Explore the vast range of titles available.

Water infiltration is one of the most important triggers of landslides. Vegetation is an effective way to mitigate water infiltration, reduce soil surface cracking, and, consequently, prevent landslides. In recent years, a soil mixture has been successfully used to grow vegetation on steep soil/rock surfaces by hydroseeding or shotcreting. The mixture contains seven ingredients, namely cement, fiber, peat, water retention agent, soil conditioner, soil, and pH adjusting agent. This study includes a germination and growth field test and a series of lab shear strength tests to assess: (1) the influence of the mixture’s ingredients on germination and growth of the vegetation and (2) the effect of cement and fiber on the shear strength of the cured mixture. For the germination and growth test, the Taguchi method was utilized to determine the content of each ingredient (i.e., the percentage of each ingredient) used to prepare different mixtures. Cynodon dactylon was planted in different mixtures and the germination and growth had been monitored for 3 months. The results indicated that the cement content had a significant influence on germination whereas the content of peat, soil conditioner, fiber, and water retention agent had a medium to negligible influence on germination. The content of all the ingredients had an influence on the plant’s growth and the influence of the cement content was the greatest. When the cement content is higher than 10 %, the growth of the plant is greatly hindered; therefore, to ensure a reasonable growth in the field, the cement content should be less than 10 %. The shear strength tests used the sample prepared with different contents of cement and fiber, but the same porosity. The results showed that the contents of cement and fiber had a negligible influence on the friction angle, and the cohesion increased with the increase of cement content or decrease of the fiber content. Curing time of 7–14 days yielded the maximal cohesion.

Revegetation effectiveness requires long-term monitoring. We analysed 50 road slopes 5–8 years and 22–25 years after revegetation. Plant cover and diversity increased over time, with differences between slope types; herbaceous cover increased greatly between revegetation works and 2002 and was similar in 2002 and 2019, while woody cover decreased from revegetation to 2002 but increased greatly between 2002 and 2019. Plant colonisation was more intense on embankments, but could also be achieved on roadcuts (2.4 points on average over a maximum of 5). The presence of sown species decreased over time, but the presence of planted species remained stable. Hydroseeding had poor results in terms of the resulting plant cover, but nevertheless succeeded in slowing erosion at least sufficiently to allow early plant establishment and thus the start of colonisation. The similarity between surrounding vegetation and the slopes was greater in roadcuts. Roads are a gateway for invasive plants. Native species can improve the results, but many are missing from the market. Slopes’ plant cover changed over time; long-term studies are required.

The demand for restoration of degraded lands to diverse native habitat is growing, requiring efficient strategies for large-scale seeding and planting of native species. Restoration is often limited by low germination and establishment rates of native plants, so identifying the most effective seeding methods and rates may speed the restoration process. We tested three different methods of seeding (broadcasting, drilling, simulated hydroseeding) and five seeding rates (ranging from 0 to 1400 seeds/m2) to determine their efficacy in establishing three common species of Pacific Northwest prairies: Festuca roemeri, Eriophyllum lanatum, and Potentilla gracilis. We sowed seeds into six arrays at three western Washington sites on two dates (January and October) and monitored plant abundance for three years. We found that broadcast and simulated hydroseeding did not produce significantly different outcomes, suggesting that the extra resources required for hydromulching are not necessary. Additionally, broadcast seeding resulted in more consistent and reliable native plant establishment than seed drilling. Increasing seeding rates increased abundance, as expected, but species remained seed limited even at the highest seeding rates. Establishment varied considerably by site and seeding date. First-year establishment was positively correlated to third-year abundance, but this also varied greatly by site and species. Due to temporal and spatial variability in establishment, managers should evaluate treatments on individual sites and monitor results for several years after sowing.

A landslide is a significant environmental hazard that results in an enormous loss of lives and properties. Studies have revealed that rainfall, soil characteristics, and human errors, such as deforestation, are the leading causes of landslides, reducing soil water infiltration and increasing the water runoff of a slope. This paper introduces vegetation establishment as a low-cost, practical measure for slope reinforcement through the ground cover and the root of the vegetation. This study reveals the level of complexity of the terrain with regards to the evaluation of high and low stability areas and has produced a landslide susceptibility map. For this purpose, 12 conditioning factors, namely slope, aspect, elevation, curvature, hill shade, stream power index (SPI), topographic wetness index (TWI), terrain roughness index (TRI), distances to roads, distance to lakes, distance to trees, and build-up, were used through the analytic hierarchy process (AHP) model to produce landslide susceptibility map. Receiver operating characteristics (ROC) was used for validation of the results. The area under the curve (AUC) values obtained from the ROC method for the AHP model was 0.865. Four seed samples, namely ryegrass, rye corn, signal grass, and couch, were hydroseeded to determine the vegetation root and ground cover’s effectiveness on stabilization and reinforcement on a high-risk susceptible 65° slope between August and December 2020. The observed monthly vegetation root of couch grass gave the most acceptable result. With a spreading and creeping vegetation ground cover characteristic, ryegrass showed the most acceptable monthly result for vegetation ground cover effectiveness. The findings suggest that the selection of couch species over other species is justified based on landslide control benefits.

Questions Is revegetation of soil slopes with the currently used plant groundcovers effective in promoting dense vegetation and ecological values of landscapes? Does the degree of urban development influence the abundance of groundcovers? Is there any relationship between slope features and the plant community of soil slopes? Location Hong Kong Special Administrative Region, China. Methods We conducted a vegetation study focusing on groundcovers on 35 revegetated soil slopes in urban and suburban areas of Hong Kong and determined differences in plant cover, diversity and community composition among areas under various degrees of development. We also assessed slope features, including presence of erosion control mats, canopy openness, slopes angle, area, elevation and substrate properties, such as soil pH, electrical conductivity (EC) and nutrient status, to examine their relationships to the plant community composition. Results Plant cover was generally about 30%, with ferns having the highest cover. The initially planted groundcover species were replaced by native graminoids and ferns, or an invasive climbing herb, Wedelia trilobata. Soil slopes covered by erosion control mats had significantly lower plant cover than those without. Contrasting plant community composition of groundcovers was found among areas with different degrees of urban development and between slopes with and without erosion control mats. Slope angle, canopy openness, sandy soil texture and soil EC were closely associated with the plant communities of soil slopes. Conclusions The current planted groundcovers used for revegetating soil slopes led to unsatisfactory plant cover but allowed colonization of other native groundcovers. Planting strategy using more adaptable native groundcovers, but not invasive species, is a feasible approach to ecologically restore soil slopes. The degree of development and certain slope features influence the plant community and should be considered in the revegetation of soil slopes. This study evaluated the growth performance and ecological enhancement of groundcovers on revegetated soil slopes in Hong Kong. This is a topic that receives little attention. Our results show that naturally occurring ferns and graminoids dominate the landscapes, although their cover percentage was generally low. The presence of erosion control mats and some slope features influence plant community composition of revegetated soil slopes.

To meet US renewable fuel mandates, perennial grasses have been identified as important potential feedstocks for processing into biofuels. Triploid Miscanthus × giganteus, a sterile, rhizomatous grass, has proven to be a high‐yielding biomass crop over the past few decades in the European Union and, more recently, in the United States. However, high establishment costs from rhizomes are a limitation to more widespread plantings without government subsidies. A recently developed tetraploid cultivar of M. × giganteus producing viable seeds (seeded miscanthus) shows promise in producing high yields with reduced establishment costs. Field experiments were conducted in Urbana, Illinois from 2011 to 2013 to optimize seeded miscanthus establishment by comparing seeding rates (10, 20, and 40 seeds m−2) and planting methods (drilling seeds at 38 and 76 cm row spacing vs. hydroseeding with and without premoistened seeds) under irrigated and rainfed conditions. Drought conditions in 2011 and 2012 coincided with stand establishment failure under rainfed conditions, suggesting that seeded miscanthus may not establish well in water‐stressed environments. In irrigated plots, hydroseeding without premoistening was significantly better than hydroseeding with premoistening, drilling at 38 cm and drilling at 76 cm with respect to plant number (18%, 54%, and 59% higher, respectively), plant frequency (13%, 30%, and 40% better, respectively), and the rate of canopy closure (18%, 33%, and 43% faster, respectively) when averaged across seeding rates. However, differences in second‐year biomass yields among treatments were less pronounced, as plant size partially compensated for plant density. Both hydroseeding and drilling at rates of 20 or 40 seeds m−2 appear to be viable planting options for establishing seeded miscanthus provided sufficient soil moisture, but additional strategies are required for this new biomass production system under rainfed conditions.

Question: Does community assembly on roadsides differ between two contrasting habitats along a stress–productivity gradient? Is establishment success determined by the regional pool, environmental filters or historical events? Location: Highway roadcuts and embankments in central Spain (40°29′N, 03°34′W). Methods: Species composition was recorded annually in 45 plots distributed on steep slopes with newly exposed surfaces (roadcuts) or newly built topsoiled substrates (embankments), for 4 years following hydroseeding with standard or native seed mixture. Frequency of appearance and local colonization and extinction rates of individual species were clustered in establishment success groups. We examined the correspondence between descriptive plant traits and species performance on both roadslope types.Results: Roadslope species richness showed a sustained increase over time, although at consistently lower levels and rates on the more productive embankments. Sixty per cent of the colonization events involved species from the surrounding vegetation. Hydroseeded species persisted through time, but did not modify community composition or dynamics. A higher establishment success rate was found in wind-pollinated species with large seeds and in exotic species. Those species growing on embankments showed an equal or higher establishment success rate on roadcuts and, conversely, species from roadcuts exhibited an equal or lower success rate on embankments. Conclusions: At the initial stages of community assemblage on unproductive newly created areas, species richness was shaped by the regional species pool. Communities on less harsh topsoiled embankments were subjected, however, to the filtering effect of competitive exclusion. In a reclamation context, efforts to increase site productivity may have detrimental consequences for in situ conservation of local diversity.

The aims of this study were to determine seed germination rate of some local plant species in two hydroseeding mulches containing different tackifier concentration, as well as to determine the optimal hydroseeding mulch media composition for germinating seeds. This study used seeds of 13 local plant species: two species of Cyperaceae (Cyperus brevifolius, C. javanicus), five species of Leguminosae (Cajanus cajan, Crotalaria pallida, Sesbania grandiflora, S. sesban, Tephrosia purpurea), and six species of Poaceae (Eleusine indica, Paspalum conjugatum, Sorghum timorense, S. bicolor, Sporobolus indicus, Themeda arundinaceae).Two hydroseeding mulch media with different tackifier composition were mixed with seeds of each species and then sowed in pots. Each treatment was repeated three times. Moistened cotton wool was used as control and comparative media for observing seed viability. Seed germination in mulch media was observed during 13 days. The results showed that only 8 of 13 species could be germinated: S. indicus, S. timorense, T. arundinaceae, C. cajan, C. pallida, S. grandiflora, S. sesban, and T. purpurea. The highest germination rate was shown by S. sesban (67%) in M2 medium and the lowest one was shown by T. arundinaceae (2%) in both media. The fastest germination time was recorded for C. pallida and S. sesban seeds that germinated in 2 days after sowing (DAS) in both media, while S. timorense and T. arundinaceae seeds showed the lowest ones in 11 DAS. The fluid M1 medium was optimal for seeds germination of S. sesban (50%) and S. grandiflora (35%), while the thicker M2 medium was optimal for seeds germination of S. sesban (67%) and S. timorense (50%) in 13 DAS. The maximum germination rate was generally reached in 11 DAS.

QUESTIONS: How do native species perform when included in seed mixtures to re‐vegetate degraded areas? Is their germination and establishment affected by seeding density? LOCATION: Limestone quarry spoil, SW Portugal. METHODS: A glasshouse experiment simulating usual hydroseeding procedures (substrate, time of the year, slurry composition, seed mixture) was performed to evaluate the suitability of six native species (Origanum vulgare, Piptatherum miliaceum, Phagnalon saxatile, Sedum album, S. sediforme, Thymus mastichina) to re‐vegetate a Mediterranean quarry. Other native species were added to create the seed mixtures. Three treatments were assayed for each target species sown: (1) alone (T), (2) in a low‐density seed mixture (ca. 15 g·m⁻²), and (3) in a high‐density seed mixture (ca. 30 g·m⁻²). Plants were monitored for 8 months. RESULTS: The target species were able to germinate, establish and grow when sown alone, but their performance was drastically impaired when included in seed mixtures. This was related to plant morphologies, as some co‐seeded species rapidly developed large leaves, which presumably reduced resource availability for the small‐leaved seedlings of most target species. Almost no seedlings of the latter survived in the mixture treatments. Low‐ and high‐seeding densities yielded similar plant covers and heights. CONCLUSIONS: Even when apparently suitable to restore a given site, candidate native species cannot simply be included in current re‐vegetation ‘recipes’, because their success largely depends on the density and seedling characteristics of the co‐seeded species (even if these are also native). The early performance and morphology of the latter must be taken into account in the design of seed mixtures used in restoration actions.

The research aimed to determine pioneer local plant seeds germination and growth on coal postmining soil, and to determine optimal mulch for producing great productivity. The research was conducted in two applications in a coal post mining area, Tanah Laut, South Kalimantan. The used seeds were 5 species of legumes, 3 species of grasses, and 3 species of sedges. Hydroseeding was applied by mixing seeds in mulch and spreading it on soil surface of 400 cm2 plots (1st application) and 10,000 cm2 plots (2nd application). There were five treatments in the 1st application and repeated four times, while in the 2nd, there were six treatments with three times repetitions. Germination rate, seedling density, plant coverage, height/length, and leaf length were observed every three days (1st application). On 60 days after sowing, root length and plant biomass (the 1st), and plant coverage, height and productivity (the 2nd) were measured. The results showed that hydroseeding mulches could be media for pioneer local plant seeds germination and seedling growth especially for Leguminosae. While the buffalo dung could be hydroseeding mulch for Poaceae growth. Although root/shoot ratio of Cyperaceae was higher than other families, Leguminosae root developed longer as shoot growth and well adapted on postmining soil. The hydroseeding mulch composed by 720 seeds per plot and applied 4 cm in depth was optimal based on seed germination percentage. Whereas mulch with 0.2 cm depth in 2nd application showed a higher effectivity for plant growth and productivity.