Provenance variation in growth characters of four subtropical pine species planted in Mexico.

摘要

In 1995 a species/provenance test was established in the state of Puebla, Mexico to assess and compare the growth of Pinus greggii var. australis, P. maximinoi, P. patula and P. tecunumanii, including 10, 5, 11 and 4 provenances of each species, respectively. Each provenance test lot consisted of seed from 7 to 10 individual trees collected in natural stands. Range-wide samples were included in the test for P. greggii var. australis and P. patula. Material of P. maximinoi and P. tecunumanii from Guatemala, Honduras and Nicaragua, as well as Mexico was established in the test. The test site is in a mountainous area at 1440 m elevation, near 20 degrees N latitude. At 5 years of age significant differences were seen at both the species and provenance levels in survival, total height, diameter and volume. The overall test survival was 93%. Variance among species was three time greater than among provenances, comprising 25-33% of the total variation. P. maximinoi had the greatest height, diameter and volume (62 dm3) followed by P. tecunumanii (53 dm3). P. greggii var. australis had an average volume of 43 dm3 and P. patula produced 30 dm3. Although P. maximinoi had the lowest survival rate, the San Jeronimo provenance was the most productive of all 30 provenances tested; 98% survival and 73 dm3 volume. This was equivalent to 2.8 cm annual diameter increment and 2 m in height growth per year. Significant growth differences among provenances within species indicate that potential gain exists using provenance selection.