Donoso, P. J. (2005): Crown Index: a canopy balance indicator to assess growth and regeneration in uneven-aged forest stands of the Coastal Range of Chile. Forestry 78(4): 337-351., doi: 10.1093/forestry/cpi046

Crown Index: a canopy balance indicator to assess growth and regeneration in uneven-aged forest stands of the Coastal Range of Chile
Pablo J. Donoso

Summary:
A balanced diameter structure, i.e. similar crown area allocated to the different cohorts in uneven-aged forest stands, has been traditionally regarded as a requirement for achieving better growth rates and regeneration. Long-term experiments have demonstrated the sustainability of these structures, but quantitative data informing on how growth and regeneration behave under a balanced diameter structures have been scarce. Similarly, vertical structure has not been properly accounted for as a variable that can affect growth and regeneration in uneven-aged stands. In this study a Crown Index (CI) was used as a surrogate of a balanced diameter structure and an indicator of vertical structure. This new index is obtained by dividing the canopy area of trees in the main and upper canopy positions in a stand by the canopy area in lower strata. A CI of 1.0 indicates, on average, an even allocation of canopy area to each of four strata, namely, a balanced structure; values>1.0 or