Chemistry Reference
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extrapolations are essential to avoid mistaken views and phenomena in a certain scale for
larger or smaller scales. As the scale is broaden, more interactions occur between the
growing number of compartments of the system, making it more difficult and laborious to
study the cause-effect relationships from models based on processes.
Thus, this study aims to describe the ecophysiological behavior of
Eucalyptus grandis x
Eucalyptus urophylla
at the leaf level in association with environmental variables in three
stages of development, in order to provide subsidies for the development of models that
can predict the ecophysiological responses of a lower scale and its extrapolation to a
larger scale.
2. Determining the scales
For a description and quantification on the water flow of
Eucalyptus grandis x Eucalyptus
urophylla
, in order to integrate information on the leaf scale from lower scales to a larger
scale, the study was conducted in three different ages (scales) of different plant
development, known as: pot, plot and watershed. For each scale, the seedlings of
Eucalyptus
grandis x Eucalyptus urophylla
were produced by the method of mini-cuttings in plastic tubes
in the clonal nursery. Within approximately 120 days, when they reached the conditions for
dispatch to the field, were destined for planting in:
Pot Scale:
The seedlings were transported to the experimental field of School Agricultural
Engineering, University of Campinas - FEAGRI / UNICAMP and transplanted to pots of 100
dm³ (Figure 1a). These pots had circular holes in their sides and bottom, in order to allow
better root aeration and drainage of excess water. The substrate was composed of
vermiculite, coconut fiber and rice hulls. The ecophysiological study began 120 days after
pot planting and measurements of transpiration, stomatal conductance, leaf water potential,
photosynthetic active radiation and atmospheric vapor pressure deficit were carried out
from February 2007 to June 2008.
Plot Scale:
The seedlings were transferred to the experimental area of FEAGRI/UNICAMP
and planted at 3 x 2 m spacing forming a clonal population. The predominant soil of the
experimental area is classified as typical dystroferric Hapludox [9]. The ecophysiological
study began at 240 days after planting (Figure 1b) and to assist data acquisition it was
necessary to implant a measurement tower of 3 meters in height disposed between the crop
rows to reach the treetops. The ecophysiological monitoring of transpiration, stomatal
conductance, leaf water potential, photosynthetic active radiation and atmospheric vapor
pressure deficit was conducted from January to July 2008.
Watershed Scale:
The study was conducted at Santa Marta Farm, located in the Igaratá, São
Paulo State. The geomorphological division of the State of Sao Paulo, according to the
Institute for Technological Research [16], the study area is located in the Atlantic plateau
that is characterized as a highland region, consisting predominantly of Precambrian
crystalline rocks, cut by basic intrusive and alkaline Mesozoic-Tertiary rocks. The relief of
