When land development projects cause environmental impacts, mitigation or conservation banks can provide an efficient offset solution. These banks preserve, restore or create habitat and are preapproved to offset development impacts to nearby streams, wetlands and threatened species. Maintaining them requires a long-term maintenance and reporting commitment, as well as the knowledge and experience to address the challenges of ecological restoration.
Working with state and federal partners (such as the U.S. Fish & Wildlife Service, the National Marine Fishery Service or the U.S. Army Corps of Engineers) to establish conservation, wetland or stream mitigation banks is just the first of many steps needed to make sure specific environmental impacts are offset in perpetuity. In the early years of managing banks, extensive effort goes into construction, restoration, planting and implementing biological improvements. Then the focus shifts to long-term maintenance, which includes both environmental upkeep and financial management.
Specific tasks vary according to the purpose of the mitigation bank, but often include:
- Implementation. Upon approval, the bank implements its agreed-upon initial restoration actions. These can include engineered restoration actions, removal of invasive species, planting native species, installing watering systems, trails, firebreaks and site protection.
- Habitat improvement. Maintaining high-quality habitat for protected species requires perpetual management. Management actions vary depending on the condition of the habitat and the desired future conditions, but could include wetland delineations, planting native grasses and forbs, controlling weeds, felling or girdling trees, and conducting prescribed burns.
- Invasive species management. Management of invasive species is important to maintain the ecological viability of a site. Invasive plant species such as bush honeysuckle, multiflora rose and autumn olive can become established quickly at a site, outcompeting native vegetation and reducing habitat quality for other species. Special management projects in these areas, such as brush hogging, herbicide application or prescribed burning, might be necessary to reduce the prevalence of invasive species. Following the management actions, these areas are monitored to determine whether additional management is warranted.
- Replanting a woodland. Restoration of old crop fields and other open areas to forest or woodland habitat can be accomplished through tree planting. Young native trees are planted in these areas and monitored over several years to make sure they are growing to a reasonable size and density.
- Performance monitoring. Monitoring the performance of a bank is a way to verify it is providing the intended environmental benefits. The land manager visits the bank at specific sites during each season to identify changes across seasons and years. Vegetation surveys also are conducted at multiple points on each property to evaluate changes in the species composition, density and size of trees over time. This data is essential to inform additional management actions.
- Species-specific surveys. These surveys provide important data on particular species using habitat on the property. At the Chariton Hills Conservation Bank, surveys for threatened and endangered bats are conducted periodically. These species are surveyed with acoustic equipment, which can detect calls produced by bats, and mist-netting equipment, which allows biologists to capture bats in flight. Radio transmitters can be attached to captured bats temporarily to allow biologists to locate and document their roost trees.
- Annual reporting. Every year, the land manager is responsible for documenting all actions taken, reporting any changes to the property, comparing progress with the management plan and sending this report to the relevant regulatory agency.
Ecological restoration poses unique challenges to project developers and conservation bankers. Whether the task at hand is maintaining properties or conducting special restoration projects, environmental scientists can determine efficient ways to address challenges, put together a plan of work and track progress against the management plan. Purchasing credits from an existing bank managed by an experienced environmental team can reduce permitting timelines and provide fixed costs for offsetting environmental impacts caused by development and make improvements to the environment in perpetuity.
Learn about how we established the Chariton Hills Conservation Bank in northern Missouri, the first conservation bank approved for the protection of the Indiana bat and northern long-eared bat.