David Biesboer - Academia.edu (original) (raw)

Papers by David Biesboer

Revista Brasileira De Biologia, Aug 1, 1999

Estimates of the rates of heterotrophic nitrogen fixation (HNF) and denitrification by acetylene ... more Estimates of the rates of heterotrophic nitrogen fixation (HNF) and denitrification by acetylene reduction and acetylene inhibition, respectively, were determined for the roots and culms of wild rice, Oryza glumaepatula, in Lake Batata, a lake severely impacted by the dumping of bauxite tailings into the lake basin. Two stations were established in different parts of the lake: one in a natural area and other in an impacted area of the lake. Plant assays were performed during the principle hydroperiods of dry (December) and flood (July) to determine both: a) Actual rates of HNF and denitrification, and b) potential rates of HNF after amending with glucose potential rates of denitrification after amending with glucose, glucose + nitrate, or nitrate alone. HNF was found to naturally exceed denitrification in this system. HNF and denitrification were consistently found to be greater for roots than culms but no correlation was found between rates of HNF or denitrification and water depth. It was determined that for HNF and denitrification that glucose and nitrate were the limiting factors in controlling those processes in roots and culms of O. glumaepatula. HNF and denitrification of O. glumaepatula does not appear to show differences between impacted and non-impacted areas.

A field-monitoring program began in the spring of 2000 to test the ability of a grassy roadside s... more A field-monitoring program began in the spring of 2000 to test the ability of a grassy roadside swale to remove pollutants in stormwater. A check dam was designed and installed into the vegetative swale. The check dam system incorporated some unique design features, including a peat filter to trap nutrients and metals and a low rock pool to trap water for the settling of suspended solids and for biological processing. The check dam was cost effective and simple to install. The system was quantified and evaluated hydrologically and qualitatively before and after the check dam installation. Pollutants monitored included total suspended solids, total phosphorus, and ortho-phosphorus. The average pollutant removal rates for the three storms following the installation of the check dam were 54 percent total phosphorus, 47 percent ortho-phosphorus, and 52 percent total suspended solids. Metals were also analyzed for two storm events, one before and one after installation of the check dam. Peat soil samples were analyzed for nutrients, organic content, water capacity, metals, and pH both before and after check dam installation. The results suggest that properly designed short vegetative strips and swales can reduce pollutant levels from the stormwater that drains off roadways.

Phytochemistry, Sep 1, 1992

... Plant Biology, St. Paul, MN). The culture medium was half strength Murashige and Skoog medium... more ... Plant Biology, St. Paul, MN). The culture medium was half strength Murashige and Skoog medium [20] with the addition of sucrose and vitamins. ... 10, 923. 5. Berlin, J. (1981) Phytochemistry 20, 53. 6. Tiburcio, AF and Galston, GW (1986) Phytochemistry 25, 107. ...

Oikos, Apr 21, 2006

Increased soil nitrogen associated with dinitrogen-fixing, terricolous lichens of the genus Pelti... more Increased soil nitrogen associated with dinitrogen-fixing, terricolous lichens of the genus Peltigera in northern Minnesota. Á Oikos 114: 37 Á48. Dinitrogen (N 2)-fixing lichens (cyanolichens) have long been recognized as a source of exogenous N in various ecosystems, yet the effects of nitrogen inputs from these lichens have been little studied. Cyanolichens of the genus Peltigera Willd. are often the dominant members of the earth-dwelling (terricolous) cyanolichen community. They occur in diverse habitats around the globe, but no studies of their influence on soil N have been reported. We conducted field and laboratory investigations with the primary objective of determining whether soil N availability is increased near healthy thalli of terricolous dinitrogen-fixing lichens. We measured available soil N in situ with ion-exchange resin bags, potentially mineralizable N with laboratory incubations, total soil N, and soil temperature. Measurements were taken along transects that extended away from thalli of Peltigera, perpendicular to and parallel to topographic contours. Studies were conducted in ten types of forest across northern Minnesota, including two contrasting sites that represent extremes of habitat for Peltigera. Soil N availability, potentially mineralizable N, and soil %N increased significantly with proximity to healthy thalli of Peltigera (P-valuesB/0.05). Moreover, potential N mineralization was highly correlated with soil %N (R 2 0/0.765). Our results suggest a potential zone of influence that extends 1.5 m from thalli of Peltigera. The data indicate that soil temperature is not a primary factor in these associations.

Canadian journal of botany, Sep 1, 1984

Seasonal changes in nitrogen fixation, numbers of nitrogen-fixing bacteria associated with the ro... more Seasonal changes in nitrogen fixation, numbers of nitrogen-fixing bacteria associated with the roots, and rhizome–root carbohydrates were studied for the broad-leaved cattail, Typha latifolia L. Populations of anaerobic and aerobic diazotrophic bacteria were present on the root surface. Anaerobic bacteria predominated in the diazotrophic association, were more active in the acetylene reduction assay, and generally outnumbered aerobic bacteria by 2 to 1 during maximum rates of seasonal nitrogen fixation. The observed maximum nitrogen fixation rate coincided closely with reproductive development in Typha and peak microbial populations. Starch levels in rhizomes were nearly depleted during the middle of the growing season, whereas free sugar concentrations remained stable. Sugar concentrations in the roots increased rapidly during rhizome–root growth and decreased rapidly prior to peak nitrogenase activity.

Canadian journal of botany, Dec 1, 1988

The acetylene-reduction technique was used on soil–root cores to examine the three species of Typ... more The acetylene-reduction technique was used on soil–root cores to examine the three species of Typha (Typhaceae) found in Minnesota for differences in rates of nitrogen fixation by associated rhizosphere diazotrophs. In 20 cattail stands sampled in 1985, Typha angustifolia showed a tendency for lower acetylene-reduction activity per ramet, with an average of 2.9 μmol∙ramer−1∙d−1, than T. latifolia and T. ×glauca, with averages of 6.5 and 7.1 μmol∙ramet−1∙d−&amp;amp;amp;amp;amp;amp;#39;, respectively. Regression analysis showed no significant differences in these values due to the variability within as well as between stands, and fixation rates were uncorrelated with the pH, soil percent carbon, and soil moisture of the study stands. In 1986, in situ assays of soil–root cores of ramets of T. angustifolia and T. latifolia from adjacent monospecific stands produced average acetylene-reduction rates of 1.4 for T. angustifolia and 1.8 μmol∙ramet−1∙d−1 for T. latifolia, with a substantial reduction in variability within stands over the 1985 data. It is estimated that, contrary to previously published reports, populations of Typha may receive as little as 1–2% of their annual nitrogen requirement from nitrogen fixation.

Canadian journal of botany, Jul 1, 1988

Nitrogen fixation in association with four plant species of a Minnesota wetland, Typha latifolia ... more Nitrogen fixation in association with four plant species of a Minnesota wetland, Typha latifolia L., Carex stricta Lam., Calamagrostis canadensis (Michx.) Beauv., and Lemna minor L., was estimated using the acetylene-reduction technique on soil – root cores. The estimated rates of nitrogen fixation (acetylene reduction) for plants growing in submerged soils, in kilograms per hectare per year, are T. latifolia, 0.91; Carex stricta, 0.47; Calamagrostis canadensis, 0.24; and L. minor, 1.90. Significantly higher fixation rates were found with plants growing in submerged areas than with those on the well-drained shore. These differences could not be correlated with differences in levels of extractable ammonium and nitrate in the substrate and were attributed to low redox potentials favoring nitrogenase activity in submerged areas. The seasonal trend in acetylene reduction activity appeared to be correlated with the reproductive stages of Typha, Carex, and Calamagrostis. Maximum acetylene reduction for these species was observed just after flower maturation, in early summer for Carex and Calamagrostis and late summer for Typha, suggesting that nitrogen fixation may be an important source of nitrogen in developing seeds. Overall, nitrogen fixation was estimated to supply as much as 11 kg N∙ha−1∙year−1 to this wetland community.

Systematic Botany, Apr 1, 1988

Natural interspecific hybridization has been proposed to account for morphological variation in t... more Natural interspecific hybridization has been proposed to account for morphological variation in the annual members of the genus Zizania, commonly known as wild-rice, although isozyme data, as reported in a single study, have disclosed no evidence of introgression. Experimental hybridizations were conducted in all possible combinations among the five varieties of the two annual species of wild-rice. Meaningful intraspecific variation in crossability was not detected, which is in agreement with morphological and isozyme data. A unilateral interspecific crossability barrier was found between the two annual species. Pistillate florets of Z. palustris typically failed to produce viable fruits when pollinated by Z. aquatica. The reciprocal interspecific cross was successful at a low level of crossability. This evidence further strengthens the taxonomic separation of the two annual species previously defined by spikelet morphology, ultrastructure, and isozyme varia- tion. Examination of pollinated stigmas of the infertile types of crosses disclosed that pollen tubes had penetrated the entire length of the stigma. The crossing barrier is therefore not due to a pollen/ stigma interaction that severely interferes with pollen tube growth. Interspecific F, hybrids ex- pressed the spikelet morphology of the Z. aquatica parent exclusively, although other morphological characters were typically expressed as intermediate to those of the parent species. The potential for natural hybridization between Z. aquatica and Z. palustris is discussed.

American Journal of Botany, May 1, 1992

Population genetic structure was analyzed in the rare, native prairie legume Lespedeza leptostach... more Population genetic structure was analyzed in the rare, native prairie legume Lespedeza leptostachya Engelm. and in the widespread L. capitata Michx. Both species produce a mixture of chasmogamous and cleistogamous flowers. Allozymes were analyzed for 32 loci from 224 individuals from 12 populations of L. leptostachya and for 34 loci in 291 individuals from 12 populations of L. capitata. L. leptostachya is entirely monomorphic at all loci studied, while L. capitata shows strong among‐population differentiation for the limited variation that occurs in that species. Allozyme data suggest that the level of gene flow among populations of L. capitata is very low, and that very low levels of outcrossing are effected by the chasmogamous flowers in L. capitata.

Journal of Natural Products, 1980

International Journal of Phytoremediation, Sep 24, 2013

The influence of flow velocity on the uptake of cadmium, copper, lead, and zinc by hydroponically... more The influence of flow velocity on the uptake of cadmium, copper, lead, and zinc by hydroponically grown soft stem bulrush (Scirpus validus) was investigated. The roots of the plants were exposed to a continually recycled, nutrient enriched, synthetic stormwater. Plants were divided into groups and the roots of each group exposed to different but constant water velocities. The metal concentrations in the roots and stems were compared after three weeks. Metal accumulation in roots was increased for water velocities between 1.3 and 4.0 cm s(-1). In a second experiment, the roots of all plants were exposed to a single velocity and the root and stem metal concentrations were determined as a function of time. Metal concentrations in the roots approached a constant value after three weeks. After this time, accumulation of metals depends upon root growth. The results suggest that long-term accumulation by the roots of hydroponic Scirpus validus can be increased by increasing water velocity, which implies that floating islands with movement will retain more metals from the water column.

American Journal of Botany, 1988

The most reliable macromorphological characters that can be used to discriminate between the annu... more The most reliable macromorphological characters that can be used to discriminate between the annual species of the genus Zizania are found in the pistillate spikelet. One aspect of this morphology is a textural dimorphism. The pistillate lemmas and paleas of Z. aquatica are chartaceous (papery) whereas those of Z. palustris are coriaceous (leathery). Pistillate lemmas and paleas of the two perennial species, Z. texana and Z. latifolia, are also chartaceous. To determine the anatomical basis for the nature of this character, pistillate lemmas and paleas were either fixed, treated with hydrofluoric acid, and sectioned; or fresh material was sectioned on a freezing microtome. Those with a chartaceous texture were found to have a single layer of thin‐walled, subepidermal fibers whereas those with a coriaceous texture had at least two layers of thick‐walled, subepidermal fibers.

American Journal of Botany, Jun 1, 1986

Page 1. Amer. J. Bot. 73(6): 847-851. 1986. IDENTIFICATION OF LATICIFERS IN EMBRYOIDS DERIVED FRO... more Page 1. Amer. J. Bot. 73(6): 847-851. 1986. IDENTIFICATION OF LATICIFERS IN EMBRYOIDS DERIVED FROM CALLUS AND SUSPENSION CULTURES OF ASCLEPIAS SPECIES (ASCLEPIADACEAE)1 KERRY B. DUNBAR ...

Verhandlungen, Jul 1, 2002

Nordic Journal of Botany, Aug 1, 1981

The micromorphology of starch grains in the nonarticulated laticifer was examined in 200 taxa of ... more The micromorphology of starch grains in the nonarticulated laticifer was examined in 200 taxa of succulent and nonsucculent Euphorbia. Rod, spindle, osteoid, discoid and intermediate shapes were found in latex. These unusual starch grain shapes are assumed derivatives from more rounded grains present in other angiospermous cells. Unbranched, rod-shaped grains were present in latex of annual and perennial herbaceous taxa. Spindle, osteoid, and discoid shapes, often branched, occurred in xerophytic, succulent taxa. Leafy taxa in several subgenera possessed rod-shaped grains. Taxa of the primitive subgenus, Esula, possessed the shortest rod-shaped grains derived from rounded grains common in parenchyma. Length of rod-shaped grains increased through herbaceous subgenera and culminated in Poinsettia where grain length may be extremely great. Dwarf or shrubby succulents with thickened roots have osteoid grains. Shrubby or arborescent coralline and cactiform species, specialized taxa, possessed large branched grains. Grain morphology of Euphorbia was compared with that from latex of other genera of the Euphorbiaceae. These in-depth analyses of laticifer plastids demonstrates the applicability of starch grain morphology for interpreting the progressive evolution of the nonarticulated laticifer as a cell type within the genus Euphorbia.

Planta, 1978

Starch biosynthesis and degradation was studied in seedlings and mature plants of Euphorbia heter... more Starch biosynthesis and degradation was studied in seedlings and mature plants of Euphorbia heterophylla L. and E. myrsinites L. Mature embryos, which lack starch grains in the non-articulated laticifers, develop into seedlings that accumulate starch rapidly when grown either in the light or the dark. Starch accumulation in laticifers of dark-grown seedlings was ca. 47 and 43% of total starch in light-grown controls in E. heterophylla and E. myrsinites, respectively. In light-grown seedlings, starch was present in laticifers as well as parenchyma of stems and leaves, whereas in dark-grown seedlings starch synthesis was almost exclusively limited to laticifers. In 7-month-old plants placed into total darkness, the starch in parenchyma was depleted within 6 d, whereas starch in laticifers was not mobilized. The starch content of latex in plants during development of floral primordia, flowering, and subsequent fruit formation remained rather constant. The results indicate that laticifers in seedlings divert embryonal storage reserves to synthesize starch even under stress conditions (darkness) in contrast to other cells, and that starch accumulated in laticifers does not serve as a metabolic reserve. The laticifer in Euphorbia functions in the accumulation and storage of secondary metabolites yet retains the capacity to produce, but not utilize starch, a primary metabolite.

Journal of Chromatography A, 1984