More than an invasive ecosystem engineer: Reconceptualizing biological invasions as socio-ecological phenomenon with the case of North American beaver research and management in Tierra del Fuego
Invasion biology has historically overlooked the phenomenon’s social dimensions. More generally, ecologists increasingly recognize that global ecological change not only has human drivers, but also social outcomes and reciprocal interactions. This modified understanding of human-nature relationships pushes the field of ecology to engage interdisciplinary approaches to research and decision-making. Here, we studied the case of the North American beaver (Castor canadensis) introduced to Tierra del Fuego (TDF) in 1946. This species is an exemplar invasive ecosystem engineer. However, not only has it caused the largest alteration to southern Patagonia’s forests in the Holocene, but it also has become part of a complex socio-cultural system and mindsets, including different political structures and histories at multiple scales (local, national, binational, international). Using 15 years of collective work on this topic, we applied the Pulse-Press Dynamics (PPD) model as a heuristic device to analyze invasive beavers from diverse disciplinary lenses (e.g., anthropology, ecology, geography, history, management, psychology, restoration) and respond to two integrated questions: 1) What is the relationship between how we conceive and study beavers? 2) How does an integrated understanding of beavers as both cause and consequence of ecological andsocial systems change the way we manage them?
Historical documentation demonstrated that mentalities in the 1940s conceived Patagonia as a “desert” to be populated with “northern” colonists and species. A government newsreel showed beavers were introduced to “enrich” local fauna with furbearers for regional development along with expanding agriculture and promoting oil extraction. Invasion biology’s rise in the 1990s led scientists and authorities to re-orient their mindsets and actions, initiating the first research focused on quantifying negative ecological impacts. These studies catalyzed control programs, culminating in an eradication agreement between Argentina and Chile in 2008 to recover “natural” forests. Nonetheless, recent social surveys found that invasive species were not a perceived environmental concern for most TDF residents, challenging the goal and means of traditional conservation perspectives. Integrating social and ecological domains, via the PPD, allowed the generation of new questions and management scenarios. For example, restoration endeavors focus on ecological studies like forest regeneration, but to effectively and holistically address this issue, new work is encompassing social and political aspects (e.g., whether private landowners will participate or how to design an international effort). Overall, conceptualizations of beavers directly affected how to study and steward this socio-ecological phenomena, illustrating the need for interdisciplinary reflection as well as methods.