An important piece of the conversation related to Scotch broom on the West Coast of North America is its successional role in the context of unmanaged or undermanaged oak savannah ecosystems. Its often found in highly disturbed ecoystems (like clearcuts), but is also found in what are often considered "undisturbed" ecosystems like oak savannahs. However, if you look into the work of M. Kat Anderson (in California) and Nancy Turner (in BC), its evident that the oak savannah ecosystem is one that was wholly created and maintained by people for a wide variety of yields - food, fodder, and medicinal crops. Removing indigenous people from their historic lands and land management practices has changed the ecosystems of the Pacific Northwest (and beyond) in profound ways, and I see Scotch broom as part of that unfortunate story. Management of oak savannah ecosystems was based on sophisticated application of directed successional management to achieve yields of different crops (camas management regimes are different from salal, which are different from tarweed, etc.) All of them involved directing succession by introducing moderate disturbance like low-intensity burning or provision of fodder for ruminants (deer and elk mostly). Lack of successional management today means that these ecosystems are moving forward in their successional trajectory, with the understory moving from grasses/forbs to shrubs (in many cases Scotch broom). So, if we want to preserve and/or restore the characteristics of the oak savannah ecosystem, we have to investigate means of reintroducing periodic moderate disturbance that facilitates the type of understory vegetation we'd like to see. Prescribed fire is a good option, though not feasible everywhere. The well-timed application of the digestive "fire" of domestic ruminants can also be helpful. If not, hand management does work, it just takes time. Scotch broom (before it goes to seed) makes great compost, and as other commenters have mentioned, can be fed to livestock either directly through grazing or cutting and feeding. With all invasive species, I like to think about how we can enhance succession by doing what they're doing anyway a little bit faster - we can move along the process that they are there doing anyway. Usually this involves building soil organic matter and mineral/nutrient profile to the point where other types of species proliferate. Scotch broom won't last forever, and eventually the role that its playing in ecosystems will no longer be "needed" by what is coming next. Its up to us to figure out what that next layer is going to be, and move our management regime toward accomplishing that goal. Your management plan is going to be different depending on whether you want the spot currently covered by Scotch broom to be native bunchgrass, multi-species food forest, or annual vegetable garden, but all of these are possible to achieve using sound holistic land management practices.
