified as percentages using the landscape reconstruction algorithm (LRA). The LRA-based estimates of the extent of four land-use categories (cropland, meadows/grassland, wetland, outland/woodland) were compared to corresponding estimates based on historical maps and aerial photographs from AD 1769–1823, 1837–1895, 1946 and 2005. Although the LRA approach tends to overestimate grassland cover by 10–30 % for the two earliest time periods, the reconstructed vegetation composition is generally in good agreement with estimates based on the historical records. Subsequently, the LRA approach was used to reconstruct the 200-year history of local land-use dynamics at 20-year intervals around two small lakes. The qualitative assessment of difference approach , which requires fewer assumptions and parameters than LRA for objective evaluation of between-site differences in plant abundances, provides consistent results in general. Significant differences exist in the land-use history between the sites. Local catchment characteristics, such as soil conditions and wetland cover, appear important for the development of human impact on the landscape. Quantifi-cations of past vegetation dynamics provide information on the amplitude, frequency and duration of the land-use changes and their effects on terrestrial and aquatic ecosystems , and should be taken into account when nature conservation strategies are developed

The Mechanics of Low Orbiting Satellites Implications in Communication

Low orbiting satellite communication networks will be competing with geosynchronous satellites for a share of the communications market. In world-wide communications that do not require immediate real time transmissions, low orbiting satellites are competitive with geosynchronous satellites because the system is reliable and low in cost. Since satellites are a clear example of Newtonian laws, the distinct patterns they make in their orbiting process are predictable. Newton\u27s law states that an object will remain in uniform motion unless acted upon by a force: a satellite remains in motion around the earth because there is no atmosphere to slow it down. A satellite stays in orbit because the pull of gravity inward is balanced by centrifugal energy outward. The rate which a satellite orbits the earth and the lifetime of the satellite depend on its altitude. Low orbiting satellites trace unique paths over the surface of the earth -- the satellite is accessible for communication if the path o the satellite comes within 1500 kilometers of a ground station. Unless there are 50 to 80 low orbiting satellites, the system is not useful for exclusive real time communication and thus requires a different operating structure. The low orbiting satellite will use a combination of two modes for communication: the transponder mode, and the store and forward mode

Flower Dance

https://digitalcommons.library.umaine.edu/mmb-ps/1517/thumbnail.jp

Advocating for Existence: The History of Environmental Justice Movements Surrounding the Port of Los Angeles

This thesis examines the forces and factors that gave rise to environmental justice movements surrounding the Port of Los Angeles in the early 21st Century. Through the spatial, economic, and migratory factors that shaped the region of Southeast Los Angeles, this thesis brings to light important tensions between port authorities, politicians, labor groups, employees, and communities that determined the economic and environmental fate of the region. These tensions came to a head through unique coalitions of labor and community-based environmental movements, ultimately achieving major regulatory wins and establishing initiatives that supported the financial and physical health of employees and communities. Through these moments of success, this thesis argues that centering environmental gains in environmental justice communities will ultimately prove to be the most promising path to climate solutions and healthy and thriving communities