Shifting ecological filters mediate postfire expansion of seedling aspen (Populus tremuloides) in Yellowstone

摘要: Abstract Determining how ecological filters (e.g., climate, soils, biotic interactions) influence where species succeed in heterogeneous landscapes is challenging for long-lived trees), because can vary over space and change slowly through time. Stand-replacing wildfires create opportunities establishment of tree-species cohorts catalyze rapid shifts occur, facilitating unique long-term study. We quantified effects multiple on a colonizing cohort aspen (Populus tremuloides) that established from seed throughout burned lodgepole pine (Pinus contorta var. latifolia) forests after the 1988 fires Yellowstone National Park (Wyoming, USA) to ask: (1) How have presence, density, size varied across postfire landscape, what explain these spatial temporal patterns? (2) does above-and belowground biomass with lodgepole-pine density? Aspen persisted year 25 58% plots which were present 11 (n = 45), mean stem density declined 522 310 stems ha−1. Mean height doubled (from 29 59 cm) this period. Ecological related competition, herbivory, soils all differentially affected persistence, size. Growing season temperature, inter-specific herbivory also changed time, altering their cohort, shifting landscape persistence growth ultimately favored. Eleven years postfire, favored at warmer, low elevations; ungulate browsing strongly constrained heights; competition was unimportant. By 25-years temperatures warmed nearly 1 °C, more likely persist cooler, high elevations. Browsing pressure declined, as populations decreased during but basal diameters by dense, rapidly growing conifers. Landscape mosaics shift time facilitate or constrain species. Long-term study post-disturbance uniquely reveal are responding real-time environmental landscapes, will help us better anticipate 21st century distributions abundances.