Biomass and growth of Pinus cembroides Zucc. And Pinus orizabensis D. K. Bailey & Hawksworth in response to water deficit

Abstract

Introduction: Selection of plants not adapted to the environment and low water availability are factors that limit the success of reforestation. Objective: To determine drought resistance in plants from three provenances of Pinus cembroides Zucc. and three of P. orizabensis D. K. Bailey and Hawksworth. Materials and methods: An irrigation experiment (38 to 45 % moisture) and a drought experiment (30 to 36 % moisture) were established for 11 months, starting with 16-month-old plants. A split-plot experimental design consisting of two moisture environments (irrigation and drought) with replicates (four blocks) nested within them was used; in each block six populations (three per species) with 10 plants per experimental unit were evaluated. Results and discussion: The biomass in different parts of the plants was 24 to 51 % lower in drought. Pinus cembroides had greater growth in height, stem base diameter and stem and root biomass in irrigation, and greater growth in diameter and biomass of branches and root in drought than P. orizabensis. The aerial/root biomass ratio was higher in P. orizabensis, which increased by 34 % in drought. In P.cembroides, roots and growth were bigger in seedlings from the most arid provenance. In P. orizabensis, the provenance with the best performance in both environments was the one from the highest elevation. Conclusion: Pinus cembroides showed greater growth and drought resistance than P. orizabensis. There are differences among provenances within each species in restrictive and non-limited moisture conditions.