Evaluating the distributional equity of ecosystem services under land use and climate change scenarios

Nature supports human well-being and sustainable development through the provision of ecosystem services (ES). While ES have been mapped, modeled, and valued with multiple methods by a wide range of disciplines, understanding the distribution of ES benefits among individuals and groups within society remains a critical gap. Addressing this gap is essential for making conservation and environmental policy-making more equitable. In this dissertation, I present four studies that evaluate the distribution of ES among demographic and socioeconomic groups under a range of land use and climate change scenarios. In my first chapter, I project changes in the supply, demand, and benefits of four ES in the conterminous US between 2020 and 2100. I find that ES benefits in the US will not only decline over the next 80 years, but that those declines will most severely affect already marginalized communities. In my second chapter, I develop a novel framework for assessing the distribution of flood risk among property owners across the Lake Champlain Basin under floodplain restoration and climate change scenarios. Similarly, I show that those who are most vulnerable to flooding – mobile home owners and lower-value property owners – are disproportionately exposed to its risks. In my third chapter, I build on this framework by optimizing investments in floodplain restoration to mitigate flood damages at the lowest cost, with explicit consideration of how the utility of avoided damages may differ for households of varying income. In my final chapter, I quantify the social benefits and costs of improving water quality in Lake Champlain under a range of nutrient reduction and climate change scenarios. Under no scenario do the combined benefits exceed the costs, and in general, groups who benefit from improvements to water quality are distinct from those who bear the costs. Together, these four chapters present broad evidence that ES are unevenly distributed across socioeconomic and demographic groups, and that marginalized and socially vulnerable populations often bear the burden of declines in ES benefits. Given the potential for ES to mediate inequality, it is critical that stakeholders, researchers, and decision-makers carefully consider how land use and climate change may alter the distribution of ES benefits. Despite the many challenges to incorporating equity into environmental decision-making, this dissertation also highlights several opportunities for conservation and land use policy to create more just outcomes

Optimizing wetland restoration to improve water quality at a regional scale

Published by IOP Publishing Ltd. Excessive phosphorus (P) export to aquatic ecosystems can lead to impaired water quality. There is a growing interest among watershed managers in using restored wetlands to retain P from agricultural landscapes and improve water quality. We develop a novel framework for prioritizing wetland restoration at a regional scale. The framework uses an ecosystem service model and an optimization algorithm that maximizes P reduction for given levels of restoration cost. Applying our framework in the Lake Champlain Basin, we find that wetland restoration can reduce P export by 2.6% for a budget of $50 M and 5.1$200 M. Sensitivity analysis shows that using finer spatial resolution data for P sources results in twice the P reduction benefits at a similar cost by capturing hot-spots on the landscape. We identify 890 wetlands that occur in more than 75% of all optimal scenarios and represent priorities for restoration. Most of these wetlands are smaller than 7 ha with contributing area less than 100 ha and are located within 200 m of streams. Our approach provides a simple yet robust tool for targeting restoration efforts at regional scales and is readily adaptable to other restoration strategies

Biodiversity offsets may miss opportunities to mitigate impacts on ecosystem services

© The Ecological Society of America Biodiversity offsets are most commonly used to mitigate the adverse impacts of development on biodiversity, but some offsets are now also designed to support ecosystem services (ES) goals. Here, we assemble a global database of biodiversity offsets (n = 70) to show that 41% already take ES into consideration, with the objective of enhancing cultural, regulating, and provisioning services. We found that biodiversity offsets were more likely to consider ES when (1) development projects reported impacts on services, (2) offsets had voluntary biodiversity goals, and (3) conservation organizations were involved. However, offsets that considered ES were similar in design (eg offsetting approach, extent, and location) to offsets focused solely on biodiversity, suggesting that including ES goals may represent an attempt to strengthen community support for development projects, rather than to offset known ES impacts. We also found that 34% of all offsets displaced people and negatively affected livelihoods. Therefore, when biodiversity and ES are linked, current practices may not actually improve outcomes, instead incurring additional costs to communities and companies

Optimizing investments in national-scale forest landscape restoration in Uganda to maximize multiple benefits

Forest loss and degradation globally has resulted in declines in multiple ecosystem services and reduced habitat for biodiversity. Forest landscape restoration offers an opportunity to mitigate these losses, conserve biodiversity, and improve human well-being. As part of the Bonn Challenge, a global effort to restore 350 million hectares of deforested and degraded land by 2030, over 30 countries have recently made commitments to national forest landscape restoration. In order to achieve these goals, decision-makers require information on the potential benefits and costs of forest landscape restoration to efficiently target investments. In response to this need, we developed an approach using a suite of ecosystem service mapping tools and a multi-objective spatial optimization technique that enables decision-makers to estimate the potential benefits and opportunity costs of restoration, visualize tradeoffs associated with meeting multiple objectives, and prioritize where restoration could deliver the greatest benefits.Wedemonstrate the potential of this approach in Uganda, one of the nations committed to the Bonn Challenge. Using maps of the potential benefits and costs of restoration and efficiency frontiers for optimal restoration scenarios, we were able to communicate how ecosystem services benefits vary spatially across the country and how different weights on ecosystem services objectives can affect the allocation of restoration across Uganda. This work provides a generalizable approach to improve investments in forest landscape restoration and illuminates the tradeoffs associated with alternative restoration strategies.UKAid from the UK government through the International Union for Conservation of Nature’s KnowFor program as well as by the Natural Capital Project, a partnership between the University of Minnesota, Stanford University, the World Wildlife Fund, and the Nature Conservancy. MG was supported by the National Research Foundation of South Africa (Grant Number 98889).http://http://iopscience.iop.org1748-9326am2017Plant Scienc

Federal incentives for community-level climate adaptation: an evaluation of FEMA’s Community Rating System

In response to growing threats of climate change, the US federal government is increasingly supporting community-level investments in resilience to natural hazards. As such federal programs become more widespread, evaluating their efficiency and equity is essential. The Community Rating System (CRS), which is part of the National Flood Insurance Program (NFIP), is a promising example of a federal policy designed to reduce flood losses by providing financial incentives for local climate adaptation. In exchange for community engagement in a range of risk communication and risk reduction activities, CRS provides discounts on NFIP premiums ranging from 5% to 45%. Using national-scale NFIP claims, policies, and CRS data between 1998 and 2020, we assess the program, asking whether it has been effective in reducing flood losses, how it can be improved, and what lessons it holds for similar programs. We find that participation in CRS is associated with reduced flood damage, with the percent reduction in claims roughly proportional to NFIP premium discounts. Among CRS activities, those related to ‘Flood Damage Reduction’ are most effective in reducing flood losses and are associated with a 20%–30% decrease in NFIP claims. Between 1998 and 2020, cumulative damage reductions attributable to CRS were $11.4 billion; over the same period, cumulative NFIP premium discounts were$12.1 billion. This close match is an endorsement of CRS historically and supports its future continuation. To improve the efficiency and equity of CRS, we recommend that Federal Emergency Management Agency: (a) reexamine the surcharge levied on NFIP premiums that cross-subsidizes premium discounts, and (b) allocate greater resources towards supporting participation among smaller, under-resourced communities. In general, CRS serves as an effective model for other federal market-based programs seeking to stimulate community-level investment in climate resilience

Improving flood hazard datasets using a low-complexity, probabilistic floodplain mapping approach.

As runoff patterns shift with a changing climate, it is critical to effectively communicate current and future flood risks, yet existing flood hazard maps are insufficient. Modifying, extending, or updating flood inundation extents is difficult, especially over large scales, because traditional floodplain mapping approaches are data and resource intensive. Low-complexity floodplain mapping techniques are promising alternatives, but their simplistic representation of process falls short of capturing inundation patterns in all situations or settings. To address these needs and deficiencies, we formalize and extend the functionality of the Height Above Nearest Drainage (i.e., HAND) floodplain mapping approach into the probHAND model by incorporating an uncertainty analysis. With publicly available datasets, the probHAND model can produce probabilistic floodplain maps for large areas relatively rapidly. We describe the modeling approach and then provide an example application in the Lake Champlain Basin, Vermont, USA. Uncertainties translate to on-the-ground changes to inundated areas, or floodplain widths, in the study area by an average of 40%. We found that the spatial extent of probable inundation captured the distribution of observed and modeled flood extents well, suggesting that low-complexity models may be sufficient for representing inundation extents in support of flood risk and conservation mapping applications, especially when uncertainties in parameter inputs and process simplifications are accounted for. To improve the accuracy of flood hazard datasets, we recommend investing limited resources in accurate topographic datasets and improved flood frequency analyses. Such investments will have the greatest impact on decreasing model output variability, therefore increasing the certainty of flood inundation extents

Applying the Analytical Hierarchy Process to Small Dam Management: A Case Study of the Ames Mill Dam, Northfield,MN

As hundreds of small dams across the United States exceed their functional life spans, decision-makers must confront the question of how to manage them. However, due to the multitude of stakeholders and the uncertainty of outcomes, decisions about managing these aging dams are highly complex. For decades, these dams have transformed their surrounding communities and ecosystems. In order to manage aging dams, it is necessary to recognize and predict the social and biophysical impacts of decisions. The Analytical Hierarchy Process (AHP) provides a framework for dividing the impacts and criteria of a complex decision into categories and weighing them against each other relative to an overall goal. We applied the AHP to the a case study of how to best manage the Ames Mill Dam, a small relic mill dam located on the Cannon River in Northfield, Minnesota. To implement the AHP, we determined the potential economic, social, hydrological, and ecological effects of two dam management options, dam retention and dam removal, by distributing surveys to Northfield businesses, conducting community focus groups, and running a hydraulic sediment transport model. We found that removing the dam would provide opportunities for economic growth and that local residents would support restoring the river to a more natural state. Based on model results, we predicted that increased downstream sediment deposition caused by removing the dam could have negative short-term effects on freshwater mussel communities, but would likely increase connectivity between fish populations in the Cannon River. We concluded that although the AHP is better suited for a publically owned dam rather than a privately owned structure, the comprehensive evaluation of decision criteria of the AHP provides decision-makers with the information necessary to select a dam management option that will have an overall positive impact on stakeholders and the watershed ecosystem

Integrating climate change induced flood risk into future population projections

Abstract Flood exposure has been linked to shifts in population sizes and composition. Traditionally, these changes have been observed at a local level providing insight to local dynamics but not general trends, or at a coarse resolution that does not capture localized shifts. Using historic flood data between 2000-2023 across the Contiguous United States (CONUS), we identify the relationships between flood exposure and population change. We demonstrate that observed declines in population are statistically associated with higher levels of historic flood exposure, which may be subsequently coupled with future population projections. Several locations have already begun to see population responses to observed flood exposure and are forecasted to have decreased future growth rates as a result. Finally, we find that exposure to high frequency flooding (5 and 20-year return periods) results in 2-7% lower growth rates than baseline projections. This is exacerbated in areas with relatively high exposure to frequent flooding where growth is expected to decline over the next 30 years

Projected losses of ecosystem services in the US disproportionately affect non-white and lower-income populations

Social inequalities may be reflected in how ecosystem services are distributed among groups of people. Here the authors estimate the distribution of three ecosystem services across demographic and socioeconomic groups in the US between 2020 and 2100, finding that non-white and lower-income groups disproportionately bear the loss of ecosystem service benefits

Increasing decision relevance of ecosystem service science

The ecosystem service (ES) community aspires to illuminate how nature contributes to human well-being, and thereby elevate consideration of nature in decision making. So far, however, policy impact of ES research has been limited. To understand why, we identify five key elements of ES research that help inform decisions by connecting the supply of ES to those who benefit from them. Our structured review of the ES literature reveals that only 13% of assessments included the full ES chain from place to value. Only 7% of assessments considered the distribution of ES benefits explicitly across demographic or other beneficiary groups (for example, private landowners versus the broader public), although disaggregation across regions or spatial units was more common (44%). Finally, crucial mediating factors that affect who benefits and how (for example, the vulnerability of beneficiaries or the availability of substitutes for ES) were considered in only 35% of assessments. Our results suggest that increasing the decision relevance of ES research requires more effectively predicting the impacts of specific decisions on the value and distribution of ES across beneficiary groups. Such efforts will need to integrate ecological models with socioeconomic and cultural dimensions of ES more closely than does the current ES literature