Methods To Establish Canopy Bridges To Increase Natural Connectivity in Linear Infrastructure Development

Abstract

Abstract The development of linear infrastructure such as pipelines can have a dramatic impact on forest connectivity through canopy fragmentation. Because many forest animals are arboreal and spend their lives in the forest canopy, fragmentation caused by linear infrastructure may isolate animals on either side. Here we present our findings on linear infrastructure effects on canopy connectivity and impact mitigation with natural canopy bridges. Natural bridges are connections between branches that are left behind in the forest canopy above, in this case, a pipeline during the clearing of the right-of-way. We share our experiences with a natural bridge case study in the Lower Urubamba Region of Peru on a project where 13 natural bridges were left on average at 410m intervals over 5km, with tree trunks 8 to 24m apart. We provide 16 recommendations for the development of such projects, from the planning stages, timeline for bridge establishment, and necessary personnel for design, to bridge selection and monitoring protocol. Natural bridges can be established with little effect on the pipeline construction timeline and cost as long as they are considered in the initial stages of pipeline design, and the locations of the bridges are selected in collaboration with the pipeline engineers and topography team as the position of the right-of-way is established. We strongly encourage companies to include natural bridges in linear infrastructure because they can be highly effective in increasing forest connectivity with little cost to the corporation and little effect on the pipeline development timeline.