Integrated Tick Management in the Upper Midwest: Impact of Invasive Vegetation Removal and Host-targeted Acaricides on Ixodes scapularis Infestation and Borrelia burgdorferi Prevalence of Small Mammals

Integration of tick management strategies has been suggested to overcome ecological variation in tick, host, pathogen, and habitat, yet empirical evidence assessing combined treatment effect on blacklegged ticks, Ixodes scapularis Say, is limited. In this 5-year study (2014-2018) we tested whether combining two methods targeting tick/mammal interactions could reduce juvenile I. scapularis parasitism of two small mammal species, Peromyscus leucopus Rafinesque and Tamias striatus Linnaeus. Infection of small mammals with Borrelia burgdorferi was used to evaluate host exposure to feeding ticks. Using a factorial design, removal of invasive vegetation (Amur honeysuckle, Lonicera maackii Ruprecht and common buckthorn, Rhamnus cathartica Linnaeus) was coupled with deployments of permethrin-treated cotton nesting materials (tick tubes) and evaluated against control sites. Removal of invasive vegetation resulted in lower captures of T. striatus suggesting that treatment impacted reservoir activity in the plots. Deployments of permethrin-treated cotton were effective at reducing the frequency of juvenile I. scapularis parasitism of P. leucopus by 91% across the study compared to controls. However, tick tubes did not offer consistent protection against mouse exposure to B. burgdorferi exposure. An additive negative effect was detected for juvenile tick intensity on P. leucopus when tick tubes were combined with invasive vegetation removal. We conclude that integration of these two methods provides very limited benefit and that permethrin treatment alone offers the best option for reducing I. scapularis infestation on P. leucopus.

Vegetation Removal on 3D Point Cloud Reconstruction of Cut-Slopes Using U-Net

The 3D point cloud reconstruction from photos taken by an unmanned aerial vehicle (UAV) is a promising tool for monitoring and managing risks of cut-slopes. However, surface changes on cut-slopes are likely to be hidden by seasonal vegetation variations on the cut-slopes. This paper proposes a vegetation removal method for 3D reconstructed point clouds using (1) a 2D image segmentation deep learning model and (2) projection matrices available from photogrammetry. For a given point cloud, each 3D point of it is reprojected into the image coordinates by the projection matrices to determine if it belongs to vegetation or not using the 2D image segmentation model. The 3D points belonging to vegetation in the 2D images are deleted from the point cloud. The effort to build a 2D image segmentation model was significantly reduced by using U-Net with the dataset prepared by the colour index method complemented by manual trimming. The proposed method was applied to a cut-slope in Doam Dam in South Korea, and showed that vegetation from the two point clouds of the cut-slope at winter and summer was removed successfully. The M3C2 distance between the two vegetation-removed point clouds showed a feasibility of the proposed method as a tool to reveal actual change of cut-slopes without the effect of vegetation.

Effect of the Gravel Filters and Plastic Cover on Improving Water Infiltration Process and Increasing Moisture Storage of Rainwater Harvesting Systems in Sloping Lands

Rainwater harvesting is a suitable method to plant seedlings in sloping lands in arid and semi-arid regions. In this research, a combination of plastic coating and gravel filter has been used to penetrate water into the soil. In this method, water is stored in the soil during the rainy months and the plant uses these waters in the warm months of the year. For this purpose, five treatments (with three replications) including control treatment, system vegetation removal with filter, system vegetation removal without filter, semi-insulated system with filter and semi-insulated system without filter are considered. Two sensors are installed in each of the treatments at a depth of 20 cm and 60 cm of soil, which will record moisture in seven-day periods. Apricot seedlings have been planted in all treatments. The information obtained was analyzed through a completely randomized block design. The results showed that the semi-insulated treatment with gravel filter stored significant moisture in the soil rather than other treatments and stored more moisture in the warm months of the year. The results showed that semi-insulated treatment with gravel filter is a suitable solution to increase soil moisture in the warm months of the year (June, July, August and September).

RECOMMENDATIONS FOR CORRECTING THE DEGREE OF DISTRIBUTION OF TECHNOLOGICAL PROCESSES OF VEGETATION REMOVAL FROM THE TERRITORIES OF LINEAR INFRASTRUCTURAL FACILITIES

With the maintenance of transport networks in proper condition, the problem of removing unwanted tree and shrub vegetation continues to be relevant. Work on cleaning the territories of the relevant infrastructure facilities from undesirable vegetation can be performed both manually and mechanically with the involvement of various machines, mechanisms and equipment. Considering that at present, when removing unwanted tree and shrub vegetation from the territories of linear infrastructure facilities, a total of more than 50 technological processes are used, the purpose of the study was to identify the possibility of adjusting the degree of their prevalence by types of infrastructure facilities. The article provides a formula for establishing the degree of prevalence of the technological process of removing vegetation along linear infrastructural objects, the distribution of the specified degree by the sites of impact on unwanted vegetation is presented, the content of the corresponding technological processes is disclosed, recommendations are proposed for adjusting the degree of prevalence of technological processes for removing vegetation from the territories of linear infrastructure facilities. The results of the study can be used by industrial enterprises performing work to maintain the territory of transport infrastructure facilities in a standard condition.

Integrated Tick Management in South Central Wisconsin: Impact of Invasive Vegetation Removal and Host-Targeted Acaricides on the Density of Questing Ixodes scapularis (Acari: Ixodidae) Nymphs

As tick-borne disease incidence increases and pathogens expand into new areas, the need for effective tick management strategies is paramount. In this 5-yr study (2014–2018) conducted in south central Wisconsin, we assessed whether an integrated tick management approach, deployed during peak tick activity (May–August), was more effective at reducing black-legged ticks (Ixodes scapularis Say (Ixodida: Ixodidae)), than individual interventions. Using a factorial design, invasive vegetation removal (Amur honeysuckle, Lonicera maackii Ruprecht (Dipsacales: Caprifoliaceae) and common buckthorn, Rhamnus cathartica Linnaeus (Rosales: Rhamnaceae)) was coupled with deployments of permethrin-treated cotton nesting materials (tick tubes) that target the white-footed mouse (Peromyscus leucopus Rafinesque (Rodentia: Cricetidae)). Results show that the probability of encountering a larval tick by drag sampling was unaffected by treatments at the cumulative 5-yr level. However, vegetation removal significantly reduced larval encounters in 2014, 2015, and 2018, by 33%, 57%, and 61% respectively, and reduced the density of questing nymphal (DON) ticks by 45% in 2015 compared to controls. Despite the limited effect on DON, vegetation removal significantly reduced the cumulative 5-yr density of Borrelia burgdorferi sensu stricto infected nymphs (DIN) (70%) compared to controls as a result of decreased nymphal infection prevalence. Sites treated with tick tubes had lower DIN (66%) and DON (54%) across the study and nymphs were reduced every year following the initial year of deployment compared to controls. Combining treatments did not further reduce DIN or DONs. We conclude that long-term integration of tick tubes with invasive vegetation removal does not provide additional benefit over individual treatments alone.

Infective endocarditis late after patent foramen ovale percutaneous closure in an addict patient

We report an uncommon case of late infective endocarditis, in a patient with a history of intravenous drug abuse and HIV positivity, 9 years after a percutaneous closure of a patent foramen ovale. Despite a target and prolonged intravenous antibiotic therapy, he was then referred for surgical device and vegetation removal. Given the high risk associated with drug addiction lifestyle, especially in HIV positive cases, it is mandatory to observe this group of patients with lifelong follow-up and support. Furthermore, it may be considered a multidisciplinary-team approach to find the best option for these patients, also evaluating a surgical correction.

Effects of Above- and Below-Ground Interactions of Plants on Growth of Tree Seedlings in Low-Elevation Tropical Rainforests on Hainan Island, China

Understanding the effects of above- and below-ground interactions on seedling growth is pivotal for identifying the key drivers of secondary forest succession. However, it is still unclear whether the effects of above- and below-ground interactions of plants are consistent for seedling growth of deciduous and evergreen species. There are two types of broadleaved forests (i.e., tropical lowland rainforest and tropical deciduous monsoon rainforest) in the low-elevation (<800 m) areas of Hainan Island in China. Here, 32 seedling transplanting plots (1 × 1 m2) were established in the tropical lowland rainforest and the tropical deciduous monsoon rainforest, respectively. Four treatments (each with 16 replicates) were carried out to reduce above- and below-ground interactions of plants in the low-elevation forests: removal of vegetation (R), root trenching (T), removal of vegetation and root trenching (R + T), and no vegetation removal or trenching (as the control) (C). Seedlings of four deciduous species and four evergreen species were planted to observe their performance in the experiments. The relative growth rates (RGR) of the seedlings were measured to distinguish the relative effects of above- and below-ground interactions. The photosynthetically active radiation (PAR) was measured as a proxy for above-ground interaction and the root biomass was used as a proxy for below-ground interaction. The relationships between seedling RGR and PAR/root biomass were examined. Results showed that: (1) R and R+T treatments significantly increased the seedlings RGR, but T treatment had no effect on the RGR; (2) the growth rates of deciduous species were greater than those of the evergreen species; and (3) seedling growth rates were increased with more PAR. Our study suggests that above-ground vegetation removal had a stronger effect than trenching on the growth and assembly of tree seedlings in the low-elevation tropical rainforests.

Effects of Understory or Overstory Removal on the Abundances of Soil Nematode Genera in a Eucalyptus Plantation

In south China, eucalyptus plantations typically consist of a single-species overstory (a eucalyptus monoculture) and a dense understory of a dominant fern species. In the current study, we assessed the effects of four treatments [control (CK), understory removal (UR), tree removal (TR), and all-plant removal (PR)] on the abundances of soil nematode genera, which can provide insight into the ecological functions of understory plants and trees. Soil nematodes were sampled six times (once before and five times after treatments were implemented) at 0–5 and 5–10 cm soil depths. The temporal dynamics of nematode genera were analyzed by the principle response curves (PRC) method. At 0–5 cm depth, the abundances of most nematode genera rapidly increased shortly after vegetation removal but then gradually decreased; the effects of UR were stronger than the effects of TR. The results might be explained by the pulsed input of plant debris to soil and its subsequent depletion. At 5–10 cm depth, the nematode communities were relatively unaffected by vegetation removal within the first 162 days, but the abundances of most genera sharply decreased on day 258 and then sharply increased on day 379 (the last sampling time). The results indicated that most nematode genera, even r-selected genera, were sensitive to vegetation removal in the upper soil layer and that understory vegetation can greatly affect soil nematode communities and presumably soil food webs. The nematode genera Prismatolaimus and Diphtherophora may be good indicators of the effects of vegetation removal. The results increase our understanding of the relationships between soil nematode genera and forest plant communities and of how soil biota is affected by forest management practices.