We discuss the prospects of developing biorepositories as a novel kind of biocollections infrastructure and service. Biorepositories resemble other natural history collections but their structured material sample composition is optimized to monitor and forecast the dimensions of ecological and evolutionary responses to change. Samples are collected to study shifts in genetic composition, species populations and traits, community composition, and ecosystem function and structure. This concept is exemplified in the design and operations of the National Ecological Observatory Network (NEON) Biorepository. To maximize impact, biorepositories have to establish practices for sample collection, preservation, diversified high-volume use, and innovative data science that both leverage and diverge from more conventional collections management strategies. In light of their constrained purpose and transcendent scale among material sample collections, biorepositories face special challenges to generate a meaningful, inclusive sense of community ownership. Properly designed and delivered, they can catalyze broader support for biocollections and open science.