scholarly journals Dynamic trait-niche relationships shape niche partitioning across habitat transformation gradients

Author(s):  
Emilio Pagani-Núñez ◽  
Dan Liang ◽  
Chao He ◽  
Yang Liu ◽  
Xu Luo ◽  
...  
2017 ◽  
Vol 7 (4) ◽  
pp. 30-34 ◽  
Author(s):  
O. A. Didur ◽  
Yu. L. Kulbachko ◽  
V. Y. Gasso

<p>The problem of transformation of natural landscapes resulted from the negative technogenic impact is highlighted. It is shown that mining enterprises are powerful anthropo-technical sources of organic and inorganic toxicants entering the environment. Their wastes pollute all components of the ecosystems and negatively influence human health by increasing a risk of disease. The nature of the accumulation of trace elements (Fe, Cu, Zn, Ni, Cd, and Pb) by invertebrate animals of various functional groups under conditions of anthropo-technogenic pressure was studied. The sample plots were located on self-overgrowing sites with ruderal vegetation located in the immediate vicinity of the Mangan ore-dressing and processing enterprise (Dnipropetrovsk region). It is quite naturally that among the studied biogenic microelements (Fe, Cu, Zn and Ni), the phyto-, zoo-, and saprophages in the investigated zone of technogenic pollution most actively accumulate Fe:<em> </em>22758, 17516 and 18884 mg/kg dry weight on average, respectively. There are significant differences (p ≤ 0.05) in the content of studied microelements between saprophages and phytophages. The saprophages accumulate such trace metals as Mn, Cu, Zn and Cd in high quantities, but Ni and Pb – in smaller ones. The saprophagous functional group of invertebrates is an active agent of detritogenesis, in the conditions of modern nature management it acts as a powerful element of ecosystem engineering (habitat transformation), the main ecological role of which is to modify the habitat of other soil biota. In addition, the saprophages fulfil their concentrating geochemical function. They actively participate in the most important soil biochemical process: the formation of humus, the migration of microelements along trophic chains, the biological cycle in general, and provide such supporting ecosystem services as increasing soil fertility and nutrient cycling.</p>


2020 ◽  
Author(s):  
Andreza Lautenschleger ◽  
Jeferson Vizentin‐Bugoni ◽  
Lis B. Cavalheiro ◽  
Cristiano A. Iserhard
Keyword(s):  

2018 ◽  
Vol 39 (2) ◽  
pp. 145-161 ◽  
Author(s):  
Inês Freitas ◽  
Soumia Fahd ◽  
Guillermo Velo-Antón ◽  
Fernando Martínez-Freiría

Abstract The Maghreb region (North Africa) constitutes a major component of the Mediterranean Basin biodiversity hotspot. During the last centuries, a consistent human population growth has led to an unprecedented rate of habitat transformation and loss in the region and thus, threatening its biodiversity. The Western Mediterranean viper Vipera latastei-monticola inhabits humid and subhumid areas in the main mountain ranges of the Maghreb, facing such threatening factors; however, its elusive character and rarity hindered data collection for distinct biological purposes. Here, we study the biogeographical patterns and conservation status of the Maghrebian V. latastei-monticola resulting from recent sampling campaigns in Morocco and Tunisia. We update species distribution, and integrate phylogeographic and ecological niche modelling analyses at both species and lineage level to identify suitable areas, and to evaluate the impact of anthropogenic transformation and level of protection of their suitable space. We identified four highly divergent mitochondrial lineages, including a new lineage endemic to the Western High Atlas, with allopatric distributions and restricted to mountain ranges, supporting the role of mountains as past climatic refugia. Despite the remoteness of suitable areas, we report widespread habitat degradation and identify the low effectiveness of the current protected areas system in preserving the species and lineages range. Our study shows the urgent need to apply management actions for the long-term conservation of this vulnerable species and suggests a revaluation of the specific status of V. monticola, as these populations likely represent an ecotype of V. latastei.


2021 ◽  
Vol 9 (6) ◽  
pp. 1200
Author(s):  
Gareth E. Thomas ◽  
Jan L. Brant ◽  
Pablo Campo ◽  
Dave R. Clark ◽  
Frederic Coulon ◽  
...  

This study evaluated the effects of three commercial dispersants (Finasol OSR 52, Slickgone NS, Superdispersant 25) and three biosurfactants (rhamnolipid, trehalolipid, sophorolipid) in crude-oil seawater microcosms. We analysed the crucial early bacterial response (1 and 3 days). In contrast, most analyses miss this key period and instead focus on later time points after oil and dispersant addition. By focusing on the early stage, we show that dispersants and biosurfactants, which reduce the interfacial surface tension of oil and water, significantly increase the abundance of hydrocarbon-degrading bacteria, and the rate of hydrocarbon biodegradation, within 24 h. A succession of obligate hydrocarbonoclastic bacteria (OHCB), driven by metabolite niche partitioning, is demonstrated. Importantly, this succession has revealed how the OHCB Oleispira, hitherto considered to be a psychrophile, can dominate in the early stages of oil-spill response (1 and 3 days), outcompeting all other OHCB, at the relatively high temperature of 16 °C. Additionally, we demonstrate how some dispersants or biosurfactants can select for specific bacterial genera, especially the biosurfactant rhamnolipid, which appears to provide an advantageous compatibility with Pseudomonas, a genus in which some species synthesize rhamnolipid in the presence of hydrocarbons.


2021 ◽  
Vol 14 ◽  
pp. 194008292110103
Author(s):  
Patrick Jules Atagana ◽  
Eric Moïse Bakwo Fils ◽  
Sevilor Kekeunou

We aimed to assess how bats are affected by habitat transformation by comparing bat assemblages in four habitat types: primary forest, secondary forest, cocoa plantations and human habitations in the Dja Biosphere Reserve of southern Cameroon. Bats were sampled in the four habitat types using mist nets. During 126 nights, a total of 413 bats were captured, belonging to four families, 16 genera and 24 species. Ninety three individuals (17 species) were captured in the primary forest, followed by plantations (105 individuals, 14 species), human habitations (159 individuals, 10 species), and secondary forest (55 individuals, eight species). Megaloglossus woermanni was recorded in all the four habitats, and was the most abundant species (105 individuals). The analysis of bat assemblage between habitat types showed a statistically significant difference in species composition. The distribution of the six most abundant species ( Epomops franqueti, Megaloglossus woermanni, Rousettus aegyptiacus, Dohyrina cyclops, Hipposideros cf. caffer and Hipposideros cf. ruber) was influenced by habitat types. Our results suggest that the decrease in species richness observed in disturbed habitats may be due to habitat perturbations of primary forest habitats. Therefore, it is important to examine the effects of habitat conversion at species level, as responses are often species-specific.


2021 ◽  
Vol 10 (3) ◽  
Author(s):  
Mariia Pavlovska ◽  
Ievgeniia Prekrasna ◽  
Evgen Dykyi ◽  
Andrii Zotov ◽  
Artem Dzhulai ◽  
...  

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