Considering plant structure in models of plant growth and development

Source: OAI
Download full-text


Available from: Jan Vos, Oct 03, 2015
1 Follower
19 Reads
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The sensitivity of the North Atlantic thermohaline circulation to the input of fresh water is studied using a global ocean circulation model coupled to a simplified model atmosphere. Owing to the nonlinearity of the system, moderate changes in freshwater input can induce transitions between different equilibrium states, leading to substantial changes in regional climate. As even local changes in freshwater flux are capable of triggering convective instability, quite small perturbations to the present hydrological cycle may lead to temperature changes of several degrees on timescales of only a few years.
    Nature 11/1995; 378(6553):145-149. DOI:10.1038/379847b0 · 41.46 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Eutrophic and dystrophic states of lake ecosystems are associated with distinct differences in phosphorus (P) input, refractory dissolved organic carbon (RDOC) input, and certain internal processes. Eutrophic lakes have high P input and high primary production. Dystrophic lakes have high RDOC input. In both types of lake, bacterial metabolism may help reduce RDOC levels. In dystrophic lakes, bacterial metabolism may be suppressed by low pH, and primary production is reduced due to light attenuation by RDOC. We analyzed several simple models to ask whether eutrophy and dystrophy are alternative stable states of lake ecosystems. In-lake processes could create alternative states under certain circumstances, but more likely watershed processes maintain eutrophy or dystrophy through contrasts in inputs of P and RDOC. Simulations suggest that pulses of RDOC result in dystrophic conditions that reverse very slowly. Land-use changes or climate fluctuations that change RDOC input rates may have long-lasting effects on trophic state of temperate and boreal lakes. Lack of information on microbial degradation of RDOC, and the dependency of degradation rate on RDOC levels, primary production, and pH, are major sources of uncertainty in our analysis and are suggested as priorities for further research.
    Oikos 02/1997; 78(1). DOI:10.2307/3545794 · 3.44 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: During the next 50 years, which is likely to be the final period of rapid agricultural expansion, demand for food by a wealthier and 50% larger global population will be a major driver of global environmental change. Should past dependences of the global environmental impacts of agriculture on human population and consumption continue, 10(9) hectares of natural ecosystems would be converted to agriculture by 2050. This would be accompanied by 2.4- to 2.7-fold increases in nitrogen- and phosphorus-driven eutrophication of terrestrial, freshwater, and near-shore marine ecosystems, and comparable increases in pesticide use. This eutrophication and habitat destruction would cause unprecedented ecosystem simplification, loss of ecosystem services, and species extinctions. Significant scientific advances and regulatory, technological, and policy changes are needed to control the environmental impacts of agricultural expansion.
    Science 05/2001; 292(5515):281-4. DOI:10.1126/science.1057544 · 33.61 Impact Factor
Show more