Millions of people worldwide depend on the harvest of non-timber forest products (NTFP) for their livelihoods, and the importance of understanding the complex relationships between NTFP harvest and conservation is increasingly recognized. This study employs a cross-disciplinary, regional approach to identify some of the links between patterns of harvest, trade, and conservation of one of South India's most heavily harvested resins, Canarium strictum Roxb. (Burseraceae), or black dammar. We focus on indigenous communities in the Nilgiri Biosphere Reserve (NBR) and ask: How is C. strictum tapped and is there variation across communities? How is C. strictum resin sold and bought, and what trade routes are involved? What are the impacts of tapping on C. strictum trees and population structure? We carried out interviews and focus-group discussions with harvesters in eight villages in three different regions, and with buyers and traders inside and outside of the NBR. We also established twenty-two 20 x 20 m plots to document population structure. Three broad resin-harvest strategies were identified: collection from natural fissures, tapping using incisions, and tapping using incisions and fire, each practiced in a different region. However, within each strategy there was large variation in tapping frequency and timing, tenure practices, and resin quality. The loss of tree tenure in some areas has led to a higher frequency of tapping and to the production of lower quality, lower value resin. Factors driving changes in both tenure and tapping strategies include rising commercial demand and value, pressure from outside harvesters, changes in livelihood strategies, and habitat destruction. Tapping leads to elevated mortality of C. strictum adults, with fire-tapping have a greater negative impact than tapping with no fire. The combination of social and ecological approaches used here provides insight on strategies for better conservation of C. strictum. These include the promotion of tapping and sale of only high-grade resin - which is a good indicator of sustainable harvest - enrichment planting to help address some of the underlying causes of overharvest, and sparing of some trees for increased reproduction.