scholarly journals Assessing ecological uncertainty and simulation model sensitivity to evaluate an invasive plant species’ potential impacts to the landscape

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Catherine S. Jarnevich ◽  
Nicholas E. Young ◽  
Catherine Cullinane Thomas ◽  
Perry Grissom ◽  
Dana Backer ◽  
...  
Keyword(s):  
Simulation Model ◽  
Native Species ◽  
National Park ◽  
Invasive Plant ◽  
Conservation Management ◽  
Fire Behavior ◽  
Simulation Models ◽  
Parameter Uncertainties ◽  
Model Uncertainties ◽  
Model Initialization

Abstract Ecological forecasts of the extent and impacts of invasive species can inform conservation management decisions. Such forecasts are hampered by ecological uncertainties associated with non-analog conditions resulting from the introduction of an invader to an ecosystem. We developed a state-and-transition simulation model tied to a fire behavior model to simulate the spread of buffelgrass (Cenchrus ciliaris) in Saguaro National Park, AZ, USA over a 30-year period. The simulation models forecast the potential extent and impact of a buffelgrass invasion including size and frequency of fire events and displacement of saguaro cacti and other native species. Using simulation models allowed us to evaluate how model uncertainties affected forecasted landscape outcomes. We compared scenarios covering a range of parameter uncertainties including model initialization (landscape susceptibility to invasion) and expert-identified ecological uncertainties (buffelgrass patch infill rates and precipitation). Our simulations showed substantial differences in the amount of buffelgrass on the landscape and the size and frequency of fires for dry years with slow patch infill scenarios compared to wet years with fast patch infill scenarios. We identified uncertainty in buffelgrass patch infill rates as a key area for research to improve forecasts. Our approach could be used to investigate novel processes in other invaded systems.

scholarly journals SEBARAN POPULASI Cobaea scandens CAV. SEBAGAI TUMBUHAN INVASIF DI KEBUN RAYA CIBODAS DAN SEKITARNYA

2019 ◽  
Vol 12 (1) ◽  
pp. 103-111
Author(s):  
Muhammad Efendi ◽  
Muhamad Muhaimin ◽  
Dadang Suherman
Keyword(s):  
Native Species ◽  
National Park ◽  
Invasive Plant ◽  
Population Distribution ◽  
Botanical Garden ◽  
Survey Method ◽  
Open Area ◽  
Purposive Sampling ◽  
Remnant Forest ◽  
Eradication Effort

AbstrakCobaea scandens Cav. (Polemoniaceae) merupakan tumbuhan riparian dari Meksiko yang telah lama ditanam di Kebun Raya Cibodas (KRC). Jenis tersebut dilaporkan sebagai tumbuhan invasif di beberapa negara. Sebagai tumbuhan invasif, jenis tersebut dapat mengancam ekosistem sekitar sehingga pertumbuhannya perlu dikendalikan. Meskipun demikian, informasi mengenai keberadaannya di KRC dan sekitarnya masih sedikit. Oleh karena itu, dalam makalah ini diuraikan mengenai sebaran populasi di kawasan KRC dan sekitarnya, dalam rangka mencari rekomendasi yang tepat dalam upaya pengendaliannya. Pengamatan dilakukan menggunakan metode survei dengan pengambilan sampel secara purposive sampling, terutama di kawasan riparian dan hutan restan KRC dan Taman Nasional Gunung Gede Pangrango (TNGGP). Hasilnya, terdapat sembilan titik populasi C. scandens terutama di Sungai Ciwalen yang juga melintasi TNGGP. Secara ekologi, C. scandens tumbuh pada habitat yang terbuka hingga sedikit naungan, daerah yang basah, di tepian sungai dan hutan restan pada ketinggian 1.255 hingga 1.425 mdpl. Cobaea scandens tumbuh memanjat pada pohon tegakan atau semak dan membentuk tutupan yang lebat di atas permukan tumbuhan bawah, sehingga dapat mengancam tumbuhan lokal di kawasan tersebut. Dari hasil yang diperoleh, rekomendasi yang disarankan adalah melakukan eradikasi secara mekanis, terutama sebelum musim buah terjadi,untuk menurunkan kelimpahan jenis dan mencegah proses regenerasinya dapat terjadi. Abstract Cobaea scandens Cav. (Polemoniaceae), anriparian species from Mexico, were cultivated in Cibodas Botanical Garden (CBG) for a long years ago. This species was reported as invasive species in several countries. As an invasive plant, this species can be threaten the surrounding ecosystem, so the growth need to be controlled. However, there is a few information of this species in CBG and its surrounding. Therefore, this paper described the population distribution of C. scandens at CBG and its surroundings, in order to find appropriate recommendation for the control efforts. Observation was conducted by survey method with purposive sampling, especially riparian and remnant forest areas. Based on our observations showed that C. scandens is fast growing on opens habitats to slighty shade, with high humidity. At least, there are nine population plot of C. scandens especially in the Ciwalen River, which also crosses in National Park of Mt. Gede Pangrango (TNGGP) areas. Ecologically, C. scandens grows in open area or slightly shaded, wet, in river banks and remnant forest at 1,255 to 1,425 masl. They can climb a tree or shrubs and forming a dense canopy over understorey, to threaten native species in thus area. From the results, a mechanical eradication effort need to be carried out, especially before fruiting season, to reduce their abundance and prevent the regeneration process from occured.

scholarly journals Guidelines to Calibrate a Multi-Residential Building Simulation Model Addressing Overheating Evaluation and Residents’ Influence

Buildings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 242
Author(s):  
Christoph Schünemann ◽  
David Schiela ◽  
Regine Ortlepp
Keyword(s):  
Simulation Model ◽  
Time Window ◽  
Residential Building ◽  
Simulation Models ◽  
Building Simulation ◽  
Night Time ◽  
Building Performance Simulation ◽  
Starting Point ◽  
3D Simulation Model ◽  
Building Physics

Can building performance simulation reproduce measured summertime indoor conditions of a multi-residential building in good conformity? This question is answered by calibrating simulated to monitored room temperatures of several rooms of a multi-residential building for an entire summer in two process steps. First, we did a calibration for several days without the residents being present to validate the building physics of the 3D simulation model. Second, the simulations were calibrated for the entire summer period, including the residents’ impact on evolving room temperature and overheating. As a result, a high degree of conformity between simulation and measurement could be achieved for all monitored rooms. The credibility of our results was secured by a detailed sensitivity analysis under varying meteorological conditions, shading situations, and window ventilation or room use in the simulation model. For top floor dwellings, a high overheating intensity was evoked by a combination of insufficient use of night-time window ventilation and non-heat-adapted residential behavior in combination with high solar gains and low heat storage capacities. Finally, the overall findings were merged into a process guideline to describe how a step-by-step calibration of residential building simulation models can be done. This guideline is intended to be a starting point for future discussions about the validity of the simplified boundary conditions which are often used in present-day standard overheating assessment.

The Biology of Invasive Alien Plants in Canada. 4. Heracleum mantegazzianum Sommier & Levier

2006 ◽  
Vol 86 (2) ◽  
pp. 569-589 ◽  
Author(s):  
Nicholas A. Page ◽  
Ronald E. Wall ◽  
Stephen J. Darbyshire ◽  
Gerald A. Mulligan
Keyword(s):  
British Columbia ◽  
Urban Areas ◽  
Native Species ◽  
Invasive Plant ◽  
Leaf Shape ◽  
Herbarium Specimens ◽  
Natural Ecosystems ◽  
Alien Plant ◽  
Invasive Alien Plant ◽  
Heracleum Mantegazzianum

Heracleum mantegazzianum (giant hogweed) is an invasive alien plant of management concern in southern Canada where it has escaped from horticulture and established and spread in natural, ruderal, and agricultural ecosystems. It poses a threat to natural ecosystems and human health, and is also a weed in agricultural and urban areas. It is a member of the Carrot family (Apiaceae) and is closely related to the native species Heracleum maximum Bartram (cow-parsnip). It is a monocarpic perennial, which generally flowers in its 3rd or 4th year. Large size, leaf shape, dark reddish pigments in patches on stems and petioles, and fruit characteristics readily distinguish H. mantegazzianum from other plants in Canada. It is increasingly common in riparian areas, floodplains, and forest edges in or near urban areas in southwestern British Columbia and southern Ontario. Based on herbarium specimens, H. mantegazzianum was first recorded in Ontario in 1949, British Columbia in 1964, Nova Scotia in 1980, Quebec in 1990, and New Brunswick in 2000. The development of dense stands of H. mantegazzianum can also reduce the richness of native plants. Contact with H. mantegazzianum can cause phytophotodermatitis, a serious skin inflammation caused by UV photo-activation of furanocoumarins present in the sap. Control methods include herbicide application, mechanical cutting, and animal grazing, but strategies to address seed dispersal and re-establishment from dormant seed must also be adopted. Widespread establishment in southern Canada suggests that eradication is unlikely. However, range expansion and rapid population growth can be prevented through strategic management including public education. Key words: Giant hogweed, Heracleum mantegazzianum, Apiaceae, HERMZ, invasive plant, weed biology, furanocoumarins

Settings, Experimentation and Evaluation of the Simulation Models

2013 ◽  
Vol 309 ◽  
pp. 366-371 ◽  
Author(s):  
František Manlig ◽  
Radek Havlik ◽  
Alena Gottwaldova
Keyword(s):  
Simulation Model ◽  
New Technology ◽  
Simulation Models ◽  
Manufacturing Processes ◽  
Customer Requirements ◽  
Evaluation Functions ◽  
Operational Management ◽  
Minimum Number ◽  
User Friendly ◽  
Setting Parameters

This paper deals with research in computer simulation of manufacturing processes. The paper summarizes the procedures associated with developing the model, experimenting with and evaluating the model results. The key area is of experimentation with the simulation model and evaluation using indicators or multi-criteria functions. With regards to the experiment the crucial variables are the simulation model. The key ideas are to set the number of variables, depending on what a given simulation will be. For example, when introducing new technology into production, modify the type of warehouse, saving workers, thus economizing. The simulation models for the operational management uses simplified models, if possible, a minimum number of variables to obtain the result in shortest possible time. These models are more user friendly and the course will be conducted mostly in the background. An example of a criteria function is the number of parts produced or production time. Multi-criteria function has given us the opportunity to make better quality decisions. It is based on the composition of several parameters, including their weight to one end point. The type of evaluation functions, whether it is an indicator or criteria function is selected and based on customer requirements. In most cases it is recommended to use the multi-dimensional function. It gives us a more comprehensive view of the results from the model and facilitates decision-making. The result of this paper is a display of setting parameters for the experimentation on a sample model. Furthermore, the comparisons of results with a multi-criteria objective function and one-criterion indicator.

A Method to Define the Best Weld Sequence Using a Limited Number of Welding Simulation Analysis

2015 ◽  
Author(s):  
Mahyar Asadi ◽  
Ghazi Alsoruji
Keyword(s):  
Simulation Model ◽  
Surrogate Model ◽  
Simulation Analysis ◽  
Combinatorial Problem ◽  
Fem Analysis ◽  
Simulation Models ◽  
Computational Time ◽  
Optimal Sequence ◽  
Welded Structure ◽  
Welding Sequence

Weld sequence optimization, which is determining the best (and worst) welding sequence for welding work pieces, is a very common problem in welding design. The solution for such a combinatorial problem is limited by available resources. Although there are fast simulation models that support sequencing design, still it takes long because of many possible combinations, e.g. millions in a welded structure involving 10 passes. It is not feasible to choose the optimal sequence by evaluating all possible combinations, therefore this paper employs surrogate modeling that partially explores the design space and constructs an approximation model from some combinations of solutions of the expensive simulation model to mimic the behavior of the simulation model as closely as possible but at a much lower computational time and cost. This surrogate model, then, could be used to approximate the behavior of the other combinations and to find the best (and worst) sequence in terms of distortion. The technique is developed and tested on a simple panel structure with 4 weld passes, but essentially can be generalized to many weld passes. A comparison between the results of the surrogate model and the full transient FEM analysis all possible combinations shows the accuracy of the algorithm/model.

Rotorcraft Lateral-Directional Oscillations: The Anatomy of a Nuisance Mode

2021 ◽  
Author(s):  
Dheeraj Agarwal ◽  
Linghai Lu ◽  
Gareth D. Padfield ◽  
Mark D. White ◽  
Neil Cameron
Keyword(s):  
Simulation Model ◽  
Simulation Models ◽  
Flight Test ◽  
Flight Simulation ◽  
Stability And Control ◽  
Systems Research ◽  
Control Derivatives ◽  
Research Aircraft ◽  
Level Of Understanding ◽  
And Control

High-fidelity rotorcraft flight simulation relies on the availability of a quality flight model that further demands a good level of understanding of the complexities arising from aerodynamic couplings and interference effects. One such example is the difficulty in the prediction of the characteristics of the rotorcraft lateral-directional oscillation (LDO) mode in simulation. Achieving an acceptable level of the damping of this mode is a design challenge requiring simulation models with sufficient fidelity that reveal sources of destabilizing effects. This paper is focused on using System Identification to highlight such fidelity issues using Liverpool's FLIGHTLAB Bell 412 simulation model and in-flight LDO measurements from the bare airframe National Research Council's (Canada) Advanced Systems Research Aircraft. The simulation model was renovated to improve the fidelity of the model. The results show a close match between the identified models and flight test for the LDO mode frequency and damping. Comparison of identified stability and control derivatives with those predicted by the simulation model highlight areas of good and poor fidelity.

scholarly journals Distribution of Blue Bull (Boselaphus tragocamelus) and its Conservation Threats in Bardia National Park, Nepal

2020 ◽  
Vol 2 (1) ◽  
pp. 50-60
Author(s):  
Pramila Koirala ◽  
Bijaya Neupane ◽  
Thakur Silwal ◽  
Bijaya Dhami ◽  
Siddhartha Regmi ◽  
...  
Keyword(s):  
National Park ◽  
Habitat Management ◽  
Invasive Plant ◽  
Flash Flood ◽  
Local Level ◽  
Buffer Zone ◽  
Grass Species ◽  
Zone Field ◽  
Conservation Threats ◽  
And Control

Blue bull is Asia’s largest antelope, a species of least concern in IUCN Red data list of 2020. In Nepal, it is vulnerable and is often considered as a problem animal for its crop raiding habit. Although, its population is restricted in India and Nepal, there are insufficient studies conducted on the distribution and threats of the species at local level. This study aimed to assess the distribution of blue bull and its conservation threats in Bardia National Park and its buffer zone. Field survey was carried out to identify the potential area with the information provided by park staff and buffer zone people and by the transect method in the selected habitat to determine the distribution of blue bull population. Additionally, six focus group discussions (1 in each of thefive sites and 1 with park staff) and a half-day workshop (involving 25 participants representing each site and park office) were organized to assess the existing threats to the species. Data were analyzed descriptively using MS Excel, while the distribution map was prepared using Arc GIS. Also, 8 major identified threats were ranked using relative threat ranking procedure and classified into four severity classes. We found that the population of blue bull was dispersed from core area of Bardia National Park towards the buffer zone area. Open grazing, invasive species, predation by tiger and flash flood were the major threats to the blue bull as perceived by the local people. Habitat management activities including control of grazing, removal of invasive plant species, plantation of palatable grass species, increase in other prey species of tiger and control of flood in blue bull’s habitats are recommended to protect the species and thus sustain their threatened population.

scholarly journals Penyebaran Jenis Jirak (Symplocos fasciculata Zoll.) di Resort Kawah Ratu Taman Nasional Gunung Halimun Salak, Jawa Barat

2021 ◽  
Vol 12 (1) ◽  
pp. 23-29
Author(s):  
Iwan Hilwan ◽  
Aldi Perdana Wiraatmadja
Keyword(s):  
Data Collection ◽  
Distribution Pattern ◽  
Native Species ◽  
National Park ◽  
Plant Parts

Jirak (Symplocos fasciculata Zoll.) is one of the native species in the Gunung Halimun Salak National Park, especially in the Kawah Ratu resort. This plant can be used as a natural coloring agent, in addition to plant parts such as leaves can also be eaten and used as medicine. Because of the benefits of jirak, this plant is considered important to be cultivated. This study aims to analyze the density and distribution pattern of jirak (Symplocos fasciculata Zoll.) at Kawah Ratu Resort, Gunung Halimun Salak National Park. Data collection was carried out in two blocks located at the Kawah Ratu Resort of Mount Halimun Salak National Park, namely the Leles block and the Pamengpeuk block using the single plot method. The results showed that jirak distribution pattern in the two observation blocks was grouped. Keywords: Distribution, Jirak, Kawah Ratu Resort, Symplocos fasciculata Zoll., Gunung Halimun Salak National Park

scholarly journals The pig of the Lençóis Maranhenses, first record of wild boar (Sus scrofa) in Maranhão State, Brazil

Check List ◽  
2019 ◽  
Vol 15 (4) ◽  
pp. 1-1
Author(s):  
Gilberto Nepomuceno Salvador ◽  
Nathali Garcia Ristau ◽  
Isabel Sanches da Silva ◽  
André Nunes
Keyword(s):  
Invasive Species ◽  
Wild Boar ◽  
Sus Scrofa ◽  
Native Species ◽  
National Park ◽  
First Record ◽  
Negative Effects ◽  
The World

The wild boar is one of the most dangerous invasive species. It is widespread in the world, including records for many Brazilian states. However, there is a lack of record from Maranhão state. In the present study, we reported a population of wild boar inside the Lençóis Maranhenses National Park, in Barrerinhas county, State of Maranhão. We discuss about the negative effects of this introduction on native species, including a record of predation by wild boar in nests of endangered turtles.

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