Plant species diversity in unmanaged moist deciduous forest of Northern India

The present study examines species recovery and change in community composition four decades after the management plan completely constrained all silvicultural activities in Doon Valley (India) moist deciduous sal forests (Shorea robusta). These forests experienced intensive commercial logging for an extended period (>100 years). To discontinue disintegration and improve the diversity and regeneration, these were declared protective and consequently all silvicultural activities were abandoned. For this, species richness and regeneration were studied in the context of overstorey structure, employing nested quadrat method. Out of 130 species reported in the earliest-most study from these forests, only 68 species were recorded here. Change in community composition has taken place with Mallotus philippensis becoming dominant in one community; this association is new for these forests. Effect of overstorey structure was noticeable, highest species richness and diversity were increasing with a decrease in tree density and basal area. These forests showed impaired regeneration progression; for all the groups there was a wide gap between the seedlings and saplings conversion to advance stages. Prospects of recovery are fair as several tree species were reported in juvenile stages with adequate density. Results demonstrated that conversion of forests having a long history of exploitation to protected forest is initially good, but for successful recovery, after a restitution time, it is desirable to emulate intermediate disturbance by selective harvesting of old and malformed trees. This will initiate gap-phase regeneration and channelize resources to lower diameter class trees to develop.