scholarly journals Edge Effects Reflect the Impact of the Agricultural Matrix on the Corticolous Lichens Found in Fragments of Cerrado Savanna in Central Brazil

2020 ◽  
Vol 12 (17) ◽  
pp. 7149
Author(s):  
Kelly Maria Zanuzzi Palharini ◽  
Luciana Cristina Vitorino ◽  
Gisele Cristina de Oliveira Menino ◽  
Layara Alexandre Bessa
Keyword(s):  
Edge Effects ◽  
Deciduous Forest ◽  
Environmental Parameters ◽  
Sensu Stricto ◽  
Percentage Cover ◽  
Cerrado Vegetation ◽  
Lichen Community ◽  
Agricultural Matrix ◽  
Pesticide Drift ◽  
The Impact

Habitat fragmentation affects lichen communities by inducing edge effects, although the dispersal of pollutants by pesticide drift from commercial crops may also provoke alterations in community structure, due to the varying sensitivity of lichen morphotypes to pollutants. In this context, we tested the hypothesis that lichen morphotype richness and diversity, and the percentage area of the trunks covered by different lichen morphotypes are modified significantly at the edges of fragments of Cerrado vegetation inserted within the agricultural matrix. We evaluated habitat fragments representing different Cerrado formations (Cerradão, Cerrado sensu stricto, and seasonal semi-deciduous forest) as well as the Emas National Park, a prominent Cerrado conservation unit. We used Generalized Linear Mixed Models (GLMMs) to test the potential of the models compiled using a mixture of phytosociological and environmental parameters, including the species, the height of the host plant (H), the circumference of its stem at breast height (CBH), total chlorophyll (TC), bark fissuring (BF) and pH, and illuminance (Lum), to explain the observed variation in the lichen morphotype richness and the percentage cover of the trunks by corticolous lichen morphotypes at the center and edge of the fragments. The central areas invariably had a greater diversity of morphotypes in all the fragments. The morphotypes considered highly sensitive to disturbance were not observed in edge areas, confirming a clear edge effect, as well as the influence of pesticide drift from the adjacent farmland matrix, on the structure of the lichen community. At both the edge and center sites, the larger trees (higher CBH) with less fissured bark tended to have the greatest diversity of lichen morphotypes, and more acidic barks had the greatest lichen cover. The models tested indicated that the variable tree species is an important determinant of the observed patterns of lichen morphotype richness and cover, either on its own or in association with pH or CBH + pH. The analyses also indicated that all the variables tested are important in some way for the definition of the percentage cover of the host trunks. The present study contributes to the understanding of the diversity of the corticolous lichen communities in the remaining fragments of Cerrado vegetation and the effects of the agricultural matrix on this community. The lichen may thus play a role as indicators of impact on other species, these organisms may provide important insights for the further investigation of the disturbance caused by the agricultural matrix on the communities of other groups of organisms.

scholarly journals The impact of environmental variables on the spread of COVID-19 in the Republic of Korea

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yong Kwan Lim ◽  
Oh Joo Kweon ◽  
Hye Ryoun Kim ◽  
Tae-Hyoung Kim ◽  
Mi-Kyung Lee
Keyword(s):  
Environmental Factors ◽  
Virus Disease ◽  
Environmental Parameters ◽  
Environmental Data ◽  
Republic Of Korea ◽  
Metropolitan Region ◽  
Health Concern ◽  
Ozone Level ◽  
The Republic ◽  
The Impact

AbstractCorona virus disease 2019 (COVID-19) has been declared a global pandemic and is a major public health concern worldwide. In this study, we aimed to determine the role of environmental factors, such as climate and air pollutants, in the transmission of COVID-19 in the Republic of Korea. We collected epidemiological and environmental data from two regions of the Republic of Korea, namely Seoul metropolitan region (SMR) and Daegu-Gyeongbuk region (DGR) from February 2020 to July 2020. The data was then analyzed to identify correlations between each environmental factor with confirmed daily COVID-19 cases. Among the various environmental parameters, the duration of sunshine and ozone level were found to positively correlate with COVID-19 cases in both regions. However, the association of temperature variables with COVID-19 transmission revealed contradictory results when comparing the data from SMR and DGR. Moreover, statistical bias may have arisen due to an extensive epidemiological investigation and altered socio-behaviors that occurred in response to a COVID-19 outbreak. Nevertheless, our results suggest that various environmental factors may play a role in COVID-19 transmission.

Degradation of Great Tit (Parus Major) Song Before And After Foliation: Implications for Vocal Communication in a Deciduous Forest

Behaviour ◽  
2004 ◽  
Vol 141 (8) ◽  
pp. 935-958 ◽  
Author(s):  
Sandra Blumenrath ◽  
Torben Dabelsteen
Keyword(s):  
Information Transfer ◽  
Structural Changes ◽  
Vocal Communication ◽  
Deciduous Forest ◽  
Parus Major ◽  
Great Tit ◽  
Transmission Experiment ◽  
Distance Information ◽  
Before And After ◽  
The Impact

AbstractSongbirds living in temperate forests experience great seasonal changes in habitat acoustics during the part of the breeding season when singing activity is high. These changes, which are brought about by accelerated vegetation growth and leaf burst in spring, affect sound propagation and potentially render vocal communication more difficult as the total number of scattering and absorbing obstacles increases. We investigated this in a sound transmission experiment in which representative great tit (Parus major) songs were broadcast in a typical forest habitat before and after foliation. Speaker and microphone were placed at natural separation distances and in typical sender and receiver positions. For each song note we quantified several aspects of sound degradation and found that they all increased considerably when leaves were present. Before foliation the same amount of degradation would only be obtained by doubling the transmission distance, i.e. foliage shortens the active space of great tit song. This inevitably alters distance information, provided that distance-dependent, structural changes of received songs are used as ranging cues. Moreover, sender and receiver positions within the canopy become unfavourable compared to heights just below the canopy when the aim is to maximise song propagation distances. Altogether, the presence of foliage greatly affects the potential for vocal information transfer in great tits and requires behavioural and/or perceptual adjustment of the communicating individuals to counteract or reduce the impact of foliage on signal degradation.

Effects of open-range cattle grazing on deciduous tree regeneration, damage, and mortality following patch logging

2014 ◽  
Vol 44 (7) ◽  
pp. 777-783 ◽  
Author(s):  
Jillian Kaufmann ◽  
Edward W. Bork ◽  
Michael J. Alexander ◽  
Peter V. Blenis
Keyword(s):  
Populus Tremuloides ◽  
Sustainable Forest Management ◽  
Deciduous Forest ◽  
Total Mortality ◽  
Cattle Grazing ◽  
Tree Regeneration ◽  
Deciduous Tree ◽  
Populus Balsamifera ◽  
Haul Road ◽  
The Impact

The impact of summer cattle grazing on deciduous tree regeneration within uncut forests, clearcuts, partially harvested areas, and in-block haul road habitats was examined in four experimental pastures of central Alberta during 2008 and 2009. Sampling of 233 field plots, both inside and outside cattle exclosures, was used to document sapling densities, height, and type of damage. Tree densities (primarily aspen (Populus tremuloides Michx.)) differed among habitats but less so with exposure to cattle. Densities were greatest in clearcuts, followed by partially harvested areas and then uncut forest and haul roads. While exposure to cattle reduced total tree regeneration, sapling densities and sizes remained sufficient to meet postharvest standards for deciduous forest regeneration in Alberta, even with exposure to cattle. Cattle damage in harvested areas was primarily from browsing (≤3.2% of saplings), with proportionally more trees affected in uncut forests (8.6%). Browsing was particularly high on balsam poplar (Populus balsamifera L.) (25%) during 2008. Although sapling damage increased with high cattle stocking in 2008 (to 10.5%), total mortality was limited to 15.5% through 2009. These findings show that despite cattle impacts to some saplings, damage levels were insufficient to alter deciduous regeneration, highlighting the compatibility of cattle grazing and sustainable forest management on public lands in this region.

scholarly journals The Impact of Sampling Season and Catching Site (Wild and Aquaculture) on Gut Microbiota Composition and Diversity of Nile Tilapia (Oreochromis niloticus)

Biology ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 180
Author(s):  
Negash Kabtimer Bereded ◽  
Getachew Beneberu Abebe ◽  
Solomon Workneh Fanta ◽  
Manuel Curto ◽  
Herwig Waidbacher ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Nile Tilapia ◽  
Alpha Diversity ◽  
Environmental Parameters ◽  
Illumina Miseq ◽  
Microbial Composition ◽  
Lake Tana ◽  
Future Work ◽  
The Impact ◽  
Sampling Season

The gut microbiota of fishes is known to play an essential role in diverse aspects of host biology. The gut microbiota of fish is affected by various environmental parameters, including temperature changes, salinity and diet. Studies of effect of environment on gut microbiota enables to have a further understanding of what comprises a healthy microbiota under different environmental conditions. However, there is insufficient understanding regarding the effects of sampling season and catching site (wild and aquaculture) on the gut microbiota of Nile tilapia. This study characterised gut microbial composition and diversity from samples collected from Lake Tana and the Bahir Dar aquaculture facility centre using 16S rDNA Illumina MiSeq platform sequencing. Firmicutes and Fusobacteria were the most dominant phyla in the Lake Tana samples, while Proteobacteria was the most dominant in the aquaculture samples. The results of differential abundance testing clearly indicated significant differences for Firmicutes, Fusobacteria, Bacteroidetes and Cyanobacteria across sampling months. However, Proteobacteria, Chloroflexi, Fusobacteria and Cyanobacteria were significantly enriched in the comparison of samples from the Lake Tana and aquaculture centre. Significant differences were observed in microbial diversity across sampling months and between wild and captive Nile tilapia. The alpha diversity clearly showed that samples from the aquaculture centre (captive) had a higher diversity than the wild Nile tilapia samples from Lake Tana. The core gut microbiota of all samples of Nile tilapia used in our study comprised Firmicutes, Proteobacteria and Fusobacteria. This study clearly showed the impact of sampling season and catching site (wild and aquaculture) on the diversity and composition of bacterial communities associated with the gut of Nile tilapia. Overall, this is the first study on the effects of sampling season and catching site on the gut microbiota of Nile tilapia in Ethiopia. Future work is recommended to precisely explain the causes of these changes using large representative samples of Nile tilapia from different lakes and aquaculture farms.

scholarly journals Performance Evaluation of Underwater Wireless Optical Communication System by Varying the Environmental Parameters

Photonics ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 74
Author(s):  
Dong-Chang Li ◽  
Chia-Chun Chen ◽  
Shien-Kuei Liaw ◽  
Shofuro Afifah ◽  
Jiun-Yu Sung ◽  
...  
Keyword(s):  
Optical Communication ◽  
Environmental Parameters ◽  
Artificial Seawater ◽  
Blue Laser ◽  
Laser Source ◽  
Water Tank ◽  
Wireless Optical Communication ◽  
Transmission Distance ◽  
Flow Turbulence ◽  
The Impact

Underwater wireless optical communication (UWOC) has been considered a promising technology for high-speed underwater transmission. Some Gb/s level UWOC systems applying visible light have been demonstrated with a transmission distance of several meters or more. Many of the previous works focus on the advanced technologies to push the systems’ capacity–distance performance. However, practical environmental factors issue such as flow turbulence and temperature variation are seldom studied through specific statistical/theoretical models. In this paper, a UWOC system using a 450 nm blue light laser source was set up using a 1.5-m water tank with mirrors located on both sides for single or multiple reflections corresponding to different transmission distances. The blue laser was modulated by a 1.25 Gbps NRZ-OOK format with PRBS of 7, 24 or 31, respectively, for system performance comparison. The bit error rate (BER) values were measured in 1.5, 3.0 and 6 m, respectively, for system evaluation. At room temperature, the BER value was down to 10 × 10−8 for a 1.25 Gbps data rate in a 6 m transmission. Then, the UWOC transmission system experiment was carried out under several environmental parameters such as temperature, turbulence, artificial seawater by adding salt to simulate practical application in river or sea. When a submerged motor with an output of 1200 L/h was used as a water flow turbulence source, the impact to BER and transmission quality was negligible. For the temperature change issue, the experiment shows that around the original temperature of 25 °C had the best BER as compared to other temperature ranges from 10 to 50 °C. For artificial seawater issues by adding salt to simulate the real seawater environment. The transmission distance was only 3-m instead of 6 m, mainly due to particle scattering and water disturbance. With the motor pump on, the power penalty was 1 dB at 10 × 10−8 BER when compared to the motor pump off.

Predicting of atmospheric corrosivity and durability of structural materials. Part II. Impact of urban traffic pollution

2021 ◽  
Vol 26 (2) ◽  
pp. 25-33
Author(s):  
Joanna Kobus ◽  
Rafał Lutze
Keyword(s):  
Zinc Coating ◽  
Environmental Parameters ◽  
Structural Materials ◽  
Traffic Volume ◽  
Urban Traffic ◽  
Traffic Pollution ◽  
Street Traffic ◽  
The Impact

The results of the atmospheric corrosivity assessment in the immediate vicinity of streets of different traffic volume in Warsaw, Krakow and Katowice are derived . On the bases of annual exposures in 2014–2018 years an equation describing the impact of environmental parameters and street traffic volume on corrosion losses of zinc and zinc coating on steel was selected.

Vegetation Effects on Soil Properties in the Monteagle Sandy Loam Series: Implications for Land‐use Change

2017 ◽  
Author(s):  
Allison Neil
Keyword(s):  
Land Use ◽  
Organic Matter ◽  
Land Use Change ◽  
Soil Properties ◽  
Soil Carbon ◽  
Sugar Maple ◽  
Agricultural Land ◽  
Deciduous Forest ◽  
Coniferous Forest ◽  
The Impact

Soil properties are strongly influenced by the composition of the surrounding vegetation. We investigated soil properties of three ecosystems; a coniferous forest, a deciduous forest and an agricultural grassland, to determine the impact of land use change on soil properties. Disturbances such as deforestation followed by cultivation can severely alter soil properties, including losses of soil carbon. We collected nine 40 cm cores from three ecosystem types on the Roebuck Farm, north of Perth Village, Ontario, Canada. Dominant species in each ecosystem included hemlock and white pine in the coniferous forest; sugar maple, birch and beech in the deciduous forest; grasses, legumes and herbs in the grassland. Soil pH varied little between the three ecosystems and over depth. Soils under grassland vegetation had the highest bulk density, especially near the surface. The forest sites showed higher cation exchange capacity and soil moisture than the grassland; these differences largely resulted from higher organic matter levels in the surface forest soils. Vertical distribution of organic matter varied greatly amongst the three ecosystems. In the forest, more of the organic matter was located near the surface, while in the grassland organic matter concentrations varied little with depth. The results suggest that changes in land cover and land use alters litter inputs and nutrient cycling rates, modifying soil physical and chemical properties. Our results further suggest that conversion of forest into agricultural land in this area can lead to a decline in soil carbon storage.

scholarly journals Effects of environmental conditions associated to the cardinal orientation on the reproductive phenology of the cerrado savanna tree Xylopia aromatica (Annonaceae)

2011 ◽  
Vol 83 (3) ◽  
pp. 1007-1020 ◽  
Author(s):  
Maria Gabriela G. Camargo ◽  
Regina M. Souza ◽  
Paula Reys ◽  
Leonor P.C. Morellato
Keyword(s):  
Edge Effects ◽  
Environmental Conditions ◽  
Fruit Production ◽  
Sensu Stricto ◽  
Southeastern Brazil ◽  
Reproductive Phenology ◽  
Canopy Openness ◽  
Cerrado Savanna ◽  
Cardinal Direction ◽  
Floral Visitation

The Brazilian cerrado has undergone an intense process of fragmentation, which leads to an increase in the number of remnants exposed to edge effects and associated changes on environmental conditions that may affect the phenology of plants. This study aimed to verify whether the reproductive phenology of Xylopia aromatica (Lam.) Mart. (Annonaceae) differs under different light conditions in a cerrado sensu stricto (a woody savanna) of southeastern Brazil. We compared the reproductive phenology of X. aromatica trees distributed on east and south cardinal faces of the cerrado during monthly observations, from January 2005 to December 2008. The east face had a higher light incidence, higher temperatures and canopy openness in relation to south face. X. aromatica showed seasonal reproduction at both faces of the cerrado, but the percentage of individuals, the synchrony and duration of phenophases were higher at the east face. The study demonstrated the influence of the environmental conditions associated to the cardinal orientation of the cerrado faces on the phenological pattern of X. aromatica. Similar responses may be observed for other species, ultimately affecting patterns of floral visitation and fruit production, which reinforces the importance of considering the cardinal direction in studies of edge effects and fragmentation.

A structural gradient in cerrado vegetation of Brazil: changes in woody plant density, species richness, life history and plant composition

2002 ◽  
Vol 18 (5) ◽  
pp. 775-794 ◽  
Author(s):  
Luci Ferreira Ribeiro ◽  
Marcelo Tabarelli
Keyword(s):  
Life History ◽  
Species Richness ◽  
Species Composition ◽  
Woody Plant ◽  
Plant Density ◽  
Lower Layer ◽  
Sensu Stricto ◽  
Life History Strategies ◽  
Cerrado Vegetation ◽  
Structural Types

Four structural types of cerrado vegetation were examined to test the following hypotheses: (1) there are predictable changes in woody plant density, species richness and life-history strategies from one structural type to another; and (2) plant species composition in the less-rich structural types represent particular and impoverished subsets of those found in the richer ones. The study was conducted at Fazenda Palmares (5°33′S, 42°37′W) Piauí State, Brazil. A 47% decrease in woody plant density between cerradão (forest) and the least-dense type of cerrado sensu stricto (scrub) was associated with a 40% decrease in species richness. The percentage of lower-layer species was reduced by 29% in the least dense type of cerrado sensu stricto compared to cerradão. The proportion of species that flower and fruit during the rainy season was also reduced by one third. Species were not distributed as impoverished subsets along the cerradão–cerrado sensu stricto gradient. It is argued that the reduction in woody plant density and richness is partly due to factors limiting the occurrence of species with particular life-history strategies. The species composition of structural types is affected by the ‘mass effect’ and also by surrounding biotas, which provide species that colonize particular types of cerrado vegetation. Both these processes reduce the likelihood that the species composition in the poorer structural types are simple subsets of those present in the richer types.

scholarly journals Molecular edge effects in the Endangered golden-brown mouse lemur Microcebus ravelobensis

Oryx ◽  
2018 ◽  
Vol 53 (4) ◽  
pp. 716-726 ◽  
Author(s):  
U. Radespiel ◽  
J. Schulte ◽  
R. J. Burke ◽  
S. M. Lehman
Keyword(s):  
Edge Effects ◽  
Deciduous Forest ◽  
Mitochondrial Control Region ◽  
Mouse Lemur ◽  
Continuous Forest ◽  
Ecological Changes ◽  
Close Proximity ◽  
Geographical Distances ◽  
Dry Deciduous Forest ◽  
Underlying Mechanisms

AbstractHabitat fragmentation creates habitat edges, and ecological edge effects can cause major changes in the ecology and distribution of many taxa. However, these ecological changes may in turn influence animal movements and lead to molecular edge effects and edge-related genetic structure, matters that are largely unexplored. This study aims to infer molecular edge effects and to test three possible underlying mechanisms in the Endangered golden-brown mouse lemur Microcebus ravelobensis, a nocturnal species in the dry deciduous forest of the Ankarafantsika National Park in north-western Madagascar. Mouse lemurs were sampled in one edge and two interior habitats in close proximity to each other (500–1,400 m) in a continuous forest. A total of 41 mouse lemur samples were genotyped with seven nuclear microsatellites, and a fragment of the mitochondrial control region was sequenced for all samples. The overall genetic diversity (allelic richness, heterozygosity, haplotype richness, nucleotide diversity) was lower in the edge habitat compared to the two interior sites and all subpopulations showed signals of relatively low genetic exchange and significant genetic differentiation between them despite the short geographical distances, supporting the local preference model. These findings can be interpreted as preliminary signals of a molecular edge effect and suggest the potential for local adaptation. They are highly relevant for the conservation of fragmented populations, because a further subdivision of already small populations may increase their vulnerability to stochastic demographic changes and collapse.

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