Similarly, carbon in inorganic carbonates shows little isotopic fractionation, while carbon in materials originated by photosynthesis is depleted of the heavier isotopes. In addition, there are two types of plants with different biochemical pathways; the C3 carbon fixation, where the isotope separation effect is more pronounced, C4 carbon fixation, where the heavier 13C is less depleted, and Crassulacean Acid Metabolism (CAM) plants, where the effect is similar but less pronounced than with C4 plants. Isotopic fractionation in plants is caused by physical (slower diffusion of 13C in plant tissues due to increased atomic weight) and biochemical (preference of 12C by two enzymes: RuBisCO and phosphoenolpyruvate carboxylase) factors. Park S. Nobel (2009) Physicochemical and Environmental Plant Physiology. P.410. The different isotope ratios for the two kinds of plants propagate through the food chain, thus it is possible to determine if the principal diet of a human or an animal consists primarily of C3 plants (rice, wheat, soybeans, potatoes) or C4 plants (corn, or corn-fed beef) by isotope analysis of their flesh and bone collagen (however, to obtain more accurate determinations, carbon isotopic fractionation must be also taken into account, since several studies have reported significant 13C discrimination during biodegradation of simple and complex substrates). Within C3 plants processes regulating changes in δ13C are well understood, particularly at the leaf level, but also during wood formation. Many recent studies combine leaf level isotopic fractionation with annual patterns of wood formation (i.e. tree ring δ13C) to quantify the impacts of climatic variations and atmospheric composition on physiological processes of individual trees and forest stands. The next phase of understanding, in terrestrial ecosystems at least, seems to be the combination of multiple isotopic proxies to decipher interactions between plants, soils and the atmosphere, and predict how changes in land use will affect climate change. Similarly, marine fish contain more 13C than freshwater fish, with values approximating the C4 and C3 plants respectively. The ratio of stable nitrogen isotopes, 15N/14N or δ15N, tends to increase with trophic level, such that herbivores have higher nitrogen isotope values than plants, and carnivores have higher nitrogen isotope values than herbivores. Depending on the tissue being examined, there tends to be an increase of 3-4 parts per thousand with each increase in trophic level. The tissues and hair of vegans therefore contain significantly lower δ15N than the bodies of people who eat mostly meat. Similarly, a terrestrial diet produces a different signature than a marine-based diet. Isotopic analysis of hair is an important source of information for archaeologists, providing clues about the ancient diets and differing cultural attitudes to food sources. Michael P. Richardsa,b,1 and Erik Trinkausc Isotopic evidence for the diets of European Neanderthals and early modern humans PNAS September 22, 2009vol. 106 no. 38 16034-16039 Oxygen isotope ratio in atmosphere varies predictably with time of year and geographic location; e.g. there is a 2\% difference between 18O-rich precipitation in Montana and 18O-depleted precipitation in Florida Keys. This variability can be used for approximate determination of geographic location of origin of a material; e.g. it is possible to determine where a shipment of uranium oxide was produced. The rate of exchange of surface isotopes with the environment has to be taken in account. Nuclear Forensic Analysis - Kenton J. Moody, Ian D. Hutcheon, Patrick M. Grant - Google Boeken Measurement of carbon isotopic ratios can be used for detection of adulteration of honey. Addition of sugars originated from corn or sugar cane (C4 plants) skews the isotopic ratio of sugars present in honey, but does not influence the isotopic ratio of proteins; in an unadulterated honey the carbon isotopic ratios of sugars and proteins should match. As low as 7\% level of addition can be detected. PDF Isotopic fingerprints are used to study the origin of materials in the Solar System. For example, the Moon's oxygen isotopic ratios seem to be essentially identical to Earth's. Oxygen isotopic ratios, which may be measured very precisely, yield a unique and distinct signature for each solar system body. Different oxygen isotopic signatures can indicate the origin of material ejected into space. The Moon's titanium isotope ratio (50Ti/47Ti) appears close to the Earth's (within 4 ppm). In 2013, a study was released that indicated water in lunar magma was 'indistinguishable' from carbonaceous chondrites and nearly the same as Earth's, based on the composition of water isotopes. Earth-Moon: A Watery "Double-Planet" A. Saal, et al - Hydrogen Isotopes in Lunar Volcanic Glasses and Melt Inclusions Reveal a Carbonaceous Chondrite Heritage
Similarly, carbon in inorganic carbonates shows little isotopic fractionation, while carbon in materials originated by photosynthesis is depleted of the heavier isotopes. In addition, there are two types of plants with different biochemical pathways; the C3 carbon fixation, where the isotope separation effect is more pronounced, C4 carbon fixation, where the heavier 13C is less depleted, and Crassulacean Acid Metabolism (CAM) plants, where the effect is similar but less pronounced than with C4 plants. Isotopic fractionation in plants is caused by physical (slower diffusion of 13C in plant tissues due to increased atomic weight) and biochemical (preference of 12C by two enzymes: RuBisCO and phosphoenolpyruvate carboxylase) factors. The different isotope ratios for the two kinds of plants propagate through the food chain, thus it is possible to determine if the principal diet of a human or an animal consists primarily of C3 plants (rice, wheat, soybeans, potatoes) or C4 plants (corn, or corn-fed beef) by isotope analysis of their flesh and bone collagen (however, to obtain more accurate determinations, carbon isotopic fractionation must be also taken into account, since several studies have reported significant 13C discrimination during biodegradation of simple and complex substrates). Within C3 plants processes regulating changes in δ13C are well understood, particularly at the leaf level, but also during wood formation. Many recent studies combine leaf level isotopic fractionation with annual patterns of wood formation (i.e. tree ring δ13C) to quantify the impacts of climatic variations and atmospheric composition on physiological processes of individual trees and forest stands. The next phase of understanding, in terrestrial ecosystems at least, seems to be the combination of multiple isotopic proxies to decipher interactions between plants, soils and the atmosphere, and predict how changes in land use will affect climate change. Similarly, marine fish contain more 13C than freshwater fish, with values approximating the C4 and C3 plants respectively. The ratio of stable nitrogen isotopes, 15N/14N or δ15N, tends to increase with trophic level, such that herbivores have higher nitrogen isotope values than plants, and carnivores have higher nitrogen isotope values than herbivores. Depending on the tissue being examined, there tends to be an increase of 3-4 parts per thousand with each increase in trophic level. The tissues and hair of vegans therefore contain significantly lower δ15N than the bodies of people who eat mostly meat. Similarly, a terrestrial diet produces a different signature than a marine-based diet. Isotopic analysis of hair is an important source of information for archaeologists, providing clues about the ancient diets and differing cultural attitudes to food sources. Oxygen isotope ratio in atmosphere varies predictably with time of year and geographic location; e.g. there is a 2\% difference between 18O-rich precipitation in Montana and 18O-depleted precipitation in Florida Keys. This variability can be used for approximate determination of geographic location of origin of a material; e.g. it is possible to determine where a shipment of uranium oxide was produced. The rate of exchange of surface isotopes with the environment has to be taken in account. Measurement of carbon isotopic ratios can be used for detection of adulteration of honey. Addition of sugars originated from corn or sugar cane (C4 plants) skews the isotopic ratio of sugars present in honey, but does not influence the isotopic ratio of proteins; in an unadulterated honey the carbon isotopic ratios of sugars and proteins should match. As low as 7\% level of addition can be detected. Isotopic fingerprints are used to study the origin of materials in the Solar System. For example, the Moon's oxygen isotopic ratios seem to be essentially identical to Earth's. Oxygen isotopic ratios, which may be measured very precisely, yield a unique and distinct signature for each solar system body. Different oxygen isotopic signatures can indicate the origin of material ejected into space. The Moon's titanium isotope ratio (50Ti/47Ti) appears close to the Earth's (within 4 ppm). In 2013, a study was released that indicated water in lunar magma was 'indistinguishable' from carbonaceous chondrites and nearly the same as Earth's, based on the composition of water isotopes. 
D
Park S. Nobel (2009) Physicochemical and Environmental Plant Physiology. P.410.
D
Michael P. Richardsa,b,1 and Erik Trinkausc Isotopic evidence for the diets of European Neanderthals and early modern humans PNAS September 22, 2009vol. 106 no. 38 16034-16039
D
Nuclear Forensic Analysis - Kenton J. Moody, Ian D. Hutcheon, Patrick M. Grant - Google Boeken
D
PDF
D
Earth-Moon: A Watery "Double-Planet" A. Saal, et al - Hydrogen Isotopes in Lunar Volcanic Glasses and Melt Inclusions Reveal a Carbonaceous Chondrite Heritage