Abstract:

To explore the response of shrubs to topographic heterogeneity, 900 perennial shrub (height (H) ≥ 30 cm, diameter at breast height (DBH) < 1 cm) quadrats of 4 m² (2 m × 2 m) were set up in a 9 ha plot in a typical mixed broadleaved-Korean pine forest in the Xiaoxing’an Mountains. All shrubs in the quadrats were tagged, measured for H and DBH, and identified to the species level. Based on census data collected in 2006, 2008, and 2010, we found that a total of 18 shrub species existed in these quadrats. Approximately 18,253, 27,383 and 23,300 individuals per hectare were found in 2006, 2008, and 2010, respectively. Topography significantly affected the distribution, mortality and recruitment of the 10 major shrub species (P < 0.05). Most shrub species preferred terrain characterized by slope degree > 6º. Aspect had less effects on the distribution of most strong shade-tolerant shrub species, but the density of the shade-intolerant species Corylus mandshurica on sunny and semi-sunny slopes was significantly higher than other aspects. For Acanthopanax senticosus, Philadelphus schrenkii, Deutzia gladata, Lonicera chrysantha, Euonymus pauciflorus, Corylus mandshurica and Lonicera praeflorens, the distribution, mortality and recruitment of shrubs with DBH < 1 cm were consistent with that of the shrubs with DBH ≥ 1 cm.

Key words: mixed broadleaved-Korean pine forest, topography, mortality, recruitment, niche separation