• IMMEDIATE FIRE EFFECT ON PLANT
• DISCUSSION AND QUALIFICATION OF FIRE EFFECT
• PLANT RESPONSE TO FIRE
• DISCUSSION AND QUALIFICATION OF PLANT RESPONSE
• FIRE MANAGEMENT CONSIDERATIONS

IMMEDIATE FIRE EFFECT ON PLANT:

Green rabbitbrush is usually top-killed by fire [45,54]. It has high resin content, and both foliage and stems may be consumed, even with relatively high moisture content. Fuel distribution as well as overall fuel loading affects the potential survival of green rabbitbrush [101].

DISCUSSION AND QUALIFICATION OF FIRE EFFECT:

The potential damage done to the plant is affected by the proximity of other shrubs, which provide additional fuel and higher fire intensity. With higher intensity or a longer burnout time, there is a greater chance of lethal heating of basal buds [101].

In sagebrush-grass communities of the Great Basin, burning during flowering when carbohydrate levels are at their lowest can be most deleterious to rabbitbrush species. If plants are defoliated by insects or browsing ungulates prior to burning they may lack sufficient reserves to resprout [69].

PLANT RESPONSE TO FIRE:

Green rabbitbrush sprouts vigorously after fire [1,45,78]. Sprouts originate from epicormic buds located just below the soil surface [69]. Typically, a single shoot appears the first year after burning [91,99]. Green rabbitbrush also reestablishes rapidly through seeds which may be carried relatively long distances [1]. Response to fire could vary by subspecies [69].

Green rabbitbrush often increases on burned range sites [46]. Production may be reduced for 1 to 3 years after fire, but then increases rapidly [45,66]. Studies have documented a 4- to 9-fold increase in production within the first 20 years after fire in northeastern Idaho [37]. After fire near Dubois, Idaho, production was reduced by 59% in the first postfire year [95]. Three years after the fire, production had doubled relative to preburn levels. It had tripled at the end of 12 years [95].

Green rabbitbrush is relatively short lived and is eventually overtaken by reinvading sagebrush. In sagebrush-grass communities of Nevada, recovery of green rabbitbrush to preburn levels may occur within 20 to 25 years, with green rabbitbrush much reduced in 40- to 50-year-old stands [45,69].

DISCUSSION AND QUALIFICATION OF PLANT RESPONSE:

Green rabbitbrush sprouts vigorously after fire [1,45,78]. Sprouts originate from epicormic buds located just below the soil surface [69]. Typically, a single shoot appears the first year after burning [91,99]. Green rabbitbrush also reestablishes rapidly through seeds which may be carried relatively long distances [1]. Response to fire could vary by subspecies [69].

Green rabbitbrush often increases on burned range sites [46]. Production may be reduced for 1 to 3 years after fire, but then increases rapidly [45,66]. Studies have documented a 4- to 9-fold increase in production within the first 20 years after fire in northeastern Idaho [37]. After fire near Dubois, Idaho, production was reduced by 59% in the first postfire year [95]. Three years after the fire, production had doubled relative to preburn levels. It had tripled at the end of 12 years [95].

Green rabbitbrush is relatively short lived and is eventually overtaken by reinvading sagebrush. In sagebrush-grass communities of Nevada, recovery of green rabbitbrush to preburn levels may occur within 20 to 25 years, with green rabbitbrush much reduced in 40- to 50-year-old stands [45,69].

FIRE MANAGEMENT CONSIDERATIONS:

Green rabbitbrush produces small stems and seed stalks annually which die but remain on the plant for a year or more. During drought periods, this dry, dead material may increase fuel accumulation and contribute to the spread of fire [64].

The recovery of green rabbitbrush after fire depends on both its ability to resprout after fire and its production of large numbers of achenes when released from competition. To prevent massive reestablishment of green rabbitbrush, potential treatment sites should be chosen carefully. An adequate cover of perennial grasses and forbs reduces green rabbitbrush reproduction. In northern Nevada, a density of not less than 2.5 perennial grass plants/m² is recommended [98].

Related categories for SPECIES: Chrysothamnus viscidiflorus | Green Rabbitbrush