<p>Living root bridges are<i>Ficus elastica</i><i>1</i><i></i>based suspension bridges within dense tropical rainforests of Meghalaya in the North Eastern Indian Himalayas (25° 30' N and 91° 00' E). Ranging in span from 15 feet to 250 feet, these bridges are grown by Khasi2 tribes over a time period of 15 to 30 years, and last for several centuries. With 1) exceptional robustness3 under extreme climatic conditions,</p><p>2) minimal material and maintenance cost, 3) no environmental damage, 4) progressive increase in load-bearing capacity, 5) carbon sequestration, 6) remedial properties on surrounding soil, water and air, 7) collective grass root involvement based on human-plant interaction across multiple generations, 8) support to other plant and animal systems, and 9) keystone4 role of<i>Ficus</i>plant species in local ecology, living root bridges offer an extraordinary model for long-term socio- ecological resilience5 and sustainable infrastructure solutions, and warrant further scientific study.</p>

Living root bridges (LRBs) are functional load-bearing structures grown from Ficus elastica by rural Khasi and Jaintia communities in Meghalaya (India). Formed without contemporary engineering design tools, they are a unique example of vernacular living architecture. The main objective of this study is to investigate to what extent LRBs can be seen as an example of regenerative design. The term "regenerative" describes processes that renew the resources necessary for their function. Whole systems thinking underpins regenerative design, in which the integration of human and non-human systems improves resilience. We adapted the living environments in natural, social, and economic systems (LENSES) framework (living environments in natural, social, and economic systems) to reflect the holistic, integrated systems present in LRBs. The regenerative / sustainable / degenerative scale provided by LENSES Rubrics is applied to 27 focal points in nine flow groups. Twenty-two of these points come from LENSES directly, while five were created by the authors, as advised by the LENSES framework. Our results show 10 focal points in which LRBs are unambiguously regenerative. One focal point is unambiguously sustainable, while 16 are ambiguous, showing regenerative, sustainable, and degenerative aspects. User perspective determines how some focal points are evaluated. The contrast between a local, indigenous perspective and a global, tourism-focused perspective is demonstrated by the results.