58 research outputs found

    Morphology and foliar chemistry of containerized Abies fraseri (Pursh) Poir. seedlings as affected by water availability and nutrition

    Get PDF
    • We present the results of a two-year (2007–2008) greenhouse study investigating the effect of water availability and nitrogen fertilization on the growth, biomass partitioning, and foliar nutrient content of Abies fraseri (Pursh) Poir. • Fertilizer and moisture content (irrigation) were varied in a factorial experiment combining four levels of irrigation and three levels of fertilization to evaluate growth and foliar nutrient content. In addition, a numerical optimization was used to estimate appropriate levels of each factor necessary to achieve simulated goals for response variables. • Irrigation increased the height growth by 12 to 35% depending on the fertilization treatment (p = 0.0001). Fertilization increased height growth by 10 to 26% (p = 0.02). A similar response was observed for stem diameter growth (SDG). Total biomass accumulation increased as result of positive response of stem and root biomass development, and foliar nitrogen content was positively affected by nitrogen fertilization and negatively affected by irrigation. The numerical optimization for simulated target growth and nitrogen content responses produced levels of input combinations with high desirability factors to achieve the target responses. • These results suggest that nutrient addition is a strong determining factor for early development of this species. The improved growth efficiency in this study is likely attributed to a combination of factors including, improved photosynthetic capacity, decreased stomatal limitations, or increased resource allocation to stems

    Above- and below-ground biomass accumulation, production, and distribution of sweetgum and loblolly pine grown with irrigation and fertilization.

    Get PDF
    Abstract: Increased forest productivity has been obtained by improving resource availability through water and nutrient amendments. However, more stress-tolerant species that have robust site requirements do not respond consistently to irrigation. An important factor contributing to robust site requirements may be the distribution of biomass belowground, yet available information is limited. We examined the accumulation and distribution of above- and below-ground biomass in sweetgum (Liqrridambar sfyrac$lua L.) and loblolly pine (Pinus taeda L.) stands receiving irrigation and fertilization. Mean annual aboveground production after 4 years ranged from 2.4 to 5.1 ~g.ha-'.year' for sweetgum and from 5.0 to 6.9 ~g.ha-l.year-l for pine. Sweetgum responded positively to irrigation and fertilization with an additive response to irrigation + fertilization. Pine only responded to fertilization. Sweetgum root mass fraction (RME)in creased with fertilization at 2 years and decreased with fertilization at 4 years. There were no detectable treatment differences in loblolly pine RMF. Development explained from 67% to 98% of variation in shoot versus root allometry for ephemeral and perennial tissues, fertilization explained no more than 5% of the variation in for either species, and irrigation did not explain any. We conclude that shifts in allocation from roots to shoots do not explain nutrient-induced growth stimulations

    Why is management research irrelevant?

    Get PDF
    At least since 1980, there has been a practically continuous, but somewhat fragmented discussion on the relevance of management research. This discussion has addressed practically all fields of management; here, besides general management, operations management, project management and construction management are examined in more detail. Although many different proposals have been made to rectify the situation, no definitive resolution has been found. In this paper, it is argued that prior analyses have not reached the root causes of the irrelevance problem. By an analysis of the recent history of management research, the following novel findings are reached. First, the root cause of the irrelevance is argued to lie in the 1959 reports on American business education, written by Pierson and Gordon & Howell. Second, while the proposed direction in the 1959 reports was deficient in several ways, the rejection of production as an integral part of organizations and management has been perhaps the most damaging feature of those reports. Third, current research on management suffers from a variety of immediate causes for irrelevance, insufficiently recognized by the scholarly community. It is suggested that reaching the root causes for irrelevance will facilitate finding suitable cures

    Piracy Control Using Secure Disks

    No full text

    Monopoly experimentation

    No full text
    Available from Centro de Informacion y Documentacion Cientifica CINDOC. Joaquin Costa, 22. 28002 Madrid. SPAIN / CINDOC - Centro de Informaciòn y Documentaciòn CientìficaSIGLEESSpai
    • …
    corecore