Background: Patterns of seed germination and subsequent seedling growth of the endemic species Nothofagus glauca (Phil.) Krasser (Lophozonia glauca) (Hualo) were studied in two provenances from Mediterranean Central Chile (pre-Andean mountain range provenance and coastal range provenance). The main aim of the study was to determine differences in seed germination and seedling growth at the intra-and inter-provenance levels. Methods: The experiment was carried out with seeds from two provenances and four to five different sites from each provenance. Seed germination tests were conducted in 10 × 1 m beds in a greenhouse. Germinated seeds were sown in 140-mL containers and cultivated under nursery conditions for 8 months. After that period, growth and survival were measured. Results: Germination, growth and survival were highly variable at the intra-provenance level. Sites from the pre-Andean mountain range provenance exhibited lower germination capacity (33.1%) and seedling survival (76.3%) than sites from the Coastal range provenance (40.2 and 91.3%, respectively). Conclusions: Provenance variability was important for seed mass and germination, and seedling survival, while intra-provenance variability was systematically higher, whatever the functional trait considered, indicating a high potential capacity of the species to adapt to climate change. This intra-provenance variability must be conserved with the use of local seed. In our case, pre-Andean sites must be established in high-elevation environments, while coastal provenances must be restricted to more lowland and coastal environments.

No abstract

No abstract

As a consequence of the megadrought in Central Chile, it is expected that most of the distribution of woody species will be narrowed in the northern limits because of restrictions imposed by soil matric potential on seed germination. In this study, we analyzed the effect of the soil matric potential on seed germination and initial recruitment of the sclerophyllous species Prosopis chilensis, Quillaja saponaria and Cryptocarya alba from contrasting geographic origins (i.e., seed sources). We evaluated the germination capacity (%) under different matric potentials (i.e., 0, −6, −33, −750 and −1250 kPa) for 100 days. Soil matric potential of −1250 kPa negatively affected the germination capacity of the three species. P. chilensis seeds stopped germinating under soil matric potential close to −1200 kPa, whereas in Q. saponaria and C. alba the complete inhibition of germination was under −1000 kPa. Seed sources also differed in their germination capacity by soil matric potential: northern seed sources of P. chilensis germinated with the lowest soil matric potential. There was no clear trend in Q. saponaria and C. alba, but in general, southern seed sources performed better than the northern ones. The results showed that Ѱm in the soil played an important role in the germinative capacity against different seed source origins, but not in soils with a north–south gradient.

Fast-growing forest plantations play an important role in reducing global warming and have great potential for carbon capture. In this study, we aimed to model the dynamics of carbon capture in fast-growing plantations. A mathematical model is proposed consisting of a tridimensional nonlinear system. The variables involved are the amount of living biomass, the intrinsic growth of biomass, and the burned area by forestry fire. The environmental humidity is also considered, assumed as a parameter by simplicity. The solutions of the model are approximated numerically by the Runge-Kutta fourth-order method. Once the equilibria of the model have been obtained and its local stability determined, the analysis of the model reveals that the living biomass, as well as the stored carbon, decreases in each harvest cycle as a consequence of the negative effects of fire on soil properties. Furthermore, the model shows that the maximum area burned is attained always after the maximum volume of biomass is obtained. Numerical simulations show that the model solutions are reasonable for the growth dynamics of a plantation, from a theoretical perspective. The mathematical results suggest that a suitable optimal management strategy to avoid biomass losses in the successive regeneration cycles of the plantation is the prevention of fires together with soil fertilization, applied to fast-growing plantations.