338
gradient of coverage produced by natural gaps. In both experiments, more than 90%
of the plants were initially established in a wide gradient of coverage. In the pot
experiment, plants at full sun exposure were damaged by frost in winter. Four years
after plantation, 70% of the plants survived in the field experiment, and mortality
was observed mostly in microenvironments with lower light incidence. They conclude that C. canjerana can establish and survive in many microenvironmental conditions within the rainforest, it acclimates in few months to sudden changes in
coverage and, 1 year after planting, its growth rises with higher availability of light.
Thus, planting seedlings under cover conditions, and the subsequent removal of the
understory (gap opening), is a good strategy for the installation of the species.
Similarly, Balducci et al. (2009) experimented in the Yungas Rainforest with 20
native species in pure and mixed plantations. Among the main species evaluated
were Tipuana tipu, Cedrela balansae, Cordia trichotoma, Handroanthus impetiginosus, Jacaranda mimosifolia, Pterogyne nitens, Enterolobium contortisiliquum,
and Astronium urundeuva, with genetic material from the Northern Sector of Yungas
Rainforest. The trials were installed between the years 2000 and 2002 in Valle
Morado (Province of Salta) located in the UBRB environment. The mortality rates
varied between less than 5% and values close to 30%. The species with the highest
diameters were E. contortisiliquum, T. tipu and C. balansae with average DBH
above 10 cm at the fifth year of planting, showing T. tipu the best forest shape. C. trichotoma, J. mimosifolia, P. nitens, A. urundeuva, and H. impetiginosus followed in
growth, with an average DBH between 6 and 8 cm. The combination of C. trichotoma and H. impetiginosus is interesting given the good stem shapes that were
observed. As for DBH, the species with best total height was T. tipu, with an average
of more than 9 m at the age of 5 years. It was followed by C. balansae, J. mimosifolia, E. contortisiliquum, and P. nitens, with a total height between 5 and 7 m. Most
of the species evaluated generally showed a high tendency to the formation of lateral branches when planted at open sky, thus losing a good forestry shape, although
this factor does not have a significant impact on the plant survival.
Del Castillo et al. (2005) performed some planting experiences with native and
exotic Meliaceae in Yuto (Jujuy), at 350 m asl. They compared three valuable wood
species: Cedrela balansae, Toona ciliata var. australis, and Melia azedarach, in
open sky plantation at age 14, obtaining a wood yield of 6.7, 9.7, and 5.6 m
3
/ha/year,
respectively.
The natural dynamics of the rainforest generate changes in the canopy coverage
and, consequently, in the quality and quantity of light that reaches the understory.
Similar effects can be achieved by the anthropogenic selective extraction of trees.
The microsites produced by the disturbances represent a continuum of environmental conditions that ensures the coexistence of many species. The knowledge of the
requirements of the species and the evaluation of the optimal microenvironments to
plant growth are useful in decision-making to restore degraded areas.
The presented trials and experiences of plantations point out the feasibility of
cultivation of the main forest tree species of the Argentinean rainforests, both with
commercial and conservation purposes. Given the current attention on mitigation of
the effects of the climate change, probably the main concern is related to active
L. F. Fornes
gradient of coverage produced by natural gaps. In both experiments, more than 90%
of the plants were initially established in a wide gradient of coverage. In the pot
experiment, plants at full sun exposure were damaged by frost in winter. Four years
after plantation, 70% of the plants survived in the field experiment, and mortality
was observed mostly in microenvironments with lower light incidence. They conclude that C. canjerana can establish and survive in many microenvironmental conditions within the rainforest, it acclimates in few months to sudden changes in
coverage and, 1 year after planting, its growth rises with higher availability of light.
Thus, planting seedlings under cover conditions, and the subsequent removal of the
understory (gap opening), is a good strategy for the installation of the species.
Similarly, Balducci et al. (2009) experimented in the Yungas Rainforest with 20
native species in pure and mixed plantations. Among the main species evaluated
were Tipuana tipu, Cedrela balansae, Cordia trichotoma, Handroanthus impetiginosus, Jacaranda mimosifolia, Pterogyne nitens, Enterolobium contortisiliquum,
and Astronium urundeuva, with genetic material from the Northern Sector of Yungas
Rainforest. The trials were installed between the years 2000 and 2002 in Valle
Morado (Province of Salta) located in the UBRB environment. The mortality rates
varied between less than 5% and values close to 30%. The species with the highest
diameters were E. contortisiliquum, T. tipu and C. balansae with average DBH
above 10 cm at the fifth year of planting, showing T. tipu the best forest shape. C. trichotoma, J. mimosifolia, P. nitens, A. urundeuva, and H. impetiginosus followed in
growth, with an average DBH between 6 and 8 cm. The combination of C. trichotoma and H. impetiginosus is interesting given the good stem shapes that were
observed. As for DBH, the species with best total height was T. tipu, with an average
of more than 9 m at the age of 5 years. It was followed by C. balansae, J. mimosifolia, E. contortisiliquum, and P. nitens, with a total height between 5 and 7 m. Most
of the species evaluated generally showed a high tendency to the formation of lateral branches when planted at open sky, thus losing a good forestry shape, although
this factor does not have a significant impact on the plant survival.
Del Castillo et al. (2005) performed some planting experiences with native and
exotic Meliaceae in Yuto (Jujuy), at 350 m asl. They compared three valuable wood
species: Cedrela balansae, Toona ciliata var. australis, and Melia azedarach, in
open sky plantation at age 14, obtaining a wood yield of 6.7, 9.7, and 5.6 m
3
/ha/year,
respectively.
The natural dynamics of the rainforest generate changes in the canopy coverage
and, consequently, in the quality and quantity of light that reaches the understory.
Similar effects can be achieved by the anthropogenic selective extraction of trees.
The microsites produced by the disturbances represent a continuum of environmental conditions that ensures the coexistence of many species. The knowledge of the
requirements of the species and the evaluation of the optimal microenvironments to
plant growth are useful in decision-making to restore degraded areas.
The presented trials and experiences of plantations point out the feasibility of
cultivation of the main forest tree species of the Argentinean rainforests, both with
commercial and conservation purposes. Given the current attention on mitigation of
the effects of the climate change, probably the main concern is related to active
L. F. Fornes