Question is found on this web page: http://www.foodtechconnect.com/2011/04/20/polyculturetech-part-i-the-permaculture-information-web-growing-guilds/ .

As part of the agricultural sustainability movement, backyard, urban, and rural gardeners and farmers are increasingly attempting to grow polycultures.  Permaculture guilds are designed polycultural systems, composed of plants, animals, fungi, and other organisms that grow particularly well together.  Perhaps the oldest and best-known guild is the Three Sisters, which consists of corn, squash, and beans and has been grown throughout Mesomerica for thousands of years.  The corn acts as a pole for the climbing beans, bacteria in the beans’ roots fertilize the corn and squash, and the squash acts as a shade structure for the roots of all three ‘sisters,’ keeping their roots cool and holding moisture in the soil.

If you’ve ever braved Permaculture guild design, you’ll know it’s challenging.  That’s because designing guilds isn’t about selecting individual crops, but about curating meaningful relationships between organisms.  It’s about designing complex adaptive systems, in this case, agroecosystems.  Designing agroecosystems requires systems design tools, tools that enable us to understand, design, and manage human and naturally systems in a more holistic way.  So, what would a design tool for curating meaningful ecological relationships look like?