A diploid form ofPhragmites communis, as a possible result of cytogenetical response to ecological stress

1979 ◽  
Vol 14 (2) ◽  
pp. 113-120 ◽  
Author(s):  
Dagmar Dykyjová ◽  
Zdenka Pazourková
Keyword(s):  
Ecological Stress ◽  
Diploid Form

Status of the rare palm Bentinckia condapanna Berry in two habitats of Goodrical Reserve Forests; Western Ghats of India

2014 ◽  
Vol 1 (1) ◽  
pp. 6-9
Author(s):  
ES Abhilash ◽  
Brijesh Sathian
Keyword(s):  
Sustainable Development ◽  
Western Ghats ◽  
Evergreen Species ◽  
Secondary Species ◽  
Ecological Stress ◽  
Lannea Coromandelica ◽  
Western Ghats Of India

Bentinckia condapanna shows more IVI values and there by dominance and ecological stress in both the sites, that is, in sparsely distributed habitats as well as in dominated habitats (Site-II). Major associations /co dominance to Bentinckia condapanna in site -I were the evergreen species like Macaranga peltata, Elaeocarpus tuberculatus, Lannea coromandelica, Schefflera venulosa etc. and for site-II was the secondary species Chionanthus ramiflorus. Higher IVI values for Bentinckia condapanna in both the sites proves the capacity of this species to establish in mono-dominant and co- dominant communities. DOI: http://dx.doi.org/10.3126/apjeesd.v1i1.9503Asia Pacific Journal of Environment Ecology and Sustainable Development 2013; 1: 6-9

Quantitative assessment of stress of economic development to environment using ecological stress index

2014 ◽  
Vol 22 (3) ◽  
pp. 368-374 ◽  
Author(s):  
Jing SONG ◽  
Huixiao WANG ◽  
Shengya LIU
Keyword(s):  
Economic Development ◽  
Quantitative Assessment ◽  
Stress Index ◽  
Ecological Stress ◽  
Assessment Of Stress

scholarly journals Calcification intensity in planktonic Foraminifera reflects ambient conditions irrespective of environmental stress

2013 ◽  
Vol 10 (10) ◽  
pp. 6639-6655 ◽  
Author(s):  
M. F. G. Weinkauf ◽  
T. Moller ◽  
M. C. Koch ◽  
M. Kučera
Keyword(s):  
Surface Water ◽  
Environmental Factors ◽  
Physiological Stress ◽  
Planktonic Foraminifera ◽  
Ambient Conditions ◽  
Shell Weight ◽  
Ambient Seawater ◽  
Ecological Stress ◽  
Water Composition ◽  
Oceanic Carbon

Abstract. Planktonic Foraminifera are important marine calcifiers, and the ongoing change in the oceanic carbon system makes it essential to understand the influence of environmental factors on the biomineralization of their shells. The amount of calcite deposited by planktonic Foraminifera during calcification has been hypothesized to reflect a range of environmental factors. However, it has never been assessed whether their calcification only passively responds to the conditions of the ambient seawater or whether it reflects changes in resource allocation due to physiological stress. To disentangle these two end-member scenarios, an experiment is required where the two processes are separated. A natural analogue to such an experiment occurred during the deposition of the Mediterranean sapropels, where large changes in surface water composition and stratification at the onset of the sapropel deposition were decoupled from local extinctions of planktonic Foraminifera species. We took advantage of this natural experiment and investigated the reaction of calcification intensity, expressed as mean area density (MAD), of four species of planktonic Foraminifera to changing conditions during the onset of Sapropel S5 (126–121 ka) in a sediment core from the Levantine Basin. We observed a significant relationship between MAD and surface water properties, as reflected by stable isotopes in the calcite of Foraminifera shells, but we failed to observe any reaction of calcification intensity on ecological stress during times of decreasing abundance culminating in local extinction. The reaction of calcification intensity to surface water perturbation at the onset of the sapropel was observed only in surface-dwelling species, but all species calcified more strongly prior to the sapropel deposition and less strongly within the sapropel than at similar conditions during the present-day. These results indicate that the high-salinity environment of the glacial Mediterranean Sea prior to sapropel deposition induced a~more intense calcification, whereas the freshwater injection to the surface waters associated with sapropel deposition inhibited calcification. The results are robust to changes in carbonate preservation and collectively imply that changes in normalized shell weight in planktonic Foraminifera should reflect mainly abiotic forcing.

Cryptospores: The Origin and Early Evolution of the Terrestrial Flora

2000 ◽  
Vol 6 ◽  
pp. 3-20 ◽  
Author(s):  
Paul K. Strother
Keyword(s):  
Reduction Division ◽  
Terrestrial Environment ◽  
Living Plant ◽  
Fine Grained ◽  
Ecological Stress ◽  
Clastic Rocks ◽  
Plant Fossil ◽  
Spore Mother Cell ◽  
Heterogeneous Polymer ◽  
Spore Walls

The Cryptogamic, or spore-producing, plants of today are composed of three nonvascular, bryophyte groups (mosses, liverworts, and hornworts) and several vascular groups (ferns, club mosses, and horsetails). All of these plants produce abundant spores, which serve as propagules for dispersing and, to some extent, preserving plants through periods of ecological stress. Plant spores are typically formed as the end products of meiosis (reduction division) from a dividing sporocyte, or spore mother cell (smc). Because of this, they typically occur in groups of four, with each individual spore bearing a characteristic trilete, or Y-shaped mark on its common contact surface. Spore walls, composed of an inert, heterogeneous polymer called sporopollenin, are extremely resistant to the chemical vicissitudes of the terrestrial environment. This property of typical plant spores ultimately allows them to be quite abundant in fine grained clastic rocks. Although fossilized spores represent only a small part of the once-living plant, in many cases, they represent an important component of the plant fossil record, especially when the preservation of macroscopic tissues is lacking.

scholarly journals Proximal versus distal ecological stress: Socio-ecological influences on political freedom, well-being, and societal confidence in 159 nations

2021 ◽  
Vol 9 (1) ◽  
pp. 306-320
Author(s):  
Lucian Gideon Conway ◽  
Linus Chan ◽  
Shailee R. Woodard ◽  
Mohsen Joshanloo
Keyword(s):  
Water Quality ◽  
Large Scale ◽  
Well Being ◽  
Political Freedom ◽  
Ecological Perspective ◽  
Contributing Factors ◽  
Stress Measurements ◽  
Ecological Stress ◽  
Societal Issues ◽  
Gallup World Poll

Previous work from a socio-ecological perspective reveals that ecological stress has important effects on political, cultural, and psychological outcomes. However, that work has been limited by (1) a focus on distal forms of ecological stress that are hard for societies to control, and (2) a lack of large-scale conceptual replications. The present study aims to fill in these gaps by simultaneously testing the effects of both more distal ecological stress (e.g., climate) and more proximal ecological stress (e.g., water quality) on political restriction, political freedom, well-being, and societal confidence measurements. In a sample from the Gallup World Poll spanning over one and a half million participants and 159 nations, we found that while both kinds of ecological stress measurements predicted greater vertical political restriction, reduced horizontal political restriction, reduced well-being, and reduced freedom, only proximal forms of ecological stress predicted a loss in societal confidence. These results not only provide key conceptual replications of prior studies on new data, they also add previously unstudied outcomes and new ecological stressors. As a result, they help us better understand contributing factors to key societal issues such as freedom, well-being, and societal confidence.

Early Jurassic phytotoxicity due to Hg-remobilization

2021 ◽  
Author(s):  
Remco Bos ◽  
Sofie Lindström ◽  
Hamed Sanei ◽  
Irene Waajen ◽  
Appy Sluijs ◽  
...  
Keyword(s):  
Dominant Role ◽  
Early Jurassic ◽  
Intermediate Step ◽  
Terrestrial Vegetation ◽  
Volcanic Emissions ◽  
Ecological Stress ◽  
Alternative Sources ◽  
Initial Deposition ◽  
Local Impacts ◽  
Extreme Seasonality

<p>The Central Atlantic Magmatic Province (CAMP) eruptions are generally regarded as the main driver of major environmental change and mass-extinction across the Triassic-Jurassic (TJ) boundary (~201.3 Ma), but the exact mechanisms linking volcanism and extinction, resilience, and recovery remain poorly constrained. Volcanogenic mercury (Hg) has been implicated as the cause for mutations in spores/pollen indicating severe ecological stress in terrestrial vegetation. Indeed, elevated sedimentary Hg concentrations coincide with the extinction interval at multiple sites across Europe. Here we show, palynological and geochemical records that gives insight in the dynamics between the Hg cycle and terrestrial vegetation, indicating repeated phytotoxicity in Early Jurassic deposits.</p><p>The abundance of mutagenic spores and the concentration of Hg are quantified in shallow marine sediments in the Schandelah-1 core (northern Germany) across the T/J boundary and the Early Jurassic (Hettangian). The results show increased mutagenic spore abundances with accompanying Hg/TOC anomalies across the end-Triassic extinction and within the lowermost Hettangian. This is consistent with studies from Sweden and Denmark and therefore confirming synchronous mutagenesis in and around coastal European margins. In addition, the Hettangian of Schandelah contains a record of long-term vegetational disturbance in the form of recurrent fern spikes and elevated mutagenic spore intervals, accompanied by Hg/TOC anomalies of similar magnitude. This suggests an overall link between volcanogenic pollution and vegetational disturbance. Based on qualitative analyses of organic matter (OM), which show an overall positive correlation between Hg concentration and terrestrial indicators, alternative sources for sedimentary Hg-enrichment such as vegetation reservoirs should be considered. This characterization of OM indicates an intermediate step in the Hg cycle, likely mediated by vegetation and/or climate feedbacks.</p><p>Atmospheric Hg-loading via volcanism can explain the synchronous enrichments of Hg concentrations at the TJ boundary interval in multiple sites across the globe. In contrast, the Hettangian anomalies of Schandelah-1, appear to be mainly driven by environmental/ecological perturbations corresponding to intensifying warm/humid conditions. Extreme seasonality alternating between high rainfall and droughts, perhaps due to eccentricity maxima, leading to increased soil erosion, wildfires and transport/degradation of terrestrial OM could potentially recycle and redistribute Hg long after initial deposition. These implications suggest a more dominant role of climate-induced Hg-remobilization, rather than direct volcanic emissions, to the mutagenesis in terrestrial vegetation. This could, in addition, lead to asynchronous and local impacts mainly in the proximity of landmasses.</p>

Sustainable Forest Use and India's Economic Growth

2016 ◽  
pp. 306-326 ◽  
Author(s):  
Jayita Bit ◽  
Sarmila Banerjee
Keyword(s):  
Economic Growth ◽  
Sustainable Forest Management ◽  
Rapid Urbanization ◽  
Ecological Stress ◽  
Long Run ◽  
Forest Coverage ◽  
Import And Export ◽  
Forest Use ◽  
The Government ◽  
Sustainable Forest Use

This paper assesses the prospect of sustainable forest management (SFM) for an emerging economy like India, where forest coverage has gone up over the last three decades in spite of population growth, rapid urbanization and fast economic growth. To assess the possibility of sustainable future growth in a globally congenial environment, the extent of ecological stress on Indian economy has been assessed by using Input-Output transaction tables and pattern of expenditure by the Government and the Private sector along with Import and Export of forestry and related products over 1993-94 to 2007-08. The change in direct forest intensity (DFI) in gross domestic product has been calculated and decomposed into effects due to material intensity, structural change and economic growth. The results reveal increasing dominance of economic growth over other effects indicating necessity of designing intervention to decouple potential future economic growth from forest resources to ensure long run sustainability.

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