by Michael Piantedosi, Native Plant Trust and Mark Anderson, Director of Conservation Science, The Nature Conservancy
Reprinted from the American Public Gardens Association’s Public Gardens magazine
Conserving Plant Diversity in New England is a groundbreaking report resulting from a two-year collaboration between Native Plant Trust and The Nature Conservancy. The report provides a scientific framework and detailed roadmap for conservation action and land protection at the species, habitat, even parcel scales that will effectively save plant diversity- and thus overall biodiversity- in New England as the climate changes. This is the first report to ever focus on regional plant diversity, climate resilience, and science-based targets as the foundation for conservation policy and action, including land purchase. The report and its interactive mapping tool give policy makers, federal and state agencies, and land trusts the tools to most effectively spend conservation dollars by protecting specific climate-resilient sites that capture plant and habitat diversity.
“We wanted to know if more than a century of conservation in New England has protected enough land in the right places to save the region’s plant diversity,” says Debbi Edelstein, Executive Director of Native Plant Trust. “The collaboration with The Nature Conservancy merged deep botanical knowledge with robust data modeling to generate a powerful approach to land protection that can direct limited funding to the best places for preserving the region’s plants and the living systems they sustain.”
“This innovative report and mapping tool will help ensure that New England’s native plants—the green foundation for functioning ecosystems—are at the forefront of conservation policy and action as climate plans develop,” says Mark Anderson, the Director of Conservation Science at The Nature Conservancy. “Conservation decision-makers are striving to bring resilience and diversity into their planning, and now policymakers and federal and state agencies will have a roadmap to guide their conservation efforts and priorities.”
The report assessed progress toward global targets for plant and land conservation that will ensure functioning, climate-resilient ecosystems. It delineates the regional distribution of forty-three unique habitats, for the first time identified 234 Important Plant Areas (IPAs) containing an abundance of rare species, assessed the current protection status of those habitats and IPAs and likely losses to development by 2050, and evaluated their ability to effectively adapt to a changing climate. With that data, the authors determined how many acres of land in each habitat or IPA needs protection to meet the benchmarks; and the mapping tool gives a regional, state, and parcel-level view of high-priority areas. The benchmarks come from two primary sources, The Global Strategy for Plant Conservation (GSPC) and The Global Deal for Nature (GDN). The Global Strategy for Plant Conservation (GSPC), part of the United Nations’ Convention on Biological Diversity, aims to protect for nature or natural processes at least 15% of each ecological region or vegetation type and 75% of Important Plant Areas. The Global Deal for Nature (GDN) seeks to preserve 30 percent of the world’s ecosystems by 2030; it was adapted for New England with targets that aim for 30% secured from conversion to another use and 5-15% protected for nature and natural processes. The GDN’s 30 x 30 is incorporated into the 2021 update to the Convention on Biological Diversity and was recently adopted by the Biden Administration in its Conserving and Restoring America the Beautiful initiative.
In addition, the authors added climate resilience to the GDN/New England targets, so that protection efforts focus on places where the land provides many microclimates or natural strongholds for current plant populations that will enable them to endure under different climate scenarios. The report maps each habitat’s and each IPA’s most resilient land and assesses the progress toward permanently protecting and conserving these lands throughout New England.
The report distinguishes between land that is secured against development and land that is protected for nature and natural processes.
Results
- To achieve the target of securing 30% of habitats against conversion to development will require conservation of 2.3 million acres of climate-resilient land in specific habitats.
- To achieve the target of protecting 15% of the region’s habitats for nature will require selective targeted conservation of 3.5 million acres.
- Forests cover 86% of the natural landscape, but only two of New England’s ten dominant forest types meet the NET of 30% secured and 5% protected, and only one meets the GSPC goal of 15% protected.
- Wetlands cover 12% of the region and are critical to sustaining almost half our plants, birds, and other wildlife. Of the eighteen types of bogs, swamps, floodplains, and marshes, only three meet the NET of 30% secured and 10% protected on resilient sites and six meet the GSPC target. These are mostly small, unique bogs and peatlands. None of our five most common wetland types meet either target, although at least 20% of each habitat is secured against conversion.
- Patch-forming habitats, like summits, cliffs, barrens, and dunes, cover only 2% of the landscape, but have rare plant densities ten times higher than wetlands and forty times higher than upland forests. Of these unusual habitat types, seven of the fourteen meet the GSPC target. However, only habitats occur on flat and fragmented land that is vulnerable to climate change.
Recommendations from the report:
In a changing climate, New England needs multi-layered, science-based approaches to saving plant diversity and the life it sustains. The rapidly changing climate will stress the ability of individual species and entire habitats to adapt, leading to migration, death or the formation of new assemblages. We recommend focusing on more proportional representation of the region’s habitats across their ranges, rather than on securing more acres of habitat types that are abundantly conserved already. Specifically, we recommend:
- That each state aim for 15% of each habitat protected (conserved for nature and natural processes), with a minimum of 5% for dominant forest types;
- Prioritizing IPAs to ensure that habitat protection also captures rare plant species;
- Focusing on habitats that are rare in New England, on relatively large areas of common habitats that lack conservation protection, and on habitats facing significant losses to development by 2050.
Finally, sustaining plant diversity is more than just land conservation. We need a multi-layered approach that includes enhanced protection and more effective management of the 5.3 million acres of forest already secured from conversion, but open to logging and mineral extraction. These forests are central to wildlife habitat and carbon storage. In addition, strategies such as seed banking, reintroduction, and assisted migration will become more important as species try to adapt to changing conditions. With this report, our goal is to ensure that New England’s native plants—the green foundation for functioning ecosystems—are at the forefront of conservation policy and action as climate plans develop.
