Restoration of California Native Grasses and Clovers: The Roles of Clipping,Broadleaf Herbicide,and Native Grass Density

One of the major challenges confronting grassland restoration of highly invaded communities is increasing the diversity of native species. There is surprisingly little research investigating how reconstructed native grasslands respond to common management techniques and how these techniques influence the relative establishment of both native grasses and forbs. Despite the diversity and wide distribution of native clovers in California, few practitioners incorporate them into grassland restoration plans. Conversely, non‐native clovers have been seeded extensively onto California rangelands. This study addresses the following questions: (1) Using readily available management tools, is there a strategy that can benefit the growth of both planted native bunchgrasses and seeded clovers? (2) Do native bunchgrasses compete with establishing clovers and non‐native grasses? (3) Do native and non‐native clovers differ in their response to management treatments or in their productivity? Plots were established to test three factors in different combinations over 3 years: (1) early spring clipping, (2) initial broadleaf herbicide, and (3) native bunchgrass planting density. Native and non‐native clovers were seeded in years 2 and 3. Early spring clipping did not have a significant effect on native bunchgrass cover, yet it did result in greater growth of native and non‐native clovers. The direction of the response to broadleaf herbicide changed between years for native bunchgrasses and was consistently negative for native clovers. Plots with higher native grass densities did not adversely affect the seeded clovers, yet non‐native grass cover was reduced. Native and non‐native clovers exhibited similar responses to clipping and established at similar densities.