Diversity and composition of trees in the cardamom agroforests in the Nelliampathy Hills of the Western Ghats, India
摘要
Elettaria cardamomum is an herbaceous plant that grows in the wet evergreen forests of the Western Ghats of India between 750 and 1500 m above mean sea level, along watercourses and where the canopy is disturbed. Its seed pod, called cardamom, is of economic value and thus the plant was brought under cultivation in the Western Ghats by manipulating the canopy of the wet evergreen forest. This study explored the stand structure, diversity, and composition of shade trees in the managed cardamom agroforests in the Nelliampathy hills of the southern Western Ghats, India. All trees ≥ 10 cm gbh were documented in 39 sample plots of size 50 × 20 m each in the cardamom agroforest and in unlogged forest. The cardamom agroforests were found to contain 93 species, 34% less than the 117 species found in the unlogged forests. Species dominance did not differ in agroforests versus the unlogged forests, but fewer species had high importance value in the cardamom agroforest. Agroforest stand density (357 trees per hectare) was only one-fifth of that in the unlogged forest (1734 trees per hectare) and stand basal area (58.9 m2 per hectare) was 30% less than that of unlogged forest (82.6 m2 per hectare). Though the stand structure and species composition in cardamom agroforests are highly modified, they are worthy of conservation. Further studies should be carried out to document the diversity and composition of shade trees in the agroforests and compare with the adjacent forests.