Ecosystem Guilds

Cap & Share has remarkable analogues in natural ecosystems. Permaculture epert Dave Jacke, author of Edible Forest Gardens, describes how sets of species often come together as "guilds" to exploit food sources in the same location. However, to avoid over-exploitation of jointly used resources, species tend to devise one or more three distinct methods for allocating resources among their members.

While ecologists and permaculturists use the word "guild" in variable ways, Jacke understand the term to denote "effective polycultures with functional relationships" among species. Guilds in this sense are important in understanding interspecies relationships that sustainably manage ecosystem functioning.

Jacke points to three types of guilds:

Community Function Guilds, in which "a set of species all perform the same community function" and fill the same community niche. When there is a redundancy in the ecosystem, community function guilds provide stability of function. E.g., there may be a variety of species (birds, frogs, snakes, insects, fungi) acting as a guild of orchard-canopy predators, but if one ore more species are lost, other members can take up the slack. Guild members may or may not compete with each other.

Resource Partitioning Guilds (aka "resource sharing guilds") entails the same role as a community function guild (species share the same community niche or resource need), "AND they partition the resource in time, space or kind so they don't compete," writes Jacke. Pertitioning reduces competition among species, allowing more species to make a living in the same space, increasing diversity in the process. In addition, "Greater productivity arises for each member of the guild, and for the community as a whole, because fewer resources are devoted to competition."

Mutual Support Guilds "consist of species from *different* community niches whose needs and yields link up for the benefit of one, the other, both or a third party." Members of this type of guild interact across food web levels (plant - predator - herbivore - plant, or plant-decomposer-plant, as well as within levels (plant-plant). In this type of guild, there are functional interconnections that help the ecosystem maintain itself because the inherent needs of one species are met by the inherent byproducts of others. This reduces stress and increases harmony, cooperation and stability. It also reduces work, waste and pollution and the need for eternal inputs of resources."