Overstory–Understory Relationships

摘要: A key issue for sustainable management of oak woodlands is understanding the complex overstory-understory relationships that influence ecosystem productivity and stability. Oak removal traditionally practiced in Californian ranches Spanish dehesas to increase forage grazing, but response understory, subsequently trees, not fully understood. Existing knowledge effects trees on understory production tree recruitment reviewed synthesize from what known identify gaps. Emphasizing few published manipulative experiments clarify importance facilitation competition, plant interactions are analyzed examine three aspects relationship between understory: production, growth regeneration. First, we find related canopy-caused gradients aboveground belowground resources such as light, nutrients, water. Second, consequences density structure oaks analyzed, including competitive use resources. Third, seedling survival discussed its effect stability sustainability woodlands. While dehesa shrub encroachment certainly favorable regeneration, it does maintain longer-term stand functions profitability livestock, wildlife, cork production. We conclude by proposing a future research agenda study plant-to-plant relationships.