Natural rubber (Hevea brasiliensis), and two other native tree species which are widely used in the local forest plantations, namely teak (Tectona grandis) and jarul (Lagerstroemia reginae) were each grown in large plots of two ha in a continuous stretch of land in the Jalpaiguri district of West Bengal. After 22 years of growth under the prevailing natural conditions with no external interference, we studied the ecological impact of these three plantations as part of a multi-disciplinary research effort. Truck girth at breast level was comparable in teak and rubber (which was left untapped for 21 years) and very low in jarul. But the total timber biomass per ha was more in rubber than in teak due to the better tree stand in the former. Canopy intensity, light interception and litter fall was comparable in rubber and jarul, but substantially smaller in teak. UNder growth were more profuse and diverse inside the rubber and jarul plantations than the teak plantation. In general, the mineral composition of the three litter was quite comparable, but the rubber litter contained slightly more N and P. Total soil N, available soil K and soil organic carbon content was on the higher side in the rubber soil than the other two soils. Soil moisture content was more or less comparable in the three plantations. After 22 years of growth, the rubber soil tended to contain fairly large proportions of silt and clay and small proportion of sand than the other two soils. The cation exchange capacity was higher and the soil was more acidic under the rubber plantation than in the other two plantations. The rubber litter harboured more number of invertebrates on the soil face than the other two types of litter. The populations of fungi, bacteria and actinomycetes found in the soil were high and comparable inthe rubber and teak plantations compared to the jarul plantation. The trunk of the rubber tree had more profuse growth of orchids, epiphytes and lichens than the other two species. Thus the studies show that rubber cultivation was in no way ecologically inferior to jarul or teak which are popular forest plantation species. Rubber soils had certainly comparable or better physical, chemical and biological properties and improved biodiversity than the other two species when they were grown naturally with no external interference.