Root studies in the Chilean matorral

Summary

The roots of matorral shrubs were excavated from an 18 m² site of a mixed matorral stand located on a 27° NE facing slope at 1000 m elevation 40 km NNW from Santiago de Chile. The climate in this area is similar to that of the Southern Californian chaparral. The main species present were Lithraea caustica, Cryptocarya alba, Colliguaya odorifera, Mutisia retusa, and Satureja gilliesii. After harvesting the above ground biomass, the soil was washed out in 20 cm layers down to a depth of 60 cm. The roots were harvested according to their position in the site, separated into species and root size classes. Soil analysis indicated a fertile and deep reaching, clayish soil. L. caustica was a deep rooting species with many thick roots growing deeper than 60 cm. This species had a massive burl of 67 kg dry weight in the excavation site. Cryptocarya was less deep rooting, and C. odorifera had a shallow root system. It is thought that the root: shoot biomass ratios of 4.9 and 1.4 for L. caustica and C. alba respectively are indicative of the forest character of this site in the past. This forest would have been destroyed by continuous charcoal manufacture. The bulk of the fine roots was found in the 20–40 cm soil layer. The average distance between fine roots was calculated as 1.9 cm. The results were compared with an earlier excavation in the Californian chaparral.