NCPC - National Capital Planning Commission
01/22/2024 | Press release | Distributed by Public on 01/22/2024 07:30
Resource Guide: Pollinators Best Practices
- By Stephanie Free
- January 22, 2024
On January 4, 2024, NCPC presented a Pollinators Best Practices Resource Guide as an Information Presentation to the Commission. The resource guide was developed by staff to clarify how NCPC incorporates plants that support pollinators in its review of proposed projects.
What Are the Pollinators and Why Are they Important?
A pollinator is anything that helps carry pollen from the male part of a flower to the female part of the same flower, or another flower. The movement of pollen must occur for the plant to produce fruits, seeds, and young plants (National Park Service). Some plants are self-pollinated, while many rely on external pollinators such as wind, water, or insects and animals for pollination. The resource guide focuses on best practices for selecting plants that support animal and insect pollinators - particularly bees and monarch butterflies, but this also includes wasps, moths, birds, flies, and small mammals.
Pollinators are extremely important for the health and longevity of the human and natural environments. For example, at least 75 percent of all the flowering plants on earth are pollinated by insects and animals. This amounts to more than 1,200 food crops and 180,000 different types of plants that help to stabilize soil, clean air, supply oxygen, and support wildlife. Despite how valuable pollinators are, recent surveys have shown disturbing population declines in insect pollinator species across Europe and the United States. For example, beekeepers are losing an average of 40 percent of their managed European honey bee colonies every year and monarch butterflies have declined 85 percent in two decades. The cause of pollinator decline is attributed to several factors. Development of natural habitats fragments pollinator habitats; invasive plant species degrade natural habitats by reducing plant diversity; urban, suburban, and agricultural landscapes offer limited nesting sites; diseases, parasites, exposure to pesticides, and a changing climate are additional reasons for their decline. (Penn State Extension).
In response to President Obama's 2014 memorandum, "Creating a Federal Strategy to Promote the Health of Honey Bees and Other Pollinators," federal agencies established their own policies to support pollinators. This includes a joint effort between the U.S. General Services Administration and the Council on Environmental Quality titled "Supporting the Health of Honey Bees and other Pollinators" and the U.S. Department of Agriculture Natural Resources Conservation Service's Field Office Technical Guidance titled, "Conservation Planting and Wildflower Habitat Establishment."
NCPC defers to these resources for best practices for selecting plants that support pollinator habitats.
Pollinator Best Practices in NCPC's Plan Review
NCPC reviews landscape plans as part of site and building plan submissions. There is a lot of existing guidance and familiarity about the importance of native plant species selection and their benefits, but more recently we have heard about including plants that support pollinators in landscape plans. As a result, staff developed the Pollinator Best Practices Resource Guide to clarify how NCPC utilizes federal guidance to support pollinator habitats in its review.The resource guide provides an outline of what NCPC can do in its plan and project review and what submitting agencies can do as plan-preparers to support pollinators. Simply put, the answer is to plant more plants that support pollinator habitats. A healthy pollinator habitat consists of plants that will provide food (primarily pollen and nectar), shelter, nest sites and materials, and/or larval hosts for pollinators animals and insects.
Additionally, there is a lot of overlap between native plants and plants that are good for pollinators. Native plants are species that evolved and occur naturally in a particular region. Many of them have co-evolved with pollinators like bees and butterflies since many plants and pollinators rely on each other for survival. Herbaceous flowering plants, like the purple coneflower, often come to mind when one thinks about a pollinator-plant, and flowering plants like this are very important for pollinators because they produce nectar, which is food for many pollinator animals and insects. However, native plants that support pollinators can also be trees, shrubs, perennials, vines, groundcovers, grasses, sedges, and others as they provide some of the other habitat benefits, like shelter, nest sites, and larval hosts.
The resource guide summarizes best practices for selecting plants that benefit pollinators in both meadow and non-meadow/or designed landscapes. Sometimes landscape plans submitted to NCPC include meadows, which are largely fields dominated by wildflowers and grasses. However, more often NCPC reviews designed landscapes, which includes cultural or commemorative landscapes, gathering spaces, and recreational areas.
Meadow Landscapes
For meadow landscapes, the Resource Guide summarizes guidance from the USDA's 2022 Maryland Conservation Planting Guide and 2023 Maryland Wildflower Habitat Establishment Guide.
This guidance recommends that meadows consist of 100 percent native plant species with 85-90 percent wildflowers and 10-15 percent grasses. In a meadow where monarch butterfly habitat is the primary purpose, at least 1.5 percent native milkweeds should be planted as food for the caterpillars and 60 percent of the wildflowers planted should be species that can provide nectar for monarch butterflies.
It also recommends at least three plant species from each bloom period (spring, summer, and fall) are specified to provide consistent and adequate resources throughout the growing season.
Non-Meadow and Designed Landscapes
For non-meadow and designed landscapes, the resource guide lists recommendations from "Supporting the Health of Honey Bees and Other Pollinators." These best practices include choosing plants native to the project's ecoregion; selecting the right plant for the site; the use of some non-native plants if they are not invasive; selecting at least three plant species from each bloom period; considering all types of plants (such as trees, shrubs, perennials, and grasses); acquiring responsible seeds; and taking care when selecting cultivars.
The resource guide also acknowledges that NCPC must balance the need to maintain historic, cultural, or commemorative significance with the demands for ecological sustainability. For example, the U.S. Department of Homeland Security Headquarters Resilience Plaza project was one where the proposed landscape plan did not include a very important pollinator-friendly plant species, milkweed (Asclepias spp.). Milkweed was intentionally not included in the proposed landscape plan because milkweed was not identified in the site's Cultural Landscape Report. However, the plan supported pollinators in other ways, with 50 percent of the plant material consisting of native trees, sedges, shrubs, and perennials, with at least nine different plant species for each bloom period.
Conclusions
Overall, the resource guide's primary takeaway is that biodiversity is KEY to a healthy pollinator habitat. Biodiversity is important to any healthy ecosystem. It provides resiliency in the event of detrimental impacts to a specific species such as from a pest or disease, or climate change. A healthy pollinator habitat will provide food and shelter, larval hosts, and nesting materials or sites, which may be provided by a diversity of plant types. Native flowering plants are especially important, as they produce nectar which attracts and feeds pollinators, and encourages pollination.