RESEARCH

Cellulose Isotope Ratios as a Proxy to Ecophysiological and Paleoclimate Record

It's well known that the hydrogen and oxygen isotope ratios of precipitation correlate with climate and global circulation patterns. In general the pattern is that the higher the ambient temperature the higher the oxygen-18 and deuterium abundance of the precipitation. The oxygen and hydrogen isotope ratios of tree ring cellulose are ultimately derived from the oxygen and hydrogen isotope ratios of plant available water which is closely correlated with that of precipitation. If cellulose is well preserved, then it holds great potential as a proxy for paleoclimate. Dr. Hope Jahren's (University of Hawaii) laboratory and mine have analyzed tree ring cellulose from samples in an arctic island approximately 50 million years old with some interesting results. The isotopic signal of cellulose, however, is a mixed signal and the challenge is to disentangle these signals. Dr. William Anderson's (Florida International University ) laboratory and mine have developed a new technique towards this end. We observed a much better correlation between the oxygen isotope ratio cellulose modified by eliminating the oxygen attached to the second carbon and the plant source water. The figure to the left illustrates the process of deriving the cellulose. First it is hydrolyzed to the glucose moieties, then the glucose reacts with phenylhydrazine to form phenyl-glucosazone a molecule having all the oxygens of the glucose moieties minus the ones attached to the first and second carbon. In addition to biochemical reactions adding "noise" to the source water isotopic signal, there are also physiological processes which can disturb the source water isotopic signal in the cellulose molecule. Namely, the processes occurring at the leaf level, which modifies the isotopic composition of leaf water. We are also studying this aspect of interference in the recording of the isotopic composition of source water in the plant stem cellulose.

Several different plant communities are found in South Florida: pinelands, hammocks, tree islands, mangroves and several others. My laboratory has done considerable research on the ecophysiology of plants from several of these plant communities. We have, for example, observed that hardwood hammocks in the Florida Keys can be sustained in a small freshwater lens above highly saline ocean water. A similar dynamics has also been observed in the mainland hardwood hammocks. Trees in these hammocks will preferentially use surface litter water during the wet season, whereas pineland trees tend to tap on the water table pretty much all year round. Another important ecosystem issue in South Florida is the presence of invasive exotics such as Brazilian Pepper, Australian Pine and several others. Sharon Ewe my previous graduate student has researched the physiology of Schinus terebinthifolius (Brazilian pepper) in comparison with freshwater plants and mangroves. She found that Schinus seems to have greater saline tolerance and physiological aspects similar to some mangrove species. This in part may explain why it is often found in the ecotones between hammocks and mangroves. Yet another important and surprising aspect related to urban expansion in South Florida is the issue of water. One may think that with the abundant water supply, water issues will not limit urban expansion. In fact, ecosystems such as those found in the Everglades require an abundant water supply to maintain them. Dr.Helena Solo's laboratory in conjunction with my laboratory used stable isotope tracers to determine whether wellfields at the edge of the Everglades National Park are indeed tapping water from the Everglades.

Water Relations of Tropical Ecosystems

Much of the rainfall in the Amazon basin is recycled; i.e. precipitation is evapo-transpired back to theatmosphere where it's re-precipitated. Crucial to conservation issues is whether the primary conduit of vapor from the forest to the atmosphere is via transpiration or evaporation. Obviously, if it's transpiration, loss of forested areas can have significant impact on climate. Using stable isotope techniques we were able to trace the source of vapor and observed that 70 to 100% of the vapor generated by the forest is via transpiration. The uptake of water by tropical tree roots is also a subject of interest in my laboratory, especially under the possibility of severe dry season brought about by climate change.The coexistence of woody species and grasses in savannas is thought to be possible because these two growth forms exploit different soil compartments for moisture. Grasses exploit the shallower layers of the soil profile and are dormant during the dry season, whereas woody species exploit the deeper layers of the soil profile and remain active during the dry season. See the figure to the left for a typical example of the Brazilian savanna known as the cerrado. In Amazonian abandoned pastures, which resemble savannas, we observed the opposite. Colonizer woody species actually seem to be acquiring water from shallower layers of the soil profile compared to grasses. Another factor which may complicate this two compartment system is hydraulic lift. Hydraulic lift is the redistribution of water in the soil profile through the plant root system. We have observed hydraulic lift for two species commonly found in the Brazilian savanna (cerrado), but need to determine its actual importance in the ecosystem water budget.

PEOPLE

Current

Leah Colucci Laboratory Technician

Lu Zhai Graduate Student

Alumni

LABORATORY OF STABLE ISOTOPE ECOLOGY IN TROPICAL ECOSYSTEMS

Water distillation line.Cryogenic distillation of water from soil and plant samples can be done on either side of this vacuum system. For large samples we use the right side of the line. Small samples are distilled on the left side. Up to 24 small samples and up to 12 large samples can be distilled in one day.	GV Isoprime Isotope Ratio Mass Spectrometers. We have two GV stable isotope mass spectrometers capable of analyzing carbon, oxygen, hydrogen, nitrogen and sulfur isotope ratios.
Eurovector. One of the GV isoprimes hooked in tandem with a Eurovector to analyze carbon and nitrogen isotope ratios of organic matter. This system can also be fitted with a chromium pyrolysis system for very accurate hydrogen isotope ratios of water samples.	Multiflow. The second GV isoprime is hooked in tandem with a multiflow system capable of analyzing oxygen and hydrogen isotope ratios of water by equilbration. This system can be modified to run breath and atmospheric carbon dioxide samples. .

Sample Submission and Price Schedule

See The New Method of Stem, Leaf and Soil Water Extraction

PUBLICATIONS

Weremijewicz, Joanna; Sternberg, Leonel da Silveira Lobo O'Reilly; Janos, David P.
Common mycorrhizal networks amplify competition by preferential mineral nutrient allocation to large host plants
New Phytologist 212(2): 461 - 471 (2016)

Larcher, Leticia; Boeger, Maria Regina Torres; Sternberg, Leonel da Silveira Lobo O'Reilly
Gas exchange and isotopic signature of mangrove species in Southern Brazil
Aquatic Botany 133: 62-69 (2016)

Lisboa Cohen, Marcelo Cancela; Lara, Ruben Jose; Cuevas, Elvira; et al.
Effects of sea-level rise and climatic changes on mangroves from southwestern littoral of Puerto Rico during the middle and late Holocene
Catena 143: 187-200 (2016)

Lee, Hyejung; Feakins, Sarah J.; Sternberg, Leonel da S. L.
Carbon and hydrogen isotopic effects of stomatal density in Arabidopsis thaliana
Geochimica et Cosmochimica Acta 179: 275-286 (2016)

Ellsworth, Patrick Z.; Sternberg, Leonel S. L.
Strategies in nitrogen uptake and use by deciduous and evergreen woody species in a seasonally dry sandhill community
Plant and Soil 400: 165-175 (2016)

Moser, Jonathan G.; Oberbauer, Steven F.; Sternberg, Leonel Da S. L.; et al.
Water uptake of Alaskan tundra evergreens during the winter-spring transition
American Journal of Botany 103(2): 298-306 (2016)

Zhai, Lu; Jiang, Jiang; DeAngelis, Donald; et al.
Prediction of Plant Vulnerability to Salinity Increase in a Coastal Ecosystem by Stable Isotope Composition (delta O-18) of Plant Stem Water: A Model Study
Ecosystems 19(1): 32-49 (2016)

Jiang, Jiang; Fuller, Douglas O.; Teh, Su Yean; et al.
Bistability of mangrove forests and competition with freshwater plants
Agricultural and Forest Meteorology 213: 283-290 (2015)

Saha S, Sadle J, Van Der Heiden C, Sternberg, L
Salinity, groundwater, and water uptake depth of plants in coastal uplands of Everglades National Park (Florida, USA).
Ecohydrology 8:128-136 (2014).

Larcher L, Hara-Nishimura I, Sternberg L.
Effects of stomatal density and leaf water content on the 18 O enrichment of leaf water.
New Phytologist 206: 141-151 (2015).

Ellsworth P, Sternberg, LSL.
Seasonal water use by deciduous and evergreen woody species in a scrub community is based on water availability and root distribution.
Ecohydrology 8(4):548-551 (2015).

Lee H, Feakins SJ, Sternberg LO.
Stomatal density influences leaf water and leaf wax D/H values in Arabidopsis.
AGU Fall Meeting Abstracts 1: 1349 (2014).

Jiang J, Fuller DO, Teh SY, Zhai L, Koh HL, DeAngelis DL, Sternberg LSL.
Bistability of mangrove forests and competition with freshwater plants.
Agricultural and Forest Meteorology 213: 283-290 (2014).

Sternberg LSL.
Comment on "oxygen isotope rations (18 O/16 O) of hemicellulose-derived sugar biomarkers in plants, soils and sediments as paleoclimate proxy I: Insight from a climate chambr experiment” by Zech et al (2014).
Geochimica et Cosmochimica Acta 141: 677-679 (2014).

Sternberg LSL, Manganiello LM.
Stomatal pore size and density in mangrove leaves and artificial leaves: effects on leaf water isotopic enrichment during transpiration.
Functional Plant Biology 41: 648-658 (2014).

Rossatto DR, Silva LCR, Sternberg LSL, Franco AC.
Do woody and herbaceous species compete for soil water across topographic gradients? Evidence for niche partitioning in a Neotropical savanna.
South African Journal of Botany 91: 14-18 (2014).

Feakins SJ, Ellsworth PV, Sternberg LSL. Lignin methoxyl hydrogen isotope ratios in a coastal ecosystem. Geochimica et Cosmo 121: 54-66 (2013).

Govender Y, Cuevas E, Sternberg LDS, Jury MR. Temporal variation in stable isotopic composition of rainfall and groundwater in a tropical dry forest in the northeastern Caribbean. Earth Interactions 17: 1-20 (2013).

Rosado BHP, Mattos EA, Sternberg LSL. Are leaf physiological traits related to leaf waters isotopic enrichment in restinga woody species? Anaid de Academia Brasileira de Ciências 85: 1035-1046 (2013).

Sternberg L, Silva CR, Dávolos P. Shrimp farming: where does the carbon go? Central European Geology 56: 13-18 (2013).

Ellsworth P, Sternberg LO. Adjustments in the effective leaf mixing length of the water pathway in pinnate leaves with partially severed veins. AGU Fall Meting Abstracts 1: 504 (2012).

Ellsworth P, Sternberg LO. Root productivity of deciduous and evergreen species identified using a molecular approach. AGU Fall Meeting Abstracts 1: 1542 (2012).

Govender Y, Munoz MC, Ramirez Camejo LA, Puente-Rolon AR, Cuevas E, Sternberg L. An isotopic study of diet and muscles of the green iguana (Iguana iguana) in Puerto Rico. Journal of Herpetology 46: 167-170 (2012).

Rossatto DR, Silva LCR, Villalobos-Vega R, Sternberg LSL, Franco AC. Depth of water intake in woody plants relates to groundwater level and vegetation structure along a topographic gradient in a neotropical savanna. Environmental and Experimental Botany 77: 259-266 (2012).

Schubert B, Jahren H, Eberle J, Sternberg LO, Ellsworth P, Eberth D, Sweet A. The best modern analog for Eocene artic forests is within today’s Korean peninsula. AGU Fall Meeting Abstracts 1: 4 (2011).

Sternberg L, Ellsworth PFV. Divergent biochemical fractionation, not convergent temperature, explains cellulose oxygen isotope enrichment across latitudes. PLoS ONE 6: 1-7 (2011).

Wilson A C C, Sternberg L S L, Hurley K B. Aphids alter host plant nitrogen isotope fractionation. Proceedings of the National Academy 108: 10220-10224 (2011).

Oikawa P Y, Giebel B M, Sternberg L S L O, Li L, Timko M P, Swart P K, Riemer D D, Mak J E, Lerdau M T. Leaf and root pectin methylesterase activity and 13C/12C stable isotopic ratio measurements of methanol emissions give insight into methanol production in Lycopersicon esculentum. New Phytologist 191: 1031-1040 (2011).

Saha A, Saha S, Sadle J, Jiang J, Ross S M, Price R M, Sternberg L S L O, Wendelberger K S. Sea level rise and South Florida coastal forests. Climate Change 107: 81-108 (2011).

Wang X, Fuller D O, Sternberg L S L O, Miralles-Wilhelm. Foliar nutrient and water content in subtropical tree islands: a new chemohydrodynamic link between satellite vegetation indices and folia 15N values. Remote Sensing of Environment 115: 923-930 (2011).

Wang X., Sternberg L. O., Ross M. S., Engel V. C. Linking water use and nutrient accumulation in tree island upland hammock plant communities in the Everglades National Park, USA. Biogeochemistry 104: 133-146 (2011).

Sun J., Oncley P., Burns SP, Stephens BB, Lenschow DH, Campos T, Monson RK, Schimel DS, Sacks WJ, De Wekker SFJ, Lai C-T, Lamb B, Ojima D, Ellsworth PZ, Sternberg LSL, Zhong S, Clements C, Moore DJP, Anderson DE, Watt AS, Hu J, Tschudi M, Aulenbach S, Allwine E, Coons T. A multiscale and multidisciplinary investigation of ecosystem-atmosphere CO2 exchange over the rocky mountains of Colorado. Bulletin of the American Meteorological Society 91: 209-230. (2010).

Silva LC, M Haridasan, L da SL Sternberg, A Franco, WA Hoffmann. Not all forests are expanding over central Brazilian savannas. Plant and Soil 333: 431-442 (2010).

Silva LC, L. da S. L. Sternberg, R F Haidar, GD do Vale. Deciphering earth mound origins in central Brazil. Plant and Soil 336: 3-14 (2010).

Saha, KS, L da SL Sternberg, MS Ross, F Miralles-Wilhelm. Water source utilization and foliar nutrient status differs between upland and flooded plant communities in wetland tree islands. Wetland Ecology and Management: 18:343-355, doi 10.1007/s11273-010-9175-1 (2010).

Greaver, TL and Sternberg LSL. Decreased precipitation exacerbates the effects of sea level on coastal sand dunes. Global Change Biology 16: 1860-1869, doi:10.1111/j.1365-2468.2010.02168 (2010).

Kosten, Sarian, Roland, Fábio, Da Motta Marques, David M.L., Van Nes, Egbert H., Mazzeo, Néstor, Da S. L. Sternberg, Leonel, Scheffer, Marten, Cole, Jon J. Climate-dependent CO2 emissions from lakes. Global Biogeochemical Cycles 24:GB2007, doi10.1029/2009GB003618 (2010).

Matlaga, D., L. da S.L. Sternberg. Ephemeral clonal integration in Calathea marantifolia (Marantaceae): Evidence of diminished integration over time. American Journal of Botany 96: 431-438 (2009).

Jahren AH, Byrne MC, Graham HV, Sternberg LSL, Summons RE. The environmental water of the middle Eocene Arctic: evidence from D, 18O and 13C within specific compounds. Palaeo-3 271: 96-103 (2009).

Sternberg L da SL. Oxygen stable isotope ratios of tree-ring cellulose: the next phase of understanding. New Phytologist 181: 553-562 (2009). 

Saha AK, Sternberg LdaSL, Miralles-Wilhelm F. Linking water sources with foliar nutrient status in upland communities in the Everglades National Park, USA. Ecohydrology 2:42-54 (2009).

Kosten S, Huszar VLM, Mazzeo N, Scheffer M, Sternberg L da SL, Jeppesen E. Limitation of phytoplankton growth in South America: no evidence for increasing nitrogen limitation towards the tropics. Ecological Applications 19: 1791-1804 (2009).

Silva LC, Sternberg L, Haridasan M, Hoffmann WA, Miralles-Wilhelm F, Franco AC. Expansion of gallery forests into central Brazilian savannas. Global Change Biology 14: 1-11. (2008).

The SY, DeAngelis DL, Sternberg L da SL, Miralles-Wilhelm FR, Smith TJ, Koh H-L. A simulation model for projecting changes in salinity concentrations and species dominance in coastal margin habitats of the Everglades. Ecological Modelling 213: 245-256 (2008)

Jahren AH, Sternberg L da SL. Annual patterns within tree rings of the Arctic Middle Eocene (~45 Ma): Isotopic signatures of precipitation, relative humidity, and deciduousness. Geology 36: 99-102. 2008.

Sternberg L da SL, Pinzon MC, Vendramini PF, Anderson WT, Jahren AH, Beuning K. Oxygen isotope ratios of cellulose-derived phenylglucosazone: an improved paleoclimate indicator of environmental water and relative humidity. Geochimica Cosmochimica Acta 71: 2463-2473. 2007.

Ewe SML, Sternberg L da SL, Childers DL. Seasonal water uptake patterns in the saline southeast Everglades ecotone. Oecologia 152: 607-616. 2007. 

Sternberg L da SL, The SY, Ewe SML, Miralles-Wilhelm F, DeAngelis DL. Competition between hardwood hammocks and mangroves. Ecosystems 10: 648-660. 2007.

Greaver TL, Sternberg L da SL. Fluctuating deposition of ocean water drives plant function on coastal sand dunes. Global Change Biology 13: 216-223. 2007.

Vendramini PF, Sternberg L da SL. A faster plant stem-water extraction method. Rapid Communications in Mass Spectrometry. 21:164-168. 2007.

Sternberg L da SL, Pinzon MC, Moutinho P, Rojas E and Herre A. Plants use macro-nutrients accumulated in leaf-cutting ant nests. Proceedings of the Royal Society: Biological Sciences. 274:315-321. 2007.

Ewe S.M.L. and Sternberg L. da S.L. Water utilization patterns of the invasive exotic Schinus terebinthifolius contrasted against native species in two coastal plant communities. Journal of Coastal Research. 23:255-264. 2007.

Lin YM, Liu JW, Xiang P, Lin P, Ye GF and Sternberg L da SL. Tannin dynamics of propagules and leaves of Kandelia candel and Bruguiera gymnorrhiza in the Jiulong River Estuary, Fujian, China. Biogeochemistry 78: 343-359. 2006.

Greaver TL and Sternberg L da SL. Linking marine resources to ecotonal shifts of water uptake by terrestrial dune vegetation. Ecology 87: 2389-2396. 2006. PDF

Sternberg L da SL, Pinzon MC, Anderson W, Jahren. Variation in oxygen isotopic fractionation during cellulose synthesis: intramolecular and biosynthetic effects. Plant Cell and Environment 29: 1881-1889. 2006.

Anderson WT, Sternberg L da SL, Pinzon MC, Gann-Troxler T, Childers DL, Duever M. Carbon isotopic composition of cypress trees from South Florida and changing hydrological conditions. Dendrochronologia 23: 1-10. 2005.

Sternberg L. da S. L., Bucci S., Franco A., Goldstein G., Hoffman W., Meinzer F. C., Moreira M. Z. and Scholz F. Long range lateral root activity by neo-tropical savanna trees. Plant and Soil 270: 169-178. 2005.

Romero-Saltos H., Sternberg L da S. L., Moreira M. Z. and Nepstad D. C. Rainfall exclusion in an Eastern Amazonian forest alters soil water movement and depth of water uptake. American Journal of Botany 93: 443-455. 2005.

Medina E., Francisco M., Sternberg L. and Anderson W.T. Isotopic signatures of organic matter in sediments of the continental shelf facing the Orinoco Delta: Possible contribution of organic carbon from savannas. Estuarine Coastal and Shelf Science 63: 527-536. 2005.

Ewe S.M.L. and Sternberg L. da S.L. Growth and gas exchange responses of Brazilian pepper (Schinus terebinthifolius) and South Florida species salininity. Trees 19:119-128. 2005.

Greaver T., Sternberg L da S. L., Schaffer B., Moreno T. An empirical method of measuring CO2 recycling by isotopic enrichment of respired CO2. Agricultural and Forest Meteorology 128: 67-79. 2005.

Wilcox W. M., Solo H. M. and Sternberg L. da S. L. Use of stable isotopes to quantify flows between the Everglades and urban areas in Miami-Dade County Florida. Journal of Hydrology 293: 1-19. 2004.

Rodicio L. P., Sternberg L. da S.L. and Walsh P. Metabolic faith of exogenous 15NH4Cl in the gulf toadfish (Opsanus beta). Comparative Biochemistry and Physiology Part C 136: 157-164. 2003.

Sternberg L. da S. L., Anderson W. T., Morrison K. Separating soil and leaf water 18O isotopic signals in plant stem cellulose. Geochimica Cosmochimica Acta 67: 2561-2566. 2003.

Williams K., Macdonald M. and Sternberg L da S. L. Interactions of storm, drought, and sea-level rise on coastal forest: a case study. Journal of Coastal Research 19: 1116-1121. 2003.

Moreira M. Z., Scholz F. G., Bucci S. J., Sternberg L da S. L., Goldstein G., Meinzer F. C., Franco A.C. Hydraulic lift in a neotropical savanna. Functional Ecology 17: 573-581. 2003.

Bucci S. J., Scholz F. G., Goldstein G., Meinzer F.C., Sternberg L da S. L. Dynamic changes in hydraulic conductivity in petioles of two savanna tree species: factors and mechanisms contributing to the refilling of embolized vessels. Plant Cell and Environment 26: 1633-1645. 2003.

Jahren A. H., Sternberg L. da S. L. Humidity estimate for the middle Eocene Arctic rain forest. Geology 31: 463-466. 2003.

Nassar, J.M., Beck, H., Sternberg, L da S.L. and Fleming, T.H. Dependence on cacti and agaves in nectar-feeding bats from Venezuelan arid Zones. Journal of Mammology 84: 106-116. 2003.

Onour, M., Sternberg, L. da S.L., Rodicio, L. P. and Walsh, P. Direct effects of ambient ammonia on the nitrogen isotope ratios of fish tissues. Journal of Experimental Marine Biology and Ecology 282: 61-66. 2003.

Ewe, S. M. L. and Sternberg L. da S. L. Seasonal gas exchange characteristics of Schinus terebinthifolius in a native and disturbed upland community in Everglades National Park, Florida. Forest Ecology and Management 179: 27-36. 2003.

Ewe, S. M. L. and Sternberg L. da S.L. Seasonal water-use by the invasive exotic, Shinus terebinthifolius, in native and disturbed communities. Oecologia 133: 441-448. 2002.

Sternberg, L da S.L. and DeAngelis, D. Carbon isotope composition of ambient CO2 and recycling: a matrix simulation model. Ecological Modelling 154: 179-192. 2002.

Jahren, H. and Sternberg, L. da S.L. Eocene Meridional Weather Patterns Reflected in the Oxygen Isotopes of Arctic Fossil Wood. Geophysical Society of America Today 12: 4-9. 2002.

Nepstad D.C., Moutinho P., Dias-Filho M.B., Davidson E., Cardinot G., Markewitz D., Figueiredo R., Vianna N., Lefebvre P., Chambers J., Sternberg L., Moreira M., Guerreiros J.B., Barros L., Ishida F.Y., Belk E. and Schwalbe K. The effects of rainfall exclusion on canopy processes and biogeochemistry of an Amazon forest. Journal of Geophysical Research 107: 1-18. 2002.

Sternberg L. da S.L, Moreira M. Z. and Nepstad D. Uptake of water by lateral roots of small trees and saplings in an Amazonian tropical forest. Plant and Soil 238:151-158. 2002.

Sternberg L. da S.L. Savanna-forest hysteresis in the tropics. Global Ecology and Biogeography 10: 369-378. 2001.

Moreira M., Sternberg L da SL, Nepstad D. Vertical patterns of soil water uptake by plants in a primary forest and an abandoned pasture in the Eastern Amazon: an isotopic approach. Plant and Soil 222: 95-107. 2000.

Yakir, D., Sternberg L da S.L. The use of stable isotopes to study ecosystem gas exchange. Oecologia 123:297-311. 2000.

Horvitz C. C., Sternberg L da S.L. 14C dating of tree falls on Barro Colorado Island (Panama): a new method to study tropical rain forest gap dynamics. Journal of Tropical Ecology 15: 723 - 735. 1999.

Ewe S.M.L., Sternberg L.da. S.L., Busch D.E. Water use patterns of woody species in Pineland and Hammock communities of South Florida. Forest Ecology and Management 118:139-148. 1999.

Sternberg L da SL, Moreira, MZ, Martinelli, LA, Victória RL, Barbosa EM, and Nepstad DC. Root distribution in an Amazonian seasonal forest as derived from ?13C profiles. Plant and Soil 205: 45-50. 1998.

Sternberg L da SL, Moreira, MZ, Martinelli, LA, Victória RL, Barbosa EM, Bonates LCM and Nepstad DC. The relationship between 18O/16O and 13C/12C ratios of ambient CO2 in two Amazonian tropical forests. Tellus 50B:366-376. 1998.

Martinelli LA, Almeida S, Brown IF, Moreira MZ, Victoria RL, Sternberg LSL, Ferreira CAC and Thomas WW. Stable carbon isotope ratio of tree leaves, boles and fine litter in a tropical forest in Rondonia, Brazil. Oecologia 114:170-179. 1998.

Herrera LG, Fleming TH, Sternberg LS. Trophic relationships in a neotropical bat community: a preliminary study using carbon and nitrogen isotopic signatures. Tropical Ecology 39:23-29. 1998.

Sternberg L da SL, Moreira, MZ, Martinelli, LA, Victoria RL, Barbosa EM, Bonates LCM and Nepstad DC. A comparison of carbon dioxide recycling between two Amazonian tropical forests. Journal of Agricultural and Forest Meteorology 88:259-268. 1997.

Sternberg, L. da S.L. Interpretation of recycling indices. [A comment on 'Vegetation effects on the isotopic composition of atmospheric CO2 at local and regional scales' by Jon Lloyd et al.] Aust. J. Plant Physiol. 24:395-398. 1997.

Moreira MZ, Sternberg L, Martinelli LA, Victoria RL, Barbosa EM, Bonates LCM, Nepstad DC.Contribution of transpiration to forest ambient vapor based on isotopic measurements. Global Change Biology. 3:439-450. 1997.

Goldstein G, Meinzer FC, Sternberg L da SL, Jackson P, Cavelier J, Holbrook NM. Evaluating aspects of water economy and photosynthetic performance with stable isotopes from water and organic matter.In: Mulkey SS, Chazdon RL, Smith AP editors. Tropical forest plant ecophysiology. 1996 Chapman Hall.

Martinelli LA, Victoria RL, Ribeiro A, Moreira MZ, Sternberg L da SL. Using stable isotopes to determine sources of evaporated water to the atmosphere in the Amazon basin. Journal of Hydrology 183:191-204. 1996.

Lin.G. and Sternberg, L.da S.L. Variation of propagule size and its effect on carbon assimilation and plant growth of Red Mangroves (Rhizophora mangle L.) in Florida, USA. Journal of Tropical Ecology 11:109-119. 1995.

Sauer, P.E. and Sternberg, L. da S.L. An Improved Method for the Determination of the Oxygen Isotopic Composition of Cellulose. Analytical Chemistry 66:2409-2411. 1994.

Luo, Y.H. and Sternberg L da S.L. Alterations in d13C values of seedling cellulose associated with respiration during germination. Phytochemistry 35: 877-880. 1994.

Ross, M.S., O'Brien, J.J., Sternberg, da S. L. Sea level rise and the reduction in pine forests in the Florida Keys. Ecological Applications 4:144-156.1994.

Lin. G. and Sternberg, L.da S.L. Utilization of surface water by Red Mangrove (Rhizophora mangle L.): an isotope study. Bulletin of Marine Science 54:94-102.1994.

Lin, G. and Sternberg, L da S.L. Effects of salinity fluctuation on photosynthetic gas exchange and plant growth of Red Mangrove (Rhizophora mangle L.). Journal of Experimental Botany 44: 9-16. 1993.

Fleming, T.H., Nunez, R.A., and Sternberg, L. da S.L. Seasonal changes in the diets of migrant and non-migrant nectarivorous bats as revealed by carbon stable isotope analysis. Oecologia 94: 72-75. 1993.

Lin, G., and Sternberg, L. da S.L. Hydrogen isotopic fractionation by plant roots during water uptake in coastal wetland plants. in: Perspective on carbon and water relations from stable isotopes, Ehleringer, J., Farquhar, G., and Hall, A. editors.Academic press. 497-510. 1993.

Lin, G., and Sternberg, L da S.L. Effects of growth form salinity, nutrient and sulfide on photosynthesis, carbon isotope discrimination and growth of red mangroves (Rhizophora mangle L.). Australian Journal of Plant Physiology 19: 509-517. 1992.

Luo, Y.H. and Sternberg, L. Spatial D/H heterogeneity of leaf water. Plant Physiology 99:348-350. 1992.

Ish-Shalom-Gordon, N., Lin, G., and Sternberg, L. da S.L., Ross, M., O'Brien, J., and Flynn, L. Water utilization of tropical hardwood hammocks of the Lower Florida Keys. Oecologia 92:108-112. 1992.

Ish-Shalom-Gordon, N., Lin, G., and Sternberg, L. da S.L. Isotopic fractionation during cellulose synthesis in two mangroves species: salinity effects. Phytochemistry 31: 2623-2626. 1992.

Lin., G., and Sternberg, L. da S.L. Differences in morphology, photosynthesis and carbon isotope ratios between scrub and fringe mangroves in Florida, USA. Aquatic Botany 42: 303-313. 1992.

Lin , G., and Sternberg, L da S.L. Comparitive study of water uptake and photosynthetic gas exchange between scrub and fringe red mangroves, Rhizophora mangle L. Oecologia 90: 399-403. 1992.

Luo, Y., and Sternberg, L. da S.L. Hydrogen and oxygen isotopic fractionation during heterotrophic cellulose synthesis. Journal of Experimental Botany 43: 47-50. 1992.

Sternberg, L.da S.L., Gordon, S.I.N, Ross, M.and O'Brien, J. Water relations of coastal plant communities at the border of ocean and freshwater. Oecologia 88: 305-310. 1991.

Medina, E, Sternberg, L., and Cuevas, E. Vertical Stratification of ?13C values in closed natural and plantation forests in the Luquillo mountains, Puerto Rico. Oecologia 87: 369-372.

Luo, Y., Sternberg, L., Suda, S., Kumazawa, S., Mitsui, A. Extremely low D/H ratios of photoproduced hydrogen by cyanobacteria. Plant and Cell Physiology 32: 897-900. 1991.

Gray, V.R., and Sternberg, L.da S.L. Carbon isotopic evidence for seasonal change in feeding habits of Camponotus planatus Roger (Formicidae) in Yucatan, Mexico. Biotropica: 23: 93-95. 1991.

Lin, G., Banks, T., and Sternberg, L da S.L. Variation in ?13C values of the seagrass Thalassia testudinum and its relation to mangrove carbon. Aquatic Botany 40: 331-341. 1991.

Luo, Y, and Sternberg, L. Deuterium heterogeneity in starch and cellulose nitrate of CAM and C3 plants. Phytochemistry 30: 1095-1098. 1991.

Pennycuick, C.J., Schaffner, F.C., Fuller, M.R., Obrecht, O.O. and Sternberg, L. Foraging Flights of the White-Tailed Tropic bird Phaethon lepturus: radiotracking and doubly labelled water. Colonial Waterbirds 13: 96-102. 1990.

Fleming, M., Lin G., and Sternberg, L da S.L. The influence of mangrove detritus in a estuarine ecosystem. Bulletin of Marine Science: 47:663-669. 1990.

Fisher, B.L., Sternberg, L. da S.L., and Price, D. Variation in the use of orchid extrafloral nectar by ants. Oecologia 83: 263-266.1990

Sternberg, L. da S.L. Aspectos fotosinteticos e isotopicos de epifitas y hemiepifitas. in (Medina, E. ed.) Monographs in Systematics and Botany of the Missouri Botanical Garden. Medellin Symposium. 27: 50 -55, 1989.

Sternberg, L da S.L., Mulkey, S. S., Wright, J. S. Oxygen isotope ratio stratification in a tropical moist forest. Oecologia 81: 51-56, 1989.

Sternberg, L da S.L. A model to estimate carbon dioxide recycling in forests using 13C/12C ratios and concentrations of ambient carbon dioxide. Agricultural and Forest Meteorology 48: 163-173, 1989.

Sternberg, L. da S.L. Oxygen and hydrogen isotope measurements in plant cellulose. In Modern Methods in Plant Analysis, Linskens, H.F. and Jackson J.F. Vol 10, Springer Verlag, Berlin Heidelberg New York Tokyo. Volume 10, pp 89-98, 1989

Swart, P.K., Sternberg L. da S.L., Steinen, R. Harrison, S. Controls on the oxygen and hydrogen isotopic composition of the waters of Florida Bay, USA. Chemical Geology 79: 113 -123, 1989.

Goldstein, G., Rada, F., Sternberg, L., Burguera, J.L., Burguera, M., Orozco, A., Montilla, M., Zabala, O., Azocar, A., Canales, M.J., and Celis, A. (1989) Gas exchange and water balance of a mistletoe species and its mangrove hosts. Oecologia 78: 176-183, 1989.

Sternberg, L da S.L., Mulkey, S.S., Wright, S.J. Ecological interpretation of leaf carbon isotope ratios: influence of recycled carbon dioxide. Ecology 70:1317-1324, 1989.

Huber, W.E., Brown, R.H. , Bouton, J.H., Sternberg L.O'R. CO2 exchange, cytogenetics and leaf anatomy of hybrids between photosynthetically distinct Flaveria species. Plant Physiology 89:839-844, 1989.

Sternberg, L. da S.L. Oxygen and hydrogen isotope ratios in plant cellulose: mechanisms and application. In Rundel P., Ehleringer J.R. and Nagy K (eds.) Applications of stable isotope ratios to ecological research. Ecological Series Monographs. Springer Verlag. Vol. 62, pp 124-141, 1989.

DeNiro M.J., Sternberg L. da S.L., Marino, B.D. , Druzik, J.R. Relation between D/H ratios and 18O/16O ratios in cellulose from linen and maize - implications for paleoclimatology and for sindonology. Geochimica et Cosmochimica Acta 52: 2189-2196, 1988.

Sternberg, L. da S.L. D/H ratios of environmental water recorded by D/H ratios of plant lipids. Nature 333: 59 - 61, 1988.

Ting, I.P., Hann, J., Holbrook, N.M., Putz, F.E., Sternberg, L. da S.L., Price, D., Goldstein, G. Photosynthesis in hemiepiphytic species of Clusia and Ficus. Oecologia 74: 339-346, 1987.

Doner, L.W., Ajie, H.O., Sternberg, L. da S.L., Milburn, J.M., DeNiro, M.J., Hicks, K.B. Detecting sugar beet syrups in orange juice by D/H and 18O/16O analysis of sucrose. Journal of Agricultural & Food Chemistry 35: 610-612, 1987.

Tang, W., Sternberg, L. , Price, D. Metabolic aspects of thermogenesis in male cones of five cycad species. American Journal of Botany 74: 1555-1559, 1987.

Sternberg, L. da S.L., Ting, I.P., Price, D., Hann, J. Photosynthesis in epiphytic and rooted Clusia rosea Jacq. Oecologia 72: 457-460, 1987.

Sternberg, L da S.L., Swart, P.K. Utilization of freshwater and ocean water by coastal plants of southern Florida. Ecology 68:1898-1905, 1987.

Holthe, P.A., Sternberg, L da S.L., Ting, I.P. Developmental control of CAM in Peperomia scandens. Plant Physiology 84:743-747, 1987.

Keeley, J.D., Sternberg, L.O., DeNiro, M.J. The use of stable isotopes in the study of photosynthesis in freshwater plants. Aquatic Botany 26:213-223,1986.

Brown, R.H. Bassett, C.L., Cameron, R.G., Evans, P.T., Bouton, J.H., Black, C.C. Sternberg, L.O. and DeNiro M.J. Photosynthesis of F1hybrids between C4 and C3-C4 species of Flaveria. Plant Physiology 82: 211-217, 1986.

Sternberg, L. da S.L., DeNiro, M.J. and Savidge, R.A. Oxygen isotope exchange between metabolites and water during biochemical reactions leading to cellulose synthesis. Plant Physiology 82: 428-431, 1986.

Sternberg, L. da S.L., DeNiro, M.J. and Ajie, H.O. Isotopic relationship between saponifiable lipids and cellulose nitrate prepared from red, brown and green algae. Planta 169: 320-324, 1986.

Sternberg, L. da S.L., DeNiro, M.J., Johnson, H.B. Oxygen and hydrogen isotope ratios of water from photosynthetic tissues of CAM and C3 plants. Plant Physiology 82: 423-427, 1986.

Sternberg, L da S.L., DeNiro, M.J., Sloan, M.E., Black, C.C. Compensation point and isotopic characteristics of C3/C4 intermediates and hybrids in Panicum. Plant Physiology 80: 242-245, 1986.

Sternberg, L. da S.L., DeNiro, M.J., McJunkin, D., Berger, R., Keeley, J.E. Carbon, oxygen and hydrogen isotope abundances in Stylites reflects its unique physiology . Oecologia 67: 598-600, 1985.

Ting, I.P., Lord, E.M., Sternberg, L. da S.L., DeNiro, M.J. Crassulacean acid metabolism in the strangler Clusia rosea Jacq. Science 229: 969-971, 1985.

Ting, I.P., Bates, L., Sternberg L., DeNiro, M.J. Physiological and isotopic aspects of photosynthesis in Peperomia. Plant Physiology 78: 246-249, 1985.

Sternberg, L., DeNiro, M.J., Ajie, H., Stable hydrogen isotope ratio of saponifiable lipids and cellulose nitrate from CAM, C3 and C4 plant. Phytochemistry 23: 2475-2477, 1984.

Sternberg, L., DeNiro, M.J., Keeley, J.E. Hydrogen, oxygen and carbon isotope ratios of cellulose from submerged aquatic CAM and non-CAM plants. Plant Physiology 76: 68-70, 1984.

Sternberg, L., DeNiro, M.J., Ting, I.P. Carbon, hydrogen and oxygen isotope ratios of cellulose from plants having intermediary photosynthetic modes. Plant Physiology 74: 104-107, 1984.

Sternberg, L., DeNiro, M.J., Biogeochemical implications of the isotopic equilibrium fractionation factor between the oxygen atoms of acetone and water. Geochimica et Cosmochimica Acta 47: 2271-2274, 1983.

Sternberg, L., DeNiro, M.J., Isotopic composition of cellulose from C3, C4 and CAM plants growing in the vicinity of one another. Science 220: 947-949, 1983.

Walker, D.B., Gysi, J., Sternberg, L., DeNiro, M.J., Direct respiration of lipids during heat production in the infloresence of the plant Philodendron selloum K. Koch (Araceae). Science 220: 419-421, 1983.

Ting, I.P., Sternberg, L., DeNiro, M.J., Variable photosynthetic metabolism in leaves and stems of Cissus quadrangularis L. Plant Physiology 71: 677-679, 1983.

Sternberg, L. Biochemical properties and habitat distribution of malate dehydrogenase isozymes in O. basilaris. In Crassulacean Acid Metabolism, I.P. Ting and M. Gibbs, eds (American Society of Plant Physiology, Rockville, Maryland, 1982), p. 309.

Cockburn, W. , Ting, I.P., Sternberg, L., Relationships between Stomatal Behavior and Internal Carbon Dioxise Concentration in CAM Plants. Plant Physiology 63: 1029-1032, 1979.

Sternberg, L., Ting, I.P., Inheritance of microbody MDH in Opuntia basilaris. Journal of Heredity 70: 220, 1979.

Sternberg, L., Ting, I.P., Hanscom, Z., Polymorphism of microbody MDH in Opuntia basilaris. Plant Physiology 59: 329-330, 1977.

Sternberg, L. Growth forms of Larrea tridentata. Madrono 23: 408-417,1976.