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The differences in CEC metabolism imposed by treatments or species warrant further investigation

The results presented in this dissertation suggest the highly chemical-, species-, and research technique- specific nature of the environmental fate of CECs. For example, cell cultures often form amino acid conjugates while whole plants form sugar conjugates during xenobiotic metabolism. Additionally, more toxicological data are needed on the effects of these and other compounds in terrestrial invertebrates, especially for those of agricultural importance. From the research conducted in this dissertation, future research should focus on the impacts of exposure and the potential for transformation of CECs under different conditions and in multiple species. Future studies should place emphasis on experimentation using bio-solids and TWW with inherent compounds and field conditions to improve environmental relevance. Future risk assessments should be conducted by taking into account the formation of biologically active and conjugated metabolites, and with regard to the potential toxicity of CECs in non-target terrestrial organisms. During the past 3–4 decades, parallel expansions of populations of non-indigenous rhizomatous grasses have occurred in aquatic and estuarine habitats around the nation. Among these expansions are Spartina alterniflora invasions in the salt marshes of the Pacific Northwest , take-over of large sections of the riparian ecosystems in Southern California by Arundo donax and Phragmites australis invasions in the upper regions of salt marshes in the mid-Atlantic states . The east coast salt marsh grass Spartina alterniflora has been invading west coast salt marshes from San Francisco Bay through Washington since the early 1970’s . Although S. alterniflora can produce seeds that are spread by water movement, it spreads mainly through the expansion of its underground rhizomes. In Washington salt marshes, S. alterniflora is large compared to other salt marsh species,blueberry pot size and it is altering ecosystem structure by affecting benthic structure and species diversity .

Likewise, in San Francisco Bay, S. alterniflora displaces the native wetland plants, as well as eelgrasses and algae. In the mid-Atlantic region, Phragmites australis has invaded many wetlands , and replaced much of the upper marsh vegetation, that was characterized by Spartina patens and Distichlis spicata. The 2–3 m tall stems die back at the end of the growing season, but the densely grown shoots remain in place, affecting sedimentation patterns, surrounding less tall vegetation, and use of the marsh by mammals and birds. The rhizomatous grass Arundo donax that in the riparian ecosystems of Southern California has expanded into large, self-sustaining populations, has become an ecological and economical pest. The populations expand through the distribution of vegetative propagules, in the form of stem and rhizome fragments by the rivers. Currently the expansions of rhizomatous grasses like these are combated with mechanical and/or chemical methods. Both these approaches have pros and cons, and their application is affected by the local environmental conditions, funding, and available manpower .The overall goal of this project was to increase the knowledge of the ecophysiology of the internal processes targeted by, or the ecological processes resulting from control efforts, and to facilitate conveyance of this type of information and knowledge to agencies and individuals engaged in control effort of rhizomatous grasses in aquatic and estuarine habitats. The physiological process that we will focus on is allocation of photosynthates to different parts of the plant and the role of internal nitrogen in this process, in order to determine the most effective time for herbicide application.In the hydroponic culture described earlier, the S. alterniflora seedlings that were precultured in deionized water showed an initially slow, but increasing growth, until the growth is reduced near the end of the experiment at week 12 . Specifically, the growth of leaves and stems stopped , as the plants exhaust the N supply from their nutrient solution , and the leaves’ internal N decreases down to their CNC . Before the leaves reached their CNC at the end of week 11, rhizome biomass showed a slow increase to 1.93 + 0.257 g. After the leaves reached their CNC in the last five weeks of the experiment, approximately 6.11 g was added to the rhizome biomass.

While at CNC, internal leaf N content was seen to increase above CNC for a short period, after nutrient additions to the culture solution. In this period, the leaves showed slight biomass increase as well . As the rhizomes grow, new roots and tillers develop at many of their internodes, and the biomass of these tissues show a significant increase , that is related to the increase of S. alterniflora rhizome length.The leaves that were collected from tall and short S. alterniflora in the DE salt marsh, showed differences in the seasonal pattern of the internal N content . At the start of the growing season in March, the leaf N/C ratio in the tall S. alterniflora is high at almost 0.06 g N/gC. In the short S, alterniflora the N/C was lower than both the tall S. alterniflora from the same marsh, and the S. alterniflora in the hydroponic greenhouse experiment early in their growing season . The internal N/C ratio in the leaves of the short S. alterniflora does not change much during the entire growing. In the second half of the growing season, the internal leaf N/C ratios in the tall S, alterniflora leaves decreases and becomes indistinguishable from the N/C ratio in the short S. alterniflora’s leaves.The difference between the growth patterns of the two groups was most pronounced in the growth of the green leaves and the stems. These variables show a reduction in the nitrogen-deprived plants when compared to the plants that continue to receive nitrogen, especially the leaves . In addition to the seemingly smaller amount of above ground plant material, the leaves of the nitrogen-deprived plants were a much lighter color green, and leaf senescence was more common for these plants . As a result of this combination of responses, the nitrogen-deprived plants appeared much smaller than those that continued to receive nitrogen. At the time of reduced leaf growth by the no-nitrogen plants, the internal N content in the nitrogen-deprived plants dropped significantly below the N content in the leaves of the N-supplied plants . This was observed through both the carbon-based and the dry-weight based determination of the tissue N content. The lowest mean N/C ratio was 0.038 + 0.001, and % N dropped below 2%, to 1.69 + 0.052%, at the time that the N content in the leaves of the control plants was lowest as well, with N/C = 0.077 + 0.004 and N = 3.446 + 0.167%.During nitrogen deprivation the growth of mature green leaves was limited or nonexistent, due to lack of mobile nitrogen. Both the function and growth of leaf tissues have a high requirement for nitrogen.

Each functional leaf cell will need to contain a minimum amount of nitrogen for both photosynthetic pigments and enzymes such as chlorophyll and Rubisco, and a full complement of DNA and nucleic acids for RNA production. Once the tissue nitrogen has been diluted to the lowest functional level, also referred to as the Critical Nitrogen Content , each cell will only contain this minimum amount of cellular nitrogen allowing it to function at maintenance level. Therefore these cells will not contain enough nitrogen to produce another complement of DNA and enzymes,blueberry plant size preventing them from dividing and the tissue to grow. During internal nitrogen limitation when leaf biomass did not increase anymore, photosynthesis was not reduced in Ipomoea batatas . Photosynthesis continued after the leaves have reached their CNC and the external nitrogen was depleted. The carbohydrates produced cannot be stored in the leaf tissue since further input of carbon compounds into leaf cells would lower the nitrogen to carbon ratio below their CNC, thus interfering with cell function. Instead of having been incorporated into the leaves, these carbohydrates were translocated to the sinks that are the rhizomes, roots, and for S. alterniflora, the rhizome tip tillers. This S. alterniflora study has shown that growth of that species’ vegetative reproductive structures, the rhizomes, occurs after the internal nitrogen content in the leaves is too low to allow for growth of the leaves. The manufacturers of systemic herbicides advise application of their product when there is substantial translocation to the below ground tissues of the plant. For the control of S. alterniflora to be effective, a systemic herbicide has to be carried in the phloem stream to the below ground permanent structures for winter survival and spring regrowth, the rhizomes and the associated rhizome tip tiller. Most rhizome growth and nearly all growth of rhizome tip tillers occur when the leaf N content has reached its CNC. It is obvious therefore that most photosynthate transport and incorporation in the rhizomes and rhizome tip tillers occurs at the time of low leaf N/C ratios, and not before.

We can expect substantial ‘delivery’ of the active ingredient in systemic herbicides which are carried in the phloem, such as glyphosate, to the target tissues would occur at the time of low leaf N/C. Therefore, it may be beneficial to take leaf N/C ratios into consideration when determining the timing of systemic herbicide applications. The field sampling in this study showed that the leaf N/C ratio of short S. alterniflora that grow away from the creek banks is almost always at its CNC level, while the leaf N/C ratio of the taller plants that grow on the creek banks showed a high level at the beginning of the growing season, and a decrease with time not unlike that of the plants in our greenhouse study. This indicates that our experimental conditions were a reasonable mimic of creek bank salt marsh conditions. Additionally, it indicates that N availability in the fine grained, and anoxic marsh sediment away from the creek banks is significantly different from that in more coarse grained creek bank sediments, through which, rather than over which, the flooding water moves during tidal movements. The low oxygen availability in this marsh sediment may interfere with the uptake of the nutrients, or the nitrogen content of this soil may be lower since exchange between the interstitial soil water and the periodically overlaying nutrient rich sea/marsh water will be limited due to the dense and fine-grained nature of the soil. In a series of studies by our laboratory that observed the role of leaf N content in the allocation of growth on multiple species, the P. australis study was the first in which we controlled the N concentration in the hydroponic nutrient solution. Continuous high concentrations were maintained for all plants until the 11th week of the experiment, at which time the N was removed from the nutrient solution for half of the remaining plants. The growth of the plants in both the no-nitrogen and the nitrogen supplied groups showed the importance of external and internal N on the allocation of growth in P. australis plants. It was interesting that even after the removal of the external N, the plants increased their living biomass by 39 g dry weight, which was almost as much as the 49 g biomass increase of the plants supplied with N. The biomass increase of the plants without external N was most likely supported by the pool of internal N in the plant. At the time the external N supply was removed, the N content in the plants was above their CNC. The critical nitrogen content of a tissue is defined as the lowest amount of nitrogen in tissues that will allow for growth the growth of that tissue. Total plant biomass increased after the removal of the external N, which was evidence that photosynthesis must have continued. As more carbohydrates are produced and incorporated into the plant without an external supply of new nitrogen, the internal N/C ratio in the tissues will decrease. As described earlier, among the different tissues, leaves have the highest CNC, and will therefore reach this CNC earlier than tissues with lower CNC values. When the leaves reached their CNC, they could no longer incorporate more C into their own tissues, since this would reduce their N/C below the CNC and interfere with their function . At this point two scenarios are possible; one is that photosynthesis could shut down, and the other is that all the carbohydrates produced in the leaves could be transported to other tissues of the plant.

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Three key policy instruments supported the price guarantee system

The most commonly used have been compensation and vice into virtue. Such is the farmers’ influence that is is nearly impossible to impose new costs on them without offering some form of compensation in return. Vice into virtue, meanwhile, has facilitated the successful overhaul of major CAP systems by presenting the task as correcting a malfunctioning program as opposed to simply shutting it down. In sum, the first part of my argument shows why CAP reform is so difficult by revealing both how farmers have managed to retain political influence despite losses in demographic and economic power and by using welfare state theories to identify key obstacles to retrenchment. The second part of my argument identifies the circumstances that may permit systemic reform. The third enumerates the welfare state retrenchment tactics policymakers use to navigate and manage the influence of the farmers. Taken together, my argument accounts for when and why CAP reform occurs as well as the final outcome of CAP reform.Chapter Two describes the history and operation of the CAP leading up to the contemporary period of reform covered in the dissertation’s empirical chapters. The chapter focuses on three main periods of the early CAP: its creation in the 1960s, including early successes and challenges, the failed Mansholt Plan of the 1970s, and the limited changes of the early 1980s. I show that even in these early periods of reform, disruptive politics were a necessary condition for reform and that policymakers utilized welfare-style tactics to achieve what limited success they could. This overview provides the background necessary to understand contemporary challenges to the CAP and obstacles to reform. Chapter Three focuses on the 1992 MacSharry Reform of the CAP. The MacSharry reforms marked the first major overhaul of the Common Agricultural Policy since its adoption in 1962. The MacSharry Reform took place under conditions of disruptive politics,blueberry container size as the negotiations overlapped with the GATT Uruguay Round. The landmark reform paired vice into virtue with compensation in order to transform the CAP’s primary function from production to income support.

Specifically, the MacSharry Reform introduced, in a limited form, a direct payment system that paid farmers regardless of how much they produced, essentially “decoupling” payments from production. Overall, the chapter demonstrates that even when reform was urgently needed, reformers still had to employ a number of welfare retrenchment tactics to overcome farmer opposition and were ultimately unable to cut spending. Chapter Four explores the so-called Agenda 2000 reform. Agenda 2000 was intended to further the objectives outlined in the MacSharry round. However, Agenda 2000 was not negotiated during a time of disruptive politics. The surplus crisis had been resolved by the MacSharry Reform, no GATT/WTO negotiations were scheduled, and the next round of enlargement was far enough in the future that no immediate reform action was required. The Agenda 2000 reform thus allows for the dissertation argument to be tested on a reform that took place under politics as usual. I show that Agenda 2000 ultimately introduced only limited, mostly voluntary change along with substantial financial compensation to farmers. Chapter Five examines the 2003 Mid-Term Review of the CAP, also known as the Fischler Reform, which was not expected to bring about a significant change. This round of reform occurred under disruptive politics, however: the CAP confronted severe financial pressure from enlargement and contentious trade negotiations in the WTO. This round of CAP reform presented a favorable context for reformers to make changes and a challenge for farmers to prevent tough amendments to a flailing policy. Fischler’s reform continued and extended the process of decoupling, begun by MacSharry and also introduced a new version of the compensation scheme called the Single Farm Payment. In addition, Fischler was able to make mandatory environmental policies that had only been optional in previous reforms. Despite these changes, many proposed policy reforms were watered down significantly and reformers had to employ a number of tactics typically used by welfare state retrenchers to achieve their goals. For example, reformers paired a compensation program with the vice into virtue strategy to successfully introduce the Single Farm Payment. Chapter Six investigates the most recent round of CAP reform concluded in 2013, which occurred largely under politics as usual. The budget was not in crisis and the EU was not involved in any WTO negotiations. The only major reform achieved during these negotiations, the recalibration of the direct payment system, is the only one with a clear link to a source of disruptive politics, in this instance enlargement.

The CAP was still contending with the consequences of the previous rounds of enlargement, in particular issues related to an imbalance in payments made to Western and Eastern countries. In order to increase the likelihood of successful reform in at least this domain, reforms linked the policy revisions to the disruptive politics of enlargement, rather than presenting the reforms as routine policy maintenance. Other reform proposals, such as adopting strict greening standards, imposing a ceiling on direct income payments, and restricting the qualifications for receiving agricultural payments, were completely blocked. The within-case variation, then, illustrates the importance of disruptive politics for achieving CAP reform. In Chapter Seven, the conclusion, I demonstrate the applicability of the dissertation argument beyond CAP reform through three mini cases. The first analyzes national government responses to the financial crisis, the second Japanese agricultural policy, and the third farmer influence over international trade negotiations. Across all three cases, each in different institutional settings, a common theme emerges: whatever changes to agricultural policy may be enacted, it is difficult if not impossible to impose spending cuts on farmers. Finally, the conclusion considers the implications of my argument for EU policymakers, for welfare retrenchers, and for scholars of social class transformation and decline.The CAP emerged out of a political deal between France and Germany. France agreed to support the common market, which would be of great benefit to Germany industry, while Germany agreed to support a common policy for agriculture. Essentially, this promise meant that Germany would be paying for French farmer subsidies, and in exchange, France would open its market to German manufactured goods. The Treaty of Rome, signed in 1957, established the European Economic Community , and with it, the common market. It also included plans for a common policy for agriculture to be established within five years. While the Treaty of Rome did not outline the design or operation of the CAP, it defined the objectives of the CAP as follows: “to increase productivity by promoting technical progress…to ensure a fair standard of living…by increasing the individual earnings of persons engaged in agriculture; to stabilize markets; to assure the availability of supplies; to ensure that supplies reach consumers at reasonable prices” . The operational details would be worked out in a series of conferences, meetings, and negotiations that followed the signing of the Treaty of Rome in 1957, culminating in the formal launching of the CAP in 19626 . There was obviously some tension among CAP objectives, and the goal of ensuring products at reasonable prices for consumers would quickly be abandoned: the CAP would be grounded in a system of inflated prices, funded by taxpayers.When the CAP was established,raspberry planter famine was a recent memory, so there was concern for ensuring self-sufficiency in food. During WWII, Europe suffered from food crises ranging from shortages to famine. The Netherlands, for example, endured what is now known as the “Hunger Winter”, when an estimated 22,000 Dutch people died from starvation.

After the war, rationing was common as Europe struggled to feed itself. In Germany alone, the US, with support from the UK had, by 1948, provided nearly $1.5 billion in food aid. The memories of Europe’s food insecurity were, and remain, powerful. Indeed, in speaking to policymakers in the Netherlands about the importance of the CAP, nearly every official referenced the Hunger Winter, even those who would not have been alive at the time . One of the core goals of the architects of the CAP , was to ensure that Europe would always be able to feed itself by boosting agricultural productivity and output. CAP founders also had a social objective, seeking to close the income gap between farmers and industrial workers. In the years just before the creation of the CAP, a noticeable gap had developed between the average earnings of farmers and those of individuals employed in other fields, most notably industry. For example, in Germany in 1958-1959, farm incomes were equal to 76% of non-farmer incomes . The situation was equally grim in the other member states. In France in 1961, farm income was estimated at “3,280 French Francs for farm owners and 2,540 French Francs for farm workers” compared to 4,690 French Francs for industrial wage and salary earners . Policymakers feared that, without intervention, this wage gap would only worsen. The ultimate result would be an uncontrolled rural exodus, collapsing the countryside and overburdening cities, as farm workers sought more lucrative industrial jobs. The CAP sought to achieve the goals of increased production and improved earnings through a system of price guarantees, with agricultural prices set well above world market prices.The first was a set of high import tariffs and other measures to limit the import of agricultural goods. The second was a guarantee to engage in intervention buying, whereby the EU would purchase those goods in excess of EU customer demand at inflated prices. The third was a system of export subsidies that allowed the EU to dispose of the excess product on the world market. Essentially, this system guaranteed that all agricultural output would find not only a buyer, but one who was willing to pay a much higher price than what the market dictated. The CAP registered three major successes in its early years. First, food production, stimulated by high guaranteed prices, increased rapidly. The CAP enabled Europe to attain food security and self-sufficiency. The Continent would never again have to rely on the US to feed its people. The CAP generated a steady supply of core goods including cereals, milk, and butter. In addition, European consumers were provided with an abundant and diverse selection of produce. The second major achievement of the CAP was the modernization of European agriculture. The high prices that incentivized production generated capital that farmers could now reinvest in their farms. In the past, European farmers had tried and largely failed to compete with cheap imports, particularly of cereals, from the United States and Canada. European farms lagged behind the United States, and most farmers did not have the means to modernize and become competitive. The CAP’s high prices and tariff barriers sheltered European farmers from US competition. Farmers who benefited from high prices were able to reinvest their profits into both new technology and more land. New technology facilitated more and faster production at a lower cost. The third achievement of the CAP was to manage Europe’s transition from a primarily agrarian and rural society to an increasingly urban and industrial society. In other words, the CAP allowed for the peaceful management of the rural community’s transformation. The new system which offered higher guaranteed prices allowed smaller and less efficient farmers to stay on the land and eke out a living instead of abandoning it as they otherwise might have done. Thus, instead of a mass rural exodus and the subsequent collapse of countryside, this system slowed the process and cushioned the decline of agriculture. That is not to say that no one left farming under the CAP. Indeed, opportunities for early retirement facilitated the permanent exit of a small number of farmers in a controlled manner. In fact, exit from the sector was used to strengthen it, as the departure of predominantly small and inefficient farmers allowed the larger and more productive farmers to buy up more land. Essentially, exit permitted a transition to a more modern, efficient model of agriculture, grounded in large farms as opposed to small family or subsistence farms that had once dominated the European countryside. Most importantly, this goal was achieved humanely and without democratic collapse, social upheaval, or economic catastrophe.