Lasting signature of planting year weather on restored grasslands

Ecological restoration — the rebuilding of damaged or destroyed ecosystems
— is a critical component of conservation efforts, but is hindered by
inconsistent, unpredictable outcomes. We investigated a source of this
variation that is anecdotally suggested by practitioners, but for which
empirical evidence is rare: the weather conditions during the first
growing season after planting. The idea of whether natural communities
face long-term consequences from conditions even many years in the past,
called historical contingency, is a debated idea in ecological research.
Using a large dataset (83 sites) across a wide geographic distribution
(three states), we find evidence that precipitation and temperatures in
the planting year (2-19 years before present) affected the relative
dominance of the sown (native target species) and non-sown (mostly
non-native) species. We find strong support for lasting planting year
weather effects in restored tallgrass prairies, thereby supporting the
historically contingent model of community assembly in a real-world
setting.