Phenology constrains opportunistic growth response in Bromus tectorum L.

摘要: Seasonal resource availability may act as a constraint on plant phenology and thereby influence the range of growth responses observed among populations annual species, especially those occupying wide environments. We compared mesic xeric population non-native, grass, Bromus tectorum, to examine in response interspecific competition water availability. Using target-neighborhood approach, we assessed how phenological patterns two affected morphological enhanced represented by late-season soil moisture. The exhibited highly constrained was unable extend growing season despite available resources. Because low phenotypic variation, allocation reproduction similar across conditions. In contrast, flowered later showed more opportunistic not able maintain consistent reproductive at levels. were density neighboring plants. suggest that post-introduction selection pressure B. tectorum habitat has resulted fixed which limits unpredictable, particularly Opportunistic represent contrasting strategies for optimizing fitness temporally varying environments and, while both play important roles ensuring success, these results local adaptation temporal variation reflect balance between flexible inflexible phenology.