A Tale of Adaptive Landscape Management

                                  

Like most designed landscapes, the entry garden for the Landscape Architecture Facility at Mississippi State University began with a plan. Specifically, this one:

I was asked to develop a planting plan in the summer of 2005, and I decided to focus on low maintenance plants to reflect our department focus on sustainable landscapes. Students helped to install plants in 2006, which looked like this:

Most of the plants did well and adapted to the sticky clay soils and persistent summer droughts. Drip irrigation was provided for the first year and then removed. Organic mulch was added periodically and the mineral soils developed a nice thick organic layer. Other than for establishment, no supplemental watering, fertilizing, or pesticides have been used. The perennials blossomed and established a quick cover within a year's time:

The trees and woody shrubs took time to grow and changes were already happening in the herbaceous layer. Some plants died out from drought or accidental weeding while others were planted to replace them. Volunteer herbaceous plants came in from local sources-- including native strawberries, evening primrose, and asters. Volunteers can spread rapidly and take advantage of late winter seasons where there is little competition. The evening primrose gave quite a display such as this:

Student workers in the garden were trained to use adaptive landscape management which they learned under one of my co-workers, Dr. Tim Schauwecker. Adaptive management, as defined by Holling, is decision-making as changes occur via system monitoring. An example of this in the landscape consists of allowing plant volunteers to come into the garden that are complementary to the already existing plants. Student workers in the LA garden actively pulled out any exotic invasive species such as Johnson grass or privet, while allowing others to exist. Some plants that took over aggressively, such as the evening primrose, and were pulled occasionally to keep them in check.

The garden today, 12 years later after install and shown above, has settled into a comfortable, more stable, plant community. Stable in the sense that vegetative changes will and are allowed to happen but there are no large wholesale changes to the landscape. The student managers allow plants to come in if they fit into the garden niche and offer a role through flowering or by providing other benefits. Plants that grow too large, or competitive, or are not suited-- are pulled out. Gardens are partnerships between the landscape and the people that care for them. By understanding the vegetative trajectories, or seres of a garden; and by allowing complementary plants to enter into that system from birds or wind; the garden co-evolves into a community of plants that exceeds the vision of the original designers or managers. Land managers--gardeners-- are really vegetative artists and allow the colors of plants to wash into the painting/plantings. We need to recognize that gardens are temporal and that all living things change. By listening to the land and allowing living things (plants and animals) to breathe and exist within the garden structure, the landscape renews itself. Gardens should, and need to be-- dynamic, instead of a static system.

How do you sample your yard to measure for biodiversity?

You can take samples in your yard just like urban researchers do, such as those in the Ecological Homogenization of Urban America project, hosted by a team of intercollegiate scientists. Funded by the U.S. National Science Foundation, the project personnel are trying to understand if cities that have similar road patterns, housing areas, and similar vegetation types create a distinct urban ecology that occurs across a continent (visit the project website at http://ecologicalhomogenization.com/). Scientists from leading universities in six U.S. cities: Baltimore, Boston, Los Angeles, Miami, Minneapolis/St. Paul, and Phoenix; are participating in understanding their local environment. They invite the public from that area to let them come to their residence and sample their yard. To do this, they:

• Identify and map all of the plants that are growing there.
• Take soil samples
• Take measurements of atmospheric conditions such as air temperature, humidity and soil moisture content.

After a few months of sampling, they send homeowners a report of their ecological index score. If you live in those cities, contact the research team to sample for you. If you don't, you can DIY by taking your own samples to see what you have. We look forward to their results.