Designing Management Programs Research Articles

Phenotypic variation of Kikuyu grass (Cenchrus clandestinus) across livestock production farms in Colombian highlands is explained by management and environment rather than genetic diversity

Context Kikuyu grass (Cenchrus clandestinus (Hochst. ex Chiov.) Morrone) is native to the Central African highlands and was introduced to Colombia in 1928 to feed animals. Despite its low genetic diversity and proven genetic clonality, this species has shown broad phenotypic variation and has become the primary forage resource for livestock production systems in the Colombian highlands. However, it is necessary to determine whether genetic diversity should be considered when designing management programs. Aims We aimed to determine which variables among location, altitude and population genetic structure explain the phenotypic variation of Kikuyu grass samples across livestock farms at high altitudes. Methods We used principal component analysis, redundancy analysis and partial redundancy analysis to understand the contribution of three explanatory variables (three high-altitude ranges, six locations and two or five genetic clusters) and 30 covariables (pasture management and soil traits of each farm) to explain 18 phenotypic variables of 146 Kikuyu grass samples from high-altitude livestock farms in Colombia. Key results All explanatory variables and covariables explained 39.1–41.5% of the phenotypic variation of Kikuyu grass in Colombia. However, the effect of the genetic structure based on two or five clusters was negligible. By comparison, locality, altitude and 13 covariables of productive system management and soil traits were significant. Conclusions Genetic population structure was insignificant in explaining the phenotypic variation of Kikuyu grass in Colombia. Implications Future research on Kikuyu grass in Colombia should focus on farm management variables and soil trait analyses.

Phenology of seed maturation in babysbreath (Gypsophila paniculata) in northwest Michigan, USA, and its relation to glyphosate efficacy

AbstractBabysbreath or perennial babysbreath (Gypsophila paniculata L.) is an aggressive invasive plant in large parts of southern Canada and the northern and western United States. It reproduces and disperses by seed, so the phenology of seed maturation is important in designing management programs. The present study provides the first quantitative assessment of G. paniculata seed-maturation phenology in a field population, as well as the first quantitative assessment of how the efficacy of herbicide treatment in preventing production of germinable seeds depends on the timing of treatment in relation to this phenology. Seeds were collected from untreated plants on five dates during July and August in both 2016 and 2017 and tested for germinability. Percent germination increased from 20% to 81% between July 22 and 28 and exceeded 90% by August 4, 2016. The seed-maturation phenology in 2017 was similar but delayed by about 4 d. On a growing degree-day scale, seed-maturation phenologies for the 2 yr were nearly identical. We also tested germinability of seeds from plants sprayed with glyphosate (23.4 ml ae L−1) on July 11, 18, and 25, 2016 (one date per plant). Percent germination increased from 0% to 13% to 20% over successive treatment dates, highlighting the importance of completing treatment early in the growing season.

Sublethal effects of diflovidazin on demographic parameters of the predatory mite, Neoseiulus californicus (Acari: Phytoseiidae)

ABSTRACTThe present study first evaluated the sublethal effects of diflovidazin (Flumite®) with three concentrations (LC5, LC10, and LC20) on life table parameters of Neoseiulus californicus (McGregor) (Acari: Phytoseiidae), as an effective predator of Tetranychus urticae (Koch) (Acari: Tetranychidae). Experimental results indicated that exposure to the sublethal concentrations of diflovidazin, has no significant effect on the development time of the treated mite offspring. Diflovidazin treatments gradually reduced the longevity and total life span of both sexes. The highest fecundity was observed in the control treatment (35.31 offspring/female), while the lowest was related to the LC20 concentration. However, the effects of different treatments on intrinsic (r), as well as finite rate of increase (λ) of this predator were insignificant. The r value, ranged from 0.2112 to 0.1989 day−1 for the mites treated with distilled water and the LC20 concentration, respectively. Furthermore, λ was not affected by enhancing the concentration, as the values were 1.2401 and 1.2205 day−1 for the mites treated with control and LC20, respectively. Those treated with LC20 had a significantly reduced R0, compared to those treated with control only. Thereby, the sublethal effects of diflovidazin in combination with N. californicus were emphasized for designing management programs of T. urticae.

Influence of attitudes and behavior of milkers on the hygienic and sanitary quality of milk.

Recognizing how human behaviors affect the milk process can be useful to understand variations in hygienic and sanitary parameters in bulk tank milk. Furthermore, this knowledge could be used to design management programs that guarantee milk quality, favoring the optimization of such processes. Forty-six milkers from the same number of dairy farms in Antioquia province (Colombia) were interviewed to establish the main factors associated to milk quality. Technical knowledge, motivations, and behavior of the personnel and its effect on hygienic and sanitary quality of milk were evaluated. Quality was assessed in terms of colony-forming units (CFU) and somatic cell count (SCC) in bulk tank milk. Two factors from a multivariate mixed data analysis were evaluated. One of those factors explained 9.51% of the total variability, related with in-farm availability and use of tools and the relationships between milker and manager. The other factor, associated with work environment and recognition, explained 6.97% of the total variability. The variables that best explained CFU levels were Knowledge of the udder condition at milking, and Milking type (parlor or pasture). The SCC was associated to knowledge of animal handling, schooling of milkers, milking site, and the groups derived from the cluster analysis by farm. In conclusion, milker attitudes and behaviors can affect CFU and SCC in bulk tank milk.

Effects of Crossed Brassiere Straps on Pain, Range of Motion, and Electromyographic Activity of Scapular Upward Rotators in Women With Scapular Downward Rotation Syndrome

BackgroundScapular downward rotation syndrome manifests as an abnormally downward-rotated scapula at rest or with arm motion and typically results in neck and shoulder pain. The brassiere strap has been suggested as a possible contributing factor to scapula downward rotation and pain in the upper trapezius because of increased downward rotational force on the lateral aspect of the scapula. No study, however, has examined the influences of a modified brassiere strap on pain in and the function of the scapular muscles. ObjectiveTo examine the effects of crossed brassiere straps on the pressure pain threshold (PPT) of the upper trapezius, neck rotation range of motion (ROM), and electromyographic activity of the scapular upward rotators in females with scapular downward rotation syndrome. DesignCross-over design. SettingLaboratory. ParticipantsIn total, 15 female subjects with scapular downward rotation syndrome were recruited at hospitals and a local university. MethodsAll participants performed neck rotation and humeral elevation under 2 different conditions: parallel and crossed brassiere straps. Main outcome measurementsThe PPT of the upper trapezius was measured using an analog algometer, whereas neck rotation ROM was quantified with a 3-dimensional ultrasonic motion analysis system. The electromyographic activities of the upper trapezius, serratus anterior, and lower trapezius during humeral elevation were assessed with a surface electromyography system. Outcome measures were assessed under parallel and crossed brassiere strap conditions, and differences in outcomes between the conditions were analyzed using a paired t-test. ResultsThe PPT and neck rotation ROM were increased when the subject was wearing the brassiere with crossed versus parallel straps (P < .001). Greater electromyographic activities of the serratus anterior, lower trapezius, and lesser upper trapezius muscles during humeral elevation were found under the crossed strap condition than the parallel strap condition (P < .05). ConclusionsThese findings provide useful information for clinicians when designing management programs to decrease pain and improve biomechanical function for females with scapular downward rotation syndrome.

Multi-level analysis of bird abundance and damage to crop fields

Bird damage to agricultural crops is an important cause of economic loss for farmers worldwide. Predictive habitat models relating bird abundance and damage to characteristics of the agricultural environment at multiple scales are a key tool for designing management programs to reduce impacts of birds on agricultural production. In this study, we explored habitat features influencing abundance and damage of monk parakeets (Myiopsitta monachus) to corn (Zea mays) and sunflower (Helianthus annuus) fields, as a basis for the design and evaluation of management strategies for preventing damage in the future. Using a multi-level approach, we evaluated within-field, field, and landscape variables at three spatial scales potentially related to monk parakeet abundance and damage in crop fields. Monk parakeet abundance and damage was greater in sunflower than in corn fields. Landscape variables, such as distance to nearest site with trees, percentage of landscape with trees, and availability of foraging sites for monk parakeets around the crop fields were more important than local variables in explaining monk parakeet damage to crop fields. However, local variables, such as field area, plant density and percentage of field border with trees, also were related to damage. Relationships varied depending on the crop under consideration and spatial scale of analysis. Based on this study, managers should consider both local and landscape factors when planning management measures to prevent bird damage to crops.

Seasonal and individual variation in selection by feral cats for areas with widespread primary prey and localised alternative prey

Context Seasonal and individual variation in predator selection for primary and alternative prey can affect predator–prey dynamics, which can further influence invasive-predator impacts on rare prey. Aims We evaluated individual and seasonal variation in resource selection by feral cats (Felis silvestris catus) for areas with European rabbits (Oryctolagus cuniculus) around a breeding colony of endangered black-fronted terns (Chlidonias albostriatus) in the Upper Ohau River, within the Mackenzie Basin of New Zealand. Methods Within a feral cat population subject to localised control (within a 1-km area surrounding the tern colony), we mapped the movements of 17 individuals using GPS collars, and evaluated individual and seasonal variation in third-order resource selection (i.e. within home ranges) by using resource-selection functions with mixed effects. The year was divided into breeding and non-breeding seasons for terns. Key results Three of the eight feral cats monitored during the breeding season used the colony in proportion to availability and one selected it. These four individuals therefore pose a threat to the tern colony despite ongoing predator control. Selection by feral cats for areas with high relative rabbit abundance was not ubiquitous year-round, despite previous research showing that rabbits are their primary prey in the Mackenzie Basin. Conclusions Results suggest that rabbit control around the colony should reduce use by feral cats that select areas with high relative rabbit abundance (less than half the individuals monitored), but is unlikely to alleviate the impacts of those that select areas with low relative rabbit abundance. Hence, predator control is also required to target these individuals. Results thus support the current coupled-control of feral cats and rabbits within a 1-km buffer surrounding the tern colony. Future research should determine what scale of coupled-control yields the greatest benefits to localised prey, such as the tern colony, and whether rabbits aid hyperpredation of terns by feral cats via landscape supplementation. Implications The present study has highlighted the importance of considering seasonal and individual effects in resource selection by predators, and the role of primary prey, when designing management programs to protect rare prey.

Face or flee? Fenitrothion resistance and behavioral response in populations of the maize weevil, Sitophilus zeamais

Insect survival in the presence of contact insecticides may be through physiological mechanisms or avoidance of contact with the compound. Curiously, although the first alternative is the object of frequent attention, the second is often neglected, but both may lead to insecticide resistance. Preliminary evidence for both physiological and behavioral resistance to pyrethroids has been obtained for a few strains of the maize weevil Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae). Here we carried out a more comprehensive survey using 15 populations of S. zeamais, by examining a long-used but relatively little studied organophosphate – fenitrothion, recording not only physiological resistance, but also the behavioral responses to exposure. Physiological resistance to fenitrothion among populations of S. zeamais reached low to moderate levels (ranging from 0.9 to 14.1× at the LC 50), an increase in resistance levels compared with previous studies. Fenitrothion-induced behavioral avoidance varied among populations, particularly regarding insecticide irritability (i.e., avoidance after contact with fenitrothion), but the behavioral responses observed were mainly stimulus-independent. However, there was no correlation between physiological and behavioral resistance to fenitrothion in S. zeamais populations. Both survival strategies to fenitrothion – facing or fleeing the insecticide exposure, were observed and may co-occur in a single population, emphasizing the need of assessing both responses and their relative importance in designing management programs against stored-product insects.

Molecular phylogenetics and population structure of Sousa chinensis in Chinese waters inferred from mitochondrial control region sequences

Phylogenetic analyses of the genus Sousa were carried out across their geographic range and focused especially on the genetic variation patterns and population structure of Sousa chinensis in Chinese waters. The analyses were based on 287-bp of the mitochondrial control region from 122 Indo-Pacific humpback dolphins ( Sousa chinensis) and two Atlantic humpback dolphins ( Sousa teuszii). All specimens from China grouped together in a well-supported clade with high bootstrap (BS) and Bayesian posterior probability values (BPP), strongly suggesting that only one species of Sousa exists in China. Six haplotypes were identified in 65 individuals from Xiamen and Pearl River Estuary in China. The extremely low level of detected mtDNA genetic diversity strongly suggests a high priority in conservation of Sousa. The highly significant genetic differentiation between the two populations in Xiamen and Pearl River Estuary supports the designation of these two populations as separate management units (MUs) when designing management programs for this species.

Detection of Magnaporthe grisea in infested rice seeds using polymerase chain reaction

To develop a diagnostic assay based on polymerase chain reaction for the detection of Magnaporthe grisea from infested rice seeds. Primers were designed based on the nucleotide sequence of the mif 23, an infection-specific gene of M. grisea. The primers amplified target DNA from genetically and geographically diverse isolates of the pathogen. The lowest concentration of template DNA that led to amplification was 20 rhog. No PCR product was detected when DNA from other fungi was used, indicating the specificity of the primers. With this PCR based seed assay, M. grisea was detected in rice seedlots with infestation rates as low as 0.2%. The PCR detection of M. grisea is simple, rapid, specific, sensitive and suitable for the routine detection of the pathogen in infested seeds. Introduction of the blast fungus into new areas where it has not been previously recorded could be avoided by the detection of infested seedlots. A PCR-based seed assay could facilitate risk assessment of naturally infested rice seeds; help design management programs and optimize fungicide use.

Challenges posed by the precautionary principle and accountability in ecological risk assessment

AbstractIn order to protect the environment, type II errors, e.g. a species is not listed as endangered (H0) when it is in fact endangered (H1), are avoided at the risk of making a type I error. However, it is almost impossible to determine if management efforts have been efficient or if many type II errors have occurred. Applying the precautionary principle to environmental protection without full scientific certainty requires a new academic code for scientists. If we manage ecosystems or bioresources under uncertainty, we need to incorporate new knowledge (accountability) and to change actions with ecosystem states (adaptability). This is called adaptive management. The extinction risk of exploited species under adaptive management is much lower than that under constant exploitation. The revised management procedure (RMP) in whaling and the deer management program in Hokkaido, Japan, share the merit of adaptive management. Under the RMP, the period allowed in considering the extinction risk of the southern hemisphere minke whale is far too long. Population management of over‐abundant deer threatened endangered eagles, because of lead contamination from bullets. Although the effect of lead contamination on the extinction risk of eagles was uncertain, the Hokkaido Government prohibited the use of lead bullets in deer hunting. When designing management programs, it is also important to consider cost–benefit measures in the ecological risks. The value of biodiversity is often much higher than the economic benefit from exploiting the bioresource by agriculture, forestry or fisheries. Copyright © 2003 John Wiley &amp; Sons, Ltd.

To enhance the environmental values of Tokyo Bay – a proposition for integrated coastal zone management

The environmental value of Tokyo Bay has substantially deteriorated in the absence of sound management. Focused coastal zone management, in conjunction with rigorous conservation policy, is necessary to avoid further degradation of the Tokyo Bay environment and to balance conflicting values and interests in the bay. It is recommended that this coastal management be integrated and brought under a single authority in order to alleviate friction among diverse departmental entities and to ensure inclusion of the entire coastal zone. This management system requires legal statutes be put in place to regulate all activities affecting the bay environment, and for this, citizens participation, including smooth access to information on the bay environment, is a prerequisite. It is suggested that quantitative financial projections for environmental policies may prove a useful tool for illuminating the value of these measures in designing management programs, and as a model, a case study is provided describing organic contamination of the bay and discussing costs, effects, and benefits associated with improving water quality.

Management Of Toxic Chemical Spills

The widespread use of toxic substances in industrial processes has inevitably led to accidental releases of dangerous chemicals into the environment. Incidents such as the recent chlorine leak in Michigan have resulted in injury, property damage, and, in certain cases, large scale temporary evacuation of impacted areas. A need has developed therefore, to design management programs to control such episodes.