Can native tree species regenerate in Pinus radiata plantations in Chile? Evidence from field and laboratory experiments

Abstract

As matrices form the major component of landscapes mosaics, assessing regeneration suitability for native species within matrices is relevant for conservation and mandatory if native remnant patches are scarce, small and contain endemic species. In central Chile, we compared in two consecutive years (2001/2002-2002/2003), seed germination and seedling establishment of Cryptocarya alba (Mol.) Looser the most dominant specie in seedling stage, in both the native Coastal Maulino Forest and in the matrix composed of Pinus radiata D. Don plantations. We also tested in the laboratory, whether watering with leachate of soil extract of P. radiata plantations had allelopathic effects on C. alba seed germination, seedling growth and survival compared to leachate from native forests and to pure water. We expected a reduction in germination and seedling establishment in R radiata plantations, due to documented allelopathic inhibition. We only found differences in germination probabilities during the 2001/2002 period, whereas seedling establishment did not vary. In addition, in the laboratory we found that watering with leachate from P. radiata plantations produced an equivalent reduction in C. alba seed germination when compared with watering with native forest litter leachate. We did not find allelopathic effects on seedling survival nor growth. P. radiata plantations might be a suitable habitat where, in some years, C. alba can regenerate. P radiata plantations should be incorporated in the conservation scenario of the Maulino Forest plant species, introducing new procedures to reduce the impact of forest replacement on native plant dynamics.