Identify Management Options Research Articles

Management of Covered Kernel Smut (Sporisorium sorghi) Disease of Sorghum (Sorghum bicolor) at Gabilley District in Somaliland

Sorghum is multi-purpose crop that plays an important role in the socio-economic life of farming communities in Somaliland. However its production and productivity is threatened due to Covered kernel smut disease. A field experiment was carried out at Aburin Agricultural Research Center at Gabilay district in Somaliland in order to identify management options for Covered kernel smut disease of sorghum. The experiment consisted of 12 factorial treatment combinations of three varieties (i.e., Faruryogele, Abadro and Kuso) and three types of seed treatments which includes synthetic and bio-fungicides (i.e., Apron star 42WS%, Cow urine, and Neem seed kernel extract) and including Untreated control, laid out in RCBD with three replications. Parameters such as disease incidence, disease severity, phenological data, grain yield (kg)/plot, actual grain yield/plot, 1000 grains weight (g) and yield loss (%) were collected. The experiment result showed that highest disease (44.0%) incidence was recorded on untreated Kuso variety while lowest disease (4.33%) incidence was Apron star with Abadiro. Similarly, the highest disease severity (37%) was scored from Untreated Abadiro whereas lowest disease severity (4%) was scored from Abadiro with Apron star and Faruryogele with Apron star. Untreated Abadiro variety reached highest AUDPC (1036.0% days). The Apron star treated varieties had the lowest AUDPC and consistently showing markedly low infection rates indicating that they were more effective to the disease relative to the other seed treatments. The highest yield (1896 kg ha-1) was recorded from Faruryogele with Apron star and lowest (933 kg ha-1) was recorded from untreated Abadiro and Faruryogele. So, Apron star was effective to reduce the yield loss of sorghum and could be recommended to manage sorghum covered kernel smut. However, the experiment should be repeated across different environments over years in order to give the right recommendations and its rate may need to be well defined.

Characterization of Pseudomonas capsici strains from pepper and tomato.

Disease outbreaks of bacterial leaf spot and blight of pepper and tomato often occur in both transplant- and field-production systems worldwide. In some cases, the outbreaks are caused by novel bacterial species. Characterization of these novel bacterial species are critical in developing diagnostic assays and identifying management options for pathogen monitoring and sustainable production, respectively. We characterized strains belonging to novel Pseudomonas species that are responsible for outbreaks in pepper and tomato both in transplant-houses and in production fields in Georgia, USA. Phylogenomic analyses and whole genome sequence indices demonstrated that the pepper and tomato strains belonged to P. capsici. The whole-genome comparison revealed that 13 Pseudomonas strains from diverse isolation sources that were curated in NCBI were indeed P. capsici indicating a potential wide-host range for this bacterial species. Our greenhouse-based host-range assay also indicated that P. capsici strains were pathogenic on pepper, tomato, eggplant, cabbage, lettuce, and watermelon corroborating a wide-host-range. A phylogenetic tree inferred from the whole genome sequence data showed that the P. capsici strains from Georgia (pepper and tomato) were genetically diverse, and were closely related to tomato P. capsici strains from Florida. Genomic presence of traditional bacterial virulence factors in P. capsici strains was also determined. Pseudomonascapsici strains encode one set of type I secretion system, two sets of type II secretion systems, one set of type III secretion system, two sets of type V secretion systems, three sets of type VI secretion systems, and various secondary metabolite gene clusters including lipopeptides. In in-vitro assays, it was demonstrated that six out of seven P. capsici strains (pepper and tomato strains from Georgia) were not sensitive to 0.8 mM CuSO4. When the genomes of copper-tolerant strains were compared with the copper-sensitive strains, it was observed that the former strains encode a cluster of genes related to copper tolerance, which were absent in the genomes of copper-sensitive strains. Considering the ability of P. capsici strains to infect a range of vegetable hosts and possession of a wide range of bacterial virulence factors, secondary metabolites, and copper-tolerance genes, we envision that the management of this pathogen might potentially be a challenge.

An integrated multimedia fate modeling framework for identifying mitigation strategy of antibiotic ecological risks: A case study in a peri-urban river

Antibiotics have been heavily used over the past decades, resulting in their frequent detections in rivers and increasing ecological risks. Recognizing characteristics of antibiotic ecological risks (AERs) and making effective strategies to mitigate the AERs are essential to ensure the safety of aquatic ecosystem and public health. In this study, an integrated technological framework has been proposed toward identifying management options for reducing AERs by jointly utilizing multimedia fugacity modelling and ecotoxicological risk assessment, and applied to characterize the AERs in a peri-urban river in Beijing. Specifically, a level III fugacity model has been successfully established to simulate the fate of antibiotics in the environment, and the manageable parameters have been screened out via sensitivity analysis of the model. Then the validated fugacity model has been used for scenario modellings to optimize mitigation strategies of AERs. Results show most of the antibiotics considered are frequently detected in the river, and pose medium or high risks to aquatic organisms. Relatively, the macrolides and fluoroquinolones present higher ecotoxicological risks than sulfonamides and tetracyclines. Furthermore, the mixture risk quotient and predictive equation of concentration addition suggest joint and synergistic/antagonistic effects of AERs for multiple or binary antibiotics in the environment. Largely, the concentrations of antibiotics in the river are determined by the source emissions into water and soil. Scenario modellings show the improvement of antibiotic removal rates would be considered preferentially to mitigate the AERs. Also, controlling human consumption is conducive to reducing the risks posed by tetracyclines, macrolides and trimethoprim, while controlling animal consumption would benefit the reduction for sulfonamides. Overall, the joint strategy presents the greatest reduction of AERs by reducing antibiotic consumption and together improving sewage treatment rate and antibiotic removal rate. The study provides us a useful guideline to make ecological risk-based mitigation strategy for reducing AERs in environment.

Acoustic telemetry provides insights for improving conservation and management at a spawning aggregation site of the endangered Nassau grouper (Epinephelus striatus)

Nassau grouper (Epinephelus striatus, Serranidae) were one of the most important fishery species in the Caribbean, but are now listed as critically endangered. Population collapse in most places occurred primarily by fishers targeting their spawning aggregation sites, where thousands of fish gathered during full moon periods from December to April. Identifying management options for protecting this vulnerable period is crucial for their survival. In the US Virgin Islands, we tagged 24 Nassau grouper with acoustic transmitters at a fish spawning aggregation (FSA) site called the Grammanik Bank, a 1.5 km2, marine protected area (MPA) closed each year from February to April. We tracked their movements over a seven-year period and found that the small MPA protected Nassau grouper only 65% of time during the spawning season. Nassau grouper arrived at the FSA from January to May, with a peak in March, and made daily roundtrip migrations (1-25 km) from the FSA site. Females swam twice as far as males, while males were more sedentary and remained longer (22 d) at the FSA than females (9 d); behavioural characteristics that may cause differential bycatch mortality among sexes. We also found nearly half of all fish were temporary residents within 5 km of the FSA site for 2 to 6 months after the spawning season. This mismatch of MPA size and timing of closed season provided the impetus for developing new guidelines for protection. The large acoustic array allowed us to calculate spatially relevant areas useful for conservation including courtship arena (1.2 km2), staging area (4.7 km2) and primary migration pathways (9.6 km2) used by Nassau grouper during spawning season. To improve conservation goals of this endangered species, increasing the Grammanik Bank seasonal closure to five months and its size to 6.4 km2 would increase protection to >96%. These spatial and temporal changes to existing management regulations incorporate the best available data to improve conservation goals by reducing potential bycatch mortality, eliminating disturbance of spawning fish, and protecting critical spawning habitat for Nassau grouper. These guidelines may also be applied more broadly to other Nassau grouper FSA sites located on large insular or continental shelfs areas throughout the Caribbean.

Planning coastal Mediterranean stone pine (Pinus pinea L.) reforestations as a green infrastructure: combining GIS techniques and statistical analysis to identify management options

Mediterranean stone pine reforestations are common characteristics of the Italian Tyrrhenian coast, which mostly maintain uniform and monolayered stand structures. However, improving structural diversity is an effective climate change adaptation strategy in forest management. The aim of this study was to implement a methodology which allows distinct reforested areas such as a single green infrastructure to be managed according to the surrounding land use and the characteristics of the forest stands. 240 hectares of Mediterranean stone pine forests located along a 16 km strip of the Lazio coast (Central Italy) were mapped. Twelve attributes describing the pine stands and showing possible constraints for future management decisions were associated to each forest patch. A hierarchical cluster analysis was performed to group the pinewood patches according to their similarity level and five different groups were identified. For each group, different silvicultural methods were proposed to guide the compositional and structural evolution of the stands, in order to make them suitable for providing services required locally and increasing overall diversity at landscape scale. The results of the study highlight how coastal land uses can offer effective inputs to differentiate the management of forest systems and therefore achieve greater variety and resilience in the landscape over time. This approach is particularly useful in the case of very homogeneous stands such as the stone pine reforestations under study.

A heuristic for innovative invasive species management actions and strategies

Conservation actions are notoriously difficult to design and implement in contexts of value pluralism. These difficulties are compounded in the case of biological invasion mitigation. Biological invasions are major threats to biodiversity and ecosystems. Preventing or mitigating biological invasions accordingly plays a key role in conservation policies. The relationship between human beings and invasive species is, however, complex, not unequivocal, and presents a variety of moral aspects. The practical and ethical reasons used to champion actions targeting populations of invasive species are questioned both in the literature and by actors and stakeholders in the field. The resulting debates between advocates and critics of biological invasion mitigation are doomed to remain sterile unless the whole diversity of points of view is considered and the relationships between human beings and non-human beings (i.e., plants and animals) are considered in their full complexity. As conservation biologists involved in invasion research, we argue that, instead of bemoaning such difficulties, conservation biologists should see the challenge to face this diversity as an opportunity to innovate. We present a heuristic, based on theories of deliberative democracy and multispecies anthropology, to help consider this pluralism and this complexity when identifying management options. This heuristic consists of identifying the spectrum of points of view of human and non-human beings concerned and assessing how acceptable the various actions are to all these points of view, until a course of action acceptable to all is found (if possible). We argue that by elaborating management options, which are arguably acceptable to all, including to members of the targeted invasive populations themselves, we can design more robust conservation solutions. We show how such an approach can be implemented in practice without paralyzing biological invasion mitigation.

A framework to estimate the contribution of weeds to the delivery of ecosystem (dis)services in agricultural landscapes

There is a pressing need for indicators and methods to quantify the provision of ecosystem services as a prerequisite to identify management options that optimize trade-offs between services. Arable weeds provide multiple services and are thus a good model to evaluate such trade–offs. This flora provides trophic resources (flowers or seeds) that support pollinators and pest natural enemies (pollination and pest control services) but can also be harmful for crop production (disservice). To date, few indicators are available to quantify the contribution of weeds to ecosystem services or their harmfulness, and no indicators account for intraspecific variability in weed traits that result from contrasting growing conditions, notably the location of weeds within fields (field edge vs field core) and crop type. Here, we developed nine proxies for potential weed harmfulness (competition, harvest difficulties and future weed infestations) and weed contributions to resources provision to pollinators (bees, bumblebees and hoverflies) and pest natural enemies (carabid beetles, birds and parasitoid wasps). These nine proxies accounted for individual weed plant response to growing conditions (combination of within-field location by crop type) for 155 weed species, resulting in 967 unique situations (combinations of species by within-field locations by crop types). Apart from harvest difficulties, all proxies were positively correlated, i.e. harmfulness increased when services increased. Weed plants located on field edges had greater contributions to all proxies than those located in field cores, especially in cereal crops. We identified that small weed species with short life cycles and low competitiveness, presented the optimum proxy combination, i.e. high services and low harmfulness. The development of these proxies and the proposed framework provide new avenues for assessing trade-offs between multiple ecosystem services at different temporal (crop sequence) and spatial scales (landscape).

Tropical land use drives endemic versus exotic ant communities in a global biodiversity hotspot

Understanding how land-use change affects biodiversity is a fundamental step to develop effective conservation strategies in human-modified tropical landscapes. Here, we analyzed how land-use change through tropical small-scale agriculture affects endemic, exotic, and non-endemic native ant communities, focusing on vanilla landscapes in north-eastern Madagascar, a global biodiversity hotspot. First, we compared ant species richness and species composition across seven land-use types: old-growth forest, forest fragment, forest-derived vanilla agroforest, fallow-derived vanilla agroforest, woody fallow, herbaceous fallow, and rice paddy. Second, we assessed how environmental factors drive ant species richness in the agricultural matrix to identify management options that promote endemic and non-endemic native while controlling exotic ant species. We found that old-growth forest, forest fragment, and forest-derived vanilla agroforest supported the highest endemic ant species richness. Exotic ant species richness, by contrast, was lowest in old-growth forest but highest in herbaceous fallows, woody fallows, and rice paddy. Rice paddy had the lowest non-endemic native ant species richness. Ant species composition differed among land-use types, highlighting the uniqueness of old-growth forest in harboring endemic ant species which are more sensitive to disturbance. In the agricultural matrix, higher canopy closure and landscape forest cover were associated with an increase of endemic ant species richness but a decrease of exotic ant species richness. We conclude that preserving remnant forest fragments and promoting vanilla agroforests with a greater canopy closure in the agricultural matrix are important management strategies to complement the role of old-growth forests for endemic ant conservation in north-eastern Madagascar.

Evaluating APSIM-and-DSSAT-CERES-Maize Models under Rainfed Conditions Using Zambian Rainfed Maize Cultivars

Crop model calibration and validation is vital for establishing their credibility and ability in simulating crop growth and yield. A split–split plot design field experiment was carried out with sowing dates (SD1, SD2 and SD3); maize cultivars (ZMS606, PHB30G19 and PHB30B50) and nitrogen fertilizer rates (N1, N2 and N3) as the main plot, subplot and sub-subplot with three replicates, respectively. The experiment was carried out at Mount Makulu Central Research Station, Chilanga, Zambia in the 2016/2017 season. The study objective was to calibrate and validate APSIM-Maize and DSSAT-CERES-Maize models in simulating phenology, mLAI, soil water content, aboveground biomass and grain yield under rainfed and irrigated conditions. Days after planting to anthesis (APSIM-Maize, anthesis (DAP) RMSE = 1.91 days; DSSAT-CERES-Maize, anthesis (DAP) RMSE = 2.89 days) and maturity (APSIM-Maize, maturity (DAP) RMSE = 3.35 days; DSSAT-CERES-Maize, maturity (DAP) RMSE = 3.13 days) were adequately simulated, with RMSEn being <5%. The grain yield RMSE was 1.38 t ha−1 (APSIM-Maize) and 0.84 t ha−1 (DSSAT-CERES-Maize). The APSIM- and-DSSAT-CERES-Maize models accurately simulated the grain yield, grain number m−2, soil water content (soil layers 1–8, RMSEn ≤ 20%), biomass and grain yield, with RMSEn ≤ 30% under rainfed condition. Model validation showed acceptable performances under the irrigated condition. The models can be used in identifying management options provided climate and soil physiochemical properties are available.

MP01-04 DIFFERENCES IN SURGICAL TREATMENT OF DE NOVO URGE INCONTINENCE OCCURRING POST-HOLMIUM LASER ENUCLEATION OF THE PROSTATE

You have accessJournal of UrologyBenign Prostatic Hyperplasia: Surgical Therapy & New Technology I (MP01)1 Sep 2021MP01-04 DIFFERENCES IN SURGICAL TREATMENT OF DE NOVO URGE INCONTINENCE OCCURRING POST-HOLMIUM LASER ENUCLEATION OF THE PROSTATE Lucas Richards, Bristol Whiles, Diego Mazzotti, and Kerri Thurmon Lucas RichardsLucas Richards More articles by this author , Bristol WhilesBristol Whiles More articles by this author , Diego MazzottiDiego Mazzotti More articles by this author , and Kerri ThurmonKerri Thurmon More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000001962.04AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Holmium laser enucleation of the prostate (HoLEP) is an effective option for patients with lower urinary tract symptoms secondary to benign prostate hyperplasia. Although HoLEP has well-established and durable outcomes, it carries a risk of iatrogenic urinary incontinence. Most patients with de novo urge incontinence (UI) experience transient symptoms with resolution rather quickly, but some patients have persistent incontinence. Due to its relative rarity, patient factors that increase the risk of post-HoLEP persistent UI requiring surgical treatment have not been examined. In this study, we identify management options for persistent UI after HoLEP and examine patient risk factors for the condition. Furthermore, we examine symptom response to three surgical treatment options for de novo UI post-HoLEP. METHODS: A retrospective study was performed to identify patients who underwent HoLEP at a single institution between 2016 and 2019. Patient demographics including age, BMI, race, smoking status, history of previous procedures, diabetes, erectile dysfunction, UTI, and pelvic floor physical therapy were evaluated. Prescriptions for alpha blockers, 5-alpha reductase inhibitors, anticholinergic agents, and beta-3 agonists were also identified. Bidirectional stepwise regression was performed using the history of a surgical treatment for UI as the outcome. These procedures include intravesical onabotulinumtoxinA (Botox) injection, peripheral tibial nerve stimulation (PTNS), or sacral neuromodulation (SNM). AUA symptom and quality of life scores were compared in patients with persistent UI that progressed to surgical treatment to those that did not. RESULTS: A total of 340 patients underwent HoLEP during the study period. We evaluated 28 possible risk factors for persistent UI requiring surgical management. Eight (2.4%) patients received one of the third line therapies, with 1 receiving PTNS, 6 receiving SNM alone, and 1 receiving both SNM and Botox. Our current model suggests that a history of UTI prior to HoLEP procedure increases the odds of developing the UI outcome by 36.98-fold; 95% CI [2.75, 496.90]; p=0.006. CONCLUSIONS: Although persistent UI after HoLEP is rare, its management and associated risk factors are important to understand. Prior UTI is associated with increased risk of post-HoLEP UI. These are preliminary results and future studies are needed to further investigate risk factors for persistent UI post-HoLEP as well as compare outcomes for management options. Source of Funding: Presenting author is a trainee supported by TL1TR002368 © 2021 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 206Issue Supplement 3September 2021Page: e2-e2 Advertisement Copyright & Permissions© 2021 by American Urological Association Education and Research, Inc.MetricsAuthor Information Lucas Richards More articles by this author Bristol Whiles More articles by this author Diego Mazzotti More articles by this author Kerri Thurmon More articles by this author Expand All Advertisement Loading ...

Defensible management decisions to overcome action paralysis in the face of uncertainty

The need to make management decisions in the context of limited information is unavoidable in endangered species’ conservation. This is especially so in the case of species with extremely small population sizes in need of intensive intervention. Managers may need to throw every possible solution at a crisis in the hope that something is effective enough to avoid extinction (Jones, 2004). Once a recovery programme has moved beyond the emergency phase, it is important to step back and assess whether individual actions are sufficiently cost-effective to justify their continued implementation. Reducing wasted effort and resources in conservation projects is essential since saved resources can be reallocated to benefit other threatened species (Goble et al., 2012). It is this refinement phase of a recovery programme that is the focus of Ferrière et al. (2021) in this issue of Animal Conservation. In their study, Ferrière et al. (2021) consider a translocated population of a critically endangered songbird – the Mauritius olive white-eye Zosterops cholorothonos – that experienced several years of population growth thanks to conservation intervention. The study combined an experiment with decision-making tools to evaluate whether a cheaper supplementary feeding regime would jeopardize population recovery. As is common for small populations of endangered species, there were important practical limitations to consider, namely the lack of an obvious control group. The beauty of the work of Ferrière et al. (2021) is to show how even within tight constraints, it is possible to identify a specific conservation action (in this case replacing expensive nectar supplements with sugar water) and design a field experiment to inform decision analysis. By showing that subsequent population growth aligned with modelled predictions, the authors show how to make clear and defensible management decisions in the face of uncertainty. Our own experience working on some of Australia’s most threatened birds has highlighted that risk aversion is a pervasive issue in many conservation programmes (Canessa et al., 2020; Stojanovic et al., 2018). Conservation managers often suffer action paralysis to avoid potential blame for exacerbating population declines or jeopardizing population recovery, if management decisions produce perverse outcomes (Meek et al., 2015). Yet there are many instances where current management actions nevertheless fail to achieve population recovery (Webb et al., 2018). By generating evidence and accounting for uncertainty in a decision framework, Ferrière et al. (2021) show how to identify management options that have the greatest probability of success. Making management decisions more defensible helps to reach consensus amongst recovery teams and reduce pressure on individuals, thus overcoming action paralysis. The real challenge for conservationists that seek to implement a similar approach to Ferrière et al. (2021) lies in the practicalities. Many threatened taxa, and particularly those not restricted to small island ecosystems, have life history traits such as high mobility and low territoriality that make them more challenging to study experimentally (Runge et al., 2014). The threats facing such species are often more complex and intertwined than would appear to be the case for the Mauritius olive white-eye. This would make it harder to tease apart the effects on population growth of an intentional change in management versus stochastic fluctuations in other threats. An important next step will therefore be to identify taxa for which an approach similar to that of Ferrière et al. (2021) is likely to be effective, and how the current approach could be adapted for species where levels of uncertainty are higher. Either way, the results of Ferrière et al.’s study will help encourage a much-needed philosophical shift in approaches to conservation decision making. It is up to conservation scientists to help facilitate that shift, and in turn maximize on-ground returns on conservation investment.

Seasonal greenhouse gases fluxes from monoculture and mixed native grasslands in the Southern Plains, USA

AbstractAgricultural practices have been linked to soil carbon (C) and nitrogen (N) stores through exchanges with the atmosphere in the form of greenhouse gases (GHGs) of carbon dioxide (CO2), nitrous oxide (N2O), and methane (CH4). However, regional and management‐specific research is needed to ultimately understand the drivers of these atmosphere warming molecules. We established research on four grassland sites: a native, mixed‐species warm‐season site and a non‐native, warm‐season, grass‐species site at the Grazinglands Research Laboratory at El Reno, OK; a native, mixed‐species warm‐season site at Noble Research Institute's Oswalt Ranch in Ardmore, OK; and a native, mixed‐species, warm‐season site at Oklahoma State University's Range Research Station at Marena, OK. Greenhouse gases, along with soil properties were measured biweekly and summed by season in 2015 and 2016. A comparison of GHGs with soil variables indicated that mineralization of soil nutrients mediated GHG fluxes. The sites were sources of CO2 and N2O emissions, but sinks for CH4, particularly in diverse native grassland sites. In spring, CO2 emissions were driven by soil water content, soil temperature, and soil N. The N2O emissions were highest in the fertilized monoculture pasture. Overall, fluxes of the GHGs were driven by primarily by water content, soil nitrate, soil temperature, and ammonia content. By better understanding GHG fluxes and the abiotic and biotic drivers, we can identify management options to foster C sequestration and mitigate the GHG footprint for these forage‐based systems.

Drylands rainwater harvesting: a community-based management approach

This study's objectives were to identify issues concerning natural resource use and identify management options for natural resources from the local community's perspective. The research methodology is based on an integrated application of field interviews with individuals, focus groups, and feedback from key informants. The results showed that less than 1% of the local community supports the construction of Earth dams on rangeland reserves. Land donation and sharing by the landowners is a possible proposal for selecting potential sites for Earth dams. The lack of active participation of local communities during the planning and execution of natural resources development projects led to project failure to secure water resources in the study area. We recommend policymakers and water resources managers seriously consider active community involvement in water harvesting programs. Hence, the present top-bottom approach should be replaced by the bottom-up approach to provide sustainable assurances to water development programs.

Advancing the Understanding of Adaptive Capacity of Social‐Ecological Systems to Absorb Climate Extremes

AbstractEnhancing the capacity of social‐ecological systems (SES) to adapt to climate change is of crucial importance. While gradual climate change impacts have been the main focus of much recent research, much less is known about how SES are impacted by climate extremes and how they adapt. Here, based on an advanced conceptualization of social‐ecological resilience, performed by an interdisciplinary group of scientists, we outline three major challenges for operationalizing the resilience concept with particular focus on climate extremes. First, we discuss the necessary steps required to identify and measure relevant variables for capturing the full response spectrum of the coupled social and ecological components of SES. Second, we examine how climate extreme impacts on coupling flows in SES can be quantified by learning from past societal transitions or adaptations to climate extremes and resulting changes in ecosystem service supply. Last, we explore how to identify management options for maintaining and enhancing social‐ecological resilience under a changing regime of climate extremes. We conclude that multiple pathways within adaptation and mitigation strategies which enhance the adaptive capacity of SES to absorb climate extremes will open the way toward a sustainable future.

Towards multifunctional land use in an agricultural landscape: A trade-off and synergy analysis in the Lower Fraser Valley, Canada

Hedgerows and riparian buffers in agricultural landscapes can help increase landscape multifunctionality and thereby mitigate conflicts among agricultural production and environmental stewardship objectives. However, the relative merits of conserving versus increasing non-production perennial vegetation (NPPV) are not well understood despite the universal conflicts among such objectives in rapidly urbanizing and intensifying agricultural regions worldwide. Hence, using the most intensive agricultural region of British Columbia, Canada as a case study, we aimed to (i) evaluate the current status of NPPV in terms of carbon stocks and landscape connectivity metrics (ii) compare options for conservation relative to agricultural expansion in terms of maintenance of landscape multifunctionality (iii) identify management options for NPPV that could maximize ecological benefits using a normative scenario analysis. We determined that 83% of the NPPV found on the farmland in our study area is likely susceptible to conversion to expanding agricultural production or urban development. Scenario analysis showed planting hedgerows along all farm parcel boundaries and riparian buffers along all farmscape waterways will not compensate for the loss of multifunctionality from agricultural intensification based on expansion. Conserving or planting hedgerows alone however resulted in a disproportionate increase in connectivity given the relative loss of productive agricultural land. This analysis clearly highlights the potential trade-offs among the indicators evaluated as well as the benefits of intensification on land already in production. In the assessed landscape, protecting existing large patches of NPPV and augmenting the landscape pattern with hedgerows is an effective approach to conflicting objectives and ensuring landscape multifunctionality.

Exploring Cooperative Transboundary River Management Strategies for the Eastern Nile Basin.

A water resource modeling process is demonstrated to support multistakeholder negotiations over transboundary management of the Nile River. This process addresses the challenge of identifying management options of new hydraulic infrastructure that potentially affects downstream coriparian nations and how the management of existing infrastructure can be adapted. The method includes an exploration of potential management decisions using a multiobjective evolutionary algorithm, intertwined with an iterative process of formulating cooperative strategies to overcome technical and political barriers faced in a transboundary negotiation. The case study is the addition of the Grand Ethiopian Renaissance Dam (GERD) and considers how its operation may be coordinated with adaptations to the operations of Egypt's High Aswan Dam. The results demonstrate that a lack of coordination is likely to be harmful to downstream riparians and suggest that adaptations to infrastructure in Sudan and Egypt can reduce risks to water supplies and energy generation. Although risks can be substantially reduced by agreed releases from the GERD and basic adaptations to the High Aswan Dam, these measures are still insufficient to assure that no additional risk is assumed by Egypt. The method then demonstrates how improvements to water security for both downstream riparians can be achieved through dynamic adaptation of the operation of the GERD during drought conditions. Finally, the paper demonstrates how the robustness of potential management arrangements can be evaluated considering potential effects of climate change, including increased interannual variability and highly uncertain changes such as increases in the future persistence of droughts.

Tracking antibiotic resistome during wastewater treatment using high throughput quantitative PCR

Wastewater treatment plants (WWTPs) contain diverse antibiotic resistance genes (ARGs), and thus are considered as a major pathway for the dissemination of these genes into the environments. However, comprehensive evaluations of ARGs dynamic during wastewater treatment process lack extensive investigations on a broad spectrum of ARGs. Here, we investigated the dynamics of ARGs and bacterial community structures in 114 samples from eleven Chinese WWTPs using high-throughput quantitative PCR and 16S rRNA-based Illumina sequencing analysis. Significant shift of ARGs profiles was observed and wastewater treatment process could significantly reduce the abundance and diversity of ARGs, with the removal of ARGs concentration by 1–2 orders of magnitude. Whereas, a considerable number of ARGs were detected and enriched in effluents compared with influents. In particular, seven ARGs mainly conferring resistance to beta-lactams and aminoglycosides and three mobile genetic elements persisted in all WWTPs samples after wastewater treatment. ARGs profiles varied with wastewater treatment processes, seasons and regions. This study tracked the footprint of ARGs during wastewater treatment process, which would support the assessment on the spread of ARGs from WWTPs and provide data for identifying management options to improve ARG mitigation in WWTPs.

Characteristics of Drainage Water Quality and Loading from Paddy Field under Cyclic Irrigation and Its Management Options

The cyclic irrigation system has been practiced in Japan for reducing pollutant outflow loadings from paddy fields. The cyclic irrigation is an irrigation method to reuse water by pumping drainage water and re-distributing it to the farmland. Quantification and assessment of the effects of the cyclic irrigation are needed to identify management options for maximizing the benefits of cyclic irrigation. The study was aimed at assessing loading characteristics from paddy field area under the cyclic irrigation and developing a model for simulating water and material flow in paddy field area that can be used as a management tool. The study was carried out in a paddy field in the Asagoi District, Oumihatiman city in Shiga Prefecture, Japan. Using the results of water quality analysis, the average net loadings of T-N and T-P were estimated for both cyclic and non-cyclic irrigation sites. The result indicates a higher nutrient absorption rate in the cyclic irrigation site than that in the non-cyclic irrigation site. The developed cyclic irrigation model showed good agreements between observed and simulated drainage volumes and nitrogen loadings. The scenario analysis by application of the model showed a potential of reducing the loading amount by increasing the cyclic irrigation ratio and reducing the amount of fertilizer application without affecting the rice yield.

Modeling the effects of management and elevation on West Texas dryland cotton production

As the Ogallala Aquifer depletes there is a need to identify management options that might make un-irrigated cotton production sustainable over the U.S. Southern High Plains (SHP). To explore those options, the CSM-CROPGRO-Cotton model was used to simulate the effects of planting options and elevation effects on SHP dryland cotton production. Of the management variables that define the 56 planting options simulated, planting date and density account for the most variability in median SHP yields. Cooler SHP growing seasons have the effect of reducing median lint yields relative to those simulated over the lower elevations of the nearby Rolling Plains. This effect is not as evident in median Rolling Plains yields, which suggests it can be traced to the cooler growing environment of the higher SHP elevations. Also, at both higher and lower elevations lower planting densities maximize median yields, while higher densities result in the lowest yields. These results suggest that the yield suppressing effect of the SHP region’s cooler growing conditions might be compensated for by planting early whenever possible and planting at lower densities. The clear decreasing effect on median yields at higher elevation also suggests the possibility of SHP cotton production moving to the lower elevations of the nearby Rolling Plains as Ogallala Aquifer levels drop.

Economic effect of reducing nitrogen and phosphorus mass balance on Wisconsin and Québec dairy farms

Our objective was to explore the trade-offs between economic performance (farm net income, FNI) and environmental outcomes (whole-farm P and N balances) of dairy farms in Wisconsin (WI; United States) and Québec (QC; Canada). An Excel-based linear program model (N-CyCLES; nutrient cycling: crops, livestock, environment, and soil) was developed to optimize feeding, cropping, and manure management as a single unit of management. In addition to FNI, P and N balances model outputs included (1) the mix of up to 9 home-grown and 17 purchased feeds for up to 5 animal groups, (2) the mix of up to 5 crop rotations in up to 5 land units and c) the mix of up to 7 fertilizers (solid and liquid manure and 5 commercial fertilizers) to allocate in each land unit. The model was parameterized with NRC nutritional guidelines and regional nutrient management planning rules. Simulations were conducted on a typical WI farm of 107 cows and 151 ha of cropland and, a Southern QC farm of 87 cows and 142 ha of cropland and all results were expressed per kg of fat- and protein-corrected milk (FPCM). In absence of constraints on P and N balances, maximum FNI was 0.12 and 0.11 $/kg of FPCM for WI and QC, respectively, with P and N balances of 1.05 and 14.29 g/kg of FPCM in WI but 0.60 and 15.70 g/kg of FPCM in QC. The achievable reduction (balance at maximum FNI minus balance when the simulation objective was to minimize P or N balance) was 0.31 and 0.54 g of P/kg of FPCM (29 and 89% reduction), but 2.37 and 3.31 g of N/kg of FPCM (17 and 24% reduction) in WI and QC, respectively. Among other factors, differences in animal unit per hectare and reliance on biological N fixation may have contributed to lower achievable reductions of whole-farm balances in WI compared with QC. Subsequent simulations to maximize FNI under increasing constraints on nutrient balances revealed that it was possible to reduce P balance, N balance, and both together by up to 33% without a substantial effect on FNI. Partial reduction in P balance reduced N balance (synergetic effect) in WI, but increased N balance (antagonistic effect) in QC. In contrast, reducing N balance increased P balance in both regions, albeit in different magnitudes. The regional comparison highlighted the importance of site-specific conditions on modeling outcomes. This study demonstrated that even when recommended guidelines are followed for herd nutrition and crop fertilization, the optimization of herd feeding, cropping, and manure spreading as a single unit of management may help identify management options that preserve FNI, while substantially reducing whole-farm nutrient balance.