Estimating disturbance in a tropical forested habitat using a modified ecological disturbance index with rank-order weights of criteria

Abstract

Anthropogenic plot-level disturbances may influence insect communities in an ecosystem. Documenting these small-scale disturbances through remote sensing in forested habitats of the developing world can be expensive. Disturbance indices can also be computed using visible signs of disturbance documented through ground-level surveys. In this study, we use a previously reported disturbance index to document the level of anthropogenic disturbances in two forested habitats in West Bengal, India, in the context of exploring plot-level habitat disturbances likely to influence the resident bee (Hymenoptera: Apoidae) fauna of the study sites. We introduce modifications to the established index by using rank-order weights of each identified criterion, instead of perceived weights. Using rank-order weights of criteria is considered suitable for removing evaluator bias when working with human-assigned weights. It is also thought that it is easier for expert as well as non-expert decision makers to arrive at a consensus when evaluating the ranks of criteria, instead of weights. This approach may be considered for calculating other ecological indices that involve multiple criteria with human-assigned weights. In addition, we report the results of our investigation into the relation between bee abundance and disturbance at each study site based on monthly surveys.