Linking photosynthesis physiology of upland hardwood reproduction to ecology and silviculture in the Arkansas Ozarks.

摘要

Oak (Quercus) forests in the Arkansas Ozarks have been important culturally, ecologically and environmentally for centuries. Historically these forests were fire dependent and dominated by oak species. In the past century, fire suppression and land management have caused these forests to densify. As a result, oaks are increasingly less abundant following disturbance in natural hardwood stands. Many applied ecological studies have explored methods and practices to maintain oak species in newly developing stands. This study attempted to link the mechanistic physiology of oak and non-oak reproduction to the applied ecological work. Varying stand conditions were generated in an undisturbed mature hardwood forest. Photosynthesis physiology was evaluated through direct and in-direct measures for six upland hardwood species in the Springfield Plateau of the Arkansas Ozarks. Environmental conditions, including sunlight canopy penetration, were significantly different based on treatment/slope position combinations. Corresponding differences in photosynthesis, development and abundance of hardwood reproduction were also significant across treatments, topographic position, and species. In conclusion, this study demonstrates that in situ measurements of photosynthetic performance are a valuable tool in predicting stand performance in oaks growing in their natural environment.