scholarly journals The mismatch in distributions of vertebrates and the plants that they disperse

2017 ◽  
Author(s):  
Jacob W. Dittel ◽  
Christopher M. Moore ◽  
Stephen B. Vander Wall

AbstractLittle is known about how mutualistic interactions affect the distribution of species richness on broad geographic scales. It has been predicted that the richness of species involved in obligate mutualisms should be positively associated across their range. Whereas, if mutualisms are facilitative, the distribution of mutualists should be correlated with other factors. This study is the first study to compare the co-distribution of mutualist species in general and seed dispersal mutualisms specifically. We used geographic distributions of plant and animal mutualists to investigate the co-distribution and patterns of seed dispersal mutualisms. We found the mutualism between dispersers and plants does not account for the distribution of either group. In fact, there is a mismatch of richness between plants and the animals that disperse their seeds. Environmental factors are better predictors of both animal distribution and seed dispersal mutualisms across North America.Statement of authorshipJD, CM, and SV conceived the original project idea. Plant data were compiled and analyzed by CM and SV, and JD compiled animal and environmental data. JD standardized and formatted all geographical data, and JD and CM performed all statistical analyses. JD wrote the first draft of the manuscript, and all authors contributed significantly to the revisions.

Biologia ◽  
2011 ◽  
Vol 66 (2) ◽  
Author(s):  
Zdenka Otýpková ◽  
Milan Chytrý ◽  
Lubomír Tichý ◽  
Vilém Pechanec ◽  
Jan Jongepier ◽  
...  

AbstractThe flora of the White Carpathians, a mountain range in the south-east of the Czech Republic, is documented by about 485,000 records of vascular plant occurrences collected since the mid-19th century. A total of 1299 species recorded in 93 grid cells of 2.8 × 3.1 km were used for an analysis of spatial patterns of floristic diversity in the White Carpathians. Multivariate statistical techniques such as ordination and classification were used to reveal the main gradients in floristic composition and species richness, and measured environmental data and Ellenberg indicator values were used to assess underlying environmental factors. There is a striking floristic contrast between the western and eastern part of the study area, which is associated with differences in climate, mean altitude, topographic heterogeneity measured as altitudinal range, and land use. The western part is characterised by thermophilous, continental and calcicolous species of open habitats. In contrast, the more forested eastern part along the state border with Slovakia and the north-eastern part of the area are characterised by acidophilous species with higher moisture requirements. This pattern is consistent with the established phytogeographical division of the Czech Republic into the phytogeographical regions of Thermophyticum and Mesophyticum. The further division of the area into four regions, based on classified grid data, is also similar to the current division into phytogeographical districts, except for the Javorníky district. There are two distinct hot spots of species richness, in the western and the extreme north-eastern part. A poorer flora was found in landscapes with intensive agriculture. Species richness is associated with different environmental factors than species composition, namely with soil types and land-use categories. Alien species are more common in areas with a higher incidence of arable land and built-up areas, and less common in areas dominated by grasslands and forests.


2018 ◽  
Vol 10 (13) ◽  
pp. 12792-12799
Author(s):  
Anupama Saha ◽  
Susmita Gupta

Aquatic and semiaquatic Hemiptera bugs play significant ecological roles, and they are important indicators and pest control agents.  Little information is currently available concerning its populations in southern Assam.  This study assessed hemipterans in four sites of Sonebeel, the largest wetland in Assam (3458.12 ha at full storage level), situated in Karimganj District.  The major inflow and outflow of the wetland are the rivers Singla and Kachua, respectively (the Kachua drains into the Kushiyara River).  Samples were trapped with pond nets and were seasonally recorded.  This study recorded a total of 28 species of aquatic and semiaquatic hemipterans belonging to 20 genera under nine families.  Population, geographical and environmental data (e.g., rainfall) were used to assess the relative abundance of species, species richness and different diversity indices, and species distribution. 


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yong Kwan Lim ◽  
Oh Joo Kweon ◽  
Hye Ryoun Kim ◽  
Tae-Hyoung Kim ◽  
Mi-Kyung Lee

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.


1992 ◽  
Vol 19 (2) ◽  
pp. 195 ◽  
Author(s):  
Zbigniew Dzwonko ◽  
Stefania Loster

2007 ◽  
Vol 50 (6) ◽  
pp. 1033-1042 ◽  
Author(s):  
Yzel Rondon Súarez ◽  
Sabrina Bigatão Valério ◽  
Karina Keyla Tondado ◽  
Alexandro Cezar Florentino ◽  
Thiago Rota Alves Felipe ◽  
...  

The influence of spatial, temporal and environmental factors on fish species diversity in headwater streams in Paraguay and Paraná basins, Brazil was examined. A total of 4,605 individuals were sampled, distributed in 60 species. The sampled streams in Paraná basin presented a larger total species richness (42) than Paraguay streams (40). However the estimated richness was larger in Paraguay basin (53) than Paraná streams (50). The streams of Paraná basin had a greater mean species richness and evenness, while more individuals per sample were found in the Paraguay basin. Difference between the sub-basins were found in the Paraguay basin, while for the basin of Paraná, richness and evenness vary significantly between the sub-basins, but the number of individuals varied seasonally. The most important environmental factors to species diversity and abundance were altitude, water temperature, stream width and stream depth for both the basins.


2018 ◽  
Vol 9 (2) ◽  
pp. 322-330
Author(s):  
Rong Sun ◽  
Xiaojie Luo ◽  
Xiangyu Meng ◽  
Yan Wang

Abstract The streams in a watershed form a hierarchical network system. From the perspective of the river continuum, this classification system is the result of gradual increase in traffic. This study analyzed the riparian species richness, diversity and environmental factors along a six-order hierarchical mountain river in the Donghe watershed, China. A total of 34 sampling sites were sampled to study the spatial distribution of riparian plants among different stream orders. The results showed: Environmental factors among stream orders had significant differences. Among stream order, species richness showed remarkable differences. The species richness rose firstly and dropped afterwards except for tree species richness; tree species richness decreased while stream order increased. The same is true for shrub quadrat species richness. Shannon-Wiener diversity, Simpson dominance and Pielou uniformity showed significant difference among stream orders; Shannon-Wiener diversity rose firstly then dropped afterwards. For integrated environmental factors and community characteristics, we found the changes of stream orders had a significant impact on riparian habitats and riparian vegetation. Further analysis showed that riparian vegetation experienced different types and degrees of disturbance in different stream orders. This meant that a hierarchical management strategy should be applied to riparian vegetation management.


Author(s):  
Charles R. Newton

The epidemiology of autism has been recently highlighted with the apparent increase in the prevalence of autism in North America and Europe, and controversy about the association of autism with vaccines. The overall prevalence is about 1%, and the apparent increase is probably due to greater awareness of the diagnosis, more facilities for diagnosis, and changes in the criteria for the diagnosis. Autism is likely to arise from an interaction between genetic susceptibility and environmental factors. Identified risk factors include maternal infection, prematurity, intrauterine growth retardation, and perinatal and postnatal exposure to toxins and infections. There is no evidence that autism is associated with vaccination. Autism is associated with premature mortality and has considerable financial burden on national health and educational systems.


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