Preparing for the Need for a Supply of Native Seed

In mid-September 2020, millions of hectares in the western U.S. were on fire and the year's second wave of seasonal hurricanes and tropical storms were queueing up to batter the states along the Gulf of Mexico. As members of a National Academies of Sciences, Engineering, and Medicine committee tasked with assessing the need for and supply of native seed in the Western United States and other regions of the country, we viewed the unfolding natural disasters as an appropriate, if troubling, backdrop for our work. The assessment of the seed supply was requested by the U.S. Bureau of Land Management (BLM), which uses native seed on a continuing basis for restoration projects on the public lands it manages, and in large quantities after major wildland fires and disasters. Like other federal agencies, BLM turned to the independent, Congressionally chartered National Academies in search of impartial scientific advice. Ultimately, our committee will recommend steps that could help to expand the quantity and diversity of native plant seeds available from commercial seed markets.

As we finalized our interim report (NASEM 2020), describing the structure of the supply chain, the drivers of the need for native seed, and a plan for additional information gathering in the next phase of our work, the assessment felt especially timely. The spectacle of habitat destruction from so many different directions at once seemed to portend a new normal, one that climate scientists have long warned about, with its costly and potentially long-lasting effects on both manmade structures and natural ecosystems.

Hurricanes and wildfires occur naturally, but global warming in tandem with other anthropogenic impacts such as invasive species, fire suppression, and habitat fragmentation have intensified their impacts to the point where natural regeneration may be impaired or impossible. The most recent U.S. catastrophes have been striking in their severity and scale, but more gradual alterations to the natural environment, from the impervious surfaces of urban sprawl that alter hydrological systems to the unsustainable use of natural resources on vast areas of public and private land, eventually cause their own slow-moving disasters that erode the resilience of ecosystems. The impacts of cataclysmic and chronic destruction of vegetated landscapes reveal a potentially large-scale need for plant material (here, "seed" for simplicity) to assist in the recovery and restoration of plant communities in diverse settings, from natural and seminatural areas to cities and other highly-managed spaces.

All of this raises the question "Will the necessary types and quantities of native plant seed be available when land managers are ready to deploy them?" The answer appears to depend partly on whether the current volatility of demand, created by the unpredictability of funding cycles coupled with the erratic timing of major disturbances, proves to be too challenging to maintain a reliable native seed industry responsive to the needs of users.

As a previous perspective in this journal noted, the proposition for restorative activities is not to recreate the past but to enable an ecosystem to endure into the future (Clewell 2009). Native plant seeds are essential to accomplish that goal and fulfill other objectives along the restorative continuum (Gann et al. 2019). The committee learned that, for most plant species, the germplasm collected from the wild and made available to the native seed industry do not represent an adequate range of the genetic diversity contained among the wild populations of these plants in different environments. Consequently, whether seeds with genetic characteristics suitable for a wide diversity of projects are even available is a question that needs further examination. Except in cases where enough seed is collected from the wild to be used directly in projects, seed collection and seed banking are the first steps in a pathway of seed increase, development, cultivation, certification, and analysis before seeds reach...