Arundo donax, or giant reed, is a large, bamboo-like plant native to Spain that has invaded several thousand acres of the Rio Grande riparian in Texas. The plant grows to 18-24 feet, consuming large quantities of water per acre per year. With concern of increased water demands in the Texas Lower Rio Grande Valley region, the United States Department of Agriculture-Agricultural Research Service (USDA)ARS) is investigating four herbivorous insects as potential biological control agents for Arundo donax to facilitate increased water supply. This study examines select economic implications for agricultural water users in the United States of applying these biological control agents along the Rio Grande. The research includes (a) estimating the value of the water saved due to the reduction of Arundo donax, (b) a benefit-cost analysis, (c) regional economic impact analysis, and (d) an estimate of the per-unit cost of water saved over a 50-year planning horizon (2009 through 2058). The model ArundoEcon is used to perform a deterministic analyses using low- and high-marginal-composite acre values. Regional results indicate present values of farmlevel benefits ranging from $97.80 to $159.87 million. Benefit-cost ratios are calculated with normalized prices and range from 4.38 to 8.81. Sensitivity analyses provide a robust set of results for Arundo water use, replacement species water use, Arundo expansion rate after control, value of water, and the cost of the program. The pre-production processes and farm-gate economic impact analysis is estimated using multipliers from the IMPLAN model. Regional results reveal a range of $8.90 to $17.94 million annually in economic output and 197 to 351 new jobs for the year 2025. Further results show the cost per acre-foot of water saved is $44.08. This amount is comparable to other projects designed to conserve water in the region. The USDA)ARS, Weslaco, Texas Arundo donax biological control project realizes positive results for the benefit-cost ratios, economic impact analyses, and competitive results for the per-unit cost of saving water. These positive results indicate this project will have positive economic implications for the U.S. and the Texas Lower Rio Grande Valley.

This study focused on an invasive riparian reed grass, Arundo donax L., a clonal plant of the family Poaceae that is widely distributed in North America. Water availability, including water taken up from the roots locally or transported from the neighboring ramets, may affect the performance of A. donax in riparian zones. The first objective was to find out how moisture gradients affected the performance of A. donax in riparian zones. I measured leaf photosynthetic rate, leaf δ13C ratio, and plant growth-related parameters across two summer growing seasons at four transects perpendicular to the water course on the Rio Grande in South Texas. The second objective was to find out whether physiological integration existed in A. donax and how resource sharing, if any, affected plant growth. A rhizome severing experiment was conducted on five paired plots to compare growth-related parameters between plots with rhizomes severed and intact at 3, 7, and 11 weeks after treatment. Heavy water (δ 2H ~1800‰) was applied on three 1-m2 area over 3 successive days and rhizome samples were collected beyond the watering zone after 5, 24, and 48 hours of last watering. At short-term scales, A. donax performance was adversely affected by both drought and inundated conditions; over longer time scales, plant performance decreased as water availability declined in general, but biomass and stem density were similar across moisture gradients. I also found evidence of physiological integration in A. donax. Water was transported through interconnected rhizomes at least 3.5 m; transport distances averaged 1.67 m. Rhizome severing stimulated higher ramet production initially but over longer periods produced shorter thinner stems with lower flood tolerance. However, after 11 weeks of re-growth, plot-level biomass was similar between plots with severed and intact rhizomes. These results suggest that performance of A. donax is affected by water availability in riparian zones; however, clonal plant plasticity, water use efficiency, and clonal integration ameliorate impacts of water stress on the performance of A. donax. Such traits enhance its resource use, which could potentially increase competitive ability rate of establishment, and extent of this invasive species in heterogeneous riparian environments.

A site within San Timoteo Canyon was revisited, 13-14 years after treatment, to look at long-term effects of Arundo donax removal. The data obtained were used to determine whether A. donax had re-invaded, other non-native species had established the area, or if native species were able to grow in place of the removed A. donax. The previous removals included a combination of grinding large patches of A. donax and then foliar spraying, foliar spraying of uncut plants, and direct spraying of hand cut stems, depending upon the location and size of the plant. The effects of the A. donax removals within San Timoteo Canyon were analyzed in relation to new percent cover of the plant species, other more recent removals, and areas that did no experience removal procedures. The project included the use of data provided by the Inland Empire Resource Conservation District (IERCD) as well as the collection of data from randomized plots to generate plant species percent cover. Plant percent cover data analyzed for this paper had been collected from eight 15 by 15 foot randomly selected plots within an overall project site of 42.3 acres. Additional sites were used to investigate what can happen if A. donax is not removed from an area into which it has been introduced., the short-term effects of A. donax removal methods, and the role the ever-changing characteristics of riparian areas can play in their own restoration. These additional sites included aerial photographs supplied by IERCD of an ecologically similar area, a plot with a more recent A. donax removal date, as well as photographs and data of a site subject to natural recovery. Based on these comparisons it is concluded that the treatment methods used led to a lessened presence of A. donax, and that other invasive species did not grow in its place. Further, as the removal procedures within the project area occurred approximately 13 to 14 years prior, it can be concluded that there is no regrowth of A. donax and that many native species have been able to re-inhabit those areas previously infested by A. donax. The treatment methods used were successful without the need to continually disrupt the habitat and allowed for the habitat to recover naturally once the invasive species had been removed.

Tesis para optar al Título Profesional de Ingeniero Agrónomo y al Grado de Magíster en Ciencias Agropecuarias, Mención Sanidad Vegetal / El desarrollo de fuentes de energía renovable, particularmente de cultivos energéticos como la caña común, Arundo donax, hace necesario identificar las potenciales plagas asociadas y sus posibles consecuencias en la producción. El áfido Melanaphis donacis (Passerini), es el principal artrópodo que se ha visto asociado a esta especie en parcelas experimentales en la región Metropolitana. Con el objetivo de aportar información básica para un futuro desarrollo de este cultivo y diseñar estrategias de manejo adecuadas y oportunas, se estudió el cambio en abundancia durante un año (2013) de la población de este áfido. Los niveles poblacionales se midieron a través de colectas quincenales de áfidos sobre hojas, desde parcelas sin tratamientos insecticidas y de una población silvestre de A. donax, realizando un recuento directo, calculando la media del número de áfidos por hoja por día de muestreo. El áfido estuvo presente durante todo el año en plantas de A. donax cultivado, siendo especialmente abundante en primavera-verano, con un número promedio máximo de 243 individuos hoja-1, mientras que en las plantas silvestres sólo se llegó a un máximo de 147 áfidos hoja-1. Además, se observaron abundantes enemigos naturales, especialmente coccinélidos y sírfidos, los que podrían estar contribuyendo a mantener las poblaciones de áfidos bajo niveles dañinos. / The development of renewable energy, particularly energy based on crops such as the giant reed, Arundo donax, this make necessary to identify potential associated pests and their possible impact on their production. The aphid Melanaphis donacis (Passerini) is the main arthropod that has been associated with this specie in experimental plots in the Metropolitan region. In order to provide basic information for future development of this crop and design management strategies that are appropriate and suitable, the variation of population of this aphid was studied for one year (2013). Population levels were measured through fortnightly collections of leaves from wild plots of A. donax without insecticide treatments, counting and recording the average per leave and sampling day. The aphid was present throughout year long, being especially abundant in spring and summer, with a maxim average number 243 individuals per leaf, while in wild plants only reached to a maximum of 147 aphids per leaf. Also natural enemies that help to keep aphid populations under damaging levels were observed abundantly, especially ladybirds and hoverflies.

Biofuels are a sought-after alternative for fossil fuels in today’s society. More specifically, cellulose-based biofuel is an avenue of research intending to limit waste and provide new renewable energy. Cellulose is a rigid polymer of glucose monomers that is found abundantly across different agriculture crops. However, its stability is a barrier to energy production from this source. Pretreatment followed by hydrolysis of cellulosic materials serves a potential to produce glucose to be used in biofuels in larger quantities compared to other methods. This project studied the effect microwave pretreatment and oxygenation have on hydrolysis of cellulose in Arundo Donax. Arundo Donax ground samples are used in solution with acetic acid buffer (pH= 5.0) along with cellulase and maintained at 50°C. The solution’s concentration, in parts per million (ppm), of glucose after hydrolysis was measured over 96 hours using the dinitro salicylic acid method. The Michaelis-Menten constant for cellulase using Arundo Donax and Microcrystalline cellulose before pretreatment were found to be 29.965 g/L and 6.684 g/L, respectively. The concentration of glucose found in Arundo Donax reached a maximum of 310 ppm after 72 hours. In addition, oxygenation, and deoxygenation of buffer and Arundo solution as pretreatment did not yield significantly higher concentrations than Arundo without oxygen manipulation averaging a glucose production of 214.5 ppm with deoxygenation and 209.2 ppm with oxygenation. Microwave pretreatment of Arundo Donax followed by hydrolysis resulted in 29.2 ppm glucose.

The climate on earth keeps getting warmer where heat waves, eutrophication, rising sea levels, extreme weather like flooding, droughts and wildfires are an expanding problem. The focus of this bachelor thesis is to determine the potential of mitigating eutrophication and while contributing to blue growth by harvesting and make use of reeds like Phragmites australis and Arundo donax. Reeds have the ability to quickly absorb nutrients from aquatic environments and there are opportunities to use them as a feedstock for producing biochar to be potentially used in areas such as soil improvement, fodder additive and carbon sequestration. Additionally, optimal biochar properties for the observed applications gets analysed. The thesis is based on a systematic literature review and an interview with Niclas Anvret at the non-profit organisation “Race for the Baltic”.  Results show that biochar produced according to parameters such as heating rate, biomass species and especially, different temperatures, results in varied characteristics that change the biochar's adsorption abilities, nutrient retention, alkalinity, stability, surface area and porosity volume. The different applications of biochar are, however, not easily determined. This is because of the fact that certain biochar properties, that are prominent in entirely different pyrolysis conditions, could both be beneficial for the same application. Additionally, the different attributes sometimes influence each other which gives rise to unclear patterns affecting use potential. To overcome these issues, more research is needed to clarify the correlations between attributes of the biochar and to determine which characteristics of biochar are best suited for each application.  In terms of how large-scale harvesting of reed could affect the ecosystem is also unclear, there is not enough research regarding the question to be able to draw clear conclusions. The reasoning behind this is that there are knowledge gaps, geographical differences, different unit measuring and methodology. The potential for biochar in the coal market is high and the demand in Sweden has risen over the past couple of years. There is also interest in using biochar as a soil amendment, to make use of nutrient content as well as applying organic matter to soils to potentially achieve long-term carbon sequestration. However, the production cost of biochar out of reed is relatively expensive, and it cannot compete with coal or other fertilisers/soil amendments on the market, with feedstock management usually being the most expensive part of production. Lastly, there is currently no harvesting method that can measure the amount of reed that needs to be harvested to be able to produce biochar on a large scale. / Klimatet på jorden blir allt varmare och värmeböljor, övergödning, stigande havsnivåer, extrema väder som översvämningar, torka och bränder är ett stigande problem. Syftet med denna kandidatuppsats är att undersöka potentialen att mildra eutrofiering och samtidigt bidra till blå tillväxt genom att skörda - och använda sig av vass som Phragmites australis och Arundo donax. Vass har en framträdande förmåga att absorbera näringsämnen. Det finns därför möjligheter att använda dem som råvara för att producera biokol som potentiellt kan användas i områden såsom jordförbättring, fodertillsatser och kolbindning. Utöver detta undersöks optimala egenskaper för biokol enligt de observerade applikationerna. Kandidatuppsatsen bygger på en systematisk litteraturstudie och en intervju med Niclas Anvret på den ideella organisationen ”Race for the Baltic”.  Resultaten indikerar att biokol, producerad i pyrolys enligt parametrar som uppvärmningshastighet, biomassa och i synnerhet olika temperaturer, resulterar i varierande egenskaper som förändrar biokolets absorptionsförmåga, bibehållande av näring, alkalinitet, stabilitet, ytarea och porositetsvolym. De olika tillämpningarna av biokol är emellertid svåra att avgöra på grund av vissa biokolegenskaper. Dessa egenskaper är framträdande under helt olika pyrolysförhållanden men kan samtidigt vara fördelaktiga för samma typ av applikation. Dessutom påverkar de olika attributen ibland varandra vilket ger upphov till komplexa trender som påverkar användningspotentialen. För att kunna dra tydliga slutsatser behövs mer forskning för att klargöra sambandet mellan biokolens attribut och för att bestämma vilken samling egenskaper hos biokol som passar bäst för varje applikation.  Hur storskalig skörd av vass kan påverka ekosystemet är fortfarande oklart. Det finns inte tillräckligt med forskning kring frågan för att kunna dra tydliga slutsatser. Detta beror på att det finns kunskapsluckor, geografiska skillnader, olika måttenheter och metoder för de studier som gjorts inom detta område. Potentialen för biokol på kolmarknaden är hög och efterfrågan i Sverige har ökat de senaste åren. Det finns också intresse för att använda biokol för jordförbättring, dels för att använda näringsinnehållet men också för att applicera biokol i jorden för att potentiellt uppnå långvarig kolbindning. Dock är produktionskostnaden för biokol gjort på vass mycket kostsam och kan därför inte konkurrera med fossilt kol eller andra gödselmedel jordförändringar på marknaden. Detta beror främst på råvaruhanteringen som är den dyraste delen av produktionen. Slutligen finns det för närvarande ingen skördemetod som kan mäta den mängd vass som behöver skördas för att kunna producera biokol i stor skala.