The composition and diversity of natural regeneration of tree species in gaps under different intensities of forest disturbance

The positive ecological interaction between gap formation and natural regeneration has been examined but little research has been carried out on the effects of gaps on natural regeneration in forests under different intensities of disturbance.This study evaluates the composition,diversity,regeneration density and abundance of natural regeneration of tree species in gaps in undisturbed,intermittently disturbed,and disturbed forest sites.Bia Tano Forest Reserve in Ghana was the study area and three gaps each were selected in the three forest site categories.Ten circular subsampling areas of 1 m2 were delineated at 2 m spacing along north,south,east,and west transects within individual gaps.Data on natural regeneration<350 cm height were gathered.The results show that the intensity of disturbance was disproportional to gap size.Species diversity differed significantly between undisturbed and disturbed sites and,also between intermittently disturbed and disturbed sites for Simpson’s(1-D),Equitability(J),and Berger-Parker(B-P)indices.However,there was no significant difference among forest sites for Shannon diversity(H)and Margalef richness(MI)indices.Tree species composition on the sites differed.Regeneration density on the disturbed site was significantly higher than on the two other sites.Greater abundance and density of shade-dependent species on all sites identified them as opportunistic replacements of gap-dependent pioneers.Pioneer species giving way to shade tolerant species is a natural process,thus make them worst variant in gap regeneration.

Natural regeneration in logging gaps of different sizes in Subri River Forest Reserve(Ghana)

Subri River Forest Reserve(SR)is the most extensive forest area in Ghana with an accompanying rich floral species.Over the years,logging from both legally prescribed and illegal operations remain the predominant forest disturbance in SR.Gap creation following logging is crucial in determining tree species composition and diversity.Hence,the study evaluated the composition and diversity of naturally regenerated tree species in logging gaps of different sizes and,again examined the roles of these tree species in fulfilling the economic and ecological agenda of sustainable forest management after logging in SR.Twelve gaps were randomly selected:4 each were grouped into small size(≤200 m^(2)),medium size(201–300 m^(2)),and large size(≥300 m^(2)).Data were gathered from 1 m^(2) circular area at gap centres and repeatedly inside 1 m width strip along 20 m individual N-S-E-W transects.Species diversity differed significantly between gap sizes.Higher diversity indices were measured in large size gaps.Gap sizes shared similar species.There were significant differences among various height groupings of tree species across all three gap sizes.Pioneers preferred medium to large size gaps,while shadetolerant tree species preferred small size gaps for their abundance.Vulnerable and Lower Risk Near Threatened tree species under Conservation Status and,Premium and Commercial tree species under Utilisation Status preferred small size gaps for their proliferation and conservation.Therefore,we recommend the single tree-based selective logging for ensuring creations of small to medium size(200–300 m^(2))gaps through adjustments to the logging permit process,revision of Allocation Quota Permit,strict adherence to the 40-year polycyclic selection system,along with more dedicated enforcement and monitoring.Changes along these protocols would tremendously facilitate natural regeneration of different suites of timber species resulting in the improvement of the overall biodiversity conservation associated with the forest,more sustainable forest harvests and more income to those who receive permits.

Comparative analysis of thinning techniques in pine forests

Thinning is a necessary and complex forestry activity.The complexity increases due to theoretical disagreements,contradictory recommendations,and errors of modern practice,which require confirmation through longtime experiments.This article presents a summary of experimental results from plantations established 20–30 years ago and explains concepts of the theory,methods,and regime of thinning in permanent sample plots of pine stands in Gatchinsky forest of the Leningrad region.The research results allow for the clarification of growth patterns and age dynamics of pine stands subject to heavy,low thinning,as well as the results of applying the crown(high)thinning technique and a mixed treatment.A combined thinning and fertilization could improve wood quality and yield compared to conventional methods.Of particular scientific importance is the analysis of change in tree diameter classes during growth and after thinning.The research results allow for optimizing the treatment regime in pine plantations and reducing labor intensity by increasing the intensity of thinning and reducing the number of techniques.