scholarly journals Vertical Migration of Adult Plecoptera and Trichoptera above Forested Headwater Streams

Insects ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 770
Author(s):  
Ruric O. Bowman ◽  
Robert F. Smith
Keyword(s):  
Food Webs ◽  
Vertical Migration ◽  
Riparian Forest ◽  
Ground Level ◽  
Ecosystem Structure ◽  
Long Distance ◽  
Forest Canopies ◽  
Stream Insects ◽  
Essential Components ◽  
Riparian Canopy

Stream insects are essential components of aquatic and terrestrial ecosystem structure and function. Terrestrial stages are important components of terrestrial food webs, and flight-capable individuals are responsible for long-distance dispersal. Horizontal migrations by flying or crawling adults away from stream channels that link insects to riparian food webs and movements across catchment boundaries are well established through empirical research, but studies examining vertical migration of adult stream insects into forest canopies are generally lacking. This study focused on differences in adult Plecoptera and Trichoptera abundance at ground level versus the riparian canopy and differences in abundances among summer and autumn sampling periods to empirically demonstrate use of canopy ecosystems by stream insects. Malaise traps at ground level and canopy traps placed 8 to 10 m above the stream at four sites in the Mosquito Creek watershed (Pennsylvania) were used to examine vertical migration. Larval assemblages were collected and compared to adult assemblage to investigate patterns of local migration in the catchment. We found significantly more stream insects at ground level than in the forest canopy for Trichoptera, Plecoptera, and all individual plecopteran families, but a meaningful number of individuals were found in the riparian canopy. Canopy abundances were similar to abundances captured in adjacent ground-level habitats in other studies. Comparisons of adult and larval abundances among sites, taxa, and stages indicated site- and taxon-specific patterns for vertical movement into riparian canopies. Demonstrating that adult stream insects utilize riparian forest canopies indicates that riparian forest conservation should be prioritized over reforestation and that several potential research questions exist to inform riparian management.

scholarly journals The influence of habitat conditions on the performance of two invasive, annuals — Impatiens glandulifera and Bidens frondosa

Biologia ◽  
2014 ◽  
Vol 69 (4) ◽  
Author(s):  
Kinga Kostrakiewicz-Gierałt ◽  
Maria Zając
Keyword(s):  
Seedling Recruitment ◽  
Riparian Forest ◽  
Fruit Production ◽  
Spatial And Temporal Variability ◽  
Habitat Conditions ◽  
Impatiens Glandulifera ◽  
Long Distance ◽  
Bidens Frondosa ◽  
Number Of Seeds ◽  
Invasive Annuals

AbstractThe investigations of habitat conditions on the variability of selected population features in the two invasive, annuals with different life-history traits were conducted in the years 2008–2010, in the Polish part of the Carpathian Mountains in communities characterized by the gradual decrease of light availability. The individuals of Impatiens glandulifera were surveyed along roadsides, in willow thickets, as well as inside and along the edges of the riparian forest, whereas the individuals of Bidens frondosa were observed in riverside gravels characterized by a different species composition. Each year, the number and density of individuals (stems) occurring in the particular sites were examined, as well as the height and the fruit production in 30 randomly chosen stems were surveyed. Moreover, the number of seeds per fruit, the diaspore dimensions and the seedling recruitment in laboratory conditions were examined during each season. As the values of height of individuals, number of fruits per stem, number of seeds per fruit, as well as the seedling abundance in some groups were not consistent with the normal distribution and the variances were not homogeneous, the non-parametric Kruskal-Wallis test was used in statistical analyses.Much greater number and density of individuals of Impatiens glandulifera were found in riparian forest, than in willow thickets and along the roadsides. In all sites the number and density of individuals increased steadily in consecutive seasons. The great number and density of Bidens frondosa individuals observed in shady and partly shady sites during the first year of studies raised in the second year and subsequently dramatically decreased in the third season. The lowest number and density of individuals noted in the first season in unshaded site raised substantially in subsequent years. The height of stems, as well as seed and fruit production of both taxa diminished with a decrease of height of neighboring plants. The seed dimensions presented the spatial and temporal variability, whereas the number of seedlings among consecutive years and in successive sites did not differ.The considerable height of the individuals of Impatiens glandulifera, high production of large fruits and seeds in open and dry roadside areas can contribute to more effective ballistic dissemination, while substantial seedling recruitment enables the colonization of new, perhaps more advantageous sites. On the other hand, lower individual height, as well as fruit and seed production and considerable seedling emergence allow the population to last and to gradually extend the area in forest communities. The considerable abundance of the high-statured Bidens frondosa individuals, substantial production of large capitula and achenes contribute to long persistence of populations in open and sun-lit sites. The gradually decrease in the height of the stems, achene number and size observed in partly-shaded and shaded places might allow to long-distance dispersal of seeds by animals, while substantial seedling recruitment might contribute to establishment in new areas.

scholarly journals Environmental forcing and Southern Ocean marine predator populations: effects of climate change and variability

2007 ◽  
Vol 362 (1488) ◽  
pp. 2351-2365 ◽  
Author(s):  
P.N Trathan ◽  
J Forcada ◽  
E.J Murphy
Keyword(s):  
Climate Change ◽  
Southern Ocean ◽  
Food Webs ◽  
Time Scales ◽  
Trophic Level ◽  
Global Ocean ◽  
Ecosystem Structure ◽  
Marine Predator ◽  
Enso Events ◽  
Biological Responses

The Southern Ocean is a major component within the global ocean and climate system and potentially the location where the most rapid climate change is most likely to happen, particularly in the high-latitude polar regions. In these regions, even small temperature changes can potentially lead to major environmental perturbations. Climate change is likely to be regional and may be expressed in various ways, including alterations to climate and weather patterns across a variety of time-scales that include changes to the long interdecadal background signals such as the development of the El Niño–Southern Oscillation (ENSO). Oscillating climate signals such as ENSO potentially provide a unique opportunity to explore how biological communities respond to change. This approach is based on the premise that biological responses to shorter-term sub-decadal climate variability signals are potentially the best predictor of biological responses over longer time-scales. Around the Southern Ocean, marine predator populations show periodicity in breeding performance and productivity, with relationships with the environment driven by physical forcing from the ENSO region in the Pacific. Wherever examined, these relationships are congruent with mid-trophic-level processes that are also correlated with environmental variability. The short-term changes to ecosystem structure and function observed during ENSO events herald potential long-term changes that may ensue following regional climate change. For example, in the South Atlantic, failure of Antarctic krill recruitment will inevitably foreshadow recruitment failures in a range of higher trophic-level marine predators. Where predator species are not able to accommodate by switching to other prey species, population-level changes will follow. The Southern Ocean, though oceanographically interconnected, is not a single ecosystem and different areas are dominated by different food webs. Where species occupy different positions in different regional food webs, there is the potential to make predictions about future change scenarios.

scholarly journals Nine-year record of Alnus pollen deposition in the Roztocze region (SE Poland) with relation to vegetation data

2012 ◽  
Vol 60 (2) ◽  
pp. 57-64 ◽  
Author(s):  
Irena A. Pidek
Keyword(s):  
Ground Level ◽  
Pollen Deposition ◽  
Long Distance ◽  
Pollen Monitoring ◽  
Future Studies ◽  
Vegetation Control ◽  
Average Value ◽  
Se Poland ◽  
Long Distance Transport ◽  
Distance Transport

Pollen deposition of alder has been measured at ground level by means of nine modifi ed Tauber traps in different plant communities according to rules of the Pollen Monitoring Programme (http://pmp.oulu.fi ). The series of data covers the period 1998-2006. The area under investigation is situated in the Roztocze (surroundings of the Guciów village) within the protective zone of the Roztocze National Park. During nine years of monitoring, significant variations were observed between single years of deposition. The occurrence of peak years (1998, 2001, 2003 and 2006) connected with higher production of <i>Alnus</i> pollen was observed at many pollen monitoring sites, but its relationship with different proportions of alder within the surrounding vegetation seems rather weak. The average value of annual pollen deposition of <i>Alnus</i> for the whole region was calculated at ca. 1370 grains &#8226; cm<sup>-2</sup>. At the sites situated within the open landscape, pollen influx values ranged from 442 (in 2005) to 6894 (in 1998). It seems that other factors than the proportion of alder within the vegetation control the deposition of <i>Alnus</i> pollen. Long-distance transport and meteorological factors such as wind speed and direction should be taken into account in future studies.

scholarly journals COVID-19 lockdowns cause global air pollution declines

2020 ◽  
Vol 117 (32) ◽  
pp. 18984-18990 ◽  
Author(s):  
Zander S. Venter ◽  
Kristin Aunan ◽  
Sourangsu Chowdhury ◽  
Jos Lelieveld
Keyword(s):  
Air Pollution ◽  
Particulate Matter ◽  
Fine Particulate Matter ◽  
Ground Level ◽  
Air Pollutant ◽  
Pollutant Emissions ◽  
Economic Activities ◽  
Long Distance ◽  
Mobility Data ◽  
Fine Particulate

The lockdown response to coronavirus disease 2019 (COVID-19) has caused an unprecedented reduction in global economic and transport activity. We test the hypothesis that this has reduced tropospheric and ground-level air pollution concentrations, using satellite data and a network of >10,000 air quality stations. After accounting for the effects of meteorological variability, we find declines in the population-weighted concentration of ground-level nitrogen dioxide (NO2: 60% with 95% CI 48 to 72%), and fine particulate matter (PM2.5: 31%; 95% CI: 17 to 45%), with marginal increases in ozone (O3: 4%; 95% CI: −2 to 10%) in 34 countries during lockdown dates up until 15 May. Except for ozone, satellite measurements of the troposphere indicate much smaller reductions, highlighting the spatial variability of pollutant anomalies attributable to complex NOxchemistry and long-distance transport of fine particulate matter with a diameter less than 2.5 µm (PM2.5). By leveraging Google and Apple mobility data, we find empirical evidence for a link between global vehicle transportation declines and the reduction of ambient NO2exposure. While the state of global lockdown is not sustainable, these findings allude to the potential for mitigating public health risk by reducing “business as usual” air pollutant emissions from economic activities. Explore trends here:https://nina.earthengine.app/view/lockdown-pollution.

Protecting the Tangible and Intangible Heritage of Rani ki Vav: A Unique Subterranean Step Well in Gujarat

2010 ◽  
Vol 133-134 ◽  
pp. 1057-1064
Author(s):  
T.Lakshmi Priya
Keyword(s):  
Soil Analysis ◽  
Ground Level ◽  
Coarse Grained ◽  
Western India ◽  
Lateral Thrust ◽  
Archaeological Survey ◽  
13Th Century ◽  
Proper Position ◽  
Historic Monument ◽  
Essential Components

The stepwells define the subterranean architecture of Western India. The term stepwell indicates the basic architectural features of a monumental well comprising of a long corridor of steps leading to five or six storeys below the ground to a well. From the 7th to the 19th century, stepwells were an integral part of the Western India. Stepwells are a response to arid regions of Western India particularly in Gujarat and Rajasthan where water is treated as a sacred element which defines the lives, myths and rituals of the people. The stepwells of Gujarat are exceptional in their monumental scale and details. One of the magnificient stepwells is located near Ahmedabad known as Rani ki Vav. The construction of this stepwell began in 1063 A.D and probably it took some ten to twenty years to complete its construction that is upto 1085 to 1090 A.D. It is constructed of bricks and decorated with stone sculptures. It measures 64m long 20m wide and 27m deep. It has the four essential components which are seen in completely developed stepwells : a staircase leading from the ground level to the underground basin, intercepted at regular intervals with multistoreyed pillared pavilion, a well at the rear end, and a large tank or kund to store the surplus water from the well. This Vav also has bracing structures just above the tank, as an extra precaution against lateral thrust. The side walls of the staircase have niches and the wall surface of the well are adorned with beautiful sculptures. The stepwell was in use during the 12th and the 13th century, during the reign of Sidharaja. During this period the niches in the stepwell were filled up with marble sculptures.Later in the 13th century huge amounts of sand and silt were deposited in the well due to major floods of the Saraswati river which flows adjacent to this well. Other floods gradually silted up the entire well. Historical records mention that the well was functional and periodically desilted. The well was buried for centuries under the soil. The Archaeological Survey of India undertook the major task of desilting and restoration of Rani ki Vav which was declared a protected monument of national importance in 1940s. Desilting of the stepwell was commenced in 1960 A.D. Extreme care was taken while resetting of the architectural members and fixing the sculptures in their proper position. The conservation works were aimed at retaining the authenticity and the integrity of the monument during the restoration works. The stone used in the construction of this Vav is sedimentary sand stone varying from fine grain to coarse grained structure. Several test such as wet chemical analysis,X ray analysis,soil analysis etc were undertaken to understand the weathering of the stone. Today Rani ki Vav reveals its original grandeur and stands testimony to the expert craftsmanship and technology of the builders of the 11th century. This paper aims to bring forth the significance of this unique typology of stepwell and the continuing efforts undertaken by Archaeological Survey of India for restoring this historic monument.

Small alteration – big impacts: effects of small-scale riparian forest management on host–parasite dynamics in streams

2017 ◽  
Vol 92 (1) ◽  
pp. 64-73 ◽  
Author(s):  
C. Lagrue ◽  
A.A. Besson ◽  
A. Lecerf
Keyword(s):  
Forest Management ◽  
Intermediate Host ◽  
Riparian Forest ◽  
Freshwater Ecosystems ◽  
Small Scale ◽  
Ecosystem Structure ◽  
Cascading Effects ◽  
Ecosystem Structure And Functioning ◽  
Riparian Forest Management ◽  
Parasite Dynamics

AbstractEnvironmental changes and ecological disturbances can have large and unpredictable effects on parasite dynamics. Increasing human impacts on freshwater ecosystems through land use may thus modify the distribution and abundance of parasites and have cascading effects on host populations. Here we tested the effects of small-scale riparian forest management on the nematode Cystidicoloides ephemeridarum and its insect intermediate host Ephemera danica in forested streams. We assessed the impacts of harvesting riparian trees on parasite prevalence and abundance concomitantly with host densities. We also looked at upstream and downstream reaches to document potential cascading effects on unaltered stream sections mediated by aerial dispersal of adult mayfly or downstream drift of E. danica larvae. We show that host densities and parasite levels (prevalence and abundance) increased significantly following riparian tree removal. Overall, parasite densities showed a 6- to 66-fold increase in harvested reaches compared to upstream, pristine reaches. Similar effects were also clear downstream of the disturbance. Thus, despite the small extent of riparian forest alteration along the study streams, both parasite and intermediate host were strongly affected. Small-scale riparian forest management may thus have large, unforeseen impacts on some aspects of freshwater ecosystem structure and functioning that are often ignored. Generally, understanding how human perturbations influence parasites is vital when trying to predict overall impacts on ecosystem structure and functioning, and how changes in infection dynamics may further affect host species.

Is the long-term sequestration of CO2 in and around deep, abandoned coal mines feasible?

2017 ◽  
Vol 232 (1) ◽  
pp. 27-38 ◽  
Author(s):  
Wei Li ◽  
Tian-wei Ren ◽  
Er-lei Su ◽  
Yuanping Cheng
Keyword(s):  
Power Plants ◽  
Solid Phase ◽  
Coal Mines ◽  
Critical Evaluation ◽  
Ground Level ◽  
Power Grids ◽  
Void Space ◽  
Long Distance ◽  
Major Power ◽  
Abandoned Coal Mines

Many of the largest fixed sources of CO2 emissions are major power stations located on or very close to major coalfields. Even when local coal reserves are exhausted, coal- and/or biomass-fired power generation often persists at such sites, as they occupy pivotal positions in the national power grids that developed around them. To date, strategies for CO2 sequestration from such power plants have focused on long-distance transport by pipeline to depleted hydrocarbon reservoirs and similar deep saline aquifers. Yet where abandoned coal mines extend more than about 800 m below ground level, the void space represented by the old mine voids themselves, and roof strata that have been rendered more permeable by void collapse, could represent convenient auxiliary loci for CO2 sequestration. Furthermore, the geochemical nature of coal and coal-bearing strata may offer mechanisms for entrapment of injected CO2 in or on the solid phase that are not available in potential storage zones considered to date. Engineering evaluation of this possibility requires consideration of the likely fate of CO2 in free, adsorbed, dissolved, and mineralized forms, and of the geotechnical integrity of enclosing strata and abandoned mine infrastructure that could serve as seals to trap injected CO2 in place. A protocol for assessing these factors has been developed, based on critical evaluation of mining records, hydrogeological conditions, and geotechnical data, resulting in a quantitative assessment of the capacity for CO2 sequestration represented by deep abandoned coal mine workings. Preliminary application of the decision logic is illustrated for the Daning coal mines in China.

Photocell Contact Mat: A New Instrument to Measure Contact and Flight Times in Running

1997 ◽  
Vol 13 (2) ◽  
pp. 254-266 ◽  
Author(s):  
Jukka T. Viitasalo ◽  
Pekka Luhtanen ◽  
Harri V. Mononen ◽  
Kare Norvapalo ◽  
Leena Paavolainen ◽  
...  
Keyword(s):  
Ground Level ◽  
Force Platform ◽  
Stride Frequency ◽  
Ground Contact ◽  
Long Distance ◽  
Long Distance Running ◽  
Coefficients Of Variation ◽  
New Instrument ◽  
Ground Contact Time ◽  
Contact Parameters

A new instrument, the photocell contact mat (PCM), was developed to measure ground contact time and flight time as well as step and stride frequency as a function of running time or running distance. The purpose of this study was to evaluate the validity and accuracy of PCM measurements against simultaneous force platform measurements. Effects of striking pattern (sprinter or long-distance), running velocity, and height of the PCM from ground level on the contact parameters were analyzed. One male sprint runner and one male distance (marathon) runner volunteered as subjects. The time difference between the PCM and force platform determinations linearly increased as a function of the PCM height and decreased as a function of running velocity (except for the lowest 10 mm PCM height). The low coefficients of variation found between corrected PCM contact times and force platform contact times suggested that the PCM is an accurate instrument to measure ground contact times.

Congruent trophic pathways underpin global coral reef food webs

2021 ◽  
Vol 118 (39) ◽  
pp. e2100966118
Author(s):  
Chloé Pozas-Schacre ◽  
Jordan M. Casey ◽  
Simon J. Brandl ◽  
Michel Kulbicki ◽  
Mireille Harmelin-Vivien ◽  
...  
Keyword(s):  
Coral Reef ◽  
Food Webs ◽  
Trophic Interactions ◽  
Weak Interactions ◽  
Biodiversity Loss ◽  
Reef Fishes ◽  
Ecosystem Structure ◽  
Critical Pathways ◽  
Energy Flows ◽  
Trophic Pathways

Ecological interactions uphold ecosystem structure and functioning. However, as species richness increases, the number of possible interactions rises exponentially. More than 6,000 species of coral reef fishes exist across the world’s tropical oceans, resulting in an almost innumerable array of possible trophic interactions. Distilling general patterns in these interactions across different bioregions stands to improve our understanding of the processes that govern coral reef functioning. Here, we show that across bioregions, tropical coral reef food webs exhibit a remarkable congruence in their trophic interactions. Specifically, by compiling and investigating the structure of six coral reef food webs across distinct bioregions, we show that when accounting for consumer size and resource availability, these food webs share more trophic interactions than expected by chance. In addition, coral reef food webs are dominated by dietary specialists, which makes trophic pathways vulnerable to biodiversity loss. Prey partitioning among these specialists is geographically consistent, and this pattern intensifies when weak interactions are disregarded. Our results suggest that energy flows through coral reef communities along broadly comparable trophic pathways. Yet, these critical pathways are maintained by species with narrow, specialized diets, which threatens the existence of coral reef functioning in the face of biodiversity loss.

scholarly journals Understanding the structure and functioning of polar pelagic ecosystems to predict the impacts of change

2016 ◽  
Vol 283 (1844) ◽  
pp. 20161646 ◽  
Author(s):  
E. J. Murphy ◽  
R. D. Cavanagh ◽  
K. F. Drinkwater ◽  
S. M. Grant ◽  
J. J. Heymans ◽  
...  
Keyword(s):  
Food Web ◽  
Food Webs ◽  
Energy Flow ◽  
Life Histories ◽  
Trophic Levels ◽  
Individual Species ◽  
Polar Regions ◽  
Ecosystem Structure ◽  
Food Web Structure ◽  
Pelagic Ecosystems

The determinants of the structure, functioning and resilience of pelagic ecosystems across most of the polar regions are not well known. Improved understanding is essential for assessing the value of biodiversity and predicting the effects of change (including in biodiversity) on these ecosystems and the services they maintain. Here we focus on the trophic interactions that underpin ecosystem structure, developing comparative analyses of how polar pelagic food webs vary in relation to the environment. We highlight that there is not a singular, generic Arctic or Antarctic pelagic food web, and, although there are characteristic pathways of energy flow dominated by a small number of species, alternative routes are important for maintaining energy transfer and resilience. These more complex routes cannot, however, provide the same rate of energy flow to highest trophic-level species. Food-web structure may be similar in different regions, but the individual species that dominate mid-trophic levels vary across polar regions. The characteristics (traits) of these species are also different and these differences influence a range of food-web processes. Low functional redundancy at key trophic levels makes these ecosystems particularly sensitive to change. To develop models for projecting responses of polar ecosystems to future environmental change, we propose a conceptual framework that links the life histories of pelagic species and the structure of polar food webs.

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