Influence of Distance to Forest Edges on Natural Regeneration of Abandoned Pastures: A Case Study in the Tropical Mountain Rain Forest of Southern Ecuador

background

This study evaluates the role that distance from forest edges plays in the restoration of abandoned pasture.

Research Goals & Methods

The authors divided 10 transects into four 25m2plots along a gradient extending from a primary forest edge and including a 400m2 reference plot within the primary forest.  The pasture had been abandoned for 38 years and a secondary forest had been established. Within both the secondary and primary forest plots, tree height, dbh, species and crown cover were measured. Additionally, tree height was measured within the secondary forest plots.

Conclusions & Takeaways

Height and diameter growth were very low within the secondary plots and only 5 trees with dbh>10cm were located within the entire abandoned pasture area in the study. Overall species diversity was the same between the primary and secondary forest plots, with 49 total species in both plot types; however, the similarity in species composition of the secondary plots to the primary forest plots decreased with increasing distance from the forest edge. Several species and families had significantly higher abundances in the primary forest plots: Clusia sp., Myrcia sp., Vochysia sp., Alchornea sp., Hyeronima sp., Miconia sp., N. reticulate, P. huantensis, Clusiaceae, Araliaceae, Lauraceae, Rosaceae and Vochysiaceae. The following families and species were found in greater abundance in the secondary forest: A. verticillata, M. revolute, P. andaluciana, C. revoluta, D. dioicum, H. anisodorum, Miconia sp., Myrcia sp., Palicourea sp., Alzateaceae, Cloranthaceae and Gentianaceae. Two species, G. emarginata and P. nutans, had similarly high relative and absolute abundances in both the primary and secondary forest. After 38 years of natural recuperation, the secondary forest had still not regained the structure of the primary forest leading the authors to suggest that natural succession be complemented with enrichment plantings.