Ecohydrology: Darwinian Expression of Vegetation Form and Function

Modelling simulations of palaeoclimate and past vegetation form and function can contribute to global change research by constraining predictions of potential earth system responses to future warming, and by providing useful insights into the ecophysiological tolerances and threshold responses of plants to varying degrees of atmospheric change. We contrasted HadCM3LC simulations of Amazonian forest at the last glacial maximum (LGM; 21 kyr ago) and a Younger Dryas–like period (13–12 kyr ago) with predicted responses of future warming to provide estimates of the climatic limits under which the Amazon forest remains relatively stable. Our simulations indicate that despite lower atmospheric CO 2 concentrations and increased aridity during the LGM, Amazonia remains mostly forested, and that the cooling climate of the Younger Dryas–like period in fact causes a trend toward increased above–ground carbon balance relative to today. The vegetation feedbacks responsible for maintaining forest integrity in past climates (i.e. decreased evapotranspiration and reduced plant respiration) cannot be maintained into the future. Although elevated atmospheric CO 2 contributes to a positive enhancement of plant carbon and water balance, decreased stomatal conductance and increased plant and soil respiration cause a positive feedback that amplifies localized drying and climate warming. We speculate that the Amazonian forest is currently near its critical resiliency threshold, and that even minor climate warming may be sufficient to promote deleterious feedbacks on forest integrity.

Download Full-text

Ecohydrology: a synthesis of Newtonian and Darwinian world views. Ecohydrology of Water-Controlled Ecosystems: Soil Moisture and Plant Dynamics. I. Rodriguez-Iturbe and A. Porporato.Cambridge University Press ISBN 0-521-81943-1 Published 2005. Ecohydrology: Darwinian Expression of Vegetation Form and Function. Peter S. Eagleson.Cambridge University Press ISBN 0-521-77245-1 Published 2002

Hydrological Processes ◽

10.1002/hyp.5884 ◽

2005 ◽

Vol 19 (11) ◽

pp. 2315-2317 ◽

Cited By ~ 1

Author(s):

Theodore A. Endreny

Keyword(s):

Soil Moisture ◽

World Views ◽

Form And Function ◽

Plant Dynamics ◽

Vegetation Form ◽

And Function

Download Full-text

Book Review: Ecohydrology: Darwinian expression of vegetation form and function

Progress in Physical Geography Earth and Environment ◽

10.1177/030913330302700412 ◽

2003 ◽

Vol 27 (4) ◽

pp. 630-631

Author(s):

Barbara A. Kennedy

Keyword(s):

Form And Function ◽

Vegetation Form ◽

And Function

Download Full-text

Scanning tunneling microscopy (STM) of DNA and RNA

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100152148 ◽

1989 ◽

Vol 47 ◽

pp. 34-35

Author(s):

Patricia G. Arscott ◽

Gil Lee ◽

Victor A. Bloomfield ◽

D. Fennell Evans

Keyword(s):

Molecular Structures ◽

Inorganic Materials ◽

Resolving Power ◽

Scanning Tunneling ◽

Tunneling Microscopy ◽

Form And Function ◽

Dna And Rna ◽

Calf Thymus ◽

And Function ◽

The Relationship

STM is one of the most promising techniques available for visualizing the fine details of biomolecular structure. It has been used to map the surface topography of inorganic materials in atomic dimensions, and thus has the resolving power not only to determine the conformation of small molecules but to distinguish site-specific features within a molecule. That level of detail is of critical importance in understanding the relationship between form and function in biological systems. The size, shape, and accessibility of molecular structures can be determined much more accurately by STM than by electron microscopy since no staining, shadowing or labeling with heavy metals is required, and there is no exposure to damaging radiation by electrons. Crystallography and most other physical techniques do not give information about individual molecules.We have obtained striking images of DNA and RNA, using calf thymus DNA and two synthetic polynucleotides, poly(dG-me5dC)·poly(dG-me5dC) and poly(rA)·poly(rU).

Download Full-text