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Abstract Plant phenology is affected by both abiotic conditions (i.e., temperature, nitrogen enrichment, and drought) and biotic conditions (i.e., species diversity). The degree of spatial heterogeneity in soil resources is known to influence community assembly and dynamics, but the relationship between resource heterogeneity and phenology or the potentially interactive effects of soil resources on phenology are less understood. We leveraged a tallgrass prairie restoration experiment that has manipulated soil nitrogen availability and soil depth over 20 years to test the effects of environmental heterogeneity, nutrient enrichment, and potentially interactive effects of global change drivers (nutrient enrichment and a drought manipulation) on the phenology of a highly dominant prairie grass (Andropogon gerardii). We recorded the timing of major developmental stages ofA. gerardiiin plots containing four soil heterogeneity treatments (control, soil depth heterogeneity, nutrient/depth heterogeneity, and nutrient/precipitation heterogeneity). We found that the boot, first spikelet, and emerged spikelet stages ofA. gerardiioccurred earlier in treatments with greater heterogeneity of soil nitrogen, and this effect was driven by the accelerative effect of nitrogen enrichment on phenology. Reduced precipitation increased the flowering length ofA. gerardiibut did not otherwise affect developmental phenology. There were no interactive effects among any soil resource treatments on phenology. These results advance our understanding of the relationship between plant phenology and global change drivers, which is important for understanding and predicting the timing of plant resource use and the provision of resources to higher trophic levels by plants under varying levels of resource availability. 

Abstract Year effects are contingencies in community assembly ascribed to differences among years in which communities begin to establish and add uncertainty to restoration outcomes. Year effects are often attributed to differences in climate, but no studies have captured enough natural variation in climate among years communities establish to evaluate how fully planting‐year climate may explain year effects.We restored prairie communities every other year for 12 years, capturing natural interannual variation in climate to test the hypothesis that dissimilarity in planting‐year climate predicts dissimilarity in developing plant community composition. We also examined the extent to which planting‐year precipitation and temperature explain cover of species and major compositional groups to interpret climate‐community dissimilarity relationships.Percent cover of each plant species was surveyed in each restoration for the first 3 years of community development. Community dissimilarity matrices were related to planting‐year climate dissimilarity matrices using multiple regression on distance matrices. The explanatory power of planting‐year climate variables on the cover of individual species and broad compositional groups was examined using linear and exponential models.Dissimilarities in planting‐year precipitation variables were typically the strongest statistical predictors of community dissimilarity, and differences in planting‐year precipitation received shortly after sowing remained a significant predictor of community dissimilarity into the third growing season.In first‐year communities, forb cover was dominated by volunteer species and positively related to annual average daily temperature, whereas total annual precipitation explained significant variation in sown C₄grasses. In subsequent years, forb cover (increasingly sown species) was best predicted by and inversely related to the early growing season window of the variable (precipitation) that predicted C₄grass cover in the establishment year. Likewise, C₄grass cover in subsequent years was best predicted by and inversely related to the early season window of the variable (temperature) that predicted forb cover in the establishment year.Synthesis and applications. This study demonstrates planting‐year climate can predict the cover of frequently occurring species and major compositional groups in prairie developing from seed. Our results advance understanding of factors contributing to variable restoration outcomes, which is needed to achieve conservation goals. 

Abstract Enhancing resilience in formerly degraded ecosystems is an important goal of restoration ecology. However, evidence for the recovery of resilience and its underlying mechanisms require long‐term experiments and comparison with reference ecosystems. We used data from an experimental prairie restoration that featured long‐term soil heterogeneity manipulations and data from two long‐term experiments located in a comparable remnant (reference) prairie to (1) quantify the recovery of ecosystem functioning (i.e., productivity) relative to remnant prairie, (2) compare the resilience of restored and remnant prairies to a natural drought, and (3) test whether soil heterogeneity enhances resilience of restored prairie. We compared sensitivity and legacy effects between prairie types (remnant and restored) and among four prairie sites that included two remnant prairie sites and prairie restored under homogeneous and heterogeneous soil conditions. We measured sensitivity and resilience as the proportional change in aboveground net primary productivity (ANPP) during and following drought (sensitivity and legacy effects, respectively) relative to average ANPP based on 4 pre‐drought years (2014–2017). In nondrought years, total ANPP was similar between remnant and restored prairie, but remnant prairie had higher grass productivity and lower forb productivity compared with restored prairie. These ANPP patterns generally persisted during drought. The sensitivity of total ANPP to drought was similar between restored and remnant prairie, but grasses in the restored prairie were more sensitive to drought. Post‐drought legacy effects were more positive in the restored prairie, and we attributed this to the more positive and less variable legacy response of forb ANPP in the restored prairie, especially in the heterogeneous soil treatment. Our results suggest that productivity recovers in restored prairie and exhibits similar sensitivity to drought as in remnant prairie. Furthermore, creating heterogeneity promotes forb productivity and enhances restored prairie resilience to drought. 

Abstract Plant community assembly outcomes can be contingent upon establishment year (year effects) due to variations in the environment. Stochastic events such as interannual variability in climate, particularly in the first year of community assembly, contribute to unpredictable community outcomes over the short term, but less is known about whether year effects produce transient or persistent states on a decadal timescale. To test for short‐term (5‐year) and persistent (decadal) effects of establishment year climate on community assembly outcomes, we restored prairie in an agricultural field using the same methods in four different years (2010, 2012, 2014, and 2016) that captured a wide range of initial (planting) year climate conditions. Species composition was measured for 5 years in all four restored prairies and for 9 and 11 years in the two oldest restored prairies established under average precipitation and extreme drought conditions. The composition of the four assembled communities showed large and significant differences in the first year of restoration, followed by dynamic change over time along a similar trajectory due to a temporary flush of annual volunteer species. Sown perennial species eventually came to dominate all communities, but communities remained distinct from each other in year five. Precipitation in June and July of the establishment year explained short‐term coarse community metrics (i.e., species richness and grass/forb cover), with wet establishment years resulting in a higher cover of grasses and dry establishment years resulting in a higher cover of forbs in restored communities. Short‐term differences in community composition, species richness, and grass/forb cover in restorations established under average precipitation and drought conditions persisted for 9–11 years, with low interannual variability in the composition of each prairie over the long term, indicating persistently different states on a decadal timescale. Thus, year effects resulting from stochastic variation in climate can have decadal effects on community assembly outcomes. 

The effects of animal homeostatic function on ecological interactions have not been well-integrated into community ecology. Animals mediate environmental change and stressors through homeostatic shifts in physiology and behavior, which likely shape ecological interactions and plant communities. Animal responses to stressors can alter their habitat use, selective foraging, and stoichiometry, which can in turn affect trophic interactions, plant growth, reproduction, and dispersal. Here, we describe a community physiological ecology framework that integrates classical ecological theory and emerging empirical approaches to test how animal homeostatic responses to environmental change mediate ecological interactions and shape communities. Interdisciplinary approaches could provide essential data to characterize and forecast community responses to rapid global environmental change.