Reintroduced megaherbivores and prescribed fire shape seed removal in restored tallgrass prairie

Restoration ecology seeks to restore entire ecosystems, including species interactions. Management practices, such as prescribed fire or megaherbivore reintroduction, strongly affect plant and animal biodiversity. It is less clear how management practices shape species interactions such as seed removal and how animals use native and non‐native food resources in restored habitats, which might influence restoration success.

We tested the hypothesis that land management practices influence seed removal of native and invasive plants.

We deployed foraging depots across a chronosequence of 17 restored tallgrass prairie plantings. Plantings varied in burn history and the presence of reintroduced bison ( Bison bison ). Foraging depots, deployed for 1 week in July and October 2024, allowed invertebrates only or invertebrates and rodents. At a subset of eight plantings, we paired seed removal data with rodent live‐trapping data to test whether seed removal was related to species‐specific rodent activity and biodiversity.

Land management had strong effects on seed removal. Four times as many seeds were removed in unburned plantings compared to burned plantings (odds ratio), and 2.5 times as many seeds were removed in plantings with bison compared to plantings without bison. These patterns were only observed in depots accessible to rodents.

At the subset of plantings where rodent live‐trapping data were collected, higher rodent biodiversity (Inverse Simpson's index) was associated with decreased seed removal of both native and invasive seeds. Plantings where the most common rodent species (deer mouse, Peromyscus maniculatus ) were absent had native seeds removed twice as often as invasive seeds. Conversely, in plantings with the highest P. maniculatus activity, invasive seeds were six times more likely to be removed than native seeds.

Practical implication . Land managers can indirectly shape food webs in restored tallgrass prairies, using tools such as grazing or prescribed fire. Where rodents are important agents of seed removal, creating open habitats through grazing and fire may reduce overall seed removal, especially in the fall. Conversely, less frequent burning may be used to promote populations of rodent species such as P. maniculatus that consume problematic invasive species at the cost of overall rodent community biodiversity.