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2021 ◽  
pp. 1-13
Author(s):  
Olga Kandelinskaya ◽  
Helena Grischenko ◽  
Yury Hihinyak ◽  
Mikhail Andreev ◽  
Peter Convey ◽  
...  

Abstract We assessed the content of some major and trace elements and lichen compounds as well as antioxidant activity in eight lichen species representing four families collected in areas > 1 km distant from Bellingshausen (King George Island) and > 1 km distant from Molodezhnaya (Thala Hills, Enderby Land) research stations. Content levels of Cu, Pb, Cd, Zn and As in Physcia caesia, Physconia muscigena, Umbilicaria aprina, Umbilicaria decussata and Usnea aurantiaco-atra thalli were similar to or lower than previously reported for these species in the Maritime and Continental Antarctic, as well as from reference sites. The first data on the contents of 15 elements in Ramalina terebrata and Thamnolecania brialmontii thalli from the Maritime Antarctic are reported. Our analyses confirmed the presence of the main photosynthetic pigments in the species examined (chlorophyll a and b, phaeophytin a and b, neoxanthin, violaxanthin, lutein and β-carotene). We identified protolichesterinic acid in T. brialmontii thalli for the first time. Antioxidant activity varied from 190 μg/g dry weight (U. decussata) to 14,740 μg/g dry weight (T. brialmontii). The data obtained complement previous research while also providing new baseline data that will have utility in monitoring and identifying future change.


2021 ◽  
Vol 13 (24) ◽  
pp. 5180
Author(s):  
Emilio Matricciani ◽  
Carlo Riva ◽  
Lorenzo Luini

In GeoSurf satellite constellations, any transmitter/receiver, wherever it is located, is linked to a satellite with zenith paths. We have studied the tropospheric attenuation predicted for some reference sites (Canberra, Holmdel, Pasadena, Robledo, and Spino d’Adda), which also set the meridian along which we have considered sites with latitudes ranging between 60° N and 60° S. At the annual probability of 1% of an average year, in the latitude between 30° N and 30° S, there are no significant differences between GEO slant paths and GeoSurf zenith paths. On the contrary, at 0.1% and 0.01% annual probabilities, large differences are found for latitudes greater than 30° N or 30° S. For comparing the tropospheric attenuation in GeoSurf paths with that expected in LEO highly variable slant paths, we have considered, as reference, a LEO satellite constellation orbiting in circular at 817 km. GeoSurf zenith paths “gain” several dBs compared to LEO slant paths. The more static total clear-sky attenuation (water vapor, oxygen, and clouds) in both GEO and LEO slant paths shows larger values than GeoSurf zenith paths. Both for rain and clear-sky attenuations, Northern and Southern Hemispheres show significant differences.


2021 ◽  
Vol 25 (8) ◽  
pp. 1357-1363
Author(s):  
I.E. Okon ◽  
K.I. Omoniyi ◽  
E.D. Paul ◽  
P.A. Ekwumemgbo

This study aimed at assessing the influence of vehicle traffic on spatial variation of ozone (O3) and its vehicular emission precursors in the air of Port Harcourt city. Sampling was carried out in ten (10) sites, eight (8) located within the high traffic density area (study sites) and two (2) located within the very low traffic density area (reference sites). The precursor pollutants measured were nitrogen dioxide (NO2), carbon monoxide (CO) and volatile organic compounds (VOCSs). Ozone and the precursor pollutants were measured in situ using AeroQUAL 500 series portable ambient air analyzer while traffic flow survey was achieved by direct counting. Measurements were carried out at morning, evening and off-peak traffic periods respectively. The mean concentrations of ozone and the precursor pollutants were significantly higher (p = 0.05) in the study sites than in the reference sites. Mean concentrations were higher at peak traffic periods than at off-peak traffic periods except for ozone that was higher at off-peak than at morning peak. There was significant correlation between traffic density and each of the pollutants including ozone. The spatial variability in concentration of pollutants was influenced by vehicular traffic. VOCs and NO2 levels were higher than the National Ambient Air Quality Standard (NAAQS) limit of 0.05 ppm and 0.04 – 0.06 ppm respectively, O3 concentration was below the standard limit (0.06 ppm) but was at the verge of exceeding. Traffic emission within the city was significant and could be mitigated through regular monitoring and control.


2021 ◽  
Author(s):  
◽  
Nicky OliverSmith

<p>Urban revegetation programmes are an important contribution to the biodiversity of our landscape environment. Wellington city has, for nearly two decades, promoted revegetation of the city with a focus in latter years on eco-sourced native species. This is a substantial urban greening project planting 100,000 native plants per annum. This thesis analyses the native revegetation programme and posits recommendations for continuance and enhancement for consideration.  Data were collected from a sample set of twenty revegetated sites and four reference sites in Wellington city. Two transects per site were set up with invertebrate pitfall traps, lizard pitfall traps, lizard tree covers, bird count stations and vegetation surveys. The data were collected over a twelve-month period. Ordination was used to examine the community composition of revegetation sites in relation to each other and the four reference sites. Multiple regression was used to examine the influence of patch age, patch size, isolation and residential land cover upon a range of biodiversity variables.   The key findings of this study are that revegetated sites lacked the level of ground cover by native seedlings that were characteristic of the mature reference sites. Also found was that revegetation sites in Wellington City require around ten years of growth before natural regeneration of native seedlings began to become apparent.  Large native birds were more likely to be found in close proximity to mature primary bush, confirming that mature primary bush is an essential element of the landscape. Weta were found in increased numbers as distance from mature primary bush increased. Northern grass skinks were the only species of lizard found, in association with a higher proportion of residential area in the matrix.   The key management recommendations of this study are; the development of a collaborative connective strategy; further enrichment planting designed to maximize structural diversity over time; the investment in well planned robust monitoring programmes.  This research contributes to the understanding of biodiversity outcomes of an urban native revegtation programme, providing baseline data for future monitoring purposes.</p>


2021 ◽  
Author(s):  
◽  
Nicky OliverSmith

<p>Urban revegetation programmes are an important contribution to the biodiversity of our landscape environment. Wellington city has, for nearly two decades, promoted revegetation of the city with a focus in latter years on eco-sourced native species. This is a substantial urban greening project planting 100,000 native plants per annum. This thesis analyses the native revegetation programme and posits recommendations for continuance and enhancement for consideration.  Data were collected from a sample set of twenty revegetated sites and four reference sites in Wellington city. Two transects per site were set up with invertebrate pitfall traps, lizard pitfall traps, lizard tree covers, bird count stations and vegetation surveys. The data were collected over a twelve-month period. Ordination was used to examine the community composition of revegetation sites in relation to each other and the four reference sites. Multiple regression was used to examine the influence of patch age, patch size, isolation and residential land cover upon a range of biodiversity variables.   The key findings of this study are that revegetated sites lacked the level of ground cover by native seedlings that were characteristic of the mature reference sites. Also found was that revegetation sites in Wellington City require around ten years of growth before natural regeneration of native seedlings began to become apparent.  Large native birds were more likely to be found in close proximity to mature primary bush, confirming that mature primary bush is an essential element of the landscape. Weta were found in increased numbers as distance from mature primary bush increased. Northern grass skinks were the only species of lizard found, in association with a higher proportion of residential area in the matrix.   The key management recommendations of this study are; the development of a collaborative connective strategy; further enrichment planting designed to maximize structural diversity over time; the investment in well planned robust monitoring programmes.  This research contributes to the understanding of biodiversity outcomes of an urban native revegtation programme, providing baseline data for future monitoring purposes.</p>


2021 ◽  
Vol 193 (12) ◽  
Author(s):  
Ulrike Kammann ◽  
Marc-Oliver Aust ◽  
Maike Siegmund ◽  
Nicole Schmidt ◽  
Katharina Straumer ◽  
...  

AbstractDumped munitions contain various harmful substances which can affect marine biota like fish. One of them is mercury (Hg), included in the common explosive primer Hg fulminate. There is still a lack of knowledge whether dumped munitions impact the Hg concentrations in the Baltic Sea environment. This study aims to answer the question if dab caught at the dump site Kolberger Heide show higher Hg concentrations released from munition sources and whether Hg in fish is a usable marker for munition exposure. Therefore, a total of 251 individual dab (Limanda limanda) were analysed including 99 fish from the dump site. In fish from the Kolberger Heide, no elevated Hg concentrations were found compared to reference sites when age-dependent bioaccumulation of mercury was considered. Therefore we conclude that Hg in fish is no suitable indicator for exposure to munition dumping, e.g. in the frame of possible future monitoring studies as Hg exposure originating from dumped munition is only a small contributor to overall Hg exposure of fish.


2021 ◽  
Author(s):  
◽  
Edward Rex Lancelot Bartholomew

<p>The small tree Fuchsia excorticata (Onagraceae) is found on disturbed riparian sites throughout New Zealand. Spatial distribution and  demographic changes in populations of F. excorticata were surveyed in the Rotoiti Nature Recovery Project (RNRP) area, and an associated non-treatment reference area, Nelson Lakes National Park, over the period 2005 to 2007. The RNRP is an intensively managed "mainland island" project in mixed beech (Nothofagus) forest, pest animal species especially possums (Trichosurus vulpecula), rodents, and mustelids are controlled. The aim of this study was to survey the condition of F. excorticata in the managed and reference areas to determine if any differences could be detected between the populations over time. The only significant (p<0.05) difference between the two areas was in sapling abundance, which was higher in the RNRP management area. This was tentatively attributed to pest management; however the concurrence of complex  environmental influences, and a lack of management replication, prevented a simple interpretation of the data. There was no significant difference in recruitment, growth, mortality, and tree or seedling abundance  between the managed and reference areas. Growth rate, especially of saplings, was significantly greater at lower elevations in the RNRP managed area, however the inverse held for the reference area. Mammalian herbivory was light; the main affect being to restrict seedling growth through hedging. Periodic heavy flooding was responsible for much of the mortality, however many newly disturbed sites were rapidly populated with fuchsia seedlings. The need for rigour in establishing ecologically comparable reference sites for comparative studies was evident. There were inherent difficulties in establishing causal relationships between ecological changes and management practices where management was not replicated geographically.</p>


2021 ◽  
Author(s):  
◽  
Edward Rex Lancelot Bartholomew

<p>The small tree Fuchsia excorticata (Onagraceae) is found on disturbed riparian sites throughout New Zealand. Spatial distribution and  demographic changes in populations of F. excorticata were surveyed in the Rotoiti Nature Recovery Project (RNRP) area, and an associated non-treatment reference area, Nelson Lakes National Park, over the period 2005 to 2007. The RNRP is an intensively managed "mainland island" project in mixed beech (Nothofagus) forest, pest animal species especially possums (Trichosurus vulpecula), rodents, and mustelids are controlled. The aim of this study was to survey the condition of F. excorticata in the managed and reference areas to determine if any differences could be detected between the populations over time. The only significant (p<0.05) difference between the two areas was in sapling abundance, which was higher in the RNRP management area. This was tentatively attributed to pest management; however the concurrence of complex  environmental influences, and a lack of management replication, prevented a simple interpretation of the data. There was no significant difference in recruitment, growth, mortality, and tree or seedling abundance  between the managed and reference areas. Growth rate, especially of saplings, was significantly greater at lower elevations in the RNRP managed area, however the inverse held for the reference area. Mammalian herbivory was light; the main affect being to restrict seedling growth through hedging. Periodic heavy flooding was responsible for much of the mortality, however many newly disturbed sites were rapidly populated with fuchsia seedlings. The need for rigour in establishing ecologically comparable reference sites for comparative studies was evident. There were inherent difficulties in establishing causal relationships between ecological changes and management practices where management was not replicated geographically.</p>


PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0258251
Author(s):  
Timothy J. Beechie ◽  
Caleb Fogel ◽  
Colin Nicol ◽  
Britta Timpane-Padgham

Identifying necessary stream and watershed restoration actions requires quantifying natural potential habitat conditions to diagnose habitat change and evaluate restoration potential. We used three general methods of quantifying natural potential: historical maps and survey notes, contemporary reference sites, and models. Historical information was available only for the floodplain habitat analysis. We used contemporary reference sites to estimate natural potential habitat conditions for wood abundance, riparian shade, main channel length, and side channel length. For fine sediment, temperature, and beaver ponds we relied on models. We estimated a 90% loss of potential beaver pond area, 91% loss of side-channel length, and 92% loss or degradation of floodplain marshes and ponds. Spawning habitat area change due to wood loss ranged from -23% to -68% across subbasins. Other changes in habitat quantity or quality were smaller—either in magnitude or spatial extent—including rearing habitat areas, stream temperature, and accessible stream length. Historical floodplain habitat mapping provided the highest spatial resolution and certainty in locations and amounts of floodplain habitat lost or degraded, whereas use of the contemporary reference information provided less site specificity for wood abundance and side-channel length change. The models for fine sediment levels and beaver pond areas have the lowest reach-specific certainty, whereas the model of temperature change has higher certainty because it is based on a detailed riparian inventory. Despite uncertainties at the reach level, confidence in subbasin-level estimates of habitat change is moderate to high because accuracy increases as data are aggregated over multiple reaches. Our results show that the largest habitat losses were floodplain and beaver pond habitats, but use of these habitat change results in salmon life-cycle models can illustrate how the potential benefits of alternative habitat restoration actions varies among species with differing habitat preferences.


Author(s):  
Hanguang Qiu ◽  
Cejun Cao ◽  
Jie Zhen ◽  
Hongyong Fu ◽  
Jixiang Zhou

A multicircle order acceptance strategy was proposed to decide whether to accept customer requests for specific last-mile delivery modes (including attended home or reception box delivery) and time slots. The strategy was composed of initializing acceptable time slot allocations, reallocating acceptable time slots, matching reference sites, and assessing time slot deviations. A strategy-oriented insertion algorithm for dynamic vehicle routing problems with hard time windows was constructed, thereby showing the proposed strategy achieves a better balance between revenue and distance than the “first come and first served” strategy. Always accepting global optimization result is not significantly better than adopting the result conditionally or based on simulated annealing theory. The distance and revenue gradually increase with the number of reference sites, while revenue/distance ratio decreases. The vehicles are available to serve more attended home delivery orders with a gradual increase in time slot interval, thereby leading to an increase of AHD and total revenue.


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