Articles
POLLEN FLOW IN THREE SPECIES OF NOTHOFAGUS IN THE SOUTH OF CHILE
In order to protect this resource, and also to conserve the existing biodiversity of the Nothofagus forests in the south of Chile, it is necessary to promote re-forestation programmes, making use of native Nothofagus species.
Knowledge of the reproductive processes in Nothofagus is therefore a necessary prerequisite for the preservation of their forest habitat.
The naturally low fertility of Nothofagus within forest stands, however, contrasts with the level of fertility required for speedy regeneration.
Trees of Nothofagus obliqua, N. dombeyi and N. nitida are all monoecious and anemophilous; they are also self-incompatible and rarely form hybrids.
Consequently,0 events regulating pollen flow between anthers and stigmas of the 
and 
flowers on different trees of the same species provide some of the first parameters to be studied in relation to fertility and in the preparation of a model that systematizes the processes that affect reproductive success.
As a first step, we established the phenological pattern.
During the flowering period of September to December, the percentage overlap between the periods of opening of and flowers of different trees that could potentially lead to fertilization was 65%, 53% and 50% in each of the three mentioned species.
The viability of pollen arriving at the stigmas was more variable: 47%, 93% and 88% of grains were viable in N. obliqua, N. dombeyi and N. nitida, respectively.
The influx of pollen, measured as the rate of capture of grains in the vicinity of the flowers, was generally low, but increased following a rise of air temperature and a diminution in relative humidity which had earlier led to an increased efflux of pollen from the anthers.
The low fertility of the three Nothofagus species could relate to abiotic factors that depress the rate of pollen flow and pollination frequency, although there is not yet enough evidence to assess the full impact of this stochastic element in our model of reproductive efficiency.
Consequently, other, biotic, factors are being considered.
These relate to processes within the reproductive organs themselves.