Breadfruit ( Artocarpus altilis (Parkinson) Fosberg) is a culturally and nutritionally significant perennial crop of the Pacific Islands. National Tropical Botanical Garden’s Kahanu Garden (Maui, Hawai‘i) maintains a breadfruit collection representing more than 150 traditional varieties, some unique or irreplaceable and requiring safety duplication to safeguard genetic diversity. However, aging trees exhibit variable vigor, potentially limiting clonal propagation outcomes. We assessed air layering as a strategy for conservation duplication, conducting 163 air-layer attempts across 26 priority accessions. We evaluated the influence of tree vigor, age, and branch characteristics on rooting success and survival to out-planting. Overall, 17% successfully rooted and 75% of those survived to out-planting, resulting in successful duplication of 16 of 26 at-risk accessions. Rooting success differed among vigor classes (33% for high-vigor trees; 11–16% for normal and feeble trees) and increased modestly with source tree age, while survival to out-planting declined with increasing age. Branch length and fruiting season were not associated with outcomes. These findings indicate that air layering can support conservation propagation in living collections, but success is strongly influenced by source tree age and condition. Initiating safety duplication while trees are physiologically robust is likely to improve long-term conservation outcomes.

Breadfruit ( Artocarpus altilis (Parkinson) Fosberg) is a staple and cultural keystone in Pacific Island agroecosystems, yet most ex-situ collections are managed as static orchards disconnected from the ecological and social systems that sustain them. Agroforestry offers a conservation-through-use approach that may reconnect crop collections with ecological function, production, and community engagement. In 2017, the Breadfruit Institute at the National Tropical Botanical Garden established the Regenerative Organic Breadfruit Agroforest at McBryde Garden on Kaua‘i, converting a former breadfruit research orchard into a ≈ 1 ha agroforest integrating conservation, cultivation, and participation. Using five years (2017–2021) of management records, plant inventories, soil analyses, yield data, and participation logs, we evaluate agroforest development within an institutional collection. Labor shifted from cultivation-dominant establishment (85–90% of activities in 2018–2019) toward harvest and maintenance; species richness increased from 54 to 148 before stabilizing; and soil indicators showed modest changes consistent with early agroforest development. All breadfruit accessions persisted through reconfiguration, and an additional hybrid breadfruit cultivar was incorporated. Edible yields increased from 0.9 to 5.4 t ha ⁻¹ yr ⁻¹ ; > 15 t donated locally during the study period, alongside 917 participation events and ≈ 1500 service hours. These results demonstrate that agroforestry-based management can maintain curatorial integrity while increasing ecological complexity and community engagement. Outcomes reflect the combined influence of agroforestry design and active management, highlighting a transferable model for integrating conservation, production, and participation within institutional living collections.

Plant domestication studies have traditionally focused on morphological factors that are under direct selection, e.g., fruit size, overlooking the consequences of domestication on ecosystem services. We addressed this knowledge gap by documenting for first time the soil carbon (C) sequestration potential in wild relatives and domesticated cultivars of breadfruit (Artocarpus), a long-lived tree crop. We evaluated aggregate-bound and bulk organic C pools in breadfruit wild relatives and domesticates in soils that varied in nitrogen (N) and phosphorus (P) fertility with management practices (fertilizer and mulch). We determined whether C levels were linked to plant domestication, abiotic factors (N, P, pH, and texture), or biotic factors with known links to C accrual (arbuscular mycorrhizal fungi (AMF), and microbial biomass). In low N or N: P soils, increasing breadfruit domestication was associated with reductions in macroaggregate C (by 50%) and bulk C (host determinism); these shifts were associated with AMF hyphal productivity (50% lower than in wild relatives), soil N and P, and microbial biomass. With a high soil N fertility, the levels of aggregate and bulk soil C were similar between wild relatives and domesticates (plasticity). Despite the limited number of cultivars sampled (n = 10) and the different management practices among sites, our findings suggest domestication effects on ecosystem services, especially those modulated by AMF and soil N fertility. The calculated soil C stocks averaged 99.5 Mg C/ha (range 70–122 Mg C/ha), supporting the possibility of C accrual in breadfruit agroforestry.