Photosynthesis Research - Springer
The relationship of plant pigments to photosynthesis
Mass extinctions always have critical geophysical aspects to them, and often geochemical. Continental shelves under shallow seas, which are home to most marine life, are vulnerable to sea level and oceanic current changes. Stagnant waters, or waters that have too many nutrients dumped into them, can lose their oxygen, which triggers anoxic events that kill complex life. A continental shelf exposed to the atmosphere by a falling sea level would obviously lose its marine life, and that marine life might have had nowhere else to go. Sea levels can rise or fall for different reasons. The most obvious reason has been advancing and retreating ice sheets, as water is removed from or added to the oceans, but the aggregate continental landmass has always grown (possibly sporadically), continents can rise and can fall during the journeys of their tectonic plates, and the ocean’s collective basin has fluctuated in size, as water was hydrated into rocks, and also falling when and rising again as they fragmented. Generally, when , the continental shelves lost their marine life, and , anoxic conditions often accompanied them. There is evidence that the ozone layer has been periodically damaged, which stressed all plants and animals that the Sun directly shined on. The positions of the continents, both in relation to each other and their proximity to the equator or poles, can have dramatic effects, including impacts on global climate. Global climate changes and moving continents can turn rainforests into deserts and vice versa.
This essay has presented Earth’s many changing faces during its journey. Earth had molten beginnings, was , and may have . Later, and and . Earth experienced swings from to conditions as atmospheric gases dramatically changed, continents moved, and vast and of complex life played out on land and sea. But the changes happened over timescales of millions and billions of years, not hundreds. No climate scientist will deny that carbon dioxide traps infrared radiation and warms Earth’s atmosphere. The vented enough carbon dioxide into the atmosphere to create 200 million years of Greenhouse Earth conditions, when reptiles ruled Earth. Volcanism waned and around 150-to-100 mya. By 35 mya, and the Antarctic ice sheet began forming. Every paleoclimate study I have seen places greenhouse gas (and primarily carbon dioxide) concentrations as the primary determinant of global surface temperatures, after the Sun's radiation, but the Sun's output is considered to have been exceptionally stable and has risen slowly over the eons. , usually by accentuating the carbon dioxide with a positive feedback effect that may have reached runaway conditions at times.
The Light Reactions of Photosynthesis
When investigating how ice ages begin and end, and feedbacks are considered. A positive feedback will accentuate a dynamic and a negative feedback will mute it. In the 1970s, and the author of today’s , , , which posits that Earth has provided feedbacks that maintain environmental . Under that hypothesis, environmental variables such as atmospheric and levels, levels, and Earth’s surface temperature have been kept relatively constant by a combination of geophysical, geochemical, and life processes, which have maintained Earth’s inhabitability. The homeostatic dynamics were mainly negative feedbacks. If positive feedbacks dominate, then “runaway” conditions happen. In astrophysics, are responsible for a wide range of phenomena. A runaway greenhouse effect may be responsible for . Climate scientists today are concerned that burning the hydrocarbons that fuel the industrial age . Mass extinctions are the result of Earth's becoming largely uninhabitable by the organisms existing during the extinction event. The ecosystems then collapse Mass extinction specialist recently proposed his as a direct challenge to the Gaia hypothesis.
Dr. Leaf has also worked with the people of all ages and backgrounds in various clinical, educational and business environments. A 78 year old former pilot even used her techniques to qualify as a chartered accounted (CPA) at the age of 84. After moving to the U.S. in 2008, Dr. Leaf worked in a charter school district in Dallas, with similar results to her school trainings in South Africa: students' grades and state test scores improved . She is currently in the process of updating her research for publication in scientific peer-reviewed journals.
Similar articles in this journal;
Some scientists treat every proboscidean extinction as a unique mystery, unrelated to other proboscidean extinctions, and climate and resulting vegetation changes are hypothesized as agents of extinction (or other causes invoked), when the most probable cause stares at them each morning in the mirror. The devil in the details, but regarding the megafauna extinctions, some specialists cannot seem to discern a very clear pattern. Scientists, because they are human, have an inherent conflict of interest when attributing such catastrophes to non-human causes. During the remainder of this essay, it will become evident that there is a human penchant for absolving one’s in-group of responsibility for catastrophes and crimes committed against the out-group, and , scientists, and other professionals regularly engage in such interest-conflicted acts, whether they were defending their species, race, gender, nation, class, ideology, ethnicity, or profession. That in-group/out-group difference in treatment has a long history and probably goes back to the beginnings of territorial social animals.
What human-agency skeptics have ignored or argued around are unique features of the megafauna that went extinct the humans that preyed on them, while they examined minutia. ever before humans arrived. As , African elephants help create the biomes they live in, as terraforming agents. They were far from idle browsers and grazers, but had outsized impacts on the vegetation, soils, and geological features such as water holes. Dinosaurs may have had similar biome impacts, and it was probably a feature of that large herbivore guild. Scientists have been finding plenty of evidence that vegetation changes that human-agency skeptics attribute to climate change may well be largely the of the guild’s disappearance, not a cause. Researchers in Africa have also discovered that changes wrought by elephants created biomes dependent on elephant management. When elephants disappeared, so did the biomes that they created, which is why smaller species could also disappear when the large herbivore guild vanished. Although Australia was the only non-Antarctic continent without proboscideans 50 kya, and its guilds were comprised of somewhat smaller animals, probably reflecting inherent differences between placental and marsupial mammals, Australia's large herbivores probably had similar biome impacts.
Photosynthetica is devoted to the investigation of photosynthesis, ..
Journal Title Photosynthetica Coverage ..
Photosynthesis Research is an international journal dealing with both basic and applied aspects of photosynthesis
Over 10 million scientific documents at your fingertips.
Scientific Paper on Photosynthesis | Photosynthesis | …
Photosynthesis - ScienceDaily
Consiga Scientific journal aqui
Because the Western Hemisphere’s inhabitants were virtually all in their Stone Age, they as greatly as Old World civilizations did, and many societies were environmentally sustainable and provided seeming answers to questions that scientists have asked about Old World civilizations’ development. The natives of coastal California were familiar with agriculture, as it was practiced by nearby inland tribes, but they never adopted it. California was so bountiful, and its climate was so human-friendly, that its natives retained their hunter-gatherer lifestyle. Similarly, northward on the Pacific Northwest's coast, natives created an economy in which half of its calories derived from salmon runs, and those peoples were relatively sedentary without agriculture. Natives turned the Great Plains into a big pasture for bison, and the biome was partly maintained by annual burning of the grasslands. In Mesoamerica, farming has been sustainable for thousands of years. In the Amazon, the natives transformed the rainforest, and a higher proportion of plants and trees provided human-digestible foods than in any other “wild” place on Earth, those natives also terraformed thin tropical soils with ceramics (maybe unintentional) and charcoals (intentional) and made super-soils called and . In summary, native practices in the Western Hemisphere were often sustainable if not quite abundant. But when civilizations arose, they had problems that were like their Old World counterparts'. Their problems were also environmental and not just the injustices of hierarchal societies, often steeply hierarchical.
Scientific FAQs | Dr. Caroline Leaf
When scientists and scholars discuss , or the demise of , or the , some will always attribute such events to climate change as they deflect responsibility from humans. Climate change has probably never been the ultimate cause for such events. The ultimate cause was probably always humans, and everything else was a proximate cause, at most. In the past several hundred years, there are clear instances when deforestation and sheep grazing quickly turned moist forests and/or , particularly in the kinds of temperate regions where the first civilizations arose. When scientists have investigated and reconstructed the dynamics that led to the collapse of , the , or the Anasazi, the story was always the same. Human civilizations altered the ecosystems, usually via deforestation and agriculture, which made them lose their resilience, and a drought did them in. Those urban areas were permanently abandoned. That civilization-collapse dynamic is like the hypothesis for why mass extinctions have punctuated the eon of complex life: those multi-tiered energy systems .
Read about Dr. Leaf's scientific frequently asked questions.
Just as with or the , there are plenty of scientists and scholars who argue that human-agency is not responsible for the decline and collapse of civilizations, question , assert that climate change did it, or invasion did it, and so on. The battle of competing hypotheses is part of the process of science, but all scientists whose hypotheses deflect responsibility from humanity (their ) have an inherent conflict of interest, and their work should be examined with that in mind. In the historical era, particularly when Europe conquered the world, the rapid deforestation and desertification of newly conquered lands was evident. Within a century of the Spanish conquest of the Aztecs, a valley of verdant forests and fertile farmland was . That valley is known as the today, because the desert-dwelling mesquite is the dominant tree in that semi-desert. British invaders of Australia did the same thing to within 50 years, via deforestation and sheep grazing. Streams quickly dried up, but flooded when it rained, as the “sponge” of the forest ecosystem was removed, so flood drought accompanied deforestation. Atlantic islands were by invading Spaniards and Portuguese.
"I have always been impressed by the quick turnaround and your thoroughness. Easily the most professional essay writing service on the web."
"Your assistance and the first class service is much appreciated. My essay reads so well and without your help I'm sure I would have been marked down again on grammar and syntax."
"Thanks again for your excellent work with my assignments. No doubts you're true experts at what you do and very approachable."
"Very professional, cheap and friendly service. Thanks for writing two important essays for me, I wouldn't have written it myself because of the tight deadline."
"Thanks for your cautious eye, attention to detail and overall superb service. Thanks to you, now I am confident that I can submit my term paper on time."
"Thank you for the GREAT work you have done. Just wanted to tell that I'm very happy with my essay and will get back with more assignments soon."