Life Sciences Commons^™

A Phylogenomic Approach Reveals A Low Somatic Mutation Rate In A Long-Lived Plant., Adam J Orr, Amanda Padovan, David Kainer, Carsten Kulheim, Lindell Bromham, Carlos Bustos-Segura, William Foley, Tonya Haff, Ji-Fan Hsieh, Alejandro Morales-Suarez, Reed A Cartwright, Robert Lanfear

Michigan Tech Publications

Somatic mutations can have important effects on the life history, ecology, and evolution of plants, but the rate at which they accumulate is poorly understood and difficult to measure directly. Here, we develop a method to measure somatic mutations in individual plants and use it to estimate the somatic mutation rate in a large, long-lived, phenotypically mosaic Eucalyptus melliodora tree. Despite being 100 times larger than Arabidopsis, this tree has a per-generation mutation rate only ten times greater, which suggests that this species may have evolved mechanisms to reduce the mutation rate per unit of growth. This adds to a …

Chromosomal Distribution Of Genes Conferring Tolerance To Abiotic Stresses Versus That Of Genes Controlling Resistance To Biotic Stresses In Plants, Richard R.-C. Wang

Forage and Range Research Laboratory Publications

Tolerance to abiotic stresses caused by environmental conditions can prevent yield loss in crops for sustaining agricultural productivity [1]. Resistance to biotic stresses caused by diseases and insects can prevent or reduce yield loss in crops [2]. For each crop or plant species, there are many abiotic threats, such as changes in temperature, soil salinity/alkalinity, water shortage, and soil contaminants, as well as biotic challenges from pathogens (bacteria, viruses, and fungi), insects, and nematodes. Plants need to possess genes conferring tolerance to these abiotic stresses to adapt to the changing environment, due to global climate changes, in which they are …

Overexpression Of Constans Homologs Co1 And Co2 Fails To Alter Normal Reproductive Onset And Fall Bud Set In Woody Perennial Poplar., Chuan-Yu Hsu, Joshua P. Adams, Kyoungok No, Haiying Liang, Richard Meilan, Olga Pechanova, Abdelali Barakat, John E. Carlson, Grier P. Page, Cetin Yuceer

College of Forest Resources Publications and Scholarship

CONSTANS (CO) is an important flowering-time gene in the photoperiodic flowering pathway of annual Arabidopsis thaliana in which overexpression of CO induces early flowering, whereas mutations in CO cause delayed flowering. The closest homologs of CO in woody perennial poplar (Populus spp.) are CO1 and CO2. A previous report showed that the CO2/FLOWERING LOCUS T1 (FT1) regulon controls the onset of reproduction in poplar, similar to what is seen with the CO/FLOWERING LOCUS T (FT) regulon in Arabidopsis. The CO2/FT1 regulon was also reported to control fall bud set. Our long-term field observations show that overexpression of CO1 and CO2 …

Slides: Delta Overview, Leo Winternitz

Western Water Law, Policy and Management: Ripples, Currents, and New Channels for Inquiry (Martz Summer Conference, June 3-5)

Presenter: Leo Winternitz, The Nature Conservancy, California Water Program, Sacramento, CA

17 slides

Evaluating Hazelnut Cultivars For Yield, Quality And Disease Resistance, Sam Tobin

Department of Environmental Studies: Undergraduate Student Theses

ABSTRACT This long term study focuses on testing various hazelnut cultivars for yield, nut quality and disease resistance. There are various cultivars that are being tested for these desired traits but only the Grand Traverse and Skinner will be applicable for the results of this localized study. The desired traits of commercial nut production are best matched by these two cultivars. Results from previous harvests will be used to draw trends to recommend commercially functional cultivars in Eastern Nebraska.

Variations In Stomatal Traits Of 14 Bornean Tree Species Growing On Soils With Different Moisture Contents In Lambir Hills National Park, Whitney Logan Cannon

Department of Environmental Studies: Undergraduate Student Theses

The goal of this study was to look at variations in stomatal traits of tree species on soils with different moisture contents and fertility at Lambir Hills National Park. Stomates are important structures on the surface of leaves that mediate conduction of moisture and gassesin and out of the leaf. If stomatalt raits are important for regulation, then there should be variation in stomatal traits in regards to their soil specialization. The 14 Borneant ree speciess ampledi ncluded6 sandyl oam specialists6, clay specialistsa nd 2 generalistsfo und growing with equald istributionso n both sandyl oam and clay. Confocal microscopy was …

Slides: City Of Arcata Community Forest, Mark André

Community-Owned Forests: Possibilities, Experiences, and Lessons Learned (June 16-19)

Presenter: Mark André, Arcata, CA, Community Forest

42 slides

Wildland Fire In Ecosystems Effects Of Fire On Flora, R. James Ansley, Stephen F. Arno, Brent L. Brock, Patrick H. Brose, James K. Brown, Luc C. Duchesne, James B. Grace, Gerald J. Gottfried, Sally M. Haase, Michael G. Harrington, Brad C. Hawkes, Greg A. Hoch, Melanie Miller, Ronald L. Myers, Marcia G. Narog, William A. Patterson Iii, Timothy E. Paysen, Kevin C. Ryan, Stephen S. Sackett, Dale D. Wade, Ruth C. Wilson

Joint Fire Science Program Synthesis Reports

This state-of-knowledge review about the effects of fire on flora and fuels can assist land managers with ecosystem and fire management planning and in their efforts to inform others about the ecological role of fire. Chapter topics include fire regime classification, autecological effects of fire, fire regime characteristics and postfire plant community developments in ecosystems throughout the United States and Canada, global climate change, ecological principles of fire regimes, and practical considerations for managing fire in an ecosytem context.

Toxicity Of Aspen Wood Leachate To Aquatic Life: Laboratory Studies, Barry R. Taylor, J. Stephen Goudey, N. Bruce Carmichael

Aspen Bibliography

No abstract provided.

Characterization Of Aspen Isoprene Synthase, An Enzyme Responsible For Leaf Isoprene Emission To The Atmosphere, Gary M. Silver, Ray Fall

Aspen Bibliography

Isoprene (2-methyl-1,3-butadiene) is a volatile hydrocarbon emitted from many plant species to the atmosphere, where it plays an important role in atmospheric chemistry. An enzyme extracted from aspen (Populus tremuloides) leaves was previously found to catalyze the Mg2+-dependent elimination of pyrophosphate from dimethylallyl diphosphate (DMAPP) to form isoprene (Silver, G. M., and Fall, R.(1991) Plant Physiol. 97, 1588-1591). This enzyme, isoprene synthase, has now been purified 4000-fold to near homogeneity. The enzyme had a native molecular mass of 98-137 kDa and isoelectric point of 4.7 and contained 58- and 62-kDa subunits, implying that it is a heterodimer. …

Carbon Allocation And Partitioning In Aspen Clones Varying In Sensitivity To Tropospheric Ozone, M.D. Coleman, R.E. Dickson, J.G. Isebrands, D.F. Karnosky

Aspen Bibliography

No abstract provided.

Hydraulic Lift And Soil Nutrient Heterogeneity, Martyn M. Caldwell, John H. Manwaring

Green Canyon Environmental Research Area, Logan Utah

Water released at night from roots into upper portions of the soil profile in the process of hydraulic lift may contribute to reducing spatial soil nutrient heterogeneity. A manipulative field experiment was conducted in a semiarid shrub stand to determine if circumvention of hydraulic lift, by nighttime illumination of the shrub canopy, would result in greater soil nutrient heterogeneity than if the hydraulic lift process was allowed to operate. Nutrient-enriched patches were superimposed on the existing soil heterogeneity and after 40 days, the patches and interspaces were sampled for ions of different mobility and for root mass. There was no …

Moose (Alces Alces L.) Browsing In Young Scots Pine Stands In Relation To The Characteristics Of Their Winter Habitats, Risto Heikkila, Sauli Harkonen

Aspen Bibliography

Moose (Alces alces L.) browsing was studied in young Scots pine (Pinus sylvestris L.) stands mixed with deciduous trees in high-density winter ranges. The proportional use of twig biomass decreased as the availability increased. The total as well as proportional biomass consumption were higher on the moist than on the dry type of forest. The per tree consumption of pine was higher on the moist type, where the availability of pine was lower. Deciduous trees were more consumed on the moist type, where their availability was relatively high. The consumption of pine saplings increased as the availability of …

Compositions Of Bud And Leaf Exudates Of Some Populus Species, W. Greenaway, J. May, T. Scaysbrook, F.R. Whatley

Aspen Bibliography

Bud and leaf exudates from Populus alba, P. balsam ifera, P. nigra and P. tremuloides were analyzed by gas chromatography/mass spectrometry and their components were identified. For three of the four species, P. alba, P. balsam ifera and P. nigra, the bud and leaf exudates were similar within each species, though there were marked differences between species. Bud and leaf exudates of P. alba contained only hydrocarbons, those of P. balsam ifera contained primarily dihydrochalcones and those of P. nigra contained primarily caffeic acid esters. Bud and leaf exudates of P. tremuloides were different both from each other and from …

Response Of Breeding Birds To Commercial Clearcutting Of Aspen In Southwestern Colorado [Usa], V.E. Scott, G.L. Crouch

Aspen Bibliography

Breeding birds on an aspen forest in southwestern Colorado increased in species diversity after 25% of the timber sale area forest was clearcut in patches of 3 to 20 acres. Bird population density on the forest with clearcuts was not significantly different from that on an uncut forest. Of the 20 species evaluated, six were more and one was less abundant than on the uncut forest.

Vertical Migration Of Onychiurus Subtenuis (Collembola) In Relation To Rainfall And Microbial Activity, M. Hassall, S. Visser, D. Parkinson

Aspen Bibliography

No abstract provided.

Fire Effects In Northeastern Forests: Aspen, C. Rouse

Aspen Bibliography

No abstract provided.

Predicting Soil Moisture Depletion Beneath Trembling Aspen, D. Mital, E. Sucoff

Aspen Bibliography

No abstract provided.

An Indirect Method To Estimate The Aerial Biomass Of Small Single Stemmed Woody Plants, R.D. Fitzgerald

Aspen Bibliography

No abstract provided.

The Utilization Of Carbohydrates In Aspen Roots Following Partial Or Complete Top Removal, R.D. Fitzgerald, J. Hoddinott

Aspen Bibliography

No abstract provided.

Decomposition Rates Of Aspen Bole And Branch Litter, W.E. Miller

Aspen Bibliography

No abstract provided.

Fire Behaviour In Aspen Slash Fuels As Related To The Canadian Fire Weather Index, M.E. Alexander

Aspen Bibliography

The characteristics and short-term results of experimental prescribed fires in 2-year-old trembling aspen (Populus tremuloides Michx.) logging slash in northern Minnesota have been described by D. A. Perala (1974. Can. J. For. Res. 4: 222-228). The associated burning conditions are expressed here in terms of the weather-dependent numerical fuel moisture codes and fire behavior indexes of the Canadian system of forest fire danger rating.

Natural Variation In Merchantable Stem Biomass And Volume Among Clones Of Populus Tremuloides Michx, G.A. Lehn, K.O. Higginbotham

Aspen Bibliography

No abstract provided.

Effect Of Container Size And Harvest Date On The Growth Of Quaking Aspen Populus-Tremuloides Seedlings, L. A. Erhard, J. T. Fisher

Aspen Bibliography

Quaking Aspen (Populus tremuloides Michaux) were
greenhouse grown in four sizes of paraffin-coated containers: 185 cubic centimeters (11 cubic inches), 492 cubic centimeters (30 cubic inches), 1132 cubic centimeters (68 cubic inches), and 1472 cubic centimeters (90cubic inches).

Ecotypic Differences In Heat Resistance Of Aspen Leaves, K.M. Peck, S.J. Wallner

Aspen Bibliography

Heat resistance of aspen (Populus tremuloides) leaves was assessed by stressing leaf discs in vitro and measuring electrolyte leakage. Leaves were obtained from trees growing at elevations of 1960, 2195, and 2454 m. Heat tolerance was greatest in leaf samples from trees growing at the lowest site. Trees propagated from these sites and grown at 1520 m for 2 years showed some increase in heat tolerance, but apparent ecotypic differences persisted

Aspen Resource Of Minnesota Usa, P.J. Jakes

Aspen Bibliography

No abstract provided.

Cryptosphaeria Canker And Libertella Decay Of Aspen, Thomas E. Hinds

Aspen Bibliography

A recently discovered, widely distributed canker disease of aspen and other poplars throughout the Rocky Mountain region is described. Inoculations with ascospore and conidial isolates of Cryptosphaeria populina show the fungus is capable of causing branch, sprout, and sapling mortality, trunk cankers, and the discoloration and decay of aspen stems previously associated with its imperfect stage, Libertella sp. The greatest average canker elongation 50 mo after September inoculations was 33.5 cm with sapwood decay and discoloration extending to 401 cm. The fungus caused an average weight loss of 13.5% in bark, 27.0% in sapwood, and 19.1% in heartwood blocks. Incidence …

Utilization Of Aspen Populus-Tremuloides Trees As A Ruminant Feed Component, M. Singh, L.D. Kamstra

Aspen Bibliography

When traditional roughages are in short supply or high in price, other fibrous feed sources for ruminants should be considered if available at a competitive price. One such fibrous material shown to have potential as a ruminant feed is the aspen tree (Populus tremuloides Michx.) harvested in its entire form to include bark, leaves and trunk. The aspen tree is the most widespread tree species in North America and the least utilized. Estimates exceed 6 million acres of mature trees in an area which would include the Black Hills (58,000 acres), the Great Lakes region and the Rocky …

Biomass And Production Of An Aspen-Mixed Hardwood-Spodosol Ecosystem In Northern Wisconsin, John Pastor, J.G. Bockheim

Aspen Bibliography

No abstract provided.

An Approach To Functionalizing Key Environmental Factors Forage Production In Rocky Mountain Aspen Populus-Tremuloides Stands, J.P. Roise, D.R. Betters, B.M. Kent

Aspen Bibliography

No abstract provided.