scholarly journals Exploring the biotic homogenization and diversity resistance hypotheses: The understorey of non‐native and native woodland canopies in three urban areas of Europe

Author(s):  
Tommaso Sitzia ◽  
Simone Iacopino ◽  
Sabina Burrascano ◽  
Thomas Campagnaro ◽  
Laura Celesti‐Grapow ◽  
...  
2020 ◽  
Author(s):  
Elizabeth A. Bergey ◽  
Benjamin E. Whipkey

AbstractResidential yards constitute a substantive biodiverse greenspace within urban areas. This biodiversity results from a combination of native and non-native species and can contribute to biotic homogenization. Geographical climatic patterns affect the distribution of native species and may differently affect non-native species. In this study, we examined biodiversity and biotic homogenization patterns of yard-dwelling land snails across 12 towns in Oklahoma and Kansas (USA). The 3 × 4 array of towns incorporated a N-S winter temperature gradient (mean low January temperature range = −8.4 to 0.1 °C) and an E-W annual rainfall gradient (annual rainfall range = 113.8 to 61.3 cm/yr). Ten yards per town were surveyed. We hypothesized that mild winter temperatures and greater annual rainfall would be associated with greater snail abundance and richness, and that the presence of non-native species would contribute to biotic homogenization. Non-native snails were present and often abundant in all towns. Snail communities varied with both rainfall and cold temperature. Contrary to our prediction, snail abundance was inversely related to annual rainfall – likely because drier conditions resulted in greater yard watering that both augmented rainfall and maintained moist conditions. Sørensen similarity between towns for the entire land snail community and for only non-native species both showed distance-decay patterns, with snail composition becoming less similar with increasing distance - patterns resulting from species turnover. The biotic homogenization index also showed a distance-decay pattern, such that closer towns were more likely to have biotic homogenization whereas more distant towns tended to have biotic differentiation. These results support the concept that biotic homogenization is more likely regionally and that climatic changes over distance result in species turnover and can reduce spatially broad biotic homogenization.


1996 ◽  
Vol 22 (3) ◽  
pp. 167-174
Author(s):  
J A Cantrill ◽  
B Johannesson ◽  
M Nicholson ◽  
P R Noyce

2001 ◽  
Vol 60 (2) ◽  
pp. 99-107 ◽  
Author(s):  
Holger Schmid

Cannabis use does not show homogeneous patterns in a country. In particular, urbanization appears to influence prevalence rates, with higher rates in urban areas. A hierarchical linear model (HLM) was employed to analyze these structural influences on individuals in Switzerland. Data for this analysis were taken from the Switzerland survey of Health Behavior in School-Aged Children (HBSC) Study, the most recent survey to assess drug use in a nationally representative sample of 3473 15-year-olds. A total of 1487 male and 1620 female students indicated their cannabis use and their attributions of drug use to friends. As second level variables we included address density in the 26 Swiss Cantons as an indicator of urbanization and officially recorded offences of cannabis use in the Cantons as an indicator of repressive policy. Attribution of drug use to friends is highly correlated with cannabis use. The correlation is even more pronounced in urban Cantons. However, no association between recorded offences and cannabis use was found. The results suggest that structural variables influence individuals. Living in an urban area effects the attribution of drug use to friends. On the other hand repressive policy does not affect individual use.


2017 ◽  
Vol 3 (3) ◽  
pp. 338-343
Author(s):  
Mohammad Didar Khan ◽  
Md. Ibrahim ◽  
Md. Mizanur Rahman Moghal ◽  
Dipti debnath ◽  
Asma Kabir ◽  
...  

Objective: The present epidemiological study was conducted with the objectives of providing an insight into the current use of antidiabetic medications to diabetics and hypertensive diabetics in urban areas and determining how the patient factors influence the prescribing of antidiabetic medications. Methodology: Data of patients of past two years were collected from Bangabandhu Sheikh Mujib Medical University (BSMMU) Hospital, Dhaka, Bangladesh. The details were entered in the structured patient profile form. Data were statistically analyzed using the Microsoft Excel 2007 software. Result: A total of 958 patient’s data were collected and analyzed of which 632 (65.97 %) were males and 326 (34.03 %) were females. These patients were further categorized based on their age. 330 patients (34.45 %) belonged to the age group 20 – 44 years, 504 (52.61 %) to the age group 45 – 65 years and 124 (12.94 %) to the age group 65 – 80 years. 684 (71.4%) patients out of the 958 patients studied were suffering from coexisting hypertension. Co-existing hypertension was found to be more prevalent in the age group 45 – 65 years (67.69%) and was found more in females (84.04%). Conclusion: Metformin was the oral hypoglycemic which was the highest prescribed. In hypertensive diabetics Metformin and Pioglitazone were most frequently prescribed drugs. Biguanides and Insulin were the most commonly prescribed antidiabetics. A combination of two or more drugs of different classes was prescribed to hypertensive diabetics. It is necessary to have an improved understanding of the etiology and pathophysiology of diabetes to focus on research efforts appropriately.


EDIS ◽  
2017 ◽  
Vol 2017 (6) ◽  
Author(s):  
Claudia Paez ◽  
Jason A. Smith

Biscogniauxia canker or dieback (formerly called Hypoxylon canker or dieback) is a common contributor to poor health and decay in a wide range of tree species (Balbalian & Henn 2014). This disease is caused by several species of fungi in the genus Biscogniauxia (formerly Hypoxylon). B. atropunctata or B. mediterranea are usually the species found on Quercus spp. and other hosts in Florida, affecting trees growing in many different habitats, such as forests, parks, green spaces and urban areas (McBride & Appel, 2009).  Typically, species of Biscogniauxia are opportunistic pathogens that do not affect healthy and vigorous trees; some species are more virulent than others. However, once they infect trees under stress (water stress, root disease, soil compaction, construction damage etc.) they can quickly colonize the host. Once a tree is infected and fruiting structures of the fungus are evident, the tree is not likely to survive especially if the infection is in the tree's trunk (Anderson et al., 1995).


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