I OF ORNL P 1820 > ILI IL . EEEEEEEE 25 L4 LEI I - -- - - - - MICROCOPY RESOLUTION TEST CHART NATIONAL BUREAU OF STANDARDS -1963 DRNL-P-1820 Coff630744- Proceedings of the First International Symposium on Ecosystems, Copenhagen, Denmark, July 29, 1965 USE OF TRACER TECHNIQUES FOR THE STUDY OF BIOGEOCHEMICAL CYCLES* Jerry S. Olson Radiation Ecology Section, Fealth Paysics Division Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA WVLIE 1 NEC 21 485 Surmary egy bucsets and ühe processes of biological productivity need plained in terms of outent circulation in whole ecosystems. to be network of plant, animal, and environmental compartments whics constitutes : Wome je Experiments with 45ca, usz, Sosr, 42, 106R6, 32p, 60 co, 2069 d cüter radionuclides illustrate great differences among element Moups in translocation within vegetation and release from leaves or wiiter. Cesium-137 and 3*cs are especially interesting for problems of edioactive contamination. Those nuclides also help us understand the -OW as well as rapid cycles and epicycles of ions in nature. For example, during spring in Tennessee, Cs and K quickly move warć inom tree boles to foliage (after tagging in troughs around Cuero-s nd Liriodendron trees). Leaf concentrations decrease throughout surmer emä autumn by transfers to undercover vegetation, litter and soil (by red leaching from leaves, animal consumption, litter fall, and especially wy dowotard translocation to small rootlets, which quickly release Cs to the 2011). The International Biological Program should also find valuable help from non-radioactive tracers (especially ->N) for answering questions about productivity budgets and processes that coacere chemical elements. Parameters unifying the whole IBP will be the turnover Tractions of energy and nutrients (1.e., the rates of income or loss divided by the amounts already accumulated) in terrestrial or aquatic ecosystems, or in their major LEGAL NOTICE compartments. The report was prepared as an account of Government sponsored work, Noither the United A. Makar my nurrunty or representation, expressed or implied, wo mapost to the noou- racy, completenes, or usefulness of the information contained in the report, or that the man RMIDASID POR ANTROVANCEMENT IN MOLLAR SCIRKCI ABSTRACTS privately owned mi dates or B. ARNU Any Habilities with respect to the we of, or for damages routing from the un at any taformation, apparatus, method, or proovn dinalowed in this reporte Ao wned to the above, "purrou notte a botal of the Commiuston" hrobudne wym ploys or contrator of the Commission, or sploy of mail contractor, to the extent that moh employs or contructor of the Commission, or employee of mooth contractor preparu, darontmate, or provided NOOO to, ang taormation par to ho deploy or contrast • wid the Commision, or Me employment with such contornotor. Research sponsored by the U. S. Atomic Energy Commission under contract with the Union Carbide Corporacion. min CUCCIO .-6. 4 - Co i Los ou com 23 Pest International 2003 cerveau transiers or energy. Other willing theras that reisis ecu.cey and other discipiides deserve equally n O o sredosia. E como requires that taese tienes i به : دننه ات نت ، تمام ن من زنده ت 5 نت .ثتنننهه نه : Orne det iis ciosem rejäved to exerzy transier is i no poden conectvö. aree vest, cvington that transiers ; . 323 C C od je coazzás eü togeccez, os at least che ac mauris ne over, CO Ustavno vesiignes de ese proposed zor the Pe r o ?:05. In accoriazee wanna wais Symposium's cerca uomo cuves evacas, I saa siomüzy äiscuss some applications is a 2 : 5050pe vaadE s o liiies cr 3:0,202. cal transfer in un ve os waasa ore 09. tvo P a lvence, suwever, Isaacüiá 20 te agreezezat with Dr. Blackman..and Co ciers; üccü elaborate appareius and tracers are by no means necessary for :: ventive measurements 0:: dry arter production. Nor are tracers essential 13 ::ు? 332. suicaiee natanamasicas dels of productivity, as by growth analysis ö zechoái. Indeed, suck analyses tuzish a logical core for deriving product- 20 vit rates 2oz cze .3.2. I would prefer also to see these methods extended 2: cobeing assicužtural accuütures with significant natural communities Os research state om ontslae Program. Practical methods for doing this 23 Gave been demonstrated by Cvington (e... 1952, 1955), Waittaker, Kornas, aza cicas. . S ound ze te present one should eacourase suggestions that will O .2comme ceas to recommend biological, playsical and chemical og erumuzamer.us chat are suitas e cor standardized, or at least intercalibrated, 2 comparisons aü many stations, large or small. Also important is the need or connects results in terms o critical comparisons of model parameters - ---- SS 4 for any network of productivacy statioas. We need truly ecological and co c e üs well as physical and matheratical bypotheses to test with the ól az oo these models. Investigations oz energy relations discussed this week furnish one 8 - 16883sary 3:23:3 to til:ing such comparisors. Ltriciencies in tixation of som energy in organic matter offer fundamental criteria for comparing eco- 10 | systems with other natural systems and with machines. Calories and power icecosie rlow per unit time) furnish unified scales for comparing the flow 12 | oi' ruiant energy and heat with the low of energy in organisms, populations 13 and communities. Microenvironments created by the transfers of heat, organic material, and water of course impose certain limits on primary production. Toey limi: patterns and rates of transier of organic energy and material through the network of living and non-living compartments, which constitutes the ecosystem. Nevertheless, the flow of energy and the very existence and role of . the living species in the ecosystem depend on the flow of nutrients. The quez-ty of organic material, e.g. su protela, n'trogen, and certain other elements, is as important to measure as is the dry weight per unit area, which is used to convert ecosystem nagsurements to protein or aitrogen per unit area. . Th: luz.ca of ana-, -to furnish Cven a static chemical Inventory of 25 a fairly simple: ecosystem means that ine pääccs and times for such chemical 26 study will have to be selected carefully, with due regard for bota climatic I las do and soil factors limiting production. Fortunately, lavestigations summarized by Ovington (1962, 1965), by many Soviet s011 scientists, Japanese ecologists, and others show that chemical Inventories of natural ecosystems are feasible, and very Instructive. Reviews of such work show that static inventories of nutrients can be supplemented by inzerences about flows of various elements, as well as of dry matter and energy. Vany 110-ties still accompany a complete modeling of chemical flow through an ecosystem. The role of isotopes is to help overcome some of these ei oi LOL. oo | difiiculties by furnishing information that is impractical, if not impossible, ona to geü - other ways. We shall note several steps by which tracers can be :1 used, in conjunction with other methods, for approaching our ultimate goal 12 of more insight regarding the functioning of ecosystems. Now wiat do we mean by the state of an ecosystem? One meaning that is Decaps most useful for this Symposium is essentially to specify the dis- izbution of pertinent variables among major parts or "compartments" of the sysvert. I shall start like Professors Monsi, Cowan, and Milthorpe separating . . - .. .. .. .. several layers even within the same kind of plant but will later find it suz-icient for nutrient or isotope cycling studies to deal only with the major compartments (foliage, wood, bark, and roots) of a major species and the liter mat, and one or more pools of soil material, as Professors Ovington and Rodin have already discussed. .. • • 21 .... .. -. -. . . Just as Dr. Gates specified the temperature and other physical var- 23 iables of a leaf as a point in multi-dimensional space, it is only slightly 24 ore taxing for the imagination to think of the contents of an element, like carcon, nitrogen, or cesium, for example, in n compartments of an ecosystem as 26 | representing a point in n dimensional space. The ordered set of coordinates (vva... Vad can be considered as a vector in n-space. This point or vector in space shifts through time by the addition of many small vectors representing increments of production (or loss)- e.s. the addition or 1088 of atoms, or packages of atoms such as leaves or tree boles. TRANSFER MODEL one step in tracer methodology is just to show whether tagged atoms introduced in one part, or compartment, of an ecosystem move to other parts, in detectable or significant quantities. If they do, then promptness of first appearar.: 2, and transfer rate per unit time become important. Often rates are expressed as a proportion pse of the material already in part 3 which move to part k. If we have conceptually abstracted our system as a compartment model with a boxes, then we should ideally like to specify a table (or matrix P) shbw- ing the proportion Pny of the constituent already in compartment 1 (row 1 of the table) which remains in compartment 1 and the page which should move into compartments k: 2,3,..., n in some ( very short) increment of time. Similarly, Pan expresses the proportion in compartment 2 which remains there, and Pok the proportions which move, and so on, until all n rows of P are filled out. P11 P12 - Pin : P = 221 222 • (1) Pal Paz ... Pan The terms P21, P22, ..., Pan on the main diagonal of this matrix (P4 or Pik or Pax where j = k) thus represent proportions of the constituent which remain ip . . .. the same compartment. Restating the model in terms of probabilities, the tracer atoms which Lare-introduced-in-part f-itsayt start moving into other compartments, subject to an element of chance. Early measurements of the radioactivity in these compartments may furnish estimates of the UCN-8567 8 9 probability that a randomly chosen atom moves to the second, or the oth com- partment, or remains in the original compartment. As soon as appreciable transier has taken place, atoms start moving from the second compartment to the nth, and perhaps also back to the first 11 1 and 2 are indeed involved | in a cyclic exchange rather than a cne-way turnover out of compartment 1. In order to make explicit allowance for export from the local ecosystem, the nth and even (5.-=, the compe: tuent, etc., may represent various losses from the sysve. There may or may not be negligible probability Prk that atoms once exported froin the local system will return to it. 1. Ii we take a stepwise view of changes in the numbers Vie of atoms of our constituent ir: the kth compartment of the system for a sufficiently short time step, At, the expected number that ramain from the last preceding stage (time -1; is vt. px.at; v. (-2323*+ -2) Pakat + ... for all terms in the xth columy of matrix (1), bes: n. the one involving Pick that was con- siderea. All terms together then represent the expected number of atoms at time t: vi(t) = Ë v.(t-1 -.- . . . . --- . temu - .-. r- 1 lul (2) j=2j roo (in different words, we can represent the state of the system more briefly as a vector vit) with n coordinates given by equation 2. The expected value of this state is given by the matrix product of vit.-)p.) Discussion of a similar deterministic model for changes in carbon : (Neel and Olson, 1962), radionuclides (Olson, 1963a, 1965) and dry matter pro- auction (1964) is given elsewhere. Sheppard (1962) explains elaborations of the compartment model approach, YO with important distinctions between aquations for the number of tracer isotope i atoms, and number of atoms of the tracer per unit of the element being tagged. ELEMENTAL CYCLES: SMALL, MEDIUM, AND LARGE Tracer isotopes can help to evaluate the probabilities of transfer 6 given in mata ix (1) for ecosystems ranging in size from the individual plant- soil (or microbe-medium) system to the biosphere as a whole. Plant physiologists and agriculturalists have long used tracers first § to show rapid, small scale transfers by contact exchange, active metabolic uptake and excretion, and translocation (de Hevesy 1947; Stout and Hoagland, 1939; Stout et as, 1947; Burris, 1950; Biddulph, 1955; Kursanov, 1955; Burton, 1957; Vlasyuck and Manorik, 1.957; Fried, 1957; Fried et al, 1958; Stenlid, 13 1958; Walker and Barber, 1961). These studies furnish insight regarding in- 14 aividual terms P, in the chemical transfers of a whole crop or other commain- 15 ity. Usually an income-loss budget for the ecosystem has not been pertinent 16 for the question asked by the physiologist. Hence there is still a paucity of data relating the inventories on a unit area basis (vx) and the transfer probabilities (Par) which bring about changes in the inventory. Environmental contamination by radioactive fallout and nuclear wastes 20 has extended the physiologist's interest to many trace elementis besides those which are nutrients. (Stout et al, 1947;Klechkovsky, 1957, and many others). Monitoring has been expressed increasingly on a unit ground area basis, and has led interpretations to differentiate between physical interception of 24 rain or dry fallout (Russell, 1965; Martin, 1963, 1965) and uptake depending 25 on şoil chemistry (Shulz, 1965; Tamura, 1963, 1964, 1965) and on plant-soil 26 relations (Wenzel, 1965; Fredriksson et al, 1961, and many other studies). re Food chain transfers of fallout to man have been emphasized not only lby accumu lation of 90sr and +34via milk, cattle and pastures (Comar, 1963), but recently by temporary high levels of +370s in Lapplanders and Alaskan Eskimos (Liden and Svensson, 1965; Hansun and Palmer, 1965 respectively). In the Artic, reindeer or caribou feed on lichen vegetation which has been very effective in intercepting fallout (as well as its normal nutrients) from the atmosphere. Simple "concentration factors" have been useful for summarizing trans- 9 fers from one step (or compartment) to another. However, the limitations of 10 monitoring approach (Auerbach, 1965) have tended to focus increasing interest on the quantitative models which treat income and loss rates explicitly (01804, 12 -sáča, 29630, 1965; Martin, 1965), in terms of coefficients 0:2 transfer like 13 those in matrix (1). By integrating the expected income and loss terms due to all significant transfer rates, it should be possible to predict the Levels and changes of accumulation under specified conditions without waiting 16 for some catastrophic accident to bring them about. Fallout problems also have stimlated the quantitative studies of Langer-scale geochemical cycles. Many fallout studies concern the transfer 1922erent parts of the hydrosphere, lithosphere, and biosphere. On this scale, 29,-. any of these "spheres" to move to the other "spheres". These probabilities, like those expressing movement within some local ecosystem, should be ex- pressible in a matrix-like equation (1), and should control the changes . summarized in equation (2). TREE-TAGGING METHODS Most ecosystem studies have been concerned with the intake of nuclides from the environment to organisias, or from one organism to another. By incort porating tracers within plants, it is a..so possible to show how promptly they are translocated between plant perts, and to measure the loss rates 1 14 from the plants to the environment completing the local cycle of the elements. Scaling up plant tagging I'rom small plants in the greenhouse or field to full-size trees involves several variations of technique. Fraser (1956, 1958) reviewed zany findings as well as methods of tagging and monitoring trees. Holes drilled into the wood, and troughs constructed around the bole (Fraser and Mawson, 1953) have been useful in our own studies reported below. The Vauget Feeder is an aluminum tube inserted by driving into the tree along with a nails and attached to a small plastic reservoir by a rubber gasket. We have found it useful under favorable transpiration conditions, but the slow emptying under other conditions (Witherspoon, 1964) has the disadvantage of leaving isotopes exposed to possible disturbance by animals, unless the insertion is actually made in a taproot below ground, as proposed by Ealy (1957). Postlethwait and Rogers (1958) used variations of the Fraser method, one including a tir can reservoir firmly sealed to one side of a tree, with suffit cient depth of liquid so that cuts through the bark could be made under water, and another method using chisel cuts without bothering to maintain the water S S column in this way. Even with these breaks in the water column, and transverse cuts which severed half the vascular system at the point of injection p moved around these cuts and up the trees, during June when transpiration con- ditions were favorable. . UCN-5567 10 .. - - - .. .. . . . . .. . ;. --- - -- - - - - . - - " . Y . - I .- .- - : - ...- . . . . . .. * .-J - - Other methods of getting the nuclides into trees (Tukey et al, 1955) In- clude foliar spraying and the wrapping of gauze around branches of trees. Single roots (Rubin and Noiseichenko, 1963) or cut branches also were tagged e2fectively by insertion into isotope solutions by Kuntz and Riker (1955). The latter authors and Bormarn and Graham (1959) showed rapid translocation below ground between grafted root systems of different individuals of the same species, 11lustrating a physiological interdependence among "individuals" of the same community. Using Bormann's method of application of nuclides on cut stumps, a 10 vrie: stray with Russel Hutnik in 1960 at Oak Ridge National Laboratory 2007: +å oniy sporadic transiers between root systems of loblolly pine (Pinus tuoda). Yet there was conspicuous transfer of °°Rb to deciduous shrubs (Rhus co: 1ing and Acer rubrum), apparently by translocation across intimate contact of ungrarted roots which had grown together. Witherspoon (1964) re- ported transier of 134Cs from tagged white oak (Q. alba) saplings to seedlings 36 * sourwood (Oxydendron arboreum), au Ericaceous tree which became as radio- active per unit weight as the donor oak. Woods and Brock (1964) likewise have shown transie: of 45ca and 32p 1rom longleaf pine (P. palustris) to other species. 19 Gerdaga (1955) measured the rapid uptake of both these nuclides into 23. the canopy of apple trees during inflorescence. Pickard et al (1962) included moi cnly 45ca and 32p but also 59 Fe and 35s in their studies of penetration 22 and translocation in fruit trees, and leaching losses from trees (cf. Tukey and Amling, 1958). -- - - - - --- - ya - - A .- - - - - - - - - - - INI In some of the following experiments, two or three radioactive isotopes were included in the same injection solution to show differential movement 26 of elements up the trees, and out of the trees. One of the simplest methods - - - - - ܐܐ - - - - - Wer 02* separe ting the counts from mix sotopes was in the case of very short- 2 nived "* (12.4 hour half-life) wh:... ractically disappeared after only one work, so that samples which were f' counted for this nuclide could simply je countec again ior measuring nuchicas originally associated with it. 5 Mee surer:ent of other nuclides in mixtures ("%sr and 45ca) also was ac- á complishec, by adjusting, liquid scintillation counter so that 45ca was mea- 7 sured only in the channel of lower radiation energy. The "sr was detected ó . Both channels and (with higher efficiency) by a solid scintillation crystal the 9 detector systext. A solid crystal spectrometer, an automatic sample changer . rox 2.5 com test tubes (Packard Auto-gamma) and a bulk counter (Packard Armac) .. ... .. . zor litte:-sized samples have been valuable for the experiments with M garma erzitters in handling numerous small samples or large samples respectively. OAK RIDGE RESULTS ON TREES - - - - - 15 The metcoas described have been useful in comparing the mobility of sev- 16 eral elements or element groups of the periodic table. Differences are con- sistent with expectations drawn from herbaceous plants, but are displayed 18 in a striking manner by trees. Furthermore, the studies on oak saplings and 19 a whole plot (20 x 25 meters) of tulip tree forest fumished unusual oppor- 20 turaties for interpreting the budgets of income and loss for an element 2] (costum) having important long-lived isotopes. -.. ... - . - ... . ... . . , - 42K, Ir ana 45 ca T::: Tag of eri 'in saSentine wa Flowering Dogwood Tagging of three nuclides in a flowering dogwood tree (Cornus florida) at Oak Ridge National Laboratory is of methodological interest in furnishing a comparison of movement of three different elements introduced together as í a "triple tag." The 2K essentially served as a temporary tag for the dilute salt solution (0.1 N KC1, pH 5) in which 45ca and 85sr were also dissolved. Approximately 20 ml of mixture and 25 ml of rinse Kci were injected into the trunk I am above the ground through a 1 cm tube, under pressure from a garden spray pump (Fig. 3). Geiger-Müller survey meters showed rapid upward movement of the radioactivity along the vascular system of the tree. The tagged "front" reached the tip of one tree fork (3 meters from source point) less than 5 hours after tagging at noon on a sunny spring day (May 4). Samples 16 collected the same afternoon (Table 1) showed that most of this activity was | due to the strong game radiation (1.6 Mev) of the K. When the same samples were recounted a week later, after the short- 29 lived -2x dad virtually disappeared by radioactive decay 5sr was found only 20 in two of the four main forks oỉ the tree, and was mainly concentrated in 21 che of these--evidently the one whose xylem was most directly aligned with the point of innoculation. Potassium had evidently diffused laterally enough so that it was present (though in very different concentrations) in all + -- -- - - otsiminimai ir sinonta sur porks on the tree. Smáatri While potassium had moved all the way to the tree top (4.8 meters in Twitter 13 2 less than 4.8 hours), »sr was not even detectable there the next day, or We expected for several weeks thereafter. Arapid movezent of free alkai metal lons, as Fraser (1956) found with Rb, and es was later found with cesium (see below) Evidently the alkaline earth ions were not moving as freely as the alkali 5 metals, and this represents a general inaing om other experiments. Exchange and dilution with stable Ca anå Sc (e... in pectic substances and cther sites in cell walls, cytoplasm, and perhaps oxalate crystals) could help 7 3 explain their lag. ace Plaats, de animals, evidently can discriminate between Sr and ca. 10 The lag of Sr was somewhat greater than that of Sca, as these two alkaline 11 earth ions continued to move up the trees during the rest of the growing sea- 12 son after the rapidly moving 42% had disappeared (Table 2). 13 The ratio of 85sr/45ca (corrected for decay) remained below that in 14 the tracer solution during summer sampling periods, but was not as low in 15 late surrer as in early July. . In spite of the differences shown here, the 16 ratios are similar enough to indicate that Sr movement shows much in common 17 with Ca in trees, and presumably after leaf fall as well. and other 13 Leaves from thisâtrees (discussed by Olson and Crossley, 1963) were 19 harvesced at the end of the growing season. These leaves were used for 20 studies of litter breakdown and succession of rites, using litter bag tech- 21 nique. Probabilities of loss from the litter bags (per day) for Osr aver- 22 aged p = 0.00137 and 0.00175 in pine and oak stands, and were not significantly different from the rates of lear weight loss (p = 0.00135 and 0.00175 per day). Except for faster breakdown and release in early weeks in the field and slower rates in midwinter (0lson and Crossley, 1963, "ig. 7), the frac- tion remaining in litter can be approximated fairly well by negative 14 بمعتمد محمد ممدو ندیدید نیز به عهدهنه سمیم 1 | exponential decay (Olson, 19630) while the lost material would be accumulating 2 in soil below the litter bag: Fraction remaining = e-pt Accumulation in soil = 1. ept ----- .--. 234cs and 42% in White Oak - - ..... . In anotiher double tag experiment (using the Mauget feeder method) with 134cs anci 42K, Witherspoon (1964) showed that both elements could be 21 detected in rainfall which leached through the canopies of small white oak 12 trees (Quercus alba L.) on the night following tagging. Generally the potas- i3 sium was similar to cesium in its distribution, but leached even more readily :* It also tended to concentrate in buds, and perhaps in other meristems (as 15 miza se inferred). :3 Whereas 42is too short-lived (and 40K too expensive) for following 37 seasonal changes, the half-lives of +34cs (2.07 years) and 137Cs (about :3 30 years) are ideally suited for longer-term experiments in the pathways 19:ená the general rates of transfer of alkali metals through the ecosystem after ions leave the foliage (Fig. 2-7). 2 In quercus (and also in later studies in Liriodendron) foliage concen- 22 trations of cessium reach a maximum in June, and decrease throughout the sum- 23 mer. The average of 12 oaks in each of 2 years showed nearly 40% of the in- 24jected -34Cs at the time of maximum activity (in June). The decrease was con 25 siderably greater than that actually accounted for by rain leaching and leaf fall. By subtraction, half of the maximum cesium foliage content evidently 18 - 94 - - - _15 withārawn into woody parts of the trees during the summer (Fig. 2). If activity in the suriace decimeter of soil, and that in litter mat and under- story, are interpreted as cue to rainout from the canopy, this totals 15 per cent or tze canopy maximum ( of which only 6 per cent was retained in the understory, ló per cento in the litter layer aná 77 per cent in the soil.) in the first year, 33 percent of the maximum foliage content reached the surface in lear fall, and turnished a new pulse of cesium activity at the ground surface, which increased the soil activity in the second year. 2 16 Transfers of +370s in a Tulip Tree Forest Alter Witherspoon's experiment on white oak, several of us at Oaks 3 Ridge National Laboratory were interested in finding how the tagging of all the dominant trees in a forest would be iollowed by transfers to other vege- t - - - - - - - - * . - - 5 tation, to soil, and to the animals and microorganisms of a whole ecosystem. Our choice of study area was a nearly pure stand of tulip tree or yellow popier (Liriodendron tulipifera L.), a mamber of the Magnolia family which 18 cze or the most important species, ecologically and economically, in North 9 America's Eastern Deciduous Forest. Our choice of methodology (described in detail by Auerbach, Olson, and Waller, 1964) was an adaptation of Fraser's . in 1939 trouga method (Fig. 3). Thirty five trees (from 37 cm dowa, to 4 cm 12 djameter at 1.37 m above ground) were tagged, with amounts of isotope ranging 13 2.0 94.2 cown to 0.4 millicuries, in proportion to total tree biomass es. 14 tirates derived from previous production studies in the same vicinity (in 15 waica the trees were cut and weighed). 26. Instead oi +34cs (which has a 2.07 year half-life), we used +37Cs which 37 has a 30.15 year half-life and will be readily detectable a century or more 13 rom now. A total of almost 0.5 curie of this isotope was used; the area 20 s coletely renced from the public and is located where there is no external 29 commentare (Olson, 1965). uptake of water from the trough was so rapid that one man had to pour 22 : water into the reservoir while I made chisel cuts at 5 cm intervals around 23 hetzee, and while others were removing the vial of 137c6c1, from its shield 2- en wanting it in water, and pouring it in the trough. More water was poured 25 to the trough to help wash the tag into the tree, before the open trough - - - --- - W . -- * . SAT - ... scaled over. On top of the trough, a new trough was constructed so that 27 17 samples of sten Ilow water could be collected later, and compared with sam- 2 ples oỉ rainfall that had dripped the cugh the tree canopy and leached cesium and other elements from it. Detailed results are explained in other papers, 12: --- - -- - so I select here only a few key points to illustrate how several physiological and environmental processes quickly change the cesium distributions in this ecosystem. Upward translocation of radioactivity was rapid, so that foliage san- 8 ples, though initially quite variable (Olson, 1965) averaged between 1.2 and 1.3 microcuries per gram of dry leat tissue during June of 1962, only 2 to 4 10 weeks after the tagging of May 20-24 (Fig. 4). Canopy concentrations de- creased steadily throughout the summer. The decreases were considerably 12 greater than could be accounted 1 oz by the measured rainout, or by premature lear fall or insect feeding. As in the case ož pak, there was apparently a 14 very important withdrawal of Cs from foliage to branches, the tree bole and roots. Abolt half the maximum leaf content of cesium moved elsewhere before latè September and iurther decrease occurred during leaf sensecence (Fig. 5). 17, Indeperdent evidence of the rapid movement of cesium down to even the is a use or roots was found in early soil sampling (Waller and Olson, 1964; 1% Olson, 1955; Witkamp and Frank, 1964). By October, about 207 millicuries, 20 almost half of that introduced in the trees in May, was found in the surface 30 con of soil. Most of this was located in roots, and most of the activity - W2S -- Ihas had been released already to the soil presumably came from excretion, leaching or death of roots. Our accourcing for rainout and leaf drop could explain only a small fraction of the betal which was present in soil and rcots. We Estimate only about 4% of ... cesium leached by the overstory was interce ited by the ground cover cation. In the first year, and even We 18 ter through the second year, ground vegetation apparently got little of its radioactivity from the soil. MODEL EVALUATION : r + arin - Lidi - .- .- a d - - . - - ------ - To account for the net changes in cesium activity in parts of the en- vironment requires allowance for simultaneous incomes and losses for various parts or the cosystem (Table 3). These changes in turn depend on the propor- t-ons (or probabilities) of transier between those compartments which are connected to one another by the relations shown in expression(1) in the model described earlier. Some of these transfers (11ke the amounts measured in rainovi, snall slabs of litter, and vegetation) were estimated fairly directly from field measurements. Without destructive sampling of the forest stana itselé, it was necessary to imate certain transfers between the Hi trouch, toë vepå, foliage, bark ar ots indirectly, by showing what values cora be issuzeå in order to get patterns of change through time like those Hii nully cioserred. Simulation methods described u isewhere (Olson, 1965) were used to gen. radio 15 crate curves for the amounts of cesium in various compartments of the forest ecosystem (Fig. 6). Essentially, these curves are created in a series of ------- --- -- .. . .. -----......... ( - - --- - res ronmem---- r ceny steps, in which the amounts of material in compartment ý today are re- a 2. úistributed to the other compartments (at the rates given in Table 3). The state oi the ecosystem tomorrow is computed as the sum of what is left in 23:after losses to other parts were subtracted, and what is added by input Ich other compartments, as summarized in equation 2. The actual calculations were done assuring that transfers were deterministic, but the model, in princi- pic, allows that an element of chance variation could be added to furnish the IT- .- - - . 'A .4 . . .. . ... _19 L kinds of iluc cuations sometimes o..ved in nature. C..ea:cl;r the amounts of +/- : a the vicinity of the trough and also į tiroughout hi rest or the wood o u tree had to decrease quickly in order to account for increases in the rest of the tree. In foliage, radioactivity first increased while translocation from the xylem exceeded leaching and return translocation to the stems (presumably mostly in phloem). But soon these losses exceeded the rate of intake explaining why the foliage radio- activity decreased as we noted before. Autoradiograms of increment borings, and biochemical studies by Brown (1963), showed that highest concentrations of cesium occurred in the phloem aná cortex regions of bark. Most cesium remains associated with cell fluids rather than any specific reclecular sites in the tissue. It is but a minor incurity in tae usual osmatic solution of the cells. High rates of transfer like those assumed in Table 4 were required in order to create the increase in activity that was found in medium to fine roois. A release from the roots in turn, of approximately 0.3 percent per osy, could account for the radioactivity in the soil, which is discussed in further detail elsewhere (Waller and Olson, 1964). The first order approxi- mation model assumed here (Olson, 1965) made no provision for seasonal trends in the transfer proportions of table 3, and hence no allow- ance for the obvious decrease in the follage activity and the corresponding increase in liiter radioactivity in the autumn due to leaf fall (dashed lines 23 of Fig. 6). Work has proceeded on the sampling of the forest in later years. The 25 , vistribution in bark and wood at various levels of the tree had fit a regular pecuern by the end of the first winter. A series of increment borings by 20 Waller 12 1953 and non-destructive measurements of cesium redistribution by class roa dosi neters by Witherspoon greed in showing an abrupt decrease in the roots in late March as the sap v:s beginning to rise, before foliage leafed ou'; in pril. The decrease : root activity was accompanied by a prompt in :reas of cesium content ... ::le main bole, followed by a delayed increase in brinches in the tree cii! :y. Iorises jy leaching, leaf fain, and by root excretion continued in the - - - 5 - Ci .. second and third years, following a seasonal pattern much like that of the --- ---- -- --- § first year. bowever, the net result of all of these losses was a decrease 20 in radioact-vity of Liriodendron in 1963 to 1/3 of the level it showed in 1: 1962. Another marked decrease was evident in 1964 (715. 4). 3y 3-gwing of leaves, radiocesium also moved out of the tagged plot into the " surrounding forest (Fig. 7). Because of the topographic depression where the plot was located and the height of surrounding trees, the distance 15 of dispersal was not as great as might have been expected under many other conačtions. Nevertheless, it illustrates the general point that ecosystems 17 are zoi closed systems (except for rare microcosms like those considered for is aerospace vehicles). We should like to evaluate the proportions or probabilities i9 . 03 transier between ecosystems as well as within ecosystems, by models like 20 : that cî expressicas (1) and (2). ROLE OF TRACERS IN THE INTERNATIONAL BIOLOGICAL PROGRAM - - - . - - - - - - - - - ... - - As the last Introductory Speaker of this Symposium, I should ada some final points to ry opening general comments in relations to the Inter- rational Biological Program. If there is a unifying theme of the I.B.P., iu concems man's relations to the ecosystems which affect him and which he - - - - - - - 21 i in turn is rapidly modifying. Radioactive isotopes and pesticides distributed around the world emphasize the transport between these ecosystems, and the cycling End accumulation in certain compartments of these ecosystems (United Nations, 1954, Udall et al., 1954). The preceding examples of tracer studies, and many others (cf. Makhonie et al., 1961; Schultz and Klement, 1953; Fungate, 1965), provide only pre- liminary nincs of the broad role oi' isotopes in evaluating the hazards of pollution and also in basic ecological research. Aquatic tracer studies are ó 7 s O developei urther than terrestrial was but are beyond the scope of this 10 Symposiu... 9:e tagged vegetatior. starting point for continuing studies 11 0.seconi azy Konsumption and deco" tion in the same tagged forest. Here 12 Crossley (per::onal communication) : distinguished between those insect lood 23 chains of herbivores and predators which lead rather directly from food 14 sources kihich became radioactive quickly and others which did not. Studies of feeding and elimination rates furnish a new basis for estimating secondary 16 production in whole comunities of arthropods, such as the cryptozoans which 17 naster the release of nutrients and isotopes from organic debris on the forest is ?loor (Reichle and Crossley, 1965). Whač trends might be predicted in the ecologist's uses of tracers? 20 The emphasis on methodology and isolated case studies will presumably con- - -- --- - e for a while because many new techniques and interpretations are still -- - - - . - . . . . . . being tested. But presumably there will be a shift toward a balanced"inter- 23 pretation of new results in the context provided by many biological, physio- 24 chemical and nathematical approaches to single systems. Hopefully, the analysis of ecosystem components and variables, evident in so many parts or . . . . -...-. --- - -- this First in srnational Symposium on Ecosystems, will provide the foundations Io? more synthesis concerned with the organizing relations and processes in argeo. 22 the world's major environments. ne'nin madrimeve Radioactive isotopes are used most freely at laboratories which have major responsibilities concerning environmental radioactivity. How- - - ... - - - ever, the number of Universities, Colleges, and Agricultural Experiment Ste- 5 tions with instrumentation and safety procedures for similar work probably will increase steadily. Where such stations serve as centers for I.B.P. research, it should be feasible to study aspects of productivity budgets and 8 processes which cannot be treated by the more widely used 'harvest methods 9 and chemical analysis alone. 10 My emphasis on radioactive isotopes should not distract attention from 11 the portance oi stable isotopes. While there is no useful radionuclide 22 07 nitrogen, 7 has long since proved its value in demonstrating the in- 13 portezce ara mates of nitrosen fixation in many plant groups besides legumes 14 3cmd, 1953). In a provocative paper Stevenson (1958) has considered broad 15 possibilities ca fixation in non-nodulated plants and even in leaves. Her 15 paper is u sual in relating laboratory studies to the extensive literature 17 ca nitrogen Oudsets of soil and vegetation on a unit area basis. Jansson 23 (150) 11]ustrates the great value of N in the study of mineralization and ig i gcaitrification. These presumably should be considered in close relation to 20 : a.xation rates per unit of ground area, in interpreting the over-all nitrogen 21 Ducret of an ecosystem. Scable isotopes nave, practical advantage of not disappearing uuring 25. The course oz a long-time ecological experiment, but the cost may be high to veu encur targed material ror use on a fielä scale. The need for a mass - - - - - -- - . - - -- . - -- - .. --- L --- - . A - - .. . the - 25. couronter may be as costly and demanding on specialized attention as the 26 : Tuccio councing icuizont needed for radionuclides. Yet these needs must v ncro in oruc co acip interpret the budgets of nitrogen or rain- and w inti. SUC252 is 1. 2 Como Wi mong the most underental parameters describing the maintenance and e ecosystems ure te proportioas or probabilities of transier (per ) 079 enervy and elements are one component of the system to another: n x Of (2.0.) surmerized in connession (1). The net rate of change ) +0% given cozporeni in ticule compartment of the system is image wiem to the sum of all 4..e races minus the sum of all loss .. . S Y . TV cu C3 i When a certain amounü ci circonic material, or tracer introduced in one material, is traced from one point in the system, the amounts in that Concert decrease, in something like an exponential manner (equation 3; 1,., Ya..want :1. C o menu I in Fis. 6) as transiers carry the material elsewhere. The Die Songs and other compartments increase until income is practically balanced How to contes (equatica 4; also the rising parts oi curves 2, 3, and 4 in. Fig. I Losses overtake income rates, amounts then remaining decline as the A cea material zoves ch into an environmental "sink" or is transferred cu cross the wroitrary boundary of the local ecosystem into neighboring environ OD sirs within plants and from trees to forest ecosystems were mm AS ce ccü by isotopes of major mtrient elements, and by trace amounts of Durchment such es cesium which happens to be an important, long-lived Doctive contaminant of the environment. The transfers thus illustrated V o ordance for the underlying theory of maintenance in ecosystems, in 24 : : . .. .. . ..... ;*. , which trascends the importance or ha particular element or isotope which * diyini 5 Selected to particular experiental study. .. a w . a je cij * - .* -.- - - , -- KA Some chemical groups of elements like cesium, potassium and rubidium apparenuly verzant the generalization that large-scale transfers may take place on a time scale of hours or deys within natural and cultivated vege- tation. Yet these alkali metals may be immobilized in soils, and may be slow to recycle through the plant-animal-microbe food chains. Strontium mü cüicu muve less rapidly through plants and probably show a wide var- o NA . *.. * * in .. . O t omatis Oi recycling in lire-rich and line-poor ecosystems. The ... ria . - - - - :0 productivity oë many ecosystems depends on an input of nitrogen from the 11, ütrosphere, 22'ona surrounding ecosystems, or from the fertilizer bag, and may 12 clarified by field tracer studies with the stable isotope +?N. 1. Tricreasing uses ož tracers can be made, measuring net transfers of is elements, even without requiring a mathematical analysis of the kinetics of ! 15 i trene. Kinetic models will be useiul lor interpreting productivity data, 16 even without requiring isotope methods (Olson, 1964). In the long run, 17 howeve:, the combination of tracer methodology and mathematical models of is income and loss should be especially helpful in deepening our understanding 19.03 prcductivity budgets and processes in the diverse ecosystems which constitute 2C men's environment. - - - 25 BIBLIOGRAFHY Auerbaca, s. I. 1965. Badionuclide cycling: current status and future needs. Health Physics 11/12). _; Olson, J. S.; Waller, H. D. 1964. Landscape investigations using caesium-137. Natura 201 (4921): 761-764. Biđâulpa, o. 1955. Studies oi mineral nutrition by use of tracers. 3st. Reviews 21, p. 251-295. Bond, G. 1963. The root nodules oi non-leguminous angiosperras. Sym- posium of Soc. General Wicrobiol. XIII, Symbiotic Associations. Bormann, 3. 31.; Gracan, B. F. Jr. 1959. The occurrence of natural root grafting in easter: white pine, Pinus atrobus L. Ecology, 40, p. 677-691. Brown, ĉ. V. 154. Cesium in Liriodendron and other woody species: organic bonding sites. Science 143, p. 368-369. p. 150-180. Burton, G. W. 1957. Role of tracers in root developrent investi- gations. In: Atomic Energy and Agriculture. Am. Assoc. Adv. Sci. publ. 49, p. 71-80. Comer, C. I. 1953. Factors influencing the biological availability of allout radionuclides ior animals and men. Federation Exper. Siol. Proc. 22, p. 2402-1409. . Ealy, R. P. 1957. A technique for the introduction of radioactive solutions into woody sters of trees and shrubs. Okla. Agr. Expt. Sta. Tech. Bull. T-70. - ... . .. . ..... 259. Freser, D. A. 1956. The translocation of minerals in trees. Canada Porest Research Div., Tech. Note 47. · 1958. The translocation of rubidiumas and calcium in trees. In: I. V. Thimann, The physiology of forest trees, Ronald, Ney York. . ..-. - .. .. .. . osa ewidomienie piersindo mierni o Sand w - - - - . Prunus", ..; 200%, C. é. ſi overeni oz radioactive isotopes 2 yello:1 durcsa sza. Hats detected with a porteble cellation counter". J. Boi. 51, p. 324-333. Trec rikson, Lars. ec al. I... Brudes on pient accumulation of 2:3501. product wider r aisa corditons, I-III. Forsvarets Forskningsanstalt, sicekoulu, FA 4 Report- A-4187-4623, 4238-4623, 1239-4623. Frica, *. -937. veesure pranü nutrient supply of soils by radio- inctive -sotopes. Atom Desy and Agriculture: 1-18 (Amer. woe. Adv. Sci.). ; *zon, 7. 3.; Van Buvei, C. 2. m. 1968. Investigations with isotopes in soil-mumu relationships research. In: W. E. Caus, Radiation Biology and väicine. Garraga, K. S. 1933. Uptake ox phosphorus and calcium by apple trees airing the period of florescence. In: V. . Klechkovsky et al. szed atoms in the study of plant nutrition...USSR Acad. Sci. (ü. S. Atom. Energy Comm. trans1. AEC-tr-3376 Biol. and Medicine: 120-227). Fanson, W. C.; Primer, H. 3. 1965. Seasonal cycle of +'Cs in some Alaskan natives and meals. Health Physics 11/12). Hevesy, 6. de. 1947. Interaction between the phosphorus atoms of wheat seedlings and the nutrient solution. Ark. Bot. (Stockholm) A 33 (2). Hungate, Frank. 1965. Symposium on Radiation in Terrestrial Ecosystems. Health Physics 11/12). Jansson, S. L. 1958. Tracer studies on nitrogen transiormations in soil with special attention to mineralization-immobilization relations. Kungl. Lantbrukshogskol. Ann. 58, 101-361. T- 27 Klecekovaky, V. X., ed. 1957. On the behavior or radioactive fission · producus in soil, their sisorption by plants and their accumulation 99s. Acad. Sci. USSR. (U. S. AEC transl. AEC-TR2867). Kuntz, ū. E.; Riker, A. J. 1955. The use of radioactive isotopes to ascertain the role of root grafting in the translocation of water, moovmients, and disease-inducing organisms among forest trees. 7.02. int. Cont. Pescerul Uses Atomic Energy 12, p. 144-148. KursuCv, A. I. 1955. Analysis oï the movement of substances in plants - ceans of radioactive isotopes. Proc. Int. Conf. Peaceful Uses oric mnergy 12, 365-169. menek, K.; Svensson, G. K. 1955. The transport of +37cs from lichen to animal and men. Hea 1-1 Paysics 11(12). come , G. .; Vochanova, I. V.; Subbotina, E. N.; Timofeev-Resovskii, . 7.; Teilyasove, A. A.; Iyuryukertov, A. N. 1961. The experi- mental investigation oỉ the distribution of isotopes in natural biogeocoenoses. Acad. Sci. USSR, Bot. Sect. 133, p._141-143. bertin, W. 2. 1953. Loss of I+S+ Iron fallout-contaminated vegetation. Zealt. Physics 9: 2141-2148. _· 1965. Interception and retention of fallout by desert shrubs. Healt. Physics 11/12). . menzel, R. G. 1955. Soil-plant relationships of radioactive elements. Health Physics 21(12). Neel, R. 3.; Olson, J. S. 1962. Use of analog computers for simulating the movement of isotopes in ecological systems. Oak Ridge National Laboratory Report ORNL-3172. 3 1 '. ce Olson, J. S. 1963a. Analog computer models for moveme:it of nuclides through ecosystens. In: V. Schultz and A. W. Klement Jr. Rad::cecology, Reinhold, New York, y. 121-125. - 9530. Energy storage and the balance of producers and de- comosers in ecological . items. Ecology 44: 322-331. _- :964. Gross and net duction of terrestrial vegetation. J::c01. 52(Suppl.), 2. -118. ..965. Equations ior transier in Liriodendron forest. ca.th Physics 11/12). C:'ossley, D. A. Jr. 190... Tracer studies of the breakdown oi Torist litter. In: V. Sezultz and A. W. Klement Jr. Radio- ecology. Reinhold, NY, p. 411-416.. Cvington, J. D. 1962. Quantitative ecology and the woodland eco- system concept. Adv. Ecol. Research 1, p. 103-192. - 1965. Organic production, turnover and mineral cycling in woodlazds. Biol. Reviews (in press). Picara, N. A.; Kirchmann, R.; Liara, O. et al. 1962. Observations by IT. trees by their aerial organs and roots. C. R. Rech. I.R.S.I.A. Postlethwait, S. N.; Rogers, 3. 1.958. Tracing the path of the trans- piration stream in trees by the use of radioactive isotopes, Amer. J. Bot. 45, p. 753-757. Reichle, D. E.; Crossley, D. A. Jr. 1965. Radiocesium dispersion in a cryptozoan food web. Health Physics 11(12). *-* ***..************ 29 Rubin, S. S.; Moiseichenko, V. F. 1963. Distribution of nutrients in Truit trees during isolated nutrition of individual roots. Vestn. s. -kh. Nauki No. 8, 211-217. (Russian). . Russell, R. S. 1965. Interception and retention of airborne material on plants. Health Physics 11/12). Semulz, R. 1958. Soil chemistry of radionuclides. Health Physics 11/12). Schultz, V.; Klement, A. W. Jr. 1963. Radioecology. Proc. First Nat. Symposium, Sept. 1961. Reinhold, New York. Sheppard, C. W. 1962. Basic principles of the tracer method. John Wiley, New York. Sterlid, a. 1953. Salt losses and redistribution of salts in higher plants. Encycl. Plt. Physiol. 4, p. 615-637. Stevenso.., Greta, 1958. Use si ns in the study of fixation of atmos- peric nitrogen by non-nodulated seed plants. Proc. 2nd Internat. Coni. Peaceful Uses of Atomic Energy. vol. 27, p. 51-57. Stout, P. R.; Hoagland, D. R. 1939. Upward and lateral movement of selt in certain plants as indicated by radioactive isotopes of pot- assium, sodium and phosphorus absorbed by roots. Amer. J. Bot. 26, p. 320-324. ; Cverstreet, Roy; Jacobson, Louis; Ulrich, Albert. 1947. The use ož radioactive tracers in plant nutrition studies. Soil Sci. Soc. Amer. Proc. 12, p. 91-97. Tercura, T. 1953. Selective ion exchange reactions for cesium and strontium by soil minerals. Proc. Internat. Conf. on Retention and Migration of Redionuclides through Soils, Presse Universite de France, Paris, p. 95-104. cerS Liu 30 1954. Selective sorption reactions of cesium with soil minerals. 444 Nuclear Safety 5, p. 262-268. · 1965. Selective sorption reactions of strontium. Nuclear Safety 6(4). mukey, m. B. Jr.; Amling, H. J. 1958. Leaching of foliage by rain and dew as an explanation of differences in the nutrient composition of geen ouse- and field-grown plants. Mich. Agr. Expt. Sta. Quart. Bull. 40(4), p. 876-881. udall, S. Io; Holway, R. T.; Thimann, K. V.; Brinkley, P. C.; Egler, F. E. 2954. The pesticide problem. Bioscience 14(11), p. 17-39. United Nations. 1964. U. N. Scientific Committee on the Effects of Atomic Radiation. U. N. General Assemoly, 19th Session Suppl. 24 (A/5814). Vlasyuk, P. A.; Manorik, A. V. 1957. The uptake of radioactive 52P, ss and t*c by plants from organic and mineral forms of their compounds. Byulm. Fiziol. Rast. 1, 20.-23 (Russian). Walker, J. M.; Barber, S. 4. 1961. Ion uptake by living plant roots. Science 133, 881-882. Walier, 7. D.; Olson, J. S. 1954. Prompt transfer of cesium-137 to the forest floor and soil of a tagged tulip poplar forest. Manuscript. Abstract, Health Physics 10, 620-621. Witherspoon, J. P. 1964. Cycling or cesium-134 in white oak trees. Ecol. Monogr. 34, p. 403-420. . Witkany, M.; Frank, M. L. 1964. First year movement, distribution and availability oí Cs-37 in the forest floor under tagged tulip pop.lars. Radiation Botany 4:' 485-495. Woods, 7. W.; Brock, K. 1964. Interspecific transfer of 45ca and 32 by root systems. Ecology 15: 886-889. C - - - . - ORNL - AEC - OFFICIAL Table 1. Casting Activity to Dogvood Bajected with mixed Lootopen, was more Distance frog sourco lom) 30 minutes after tagging lower trunk branches Lover crown branches upper crown branchen 33,994 3 hours after tapping branches from Lour torles 115 110 140 210 top of tree selected top branchlet 330-480 480 2,697 18, 301 4,193 22 hours after tagging top of tree 330-480 selected top branchlet 480 * No activity detectable above background. Total activity 10 ] KCI (PAL). Ca. 2.18 mes : Br 0.79.mcs hex 4.0 mc. . ORNL - AEC - OFFICIAL Table 2. Diocriadnation Between dr and ca in novering Dogvood Froos (Cornus florida L.) Laput to Output into tres bols tres leaves Muellda HAL-N More on July? Aprut 26 Elliourios dipin per ns of leaves in tas (composite samples corrected for decay) 1 . 55 days 0.79 57 1. ba • , 208" 155 days 2.18 0.362 374 0.153 2080 0.193 Rato 88/45 ca . . Table 3. Coustent coefficient model for - cesium transfer during first summer in Liriodendron forest: proportion PA (per day) of cesium remaining in part j that moves to part k. __k = *ceiving Compartment Cuma 0 0. "Source" Leaves Bed Roots Undercover Littermat Soil i "Source" .954 2 Leaves .028€ .9555 .Cose .000056 .00035 .CC52 .com .915 .007 3 Dars .0058 .0158 .99 socis ..0039 5 Endercover .98 .02 .98 6 litterat W .020 7. Soil .0001 00001 .99989 ), anajusted primarily for fitting increase and decrease in foliage activity. Derived from undercover sampling in August. CDerived from Jilly sampling, small boxes, and lear fall. adjusted to make soil samples (July and October) account for appropriate practicas or theoretical soil and root activity. Diagonal terms are adjusted to equal (1 - non-diagonal terms in same row), i.e. the proportions assured to remain in the same compartments each day. 2.SS. O, I. Á ac:: 2703suna O r essure are used to hasten movement or .; tracer mixture froza ireon tuoing into a pipe threaded in cole of aurering cos ocā uzca (Coraus_florida). 10. 2. edistribution 03 C 12 ite oak (Quercus alba) based on an average I trees on fees ngów only for soil), Irom Witherspoon, 1964. ;3. Preparation comme uno o trouxins 20tazying culin tree (Liriodenäron white 020.st. Wanable permasum sipe-sealing compcuna 100 zornbü into ü 30 Cond plastic tape over smoothed barks, ana che serveä sy cience 2011 and wire. 3. Water was poured into som mnie civilis zene seize mede every 5 cm around the tree, 13?cc . co 120 ke . Cei locked by air intil the was re- ...me me me. cl C minion Woon - .13? ( wydü om tze leuü incelë end goured in, and followed by rinse jim Wä с. . : w 7,79 e Ovo . aga siial rise in 10lage activity (casted line) followed by usc.ea - 'C's contenu throuzout the summer of 1962, 1963, and 1964. 3. Somery or movement of 15 Cs from Lirodendron tree canopy in 1962, and income to the soil by main alling leaves, and especially by corsiarü movezeni inough the cole to fine roots, which in turn release C's to the soul. (waller anë 02:00). 6. Computer sciation oz alcs movenient our oí tree wood (compartment 2) io polieve 2.2), bars and zoots understory (200. 5), litter (0.5) .3. soil (nie. ?), assuming constant coefricients given in cui le 3 !Cissa, 1907. 0 CI ne- . 7. HVO 300 cc ciis2275.. von Succa Liz'iodenáron leaves outside the * 20 x 25 meter ploü ...963 (Olson and Waller). YEALTH PHYSICS PROGRESS REPORT .. - UNCLASSIFIED .. PHOTO 49205 - . TIMU UP - . 2 . !.. 1 11 2 - i . - . * ! . I . 1 1 :14 E SU . >> . . 1 . . . D . . . . X " - 1 . . . N PS . VI. ..* N 11191 - . . . 12 17 . L. . " ! 2 t. 1.1 11 EC mic, SNC . Wor . - R90 VD YURI . E 111 - Xit - . 29 . - 11 NYX Truth INUITY NE - S . . .1111 . ..11 N . + 1 ! NR . . : 10 . A B 4 . ET . . . . . ? 11. 21 # . . 15 . . . . .. . 1 . 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OCT ORNL-DWG 64-4797AR FOLIAGE LATE JUNE 53% SEPT 249 REDUCTION ( 26%) LEAFDROP -~OCTOBER PRE-OCTOBER 49 RAINOUT 3.6 9.0 12.6 (5%) TOTAL (SURFACE) 52.6 33.0 85.6 24 73(29%) i RETURN TO WOODY TISSUE 8 $ 0.6 STEM FLOW 12 THROUGHFALL 57 w16 OUT OF AREA. TOTAL TRANSFER = 85 wyz OF MAX CANOPY | CONTENT INPUT 934 w6k1% REMAINED) 826 views 0.5 (4% THROUGHFALL) GROUND COVER VEGETATION 11.5 57 . ORGANIC FOREST FLOOR ~68 LITTER (ORGANIC) LAYER > >351 ROOT CONTRIBUTIOI MINERAL SOIL 130cm . OCT 1962 UNITS IN uc/m? AREA OF FOREST FLOOR N 10 ORNL-DWG 64-7914 CONTROL 9.0 15.0 17.0 2.0 l/ .0 0. 5604 0,5 11 2.0 20 X 25 m 137CS TAGGED FOREST PLOT CONTROL CONTROL S40 W 20 W 45 W 10W 5 10 15 20 25 E5 E 40 E 45 E 20 0 /31/66 DATE FILMED END Dimidiw. das in die V isiert:W !**.! Ook dia..'... , pinkovit irisind....63.6.,vchipowniki.!.! Sre i wody is V ri . WWW. YS AN m .