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Articles 91 - 120 of 2070
Full-Text Articles in Life Sciences
Forecasting Climate Change Impacts On The Distribution Of Wetland Habitat In The Midwestern United States, Heath Garris, Randall Mitchell, Lauchlan Fraser, Linda Barrett
Forecasting Climate Change Impacts On The Distribution Of Wetland Habitat In The Midwestern United States, Heath Garris, Randall Mitchell, Lauchlan Fraser, Linda Barrett
Randall J. Mitchell
Shifting precipitation patterns brought on by climate change threaten to alter the future distribution of wetlands. We developed a set of models to understand the role climate plays in determining wetland formation on a landscape scale and to forecast changes in wetland distribution for the Midwestern United States. These models combined 35 climate variables with 21 geographic and anthropogenic factors thought to encapsulate other major drivers of wetland distribution for the Midwest. All models successfully recreated a majority of the variation in current wetland area within the Midwest, and showed that wetland area was significantly associated with climate, even when …
Reef Fish Assemblages And Fisheries In Parque Nacional Del Este, Dominican Republic, Emily Schmitt Lavin, Mark Chiappone, Kathleen Sullivan-Sealey, F. Geraldes, E. Pugibet, Robert Sluka, R. Torres, M. Vega, Y. Rodriguez, J. Alarcon, Y. Lictensztain, G. Bustamante
Reef Fish Assemblages And Fisheries In Parque Nacional Del Este, Dominican Republic, Emily Schmitt Lavin, Mark Chiappone, Kathleen Sullivan-Sealey, F. Geraldes, E. Pugibet, Robert Sluka, R. Torres, M. Vega, Y. Rodriguez, J. Alarcon, Y. Lictensztain, G. Bustamante
Emily F Schmitt Lavin
Parque National del Este is the second largest protected area in the Dominican Republic, comprising 110 km2 of terrestrial habitats located in the southeastern Dominican Republic. Established in 1975, the park delineation did not include the adjacent marine area, despite its long history of commercial fisheries. Since 1994, several U.S. and Dominican partner organizations have conducted scientific investigations of the marine resources of the area. This paper provides data on the status of snapper and groupers reef assemblages and finfish fisheriescollected during 1995 1997. Methods used in the study included: 1) visual transects (20 m x 5 m) of predatory …
Service Learning In Science Education: A Valuable And Useful Endeavor For Biology Majors, Emily Schmitt Lavin, Kaitlin Donovan
Service Learning In Science Education: A Valuable And Useful Endeavor For Biology Majors, Emily Schmitt Lavin, Kaitlin Donovan
Emily F Schmitt Lavin
All college students can benefit from becoming more engaged in their local community. This is especially true for biology majors who can play an active role in enhancing science education opportunities for students in the local K-12 school system. One such service-learning (SL) opportunity is presented where Nova Southeastern University college students work together with local schools by engaging young students in the excitement of hands-on science learning. This type of SL activity is beneficial to all those involved. College students gain valuable public speaking experience while learning how to explain potentially complex scientific concepts in a fun and engaging …
Evaluating The Use Of Roving Diver And Transect Surveys To Assess The Coral Reef Fish Assemblage Off Southeastern Hispaniola, Emily Schmitt Lavin, Robert Sluka, Kathleen Sullivan-Sealey
Evaluating The Use Of Roving Diver And Transect Surveys To Assess The Coral Reef Fish Assemblage Off Southeastern Hispaniola, Emily Schmitt Lavin, Robert Sluka, Kathleen Sullivan-Sealey
Emily F Schmitt Lavin
The relatively little-studied fish fauna off southeastern Hispaniola was rapidly assessed using a combination of visual survey techniques including transects and roving diver surveys. It was found that when combined, both methods provided a more complete overall species assessment than either method was able to provide in isolation. Being able to conduct rapid species assessments is becoming increasingly more important as a conservation tool. Data on species composition, sighting frequency, and abundance of all fishes were collected using both methods. Abundance was recorded in four logarithmic-based categories (roving diver method) while the number of fishes were counted within 40-m2 transects …
Analysis Of A Volunteer Method For Collecting Fish Presence And Abundance Data In The Florida Keys, Emily Schmitt Lavin, Kathleen Sullivan-Sealey
Analysis Of A Volunteer Method For Collecting Fish Presence And Abundance Data In The Florida Keys, Emily Schmitt Lavin, Kathleen Sullivan-Sealey
Emily F Schmitt Lavin
A roving diver fish survey method that requires relatively little time and equipment was developed for use by trained volunteer divers to regularly, rapidly, and inexpensively document patterns of reef fish distribution and abundance, In this method, a diver searches a dive site and records all observed fish species and their abundance in log10 categories, Results from 130 h of observation were analyzed from three regional surveys conducted in the Florida Keys at a total of 27 reefs by four observers during the summer of 1994. The Upper Keys had the most species (166) followed by the Lower Keys (151) …
The Grilled Cheese Principle. Personal Belief Essay As Part Of A Public Dialog About Belief, Emily Schmitt Lavin
The Grilled Cheese Principle. Personal Belief Essay As Part Of A Public Dialog About Belief, Emily Schmitt Lavin
Emily F Schmitt Lavin
No abstract provided.
Comparison Of Grouper Assemblages In Northern Areas Of The Wider Caribbean: A Preliminary Assessment, Emily Schmitt Lavin, Robert Sluka, Kathleen Sullivan-Sealey
Comparison Of Grouper Assemblages In Northern Areas Of The Wider Caribbean: A Preliminary Assessment, Emily Schmitt Lavin, Robert Sluka, Kathleen Sullivan-Sealey
Emily F Schmitt Lavin
Groupers (Pisces: Serranidae) are important top-level predators in wider Caribbean, but have experienced significant exploitation, resulting in declines in abundance, size, spawning aggregations, and changes in species composition. Larger groupers are particularly vulnerable to intense fishing because of their longevity, slow growth, delayed reproduction, and aggregate spawning. Marine fishery reserves (MFR), areas permanently closed to consumptive use, offer a viable means to protect grouper resources. This study reports on fishery-independent surveys of groupers in four regions of the tropical western Atlantic during 1995 - 1997: Florida Keys, central Bahamas, southeastern Cuba, and Dominican Republic. The regions surveyed included two national …
Breaking Through The Spiral Ceiling: An American Woman Becomes A Dna Scientist By Laura L. Mays Hoopes, Emily Schmitt Lavin, Laura Mays
Breaking Through The Spiral Ceiling: An American Woman Becomes A Dna Scientist By Laura L. Mays Hoopes, Emily Schmitt Lavin, Laura Mays
Emily F Schmitt Lavin
No abstract provided.
Density, Species, And Size Distribution Of Groupers (Serranidae) In Three Habitats At Elbow Reef, Florida Keys, Robert Sluka, Mark Chiappone, Kathleen Sullivan-Sealey, Thomas Potts, Jose Levy, Emily Schmitt Lavin, Geoff Meester
Density, Species, And Size Distribution Of Groupers (Serranidae) In Three Habitats At Elbow Reef, Florida Keys, Robert Sluka, Mark Chiappone, Kathleen Sullivan-Sealey, Thomas Potts, Jose Levy, Emily Schmitt Lavin, Geoff Meester
Emily F Schmitt Lavin
We examined the density, size and species distribution of groupers in three habitats on an inshore-to-offshore transect across Elbow Reef, Florida Keys: high-relief spur-and-groove (4–9 m depth), relict spur-and-groove (10–20 m), and deep fore reef slope (21–30 m). Physical relief was greatest in the high-relief spur-and-groove (up to 3 m), lowest in the relict spur-and-groove habitat (<0.5–1 m), and intermediate in the deep fore reef slope habitat (1–1.5 m). Benthic coverage in the three habitats was dominated by algae (>30%). There were significant differences in the density, size, and species distribution of groupers among the three habitats. Graysby, Epinephelus cruentatus, was numerically dominant, constituting 82–91% of individual observed. Black grouper, Mycteroperca bonaci, and Nassau grouper, E. striatus, were more abundant in high …
Ontogenetic Scaling Of Metabolism, Growth, And Assimilation: Testing Metabolic Scaling Theory With Manduca Sexta Larvae., Andrew Kerkhoff, Harry Itagaki
Ontogenetic Scaling Of Metabolism, Growth, And Assimilation: Testing Metabolic Scaling Theory With Manduca Sexta Larvae., Andrew Kerkhoff, Harry Itagaki
Harry Itagaki
Metabolism, growth, and the assimilation of energy and materials are essential processes that are intricately related and depend heavily on animal size. However, models that relate the ontogenetic scaling of energy assimilation and metabolism to growth rely on assumptions that have yet to be rigorously tested. Based on detailed daily measurements of metabolism, growth, and assimilation in tobacco hornworms, Manduca sexta, we provide a first experimental test of the core assumptions of a metabolic scaling model of ontogenetic growth. Metabolic scaling parameters changed over development, in violation of the model assumptions. At the same time, the scaling of growth rate …
The Use Of Mock Nsf-Type Grant Proposals And Blind Peer Review As The Capstone Assignment In Upper-Level Neurobiology And Cell Biology Courses., Harry Itagaki
Harry Itagaki
Although the use of grant proposals and blind peer review are standard in the natural sciences, their use as a pedagogical tool is rarely mentioned in the literature. As a consequence of dissatisfaction with term papers and literature reviews as the capstone writing experience in 300-level undergraduate biology courses, I have been experimenting with mock NSF-type grant proposals followed by blind peer review as the major assignment in my junior/senior-level classes. The improvement in educational outcomes and competencies due to this assignment appears to be substantial and worth the additional effort on both the students' and instructor's parts. Here, I …
Peripheral And Central Structures Involved In Insect Gustation., Harry Itagaki
Peripheral And Central Structures Involved In Insect Gustation., Harry Itagaki
Harry Itagaki
Studies in insect gustation have a long history in general physiology, particularly with work on fly labellar and tarsal sensilla and in the general field of insect-plant interactions, where work on immature Lepidoptera and chrysomelid beetles has been prominent. Much more emphasis has been placed on the physiological characteristics of the sensory cells than on the central cellular mechanisms of taste processing. This is due to the fairly direct access for physiological experimentation presented by many taste sensilla and to the obvious importance of tastants in insect feeding and oviposition behaviour. In some of the insect models used for gustatory …
The Olfactory Responses Of The Antenna And Maxillary Palp Of The Fleshfly, Neobellieria Bullata (Diptera: Sarcophagidae), And Their Sensitivity To Blockage Of Nitric Oxide Synthase, Harry Itagaki
Harry Itagaki
The relative sensitivities of the olfactory receptors in the antenna and maxillary palp of the fleshfly,Neobellieria bullata, were assessed using simultaneous electroantennograms (EAGs) and electropalpograms (EPGs). In general, the antennae and maxillary palps were more sensitive to odors related to animals (blood extract and saturated carboxylic acid) than to odors that were plant-derived (citral, hexenol, hexenal). In addition, the maxillary palps were relatively less sensitive to plant-derived odorants than the antennae, perhaps related to their anatomical position. Scanning electron microscopy was also used to assess the types of sensilla found on the two organs. In addition, NADPH-diaphorase histochemistry …
The Cation-Chloride Cotransporter, Masbsc, Is Widely Expressed In Manduca Sexta Tissues., Haruhiko Itagaki, Christopher Gillen, Kathy Gillen
The Cation-Chloride Cotransporter, Masbsc, Is Widely Expressed In Manduca Sexta Tissues., Haruhiko Itagaki, Christopher Gillen, Kathy Gillen
Harry Itagaki
Cation-chloride cotransporters, including the Na-K-Cl cotransporter, play an important role in epithelial ion transport in insects. We have determined the tissue distribution of Manduca sexta bumetanide sensitive cotransporter (masBSC), a putative Na-K-Cl cotransporter that was originally cloned from M. sexta Malpighian tubules. We developed a polyclonal antibody (M6) against a C-terminal fragment of masBSC. masBSC protein was detected by M6 at an apparent molecular mass of approximately 220kDa in M. sexta foregut, midgut, hindgut, Malpighian tubule, salivary gland, fat body, trachea, and nerve cord. Higher expression was observed in the foregut than in other tissues. M6 stained the apical membrane …
Arabidopsisearly-Flowering Mutants Reveal Multiple Levels Of Regulation In The Vegetative-To-Floral Transition, Karen Hicks
Arabidopsisearly-Flowering Mutants Reveal Multiple Levels Of Regulation In The Vegetative-To-Floral Transition, Karen Hicks
Karen Hicks
The isolation and characterization of flowering time mutants should further the understanding of the developmental pathways that regulate the transition to reproductive development. Because plant development is a sequential and continuous process, the genetic analysis of floral initiation is likely to benefit from the analysis of mutations that cause pleiotropic phenotypes. This review focus on early-flowering mutants ofArabidopsisthat display additional phenotypes in either inflorescence development or light perception, and discusses the possibility that genes controlling early flower development are regulated by environmentally responsive genetic pathways.
The Arabidopsis Elf3 Gene Regulates Vegetative Photomorphogenesis And The Photoperiodic Induction Of Flowering., Karen Hicks
The Arabidopsis Elf3 Gene Regulates Vegetative Photomorphogenesis And The Photoperiodic Induction Of Flowering., Karen Hicks
Karen Hicks
Flowering in Arabidopsis thaliana is promoted by longday (LD) photoperiods such that plants grown in LD flower earlier, and after the production of fewer leaves, than plants grown in short-day (SD) photoperiods. The early-flowering 3 (elf3) mutant of Arabidopsis, which is insensitive to photoperiod with regard to floral initiation has been characterized elf3 mutants are also altered in several aspects of vegetative photomorphogenesis, including hypocotyl elongation. When inhibition of hypocotyl elongation was measured, elf3 mutant seedlings were less responsive than wild-type to all wavelengths of light, and most notably defective in blue and green light-mediated inhibition. When analyzed for the …
Conditional Circadian Dysfunction Of The Arabidopsis Early-Flowering 3 Mutant, Karen Hicks
Conditional Circadian Dysfunction Of The Arabidopsis Early-Flowering 3 Mutant, Karen Hicks
Karen Hicks
Photoperiodic responses, such as the daylength-dependent control of reproductive development, are associated with a circadian biological clock. The photoperiod-insensitive early-flowering 3(elf3) mutant of Arabidopsis thaliana lacks rhythmicity in two distinct circadian-regulated processes. This defect was apparent only when plants were assayed under constant light conditions. elf3 mutants retain rhythmicity in constant dark and anticipate light/dark transitions under most light/dark regimes. The conditional arrhythmic phenotype suggests that the circadian pacemaker is intact in darkness in elf3 mutant plants, but the transduction of light signals to the circadian clock is impaired.
The Importance Of Feminist Critique For Contemporary Cell Biology, A. Baldecos, S. Bailey, Scott Gilbert, Karen Hicks, Lori Kenschaft, Nancy Niemczyk, Stephanie Schaertel, Andrew Wedel
The Importance Of Feminist Critique For Contemporary Cell Biology, A. Baldecos, S. Bailey, Scott Gilbert, Karen Hicks, Lori Kenschaft, Nancy Niemczyk, Stephanie Schaertel, Andrew Wedel
Karen Hicks
No abstract provided.
Early Flowering3 Encodes A Novel Protein That Regulates Circadian Clock Function And Flowering In Arabidopsis, Karen Hicks
Early Flowering3 Encodes A Novel Protein That Regulates Circadian Clock Function And Flowering In Arabidopsis, Karen Hicks
Karen Hicks
Higher plants use photoperiodic cues to regulate many aspects of development, including the transition from vegetative to floral development. The EARLY FLOWERING3 (ELF3) gene is required for photoperiodic flowering and normal circadian regulation in Arabidopsis. We have cloned ELF3 by positional methods and found that it encodes a novel 695–amino acid protein that may function as a transcriptional regulator. ELF3transcript level is regulated in a circadian manner, as is expected of a zeitnehmer input pathway component. Overexpression of the LATE ELONGATED HYPOCOTYL gene, which has been proposed to function as a clock component, did not abolish circadian regulation of ELF3 …
Independent Roles For Early Flowering 3 And Zeitlupe In The Control Of Circadian Timing, Hypocotyl Length, And Flowering Time., Karen Hicks
Karen Hicks
The circadian clock regulates many aspects of plant development, including hypocotyl elongation and photoperiodic induction of flowering. ZEITLUPE (ZTL) is a clock-related F-box protein, and altered ZTL expression causes fluence rate-dependent circadian period effects, and altered hypocotyl elongation and flowering time. EARLY FLOWERING 3 (ELF3) is a novel protein of unknown biochemical function. elf3 mutations cause light-dependent circadian dysfunction, elongated hypocotyls, and early flowering. Although both genes affect similar processes, their relationship is unclear. Here we show that the effects of ZTL and ELF3 on circadian clock function and early photomorphogenesis are additive. The long period of ztl mutations and …
Effect Of Body Size On Expression Of Manduca Sexta Midgut Genes, Christopher Gillen
Effect Of Body Size On Expression Of Manduca Sexta Midgut Genes, Christopher Gillen
Christopher M. Gillen
Isometric growth of larval insect midgut predicts that the ratio of midgut surface area to body mass decreases as larvae grow. Gut tissue and gut content masses were measured in first through fifth instar Manduca sexta larvae. Wet mass of gut tissue increased in relationship to body mass with a scaling exponent of 0.85 compared to an exponent of 1.33 for gut content mass, suggesting that surface area becomes increasingly limiting in larger larvae. To test the hypothesis that compensation for the decrease in relative surface area of the midgut occurs by increased expression of membrane proteins, we compared midgut …
Expression Of Genes Encoding Ca2+ Exporting Proteins In Freshwater Crayfish Procambarus Clarkii During Cold Exposure, Christopher Gillen
Expression Of Genes Encoding Ca2+ Exporting Proteins In Freshwater Crayfish Procambarus Clarkii During Cold Exposure, Christopher Gillen
Christopher M. Gillen
1. This study examined expression of two primary transmembrane Ca2+ export proteins (plasma membrane Ca2+ ATPase, (PMCA); Na+/Ca2+ exchanger, sodium/calcium exchanger (NCX)) in epithelial (antennal gland, kidney) and non-epithelial (axial abdominal muscle) tissues of the freshwater crayfish Procambarus clarkii following exposure (28 days) to 4 °C (compared with control 23 °C). 2. Crayfish tissues responded to cold exposure within 5–7 days by upregulating the mRNA (determined through real-time polymerase chain reaction (PCR)) for both PMCA and NCX. After 28 days, levels were 4–5× higher in antennal gland and 2–3× higher in muscle. In situ hybridization localized the mRNA increase to …
The Cation-Chloride Cotransporter, Masbsc, Is Widely Expressed In Manduca Sexta Tissues., Haruhiko Itagaki, Christopher Gillen, Kathy Gillen
The Cation-Chloride Cotransporter, Masbsc, Is Widely Expressed In Manduca Sexta Tissues., Haruhiko Itagaki, Christopher Gillen, Kathy Gillen
Christopher M. Gillen
Cation-chloride cotransporters, including the Na-K-Cl cotransporter, play an important role in epithelial ion transport in insects. We have determined the tissue distribution of Manduca sexta bumetanide sensitive cotransporter (masBSC), a putative Na-K-Cl cotransporter that was originally cloned from M. sexta Malpighian tubules. We developed a polyclonal antibody (M6) against a C-terminal fragment of masBSC. masBSC protein was detected by M6 at an apparent molecular mass of approximately 220kDa in M. sexta foregut, midgut, hindgut, Malpighian tubule, salivary gland, fat body, trachea, and nerve cord. Higher expression was observed in the foregut than in other tissues. M6 stained the apical membrane …
Influence Of Diurnal Variation In Mesophyll Conductance On Modelled 13c Discrimination: Results From A Field Study, Christopher Bickford
Influence Of Diurnal Variation In Mesophyll Conductance On Modelled 13c Discrimination: Results From A Field Study, Christopher Bickford
Christopher P Bickford
Mesophyll conductance to CO2 (gm) limits carbon assimilation and influences carbon isotope discrimination (Δ) under most environmental conditions. Current work is elucidating the environmental regulation ofgm, but the influence of gm on model predictions of Δ remains poorly understood. In this study, field measurements of Δ and gm were obtained using a tunable diode laser spectroscope coupled to portable photosynthesis systems. These data were used to test the importance ofgm in predicting Δ using the comprehensive Farquhar model of Δ (Δcomp), where gm was parameterized using three methods based on: (i) mean gm; (ii) the relationship between stomatal conductance (gs) …
High-Frequency Field Measurements Of Diurnal Carbon Isotope Discrimination And Internal Conductance In A Semi-Arid Species, Juniperus Monosperma., Christopher Bickford
High-Frequency Field Measurements Of Diurnal Carbon Isotope Discrimination And Internal Conductance In A Semi-Arid Species, Juniperus Monosperma., Christopher Bickford
Christopher P Bickford
We present field observations of carbon isotope discrimination (Delta) and internal conductance of CO(2) (g(i)) collected using tunable diode laser spectroscopy (TDL). Delta ranged from 12.0 to 27.4 per thousand over diurnal periods with daily means from 16.3 +/- 0.2 per thousand during drought to 19.0 +/- 0.5 per thousand during monsoon conditions. We observed a large range in g(i), with most estimates between 0.04 and 4.0 micromol m(-2) s(-1) Pa(-1). We tested the comprehensive Farquhar, O'Leary and Berry model of Delta (Delta(comp)), a simplified form of Delta(comp) (Delta(simple)) and a recently suggested amendment (Delta(revised)). Sensitivity analyses demonstrated that varying …
Regulation And Acclimation Of Leaf Gas Exchange In A Piñon–Juniper Woodland Exposed To Three Different Precipitation Regimes, Christopher Bickford
Regulation And Acclimation Of Leaf Gas Exchange In A Piñon–Juniper Woodland Exposed To Three Different Precipitation Regimes, Christopher Bickford
Christopher P Bickford
Leaf gas-exchange regulation plays a central role in the ability of trees to survive drought, but forecasting the future response of gas exchange to prolonged drought is hampered by our lack of knowledge regarding potential acclimation. To investigate whether leaf gas-exchange rates and sensitivity to drought acclimate to precipitation regimes, we measured the seasonal variations of leaf gas exchange in a mature piñon–juniper Pinus edulis–Juniperus monosperma woodland after 3 years of precipitation manipulation. We compared trees receiving ambient precipitation with those in an irrigated treatment (+30% of ambient precipitation) and a partial rainfall exclusion (−45%). Treatments …
Microclimate Characteristics Of Alpine Bluff Ecosystems Of New Zealand's South Island, And Implications For Plant Growth, Christopher Bickford
Microclimate Characteristics Of Alpine Bluff Ecosystems Of New Zealand's South Island, And Implications For Plant Growth, Christopher Bickford
Christopher P Bickford
Descriptions of alpine climate in areas of high solar radiation are increasing, but there is a paucity of microclimate data for shaded alpine rock bluff ecosystems. These shaded systems are important because they represent plant habitats that are subject to unique climate drivers within the alpine ecosystem, but which are poorly characterised globally. We describe microclimate characteristics, including photosynthetically active radiation (PAR), atmospheric vapour pressure deficit, and air (Tair) and soil temperature (Tsoil) for three shaded alpine bluff sites at 1370–1800 m altitude on the South Island of New Zealand that support a diverse flora, including …
A New Measurement Technique Reveals Rapid Post-Illumination Changes In The Carbon Isotope Composition Of Leaf-Respired Co2, Christopher Bickford
A New Measurement Technique Reveals Rapid Post-Illumination Changes In The Carbon Isotope Composition Of Leaf-Respired Co2, Christopher Bickford
Christopher P Bickford
We describ an open leaf gas exchange system coupled to a tunable diode laser (TDL) spectroscopy system enabling measurement of the leaf respiratory CO2 flux and its associated carbon isotope composition (δ13CRl) every 3 min. The precision of δ13CRl measurement is comparable to that of traditional mass spectrometry techniques. δ13CRl from castor bean (Ricinus communis L.) leaves tended to be positively related to the ratio of CO2 produced to O2 consumed [respiratory quotient (RQ)] after 24–48 h of prolonged darkness, in support of existing models. Further, the apparent fractionation between respiratory substrates and respired CO2 within 1–8 h after the …
Host Physiological Condition Regulates Parasitic Plant Performance: Arceuthobium Vaginatum Subsp. Cryptopodum On Pinus Ponderosa., Christopher Bickford
Host Physiological Condition Regulates Parasitic Plant Performance: Arceuthobium Vaginatum Subsp. Cryptopodum On Pinus Ponderosa., Christopher Bickford
Christopher P Bickford
Much research has focused on effects of plant parasites on host-plant physiology and growth, but little is known about effects of host physiological condition on parasite growth. Using the parasitic dwarf mistletoe Arceuthobium vaginatum subsp. cryptopodum (Viscaceae) and its host Pinus ponderosa, we investigated whether changes in host physiological condition influenced mistletoe shoot development in northern Arizona forests. We conducted two studies in two consecutive years and used forest thinning (i.e., competitive release) to manipulate host physiological condition. We removed dwarf mistletoe shoots in April, before the onset of the growing season, and measured the amount of regrowth in the …
Δ13c Of Leaf-Respired Co2 Reflects Intrinsic Water-Use Efficiency In Barley, Christopher Bickford
Δ13c Of Leaf-Respired Co2 Reflects Intrinsic Water-Use Efficiency In Barley, Christopher Bickford
Christopher P Bickford
Leaf intrinsic water-use efficiency (WUE), the ratio of photosynthetic rate to stomatal conductance (A/gs), is a key plant trait linking terrestrial carbon and water cycles. A rapid, integrative proxy for A/gs is of benefit to crop breeding programmes aiming to improve WUE, but also for ecologists interested in plant carbon-water balance in natural systems. We hypothesize that the carbon isotope composition of leaf-respired CO2 (δ13CRl), two hours after leaves are transferred to the dark, records photosynthetic carbon isotope discrimination and so provides a proxy for A/gs. To test this hypothesis, δ13CRl was measured in four barley cultivars grown in the …