Agroecosystem sustainability as a framework for agriculture production systems requires attention to detail to multiple facets of the underlying production system. Production systems must achieve optimal cash crop yields while remaining profitable. Likewise, production practices must be tailored to reduce its environmental footprint. Identifying practices that encourage improved soil physical and chemical properties while maintaining yields have largely been challenging. Cover crops have been an integral part of the conversation regarding practices that can generally improve those properties of soil responsible for overall soil health. Use of winter cereal cover crops (WCCC’s) have shown promise as a tool for reducing soil and nutrient run-off, thereby reducing nitrogen (N) and phosphorus (P) nonpoint source pollution in the Upper Mississippi River Basin (UMRB). However, corn-cash crop yield penalties are often incurred following the use of WCCC’s such as winter cereal rye (Secale cereal) (WCR), as N is immobilized by cover crop residues in the decomposition processes. Additionally, traditional planting methods of cover crops have resulted in reductions of harvestable populations of corn and soybeans. These problems indicate a necessity for novel cover crop planting methods that reduce the consequential outcomes of implementing traditional cover crop practices. Using a method called “Skipping the corn row” (STCR), otherwise identified as “precision planted” cover crops, we aimed to reduce the cash crop yield-limiting interactions of cover crop residues within the cash crop row. We hypothesized that removing cover crop biomass from the subsequently planted cash crop row (chapter 1) could minimize N immobilization by residues, thereby increasing our subsequent yield potential and economic optimum return to N (EORN). In novel cover crop planting methods preceding soybeans (chapter 3), our hypothesis indicated that mixtures of WCR and crimson clover (Trifolium incarnatum) would impact biomass accumulation of weed communities, while novel measures that allowed for reduced seeding rates would permit competitive soybean yields while reducing input costs for cover crop seed. Chapter 2 focused on interseeding mixtures of WCR and crimson clover, where we hypothesized that residual rates would marginally impact percent cover of WCR and crimson clover mixtures. Our results indicated, in chapter one, that reducing seeding rate by using STCR planting method did indeed drive seed cost savings while improving yield and EORN in comparison to a traditionally planted cover crop. Our results in chapter 3 also indicated reduced seeding rates found in novel planting methods improved the on-farm economics of using cover crops while maintaining healthy soybean yields. Lower-than-average rainfall accumulations later in the growing season coupled with cover crop residues likely influenced soil moisture retention, benefiting the cash crop during the dry spell, helping maintain yields. Interseeding methods, as studied in chapter 2, did not show any significant impact on corn grain yield or yield components. Subsequently, half- and full-rate residual herbicides did not impact percent cover of cover crops. However, use of residual herbicides should be consistent with all herbicide labels and laws, and producers should use label-recommended amounts to maintain maximum efficacy of herbicides and to prevent resistant weed populations. Also, interseeded cover crops failed to successfully establish, resulting in minimal cover crop biomass in later sampling dates.

Coastal restoration has become a necessary and ubiquitous practice to enhance and conserve the many ecosystem services lost by marsh degradation. Wave climate is one of the most critical factors to consider for restoration projects. However, knowledge of the ways that waves affect marsh plants and the ecosystem services they provide is limited. The purpose of my dissertation was to improve the effectiveness of coastal marsh restoration by addressing the limitations and gaps associated with plant and ecosystem responses to waves through empirical research with three primary goals: 1) develop and test a low-cost wave gauge, 2) use it to compare above- and below-ground plant growth responses along a wave climate gradient, and 3) evaluate the effects of waves on nutrient removal in constructed marshes. I used three field and laboratory experiments to accomplish these goals. The low-cost wave gauge was developed using an Arduino microcontroller and various accessories. After development, the gauge was evaluated against a commercial gauge in a series of laboratory and field tests. Comparisons revealed over 90% agreement between the gauges and confirmed the applicability of the low-cost gauge. A total of thirty gauges were then constructed and deployed at sites within Mobile Bay, Alabama and surrounding tributaries. In addition to wave energy, plant data was also collected at each site, including above- and below-ground biomass, shoot density, height, and diameter. These data suggested that waves affect plant growth responses in ways not explained by the current plant response paradigm. For example, while greater diameter shoots best attenuate waves, shoot diameter declined with greater wave exposure in this study. This response was common among the study species. Other plant responses were species-specific. Finally, a field experiment was constructed to examine the main and interactive effects of sediment type, initial planting density, platform slope, and platform position at sites exposed to and protected from waves. Results from this experiment suggested that waves may potentially mitigate the effective removal potential of constructed marshes. Taken together, this dissertation advances research on plant responses to waves and provides new tools for land managers working on coastal restoration and conservation projects.

The State of Mississippi wants to manage its oyster resource to increase production, quality, ecological, and economic benefits. In this study, we employ modern portfolio theory (MPT) to test if there are potential gains to hold multiple oyster resources for multiple benefits to aid the state's effort in achieving its goal. Using a Delphi approach, we elicit complete sets of data on ecosystem services (on oxygen, nutrients, sedimentation, and salinity) across multiple oyster resources (traditional plantings, off-bottom farms, and restored reefs). A benefit transfer method is used later to assigned money-metric value to each service estimate. The multiple service values are then aggregated into net service value. We compute the means, standard deviations, and correlations of benefits across all resources using the net service values, and generate efficient frontiers from that information. Results indicate that Mississippi could benefit from holding multiple oyster resources while focusing more on off-bottom oyster farms.

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Environmental degradation is threatening the provision of ecosystem services (IPBES, 2019). In an attempt to reverse this degradation trend, the use of economic incentives has increasingly gained prominence in environmental policy. In particular, payments for ecosystem services (PES), a type of economic incentive in which ecosystem services providers voluntarily receive a payment in exchange for the provision of ecosystem services, has increasingly gained relevance worldwide (Salzman et al., 2018). PES aim to enhance environmental conservation by altering the economic costs or benefits associated with targeted pro-environmental actions. However, a large amount of empirical evidence shows that PES, like other economic incentives, could potentially crowd out (or crowd in) intrinsic motivations for environmental conservation, which may sometimes translate into unexpected undesirable overall effects (for reviews, see Bowles and Polania-Reyes, 2012; Rode et al., 2015). Up to date, the conditions under which PES, and economic incentives in general, induce such motivational crowding effects are still not fully understood. In analyzing these effects, economic theory has often taken for granted non-monetary factors of economic incentives because they do not involve changes in prices or incomes. However, experimental evidence show that such factors could be relevant to preventing crowding-out effects or even creating crowding-in effects (e.g., see Ariely et al., 2009; Heyman and Ariely, 2004). In the context of PES, a large proportion of the experimental literature has focused on studying the effect of design features related to the monetary elements of these programs (e.g., Kerr et al., 2012; Kolinjivadi et al., 2019; Midler et al., 2015; Moros et al., 2019; Narloch et al., 2012), while fewer experimental studies have focused on non-monetary factors such as the degree of participation in the design or implementation process (e.g., Jack, 2009; Moros et al., 2019; Vollan, 2008). The present thesis contributes to this line of literature by examining whether PES could be more or less effective when specific non-monetary factors are adjusted in PES design or implementation. This thesis comprises an introductory chapter (Chapter 1) and a concluding chapter (Chapter 5) that serve as an overview of the thesis, together with three research articles (Chapters 2, 3 and 4). In each of the research articles belonging to this thesis, a specific non-monetary factor in the design or implementation context of PES is analyzed. Prior versions of the research articles in chapters 2-4 have been published as working papers on SSRN. Their content is briefly summarized below. Chapter 2 is entitled “Beyond a Market Discourse: Is Framing a Solution to Avoid Motivational Crowding-Out in Payments for Ecosystem Services?” and is co-authored by S. Engel and E. Midler. The goal of this article is to examine the role of the framing of a PES policy in preventing motivational crowding effects. In particular, it focusses on the short- and long-term effects of two dimensions of framing on: 1) using different terms to denote the payment, and 2) emphasizing different types of ecosystem services obtained from nature to motivate its conservation. This article analyses this topic with a lab-in-the-field experiment conducted with 157 farmers from a Colombian municipality. The findings of this article suggest that the framing of a policy could be a rather inexpensive tool to mitigate motivational crowding effects. In particular, a framing that acknowledges forest conservation as an achievement and a framing that emphasizes the cultural ecosystem services obtained from forest results in better conservation outcomes relative to a control framing. Chapter 3 is entitled “Who is Benefiting Downstream? Experimental Evidence on the Relevance of Upstream-Downstream Geographic Distance for Water Provision.” and is co-authored by S. Engel, E. Midler and T. Vorlaufer. The goal of this article is to study the relevance of the social distance between ecosystem service providers and beneficiaries for the short- and long-term motivational crowding effects of a PES policy. This article analyses this topic with a lab-in-the-field experiment in which the salience of social identity is defined by the real geographical distance between ecosystem service providers and beneficiaries, rather than being artificially induced. In particular, the experiment involves 60 rural farmers from a Colombian municipality, whose water provision decisions affected passive downstream beneficiaries in either the same municipality or the capital city of Bogotá. The findings suggest that although sharing a closer place identity with downstream beneficiaries is relevant to determine baseline water provision, it does not affect average motivational crowding effects in the short and long term. Nonetheless, predictions from the econometric analysis of the heterogeneous treatment effects suggest that emphasizing the benefits provided to people with whom upstream providers feel more socially identified could mitigate long-term crowding-out effects on providers with weak levels of place identification, without compromising the short-term effectiveness on farmers with a strong place identity and already high provisioning levels. Therefore, in the absence of a well-defined group of downstream beneficiaries financing a PES program, it could be more effective to emphasize local benefits, rather than the general benefits to society. Chapter 4 is entitled “Behavioral Spillovers from Mixing Conservation Policies in Neighboring Areas: An Experimental Analysis on Fairness Perceptions toward Unequal Policies.” and is co-authored by S. Engel and E. Midler. The goal of this article is to analyze the impact of fairness concerns on the effectiveness of a policy that is implemented in an unequal institutional context. In particular, it compares the effectiveness of implementing a specific economic incentive when a monetary reward is being implemented in a neighboring area, to the effectiveness of implementing the same economic incentive over the entire area. This article analyses this topic with a lab-in-the-field experiment conducted with 276 farmers from a Colombian municipality. In particular, the treatment recreated three institutional contexts: 1) a high priority area where PES are implemented next to a low priority area that is excluded from PES, 2) a protected area with land-use restrictions surrounded by a buffer area where PES are implemented, and 3) a protected area where PES are implemented on top of land-use restrictions, surrounded by a buffer area with only PES. Surprisingly, the findings show that fairness concerns do not increase with the level of inequality between neighbors. Although PES exclusion and simultaneously implementing PES inside and outside a protected area tend to increase fairness concerns and reduce forest conservation relative to the control groups, implementing PES only in the buffer area of a protected area decreases fairness concerns and increases forest conservation by those within the protected area, even after the policies are removed. Overall, this article stresses the relevance of considering the institutional context and context-specific fairness perceptions as a relevant factor when defining the targeting criteria for the implementation of environmental policies.

Our motivation for this research is the interest we have for positive influences of green areas on people's well-being and social improvement. We see nature, the ecosystems and its services, integrated with humans as a whole, making our lives physically and mentally more sustainable. Therefore the purpose of this study is to investigate the social benefits of selected ecosystem services in sub-urban parks in Malmö City, and to explore how the respected services can be enhanced with a greater connectivity of the parks. A survey and interviews were used to collect information about people's preferences and values about nature parks and their opinion on possible connectivity of three sub-urban parks in Malmö, Sweden. The results show that people are overall positive with the recreational and aesthetic values of parks but show less appreciation for the parks as pure nature represents. Connectivity is not clearly understood by the participants but seems to be positively accepted. To give an idea on how Malmö could improve urban biodiversity and facilitate enjoyable nature experiences we give some practical suggestions for a green corridor.

The world is increasingly urbanizing with approximately 54% of the world population livingin cities (Langemeyer, 2015). This number is expected to rise to 66% by 2050 (UN, 2014),which means that urbanized areas will expand in size with an additional 2.5 billion new urbaninhabitants (Langemeyer, 2015). Studies show that urban expansion has the effect ofdecreasing, fragmenting, and isolating natural patches by altering the size, shape, andinterconnectivity of the natural landscape (Ricketts, 2001; Alberti, 2005). The consequentloss and degradation of urban and peri-urban green/blue space and elements couldadversely affect ecosystem and its services as well as human health and well-being.Through literature review, the concepts of urban ecosystem services and green-blueinfrastructures are introduced, as well as the main design principles for green-blueinfrastructures. The thesis also briefly introduces urban policies and implementation throughcase study with a focus on Malmö city. Meanwhile, the thesis discusses how the planninginstruments of Green Space Factor and Green Points are used in the Bo01 project and howthey contributed to promote ecosystem services in built environment.Through literature review and case study, the aim of this thesis is to collect design solutionsthat can be used as inspiration and guidance to promote urban ecosystem services throughgreen-blue infrastructures in built environments at different scales.

The world is increasingly urbanizing with approximately 54% of the world population livingin cities (Langemeyer, 2015). This number is expected to rise to 66% by 2050 (UN, 2014),which means that urbanized areas will expand in size with an additional 2.5 billion new urbaninhabitants (Langemeyer, 2015). Studies show that urban expansion has the effect ofdecreasing, fragmenting, and isolating natural patches by altering the size, shape, andinterconnectivity of the natural landscape (Ricketts, 2001; Alberti, 2005). The consequentloss and degradation of urban and peri-urban green/blue space and elements couldadversely affect ecosystem and its services as well as human health and well-being.Through literature review, the concepts of urban ecosystem services and green-blueinfrastructures are introduced, as well as the main design principles for green-blueinfrastructures. The thesis also briefly introduces urban policies and implementation throughcase study with a focus on Malmö city. Meanwhile, the thesis discusses how the planninginstruments of Green Space Factor and Green Points are used in the Bo01 project and howthey contributed to promote ecosystem services in built environment.Through literature review and case study, the aim of this thesis is to collect design solutionsthat can be used as inspiration and guidance to promote urban ecosystem services throughgreen-blue infrastructures in built environments at different scales.