Seed availability and insect herbivory limit recruitment and adult density of native tall thistle

• DOI: 10.1890/09-1101.1
• Publication Date: 2010-10-01T20:55:52Z
• Authors: F. Leland Russell; Karen E. Rose; Svata M. Louda
• Keywords: Density dependence

Understanding spatial and temporal variation in factors influencing plant regeneration is critical to predicting population growth. We experimentally evaluated seed limitation, insect herbivory, their interaction the density of tall thistle ( Cirsium altissimum ) across a topographic ecosystem productivity gradient tallgrass prairie over two years. On ridges valleys, we used factorial experiment manipulating availability herbivory quantify effects of: input on seedling density, juvenile cumulative impacts both reproductive adult density. Seed addition increased densities at three five sites 2006 all 2007. Insect reduced survival years, as well rosette from previous year's seedlings. In insecticide treatment plots led greater following year, reflecting increase experimental year. Seedling was not dependent. Our analytical projection model predicts significant long‐term input, with under herbivory. While community biomass water stress varied significantly between did vary position. These results support conceptual models that predict short‐lived monocarpic perennial plants should be limited. Further, demonstrates even high densities, which dependence potentially could have overridden herbivore survival, strongly affected performance this native species.