Person:
Marshall, Charles

Profile Picture

Email Address

AA Acceptance Date

Birth Date

Research Projects

Organizational Units

Job Title

Last Name

Marshall

First Name

Charles

Name

Marshall, Charles

Filters

2008 - 200912010 - 20171

Settings

Author's Publications: search.filters.isAuthorOfPublication.658f0316-f34b-428b-b29e-7557f2bbbab7

Search Results

Now showing 1 - 2 of 2
  • No Thumbnail Available
    Publication
    Merging paleobiology with conservation biology to guide the future of terrestrial ecosystems
    (American Association for the Advancement of Science (AAAS), 2017) Barnosky, Anthony D.; Hadly, Elizabeth A.; Gonzalez, Patrick; Head, Jason; Polly, P. David; Lawing, A. Michelle; Eronen, Jussi T.; Ackerly, David D.; Alex, Ken; Biber, Eric; Blois, Jessica; Brashares, Justin; Ceballos, Gerardo; Davis, Edward; Dietl, Gregory P.; Dirzo, Rodolfo; Doremus, Holly; Fortelius, Mikael; Greene, Harry W.; Hellmann, Jessica; Hickler, Thomas; Jackson, Stephen T.; Kemp, Melissa; Koch, Paul L.; Kremen, Claire; Lindsey, Emily L.; Looy, Cindy; Marshall, Charles; Mendenhall, Chase; Mulch, Andreas; Mychajliw, Alexis M.; Nowak, Carsten; Ramakrishnan, Uma; Schnitzler, Jan; Das Shrestha, Kashish; Solari, Katherine; Stegner, Lynn; Stegner, M. Allison; Stenseth, Nils Chr.; Wake, Marvalee; Zhang, Zhibin
    Conservation of species and ecosystems is increasingly difficult because anthropogenic impacts are pervasive and accelerating. Under this rapid global change, maximizing conservation success requires a paradigm shift from maintaining ecosystems in idealized past states toward facilitating their adaptive and functional capacities, even as species ebb and flow individually. Developing effective strategies under this new paradigm will require deeper understanding of the long-term dynamics that govern ecosystem persistence, and reconciliation of conflicts among approaches to conserving historical versus novel ecosystems. Integrating emerging information from conservation biology, paleobiology, and the Earth sciences is an important step forward on the path to success. Maintaining nature in all its aspects will also entail immediately addressing the overarching threats of growing human population, overconsumption, pollution and climate change.
  • Thumbnail Image
    Publication
    Modeling Fluid Flow in Medullosa, an Anatomically Unusual Carboniferous Seed Plant
    (Paleontological Society, 2008) Wilson, Jonathan; Knoll, Andrew; Holbrook, N. Michele; Marshall, Charles
    Medullosa stands apart from most Paleozoic seed plants in its combination of large leaf area, complex vascular structure, and extremely large water-conducting cells. To investigate the hydraulic consequences of these anatomical features and to compare them with other seed plants, we have adapted a model of water transport in xylem cells that accounts for resistance to flow from the lumen, pits, and pit membranes, and that can be used to compare extinct and extant plants in a quantitative way. Application of this model to Medullosa, the Paleozoic coniferophyte Cordaites, and the extant conifer Pinus shows that medullosan tracheids had the capacity to transport water at volume flow rates more comparable to those of angiosperm vessels than to those characteristic of ancient and modern coniferophyte tracheids. Tracheid structure in Medullosa, including the large pit membrane area per tracheid and the high ratio of tracheid diameter to wall thickness, suggests that its xylem cells operated at significant risk of embolism and implosion, making this plant unlikely to survive significant water stress These features further suggest that tracheids could not have furnished significant structural support, requiring either that other tissues supported these plants or that at least some medullosans were vines. In combination with high tracheid conductivity, distinctive anatomical characters of Medullosa such as the anomalous growth of vascular cambium and the large number of leaf traces that enter each petiole base suggest vascular adaptations to meet the evapotranspiration demands of its large leaves. The evolution of highly efficient conducting cells dictates a need to supply structural support via other tissues, both in tracheid-based stem seed plants and in vessel-bearing angiosperms.