Leonel da Silveira Lobo O’Reilly Sternberg

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Carbon and hydrogen isotope ratios of cellulose nitrate and oxygen isotope ratios of cellulose from species of greenhouse plants having different photosynthetic modes were determined. When hydrogen isotope ratios are plotted against carbon isotope ratios, four clusters of points are discernible, each representing different photosynthetic modes: C(3) plants,(More)
Hydrogen and carbon isotope ratios of cellulose nitrate and oxygen isotope ratios of cellulose from C(3), C(4), and Crassulacean acid metabolism (CAM) plants were determined for plants growing within a small area in Val Verde County, Texas. Plants having CAM had distinctly higher deuterium/hydrogen (D/H) ratios than plants having C(3) and C(4) metabolism.(More)
Tree islands in the Everglades wetlands are centers of biodiversity and targets of restoration, yet little is known about the pattern of water source utilization by the constituent woody plant communities: upland hammocks and flooded swamp forests. Two potential water sources exist: (1) entrapped rainwater in the vadose zone of the organic soil (referred to(More)
The tree island hammock communities in the Florida Everglades provide one of many examples of self-organized wetland landscape. However, little is understood about why these elevated tree island communities have higher nutrient concentration than the surrounding freshwater marshes. Here we used stable isotopes and elemental analysis to compare dry season(More)
Physiological and isotopic aspects of several Peperomia species were investigated. All but one species had C(3)-like stomatal behavior, in that stomata were open during the day and closed during the night. In these species, most atmospheric CO(2) uptake occurred during the day. Concurrent with this stomatal behavior, there were Crassulacean acid(More)
Keeley, J.E., Sternberg, L.O. and DeNiro, M.J., 1986. The use of stable isotopes in the study of photosynthesis in aquatic plants. Aquat. Bot., 26:213--223. The ratio of ~3C/'2C for photosynthetic tissues of 22 aquatic species was unrelated to photosynthetic pathway. In three aquatic environments CAM and non-CAM species were shown to have similar 513C(More)
An isotopic study was performed to assess the movement of groundwater for a site located in Miami-Dade County, Florida. The site encompasses portions of a protected wetland environment (northeast Everglades National Park) and suburban residential Miami, incorporating municipal pumping wells and lakes formed by rock mining. Samples of ground, surface, and(More)
By measuring titratable acidity, gas exchange parameters, mesophyll succulence, and (13)C/(12)C ratios, we have shown that Cissus quadrangularis L. has C(3)-like leaves and stems with Crassulacean acid metabolism (CAM). In addition, the nonsucculent leaves show the diurnal fluctuations in organic acids termed recycling despite the fact that all CO(2) uptake(More)
Photosynthetic characteristics were studied in several F(1) hybrids between C(4) and C(3)-C(4) species of Flaveria. Stable carbon isotope ratios, O(2) inhibition of apparent photosynthesis, and phosphoenolpyruvate carboxylase activities in the hybrids were similar to the means for the parents. Values of CO(2) compensation concentrations were nearer to those(More)
Arbuscular mycorrhizal fungi form extensive common mycorrhizal networks (CMNs) that may interconnect neighboring root systems of the same or different plant species, thereby potentially influencing the distribution of limiting mineral nutrients among plants. We examined how CMNs affected intra- and interspecific interactions within and between populations(More)