Impact of Forest Management on Insect Abundance and Damage in a Lowland Tropical Forest in Southern Cameroon

Background

A burgeoning timber industry in Cameroon, which became the fifth largest producer of timber in the world in the 1990’s, led to unsustainably high deforestation rates and high demand for forest regeneration interventions. Research in the Mbalmayo Forest Reserve in southern Cameroon has compared different silvicultural techniques for forest regeneration including complete and partial clearance methods.

Research Goals & Methods

The objective of this research was to examine and contrast the impact of each silvicultural technique on insect abundance as well as to quantify the damage caused by insects on Terminalia ivorensis, the species of tree used for regeneration. Replicate 1-ha plots were established in 3 different areas of the reserve and monitored over 1 year. Two of the sites were then treated with insecticide knockdown fogging to assess arthropod abundance.

Conclusions & Takeaways

Researchers found that Ants, Diptera, Aranae, Thysanoptera, Homoptera, Coleoptera, and Orthoptera were more abundant in the partial clearance plot than the complete clearance plot. However, they also concluded that the degree of clearance did not noticeably affect the amount of arthropod-caused damage since most of the groups that increase in abundance are composed of predatory species. Researchers therefore hypothesize that the long-term potential for pest outbreaks is lower in partial clearance plots than complete clearance plots.