Chemistry Reference
In-Depth Information
Scaling Up of Leaf Transpiration and
Stomatal Conductance of
Eucalyptus grandis x
Eucalyptus urophylla
in Response
to Environmental Variables
Kelly Cristina Tonello and José Teixeira Filho
Additional information is available at the end of the chapter
http://dx.doi.org/10.5772/55288
1. Introduction
Estimates of water use by plants are becoming increasingly important to forest science.
Researchers apply water use estimates to predict the control of canopy conductance and
transpiration [14, 26, 46], where this information is useful to help troubleshooting the water
resources management [37, 24, 32], the role of transpiration in native forests [3] and to quantify
the demand for water in short rotation forests and in plantations of
Eucalyptus
sp [10, 40, 41].
The growth and development of plants is a consequence of several physiological processes
controlled by environmental conditions and genetic characteristics of each plant species.
Therefore, in order to better understand the growth, development and hydrological impact
of a
Eucalyptus
plantation, it is necessary to know the factors that control water use. Great
efforts come up in order to investigate the contribution of water balance components in the
productivity of eucalyptus, with the need to integrate the effects of climate and management
practices on the production of wood from planted forests of Eucalyptus.
Process-based models consist in evidence-based relationships, which necessarily contain a
relation of cause and effect, whether physical or biological [42]. A fundamental aspect of
ecological processes is that they are affected by spatial and temporal dimensions. In spatial
terms, for example, measurements made on a leaf in terms of net primary productivity, can
not be extrapolated directly to the tree's canopy , because for this extrapolation is necessary
knowledge about the distribution of the canopy, the arrangement of leaves, availability of
soil water and others. Likewise, the extrapolation to the forest and the ecosystem needs
information previously dispensable in smaller scales. This notion of scales and their
