scholarly journals Vegetation and soil seedbank dynamics in Parthenium hysterophorus L. invaded subtropical grassland in Nepal

2019 ◽  
Author(s):  
Maan Bahadur Rokaya ◽  
Jyoti Khatri-Chettri ◽  
Shiba Raj Ghimire ◽  
Bharat Babu Shrestha
Keyword(s):  
Plant Species ◽  
Grazing Intensity ◽  
Soil Surface ◽  
Parthenium Hysterophorus ◽  
Deep Soil ◽  
Potential Threat ◽  
Invasive Weed ◽  
South Central ◽  
Introduced Range ◽  
Soil Seedbank

AbstractParthenium hysterophorus is a noxious invasive weed and is ever expanding in its introduced range including Nepal. Understanding vegetation dynamics including soil seedbank in Parthenium invaded communities and the growth pattern of the weed itself is essential for effective management of Parthenium. We monitored growth of Parthenium (height, density, cover and soil seedbank) and plant species composition of associated species for 5-year period from 2009 in a grassland invaded by Parthenium in south-central Nepal. We found that Parthenium cover and height decreased from 2009 to 2010 and then slightly increased in 2013. Parthenium density decreased from 2009 to 2010 and then was variable until 2013. Year × grazing interactions had significant effect on Parthenium cover and density. Parthenium soil seedbank was eight times higher near the soil surface than in deep soil. It increased from 2009 to 2012 but decreased in 2013. Seedbank was also affected by interactions of year × depth, depth × grazing, and year × depth × grazing. Altogether, 87 plant species were recorded in Parthenium invaded sites and their species richness decreased until 2012 but slightly increased in 2013. The composition of associated plant species was affected by animal grazing intensity, Parthenium density, cover, and their interactions. Parthenium invasion has been ever increasing in our study site and many palatable plant species are under potential threat. Thus, there is an urgent need to carry out awareness campaign, formulate proper management plans, and implement such plans properly to manage Parthenium weed in Nepal.

scholarly journals EFFECTS OF THE ABUNDANCE OF PARTHENIUM HYSTEROPHORUS ON THE COMPOSITION AND DIVERSITY OF OTHER HERBACEOUS PLANT SPECIES IN SIMANJIRO RANGELAND, TANZANIA

2020 ◽  
Vol 7 (5) ◽  
pp. 11-20
Author(s):  
Leticia J. Musese ◽  
Samora M. Andrew ◽  
Deo D. Shirima ◽  
Arne Witt ◽  
Ramadhan Kilewa
Keyword(s):  
Plant Species ◽  
Invasive Plant ◽  
Linear Models ◽  
Similarity Index ◽  
Parthenium Hysterophorus ◽  
Herbaceous Plant ◽  
Potential Threat ◽  
Significant Difference ◽  
Abundance And Diversity ◽  
Jaccard's Similarity Index

Parthenium hysterophorus is an annual herbaceous plant native to tropical America; and an invasive plant in Africa causing distressing effects on natural flora. This study investigated the effects of P. hysterophorus on the composition and diversity of native herbaceous plant species in Simanjiro rangeland, Tanzania. Plant species count data were collected from 60 (1m2) quadrats. Using generalized linear models (GLM), the abundance of P. hysterophorus was regressed against the abundance and diversity of the native herbaceous plants. Also, Jaccard’s similarity index was used to compare species composition. Results showed that there were 14 herbaceous plant species belonging to 13 genera and 10 families in the study area. Parthenium hysterophorus was the most dominant species recorded. The abundance of P. hysterophorus has a substantial negative effect on the abundance and diversity of other herbaceous plant species. Moreover, Jaccard’s similarity index showed a slightly significant difference between the infested and non-infested areas. This finding suggests that P. hysterophorus has a substantial potential threat on other herbaceous flora which are sources of food and nutrients to livestock and wild animals in the area. Thus, integrated management strategies are required to control the weed from spreading to other nearby rangelands.

scholarly journals The Host Range and Risk Assessment of the Stem-Boring Weevil, Listronotus setosipennis (Coleoptera: Curculionidae) Proposed for the Biological Control of Parthenium hysterophorus (Asteraceae) in Pakistan

Insects ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 463
Author(s):  
Philip Sebastian Richard Weyl ◽  
Abdul Rehman ◽  
Kazam Ali
Keyword(s):  
Risk Assessment ◽  
Host Range ◽  
Plant Species ◽  
Agricultural Research ◽  
Animal Health ◽  
Crop Productivity ◽  
Control Measures ◽  
Parthenium Hysterophorus ◽  
Jammu And Kashmir ◽  
Introduced Range

Parthenium, or Parthenium hysterophorus, has extended its range in Pakistan throughout Punjab and into Khyber Pakhtunkhwa, the Federally Administrated Tribal Areas, Azad Jammu and Kashmir, and Sindh Provinces. Without control measures against parthenium, the negative impacts of this weed will go unchecked having deleterious effects on native biodiversity, human and animal health, as well as crop productivity. The weevil Listronotus setosipennis was obtained and imported from the Plant Health and Protection of the Agricultural Research Council (ARC-PHP), in Cedara, South Africa, in April 2019. A total of 22 plant species or cultivars in the Asteraceae family were assessed during no-choice oviposition tests in Pakistan. During these tests, the only plant species accepted for oviposition were the 10 cultivars of Helianthus annuus that are grown in Pakistan. All cultivars were thus tested for development of L. setosipennis from egg to adult. Only three cultivars were able to support some larval development, but at such low levels that it is unlikely to be the basis of a viable population. To support this, a risk assessment was conducted to ascertain the probability of L. setosipennis being able to sustain viable populations in the field, the results of which concur with native (Argentina) and introduced (Australia) field host-range information where L. setosipennis has never been recorded as a pest of sunflowers. The results of laboratory-based host-range trials, together with host records from its native and introduced range, indicate that L. setosipennis is sufficiently specific to parthenium and is thus suitable for release in Pakistan.

Analytical Model to Predict Nonhomogeneous Soil Temperature Variation

1995 ◽  
Vol 117 (2) ◽  
pp. 100-107 ◽  
Author(s):  
M. Krarti ◽  
D. E. Claridge ◽  
J. F. Kreider
Keyword(s):  
Thermal Properties ◽  
Soil Temperature ◽  
Temperature Variation ◽  
Analytical Model ◽  
Soil Surface ◽  
Deep Soil ◽  
Soil Thermal Properties ◽  
Order Of Magnitude ◽  
Soil Surface Temperature ◽  
Annual Time

This paper presents an analytical model to predict the temperature variation within a multilayered soil. The soil surface temperature is assumed to have a sinusoidal time variation for both daily and annual time scales. The soil thermal properties in each layer are assumed to be uniform. The model is applied to two-layered, three-layered, and to nonhomogeneous soils. In case of two-layered soil, a detailed analysis of the thermal behavior of each layer is presented. It was found that as long as the order of magnitude of the thermal diffusivity of soil surface does not exceed three times that of deep soil; the soil temperature variation with depth can be predicted accurately by a simplified model that assumes that the soil has constant thermal properties.

Seed germination response of a noxious agricultural weed Echium plantagineum to temperature, light, pH, drought stress, salinity, heat and smoke

2018 ◽  
Vol 69 (3) ◽  
pp. 326 ◽  
Author(s):  
Singarayer Florentine ◽  
Sandra Weller ◽  
Alannah King ◽  
Arunthathy Florentine ◽  
Kim Dowling ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Drought Stress ◽  
Invasive Weed ◽  
Germination Response ◽  
Elevated Salinity ◽  
Wide Range ◽  
Agricultural Weed ◽  
Soil Seedbank ◽  
Response To Temperature ◽  
Salinity Management

Echium plantagineum is a significant pasture weed in the Mediterranean climatic zone of several countries, including Australia. This invasive weed, introduced as an ornamental into Australia (where it is known as Paterson’s curse), quickly became established and is now a significant weed of agriculture. Although E. plantagineum is a well-established, highly competitive weed that thrives under disturbance and is tolerant of a wide variety of conditions, including varying soil moisture and drought, and some aspects of its ecology remain unknown. This study investigated germination response to temperature and light, pH, soil moisture, salinity, and pre-germination exposure of seed to heat and smoke. Temperature was found to be more influential on germination than light and the species is tolerant to a wide range of pH. However, available moisture may limit germination, as may elevated salinity. Management of this weed requires approaches that minimise soil seedbank input or prevent germination of soil seedbanks.

scholarly journals Potential threat of southern Moravia soils by wind erosion

2004 ◽  
Vol 52 (2) ◽  
pp. 33-42 ◽  
Author(s):  
Jana Dufková
Keyword(s):  
Wind Velocity ◽  
Wind Erosion ◽  
Linear Trend ◽  
Soil Surface ◽  
Potential Threat ◽  
Soil Humidity ◽  
Average Wind ◽  
Humidity Index ◽  
Southern Moravia ◽  
Average Wind Velocity

Wind erosion is caused by meteorological factors such as wind, precipitation and evaporation that influence the soil humidity. Erosive-climatological factor expresses wind and humidity conditions of particular landscape. This is an index of the influence of average soil surface humidity and average wind velocity on average soil erodibility by wind. On the basis of average wind velocity and Konček’s humidity index, the values of the erosive-climatological factor for three chosen areas of Czech republic (Telč-Kostelní Myslová, Znojmo-Kuchařovice and Brno-Tuřany), where the pro-cesses of wind erosion could exist, were evaluated. Thus, the change of the factor’s value during the period of 1961 – 2000 was studied. The linear trend for the region of Brno and Znojmo (dry areas) shows increasing threat of soils by wind erosion, the contrary situation is at the humid area (Telč). The results prove the influence of soil humidity on the erosive-climatological factor and hereby the influence on wind erosion spreadout.

scholarly journals Assessment of the Potential Risk of Rock-Climbing for Cliff Plant Species and Natural Protected Areas of Spain

2021 ◽  
Vol 9 ◽  
Author(s):  
Indradatta deCastro-Arrazola ◽  
Martí March-Salas ◽  
Juan Lorite
Keyword(s):  
Protected Areas ◽  
Plant Species ◽  
Potential Risk ◽  
Field Studies ◽  
Rock Climbing ◽  
Future Research ◽  
Small Scale ◽  
Potential Threat ◽  
Natural Protected Areas ◽  
Priority Species

In recent years, the popularity of rock-climbing has grown tremendously, setting an increasing pressure on cliff habitats. Climbing may be particularly harmful in the Mediterranean biome due to its appropriate environmental conditions for climbing. A few studies have identified the effect of climbing on plant diversity at a small-scale (namely locally or even just in specific climbing areas). However, no studies exist assessing the potential risk of rock-climbing on a broad-scale (e.g., regional or national). The study aims to identify the priority locations and priority cliff plant species in Spain to focus future study efforts. Spain was selected because it is a plant biodiversity hotspot, with a great diversity of endemic and endangered species, and one of the most popular destinations for climbers. We used a geographic information system-based approach to model the spatial concurrence among Spanish climbing areas (and climbing intensity), natural protected areas (NPAs), and distribution of threatened cliff plants (and their IUCN threat category). We found that 53.5% of climbing areas in Spain are located within a NPA, most of them falling into NPAs of medium protection level. We mapped 151 threatened cliff plants, identifying four medium priority Mediterranean locations and eight priority species in which future research efforts should be focused. High-priority study locations are absent in Spain according to our spatial modeling. For the first time on a national scale, this study identifies areas in which climbing represents a potential threat for cliff habitats and threatened plants. These findings contribute to designing field studies on the effects of rock-climbing on Mediterranean cliffs, laying the groundwork for a sustainable, yet challenging, balance between the protection of these unique habitats and rock-climbing.

scholarly journals Molecular Characterization of a Begomovirus, α-Satellite, and β-Satellite Associated with Leaf Curl Disease of Parthenium hysterophorus in India

Plant Disease ◽  
2016 ◽  
Vol 100 (11) ◽  
pp. 2299-2305 ◽  
Author(s):  
Susheel Kumar ◽  
Ashish Srivastava ◽  
Meraj Jaidi ◽  
Puneet Singh Chauhan ◽  
S. K. Raj
Keyword(s):  
Satellite Dna ◽  
Rolling Circle Amplification ◽  
Tomato Leaf ◽  
Parthenium Hysterophorus ◽  
Alternate Host ◽  
Invasive Weed ◽  
Tomato Leaf Curl Disease ◽  
Tomato Leaf Curl ◽  
Leaf Curl Disease ◽  
Leaf Curl

Parthenium hysterophorus plants exhibiting severe leaf curl and stunting symptoms were observed near agriculture fields in Lucknow, India. The association of a begomovirus, β-satellite, and α-satellite with these symptoms of a Parthenium disease was investigated by sequence analyses of virus and satellite DNA amplified by rolling circle amplification and polymerase chain reaction. The highest sequence identities and closest phylogenetic relationships for the begomovirus, β-satellite, and α-satellite detected in P. hysterophorus plants were to Tomato leaf curl virus (ToLCV), papaya leaf curl β-satellite (PaLCuB), and Ageratum yellow vein India α-satellite (AYVIA), respectively. These findings identified the virus and satellites infecting the Parthenium sp. as ToLCV, PaLCuB, and AYVIA, respectively. P. hysterophorus and tomato seedlings infected with cloned ToLCV, PaLCuB, and AYVIA by agroinoculation developed leaf curl symptoms, whereas plants infected with ToLCV alone or with ToLCV and AYVIA developed mild yellowing. The results show that this complex infects and causes disease in P. hysterophorus and tomato. P. hysterophorus is an invasive weed commonly found around agricultural fields and along roadsides in India. These results indicate that P. hysterophorus plants infected with ToLCV and associated satellite DNA act as an alternate host (reservoir), and that could lead to increased incidence of tomato leaf curl disease.

A thermal analysis of a sub-surface, vertical flow constructed wetland

1997 ◽  
Vol 35 (5) ◽  
pp. 55-62 ◽  
Author(s):  
Ian D. Smith ◽  
George N. Bis ◽  
Edgar R. Lemon ◽  
Lloyd R. Rozema
Keyword(s):  
Thermal Energy ◽  
Constructed Wetland ◽  
Transport Model ◽  
Thermal Design ◽  
Sensitivity Analyses ◽  
Municipal Sewage ◽  
Deep Soil ◽  
Design Assessment ◽  
South Central ◽  
Thermal Data

Since November of 1991, an experimental constructed wetland has successfully treated municipal sewage effluent on a year round basis in a cool climate. The sub-surface, vertically pulsed flow system is located at a latitude of approximately 43 degrees, 15 minutes north latitude in south-central Canada. The 5 metre long by 5 metre wide by 1.2 metre deep constructed wetland cells were designed to operate through extended freezing periods via a number of specific features. The most important features being the allowance of thatch accumulation atop the system, ice accretion within the upper cell strata both acting as insulating layers, and the transfer of thermal energy to the system from warmer deep soils. The cells were hydraulically loaded below this frozen layer of granular matrix six times a day. A dense three dimensional array of thermocouples was planted within the first of the three constructed wetland cells in a series to allow for the assessment of thermal data at a high level of temporal and spatial resolution. Thermal data were sampled every five minutes and averaged and stored every hour over a two year period (1994 and 1995). The data were reviewed statistically to determine the operating envelope experienced at the Niagara-On-The-Lake experimental constructed wetland site. A detailed review of winter thermal data was made to provide parameters for the use of the HEATFLOW density-dependent ground water flow and thermal energy transport numerical model (Molson and Frind, 1995). The use of this coupled Darcy flux, thermal transport model has allowed for a better understanding of the importance of various thermal design considerations, and has allowed for the undertaking of sensitivity analyses for design assessment and optimization. The sensitivity analyses indicate that the retention of deep soil heat and top insulation from plant thatch are the most important thermal features. It is likely that this technology can be used in areas colder than Niagara-On-The-Lake.

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