INTERACTION WITH OTHER IMPERATIVES
Project teams are encouraged to design elements in an integrated fashion so that they contribute to the intent and requirements of more than one Imperative. Take the example of a rain garden. A primary function would be to infiltrate stormwater as required in I05 Responsible Water Use (C3). If the soil structure and chemical properties as well as the plantings are designed to emulate the Reference Habitat, the rain garden could also contribute to the intent and requirements of this Imperative (I01). If edible-fruit-bearing shrubs were a part of the Reference Habitat plant palette and they were incorporated within the rain garden, then they would also count toward Imperative 02, Urban Agriculture. Further, if the stormwater were delivered to the rain garden in a way that took into account biophilia and biophilic design elements and attributes, the rain garden could also contribute to meeting the requirements of Imperative 19, Beauty + Biophilia (C9).
A site assessment and assessment of the surrounding community are necessary to meet the intent and requirements of this Imperative. The information gathered during each of these assessments may also inform the approach and strategies undertaken for a variety of other Imperatives. For example, an understanding of soil properties on the site will inform strategies for complying with Imperative 02, Urban Agriculture, while an understanding of pre-development hydrology and current ecological conditions is the basis for devising strategies to meet the stormwater treatment requirements of Imperative 05, Responsible Water Use (C3). Additionally, developing the framework and plan called for under Imperative 19, Beauty + Biophilia (C9) requires the compilation and review of historical, cultural, ecological, and climatic studies that will help inform strategies for improving the ecological performance of the site. Project teams are encouraged to take a holistic approach to these characterizations of the site and to look for relationships and interactions among elements that may yield more integrated solutions than when considered in isolation.
LANDSCAPE
On-site landscape is considered to be any planted area inside the Project Area but outside of the square footage of agricultural cover required for Imperative 02, Urban Agriculture. Project teams that wish to produce food within the Project Area may grow non-native plants for agricultural purposes, even if they are not pursuing Imperative 02, Urban Agriculture. However, projects are encouraged to consider ways to incorporate native edible plantings into the landscape plan.
Ideally, all of the onsite landscape will contribute positively to the site’s ecology. In all cases, the Adaptive Plan must take into account all of the onsite landscape and make specific reference to how each component of the onsite landscape affects the site ecology. Under no circumstances can invasive or exotic species be used that might be toxic or harmful to the local ecosystem.
Interior landscape does not need to be native or naturalized, but must comply with all other Imperative requirements. For example, interior plants must be watered from on-site sources such as greywater or rainwater.
QUALIFIED PROFESSIONALS
In all Transects, the involvement at a fundamental level of personnel with knowledge and practical experience in restoration ecology or similar will be a significant factor in the success of the ecological improvement effort. In Transects L1–L4, training and experience in restoration ecology or comparable is likely necessary for evaluating the pre-project baseline site condition, developing the Adaptive Plan, including the monitoring and maintenance plan, and evaluating the condition of the site at the end of the performance period. In Transects L5 and L6, while involvement of a restoration ecologist or similar is encouraged, knowledge and skills related to soils and native plant systems such as may be possessed by a landscape architect or master gardener, may be sufficient.
RECOMMENDED BUFFERS
Where a project site risks impacting Priority Natural Lands, buffers should be incorporated to protect ecological function. Project teams must make the case that buffer distances are sufficient to avoid negative impacts. The following are recommended buffers for some sensitive habitats.
- Old-growth forest: maintain at least 60 meters separation.
- Primary dunes: maintain at least 40 meters separation.
- Virgin prairie: maintain at least 30 meters separation.
- Wetlands: maintain at least 15 meters and up to 70 meters separation, depending on the context.
TOOLS AND RESOURCES
The guidance in this handbook incorporates metrics from the Society for Ecological Restoration’s International Standards for the Practice of Ecological Restoration (SER Standards). Project teams are encouraged to also reference and utilize, as appropriate to the Transect and Project, the Standard Practices for Planning and Implementing Ecological Restoration Projects in the SER Standards. For more urban sites, teams are also referred to “Making Nature’s City” from the San Francisco Estuary Institute (see link in Resources). While less focused on designing site specific enhancement projects, this resource provides guidance on strategies providing the biggest impact within constrained landscapes.
THRIVING VIBRANT ECOLOGICAL ENVIRONMENTS AND HABITATS
For purposes of this Imperative, “thriving, vibrant ecological environments and habitats” are one class of Priority Natural Land which includes places with high-quality or important ecological function, and/or critical ecology, that may not meet the definition of wilderness or pristine greenfield. An example of a thriving, vibrant ecological environment or habitat that isn’t wilderness or pristine greenfield might be a site that was subject to disturbance by human activity, but which has been allowed to evolve back toward its natural state, such as a well-established second-growth forest, or a grassland that has been lightly grazed but which retains a substantial diversity of indigenous species.
Wherever thriving, vibrant ecological environments and habitats exist on a site or a portion of a site, they must be protected from building and any other significant impacts.
