Tesis
Intercâmbio gasoso e relações hídricas de duas espécies de Combretum no Pantanal mato-grossense
Fecha
2015-02-23Registro en:
PRADO, Magdiel Josias do. Intercâmbio gasoso e relações hídricas de duas espécies de Combretum no Pantanal mato-grossense. 2015. vi, 53 f. Dissertação (Mestrado em Física Ambiental) - Universidade Federal de Mato Grosso, Instituto de Física, Cuiabá, 2015.
Autor
Ortíz, Carmen Eugenia Rodríguez
http://lattes.cnpq.br/2783222284467182
Ortíz, Carmen Eugenia Rodríguez
830.350.526-20
http://lattes.cnpq.br/2783222284467182
Lobo, Francisco de Almeida
346.659.001-91
http://lattes.cnpq.br/0296723198831816
830.350.526-20
Pereira, Eduardo Gusmão
830.350.526-20
http://lattes.cnpq.br/5808479722023755
Institución
Resumen
The North Pantanal of Mato Grosso is characterized by four seasonal periods: the
flood, full, the ebb and dry. These periods determine an intense variation in water
availability and the degree of oxygenation of the soil of the region, acting as a
selective filter that allows only the species with adaptability able to survive there.
Considering these aspects, the aim of this study was to analyze the adaptive capacity
of two species of the genus Combretum, C. lanceolatum Pohl ex Eickl and C. laxum
Jacq, listed as invasive species in the region. Two physiological aspects were taken
into account in this assessment, the gas exchange and water relations. For both
aspects analyzed were measured variables inherent in each of the four seasonal
periods. For gas exchange, measurement was performed using a portable infrared gas
analyzer, Model LI-6400 (Li-COR Inc., Lincoln, NE, USA) and water relations
analysis was used a pressure type pump Scholander. It was observed that the
seasonality, affected in a particular way the gas exchange of the species studied.
Although both species occur extensively in the Pantanal, which in itself is an
indicator of the adaptability of the same location, the physiological strategies adopted
by them are different. Carbon assimilation of view, while the ebb period causes a
reduction in photosynthetic rate of C. lanceolatum, is the dry season, which causes
the same effect on C. laxum. While the reduction in net photosynthetic rate in C.
laxum may be associated with a stomatal effect because this period, regardless of
species, when there is the lowest value of stomatal conductance; for C. lanceolatum
the reduction must be more related to aspects not stomatal. In water relations noted
that the resaturation capacity of both species with varied seasonally, being more
effective during flood periods and full and less effective during ebb tide and dried.
Both species showed no significant changes in relative water content at full turgor
and bulk modulus of elasticity of the cell wall. Changes in osmotic potential at full
turgor and swelling incipient not clearly reveal the search for a seasonal adjustment
of these variables. Apparently, the relative constancy of variable water relations
values observed for both species along seasonal periods suggests an adaptation to
any extreme variation in water availability in the environment.