scholarly journals Stochastic flowering phenology in Dactylis glomerata populations described by Markov chain modelling

Aerobiologia ◽  
2021 ◽  
Author(s):  
Carl A. Frisk ◽  
Beverley Adams-Groom ◽  
Carsten A. Skjøth
Keyword(s):  
Markov Chain ◽  
Temporal Dynamics ◽  
Dactylis Glomerata ◽  
Flowering Plants ◽  
Grass Species ◽  
Distribution Ranges ◽  
Full Flowering ◽  
Pollen Release ◽  
Markov Chain Modelling ◽  
Flowering Process

AbstractUnderstanding the relationship between flowering patterns and pollen dispersal is important in climate change modelling, pollen forecasting, forestry and agriculture. Enhanced understanding of this connection can be gained through detailed spatial and temporal flowering observations on a population level, combined with modelling simulating the dynamics. Species with large distribution ranges, long flowering seasons, high pollen production and naturally large populations can be used to illustrate these dynamics. Revealing and simulating species-specific demographic and stochastic elements in the flowering process will likely be important in determining when pollen release is likely to happen in flowering plants. Spatial and temporal dynamics of eight populations of Dactylis glomerata were collected over the course of two years to determine high-resolution demographic elements. Stochastic elements were accounted for using Markov chain approaches in order to evaluate tiller-specific contribution to overall population dynamics. Tiller-specific developmental dynamics were evaluated using three different RV matrix correlation coefficients. We found that the demographic patterns in population development were the same for all populations with key phenological events differing only by a few days over the course of the seasons. Many tillers transitioned very quickly from non-flowering to full flowering, a process that can be replicated with Markov chain modelling. Our novel approach demonstrates the identification and quantification of stochastic elements in the flowering process of D. glomerata, an element likely to be found in many flowering plants. The stochastic modelling approach can be used to develop detailed pollen release models for Dactylis, other grass species and probably other flowering plants.

Influence of neighbors on node production, stolon growth, and branching of Trifolium repens transplants in a pasture

1993 ◽  
Vol 71 (9) ◽  
pp. 1266-1269 ◽  
Author(s):  
Roy Turkington ◽  
Elena Klein
Keyword(s):  
Trifolium Repens ◽  
Maximum Rate ◽  
Light Quality ◽  
Dactylis Glomerata ◽  
Phleum Pratense ◽  
Grass Species ◽  
Holcus Lanatus ◽  
Subsequent Growth ◽  
Local Environments ◽  
Trifolium Repens L

Ten individual plants of Trifolium repens L. were transplanted into a 49-year-old cattle pasture in British Columbia. They were protected from grazing and their subsequent growth was monitored at 2- to 3-week intervals throughout the summer from May to October. The rate of stolon elongation was greatest (2.01 cm ∙ week−1) in late July and a maximum rate of node production (1.48 new nodes per stolon ∙ week−1) occurred in early August. As stolons extended through the pasture they encountered a number of different grass species: Dactylis glomerata, Holcus lanatus, Lolium perenne, Phleum pratense, and Poa spp. The stolons grew through a total of 2 m of H. lanatus neighborhood and produced only 3 branches, whereas they produced 11 branches in only 57.2 cm of P. pratense neighborhood. Neighboring grasses impose different local environments on the nodes and stolons of T. repens and consequently influence the dynamics of node production, the rate of stolon elongation, and the amount of stolon branching. Key words: stolon branching, neighbors, light quality, Trifolium repens.

scholarly journals Diversity of Angiospermic Plants in estuarine and Adjoining Riparian Areas of Sabarmati and Mahi Rivers, Gujarat, India

2020 ◽  
pp. 116-124
Author(s):  
Raj B. Patel ◽  
Ketan Tatu ◽  
R. D. Kamboj
Keyword(s):  
Tree Species ◽  
Flowering Plants ◽  
Grass Species ◽  
Riparian Zones ◽  
Ecological Groups ◽  
View Point ◽  
Riparian Areas ◽  
Shrub Species ◽  
Religious Importance ◽  
Herb Species

The present study was conducted with an aim of documenting the diversity of flowering plants in selected localities in the estuarine and adjoining riparian zones of Sabarmati and Mahi rivers of Gujarat, India. The Sabarmati and Mahi rivers are west-flowing perennial rivers having considerable ecological and religious importance. A total of 40 species of flowering plants belonging to 26 different families were recorded in the study area which were dominated by herbaceous plants. Among the 40 species recorded 2 species were trees, 8 species were shrubs, 28 species were herbs and 2 species were grasses. Moreover, as far as ecological groups are concerned, 6 species were halophytes, 13 species were hydrophytes, 17 species were mesophytes and 4 species were xerophytes. In the study area of Sabarmati river, 28 species were recorded that included 2 tree species, 6 shrub species, 18 herb species and 2 grass species. From the view point of ecological groups 5 species were halophytes, 3 species were hydrophytes, 16 species were mesophytes and 4 species were xerophytes. In the study area of Mahi river, 24 species were recorded that included 2 tree species, 6 shrub species, 14 herb species and 2 grass species. From the view point of ecological groups 5 species were halophytes, 12 species were hydrophytes, 5 species were mesophytes and 2 species were xerophytes.

scholarly journals The search for alternative temperate perennial pasture species for low to medium rainfall environments in Tasmania

2016 ◽  
Vol 16 ◽  
pp. 275-279
Author(s):  
E.J. Hall ◽  
R. Reid ◽  
B. Clark ◽  
R. Dent
Keyword(s):  
Perennial Grass ◽  
Dactylis Glomerata ◽  
Red Clover ◽  
Perennial Grasses ◽  
Grass Species ◽  
Sheep Grazing ◽  
Cool Temperate ◽  
Perennial Legume ◽  
Perennial Legumes ◽  
Pasture Plants

In response to the need to find better adapted and more persistent perennial pasture plants for the dryland pastures in the cool-temperate low to medium rainfall (500-700 mm) regions, over 1000 accessions representing 24 species of perennial legumes and 64 species of perennial grasses, were introduced, characterised and evaluated for production and persistence under sheep grazing at sites throughout Tasmania. The work has identified four alternative legume species in Talish Clover (Trifolium tumens). Caucasian Clover (T. ambiguum), Stoloniferous Red Clover (T. pratense var. stoloniferum), Lucerne x Yellow Lucerne Hybrid (Medicago sativa x M.sativa subsp. falcata); and two grass species in Coloured Brome (Bromus coloratus) and Hispanic Cocksfoot (Dactylis glomerata var hispanica). Keywords: persistence, perennial grass, perennial legume

scholarly journals Can pasture persistence be improved through the use of nonryegrass species?

2011 ◽  
Vol 15 ◽  
pp. 157-162
Author(s):  
G.D. Milne
Keyword(s):  
New Zealand ◽  
Water Temperature ◽  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Tall Fescue ◽  
Festuca Arundinacea ◽  
Dactylis Glomerata ◽  
Grass Species ◽  
Nutrient Deficiencies ◽  
Recent Discussion

Recent discussion about pasture persistence concentrates on pastures based on perennial ryegrass, the most commonly used grass species. This paper raises the question as to whether some of the causes of poor pasture persistence are due to perennial ryegrass being used in environments to which it is not suited. The adaptation to environmental stresses, particularly water, temperature and nutrient deficiencies, in different regions of New Zealand of tall fescue, cocksfoot, phalaris, and lucerne are discussed, and how this impacts on persistence advantages over perennial ryegrass. Keywords: persistence, pasture, Dactylis glomerata, Festuca arundinacea, Lolium perenne, Medicago sativa, Phalaris aquatica

Spatiotemporal patterns of alcohol outlets and violence: A spatially heterogeneous Markov chain analysis

2020 ◽  
pp. 239980832096556
Author(s):  
Ran Wei ◽  
Tony H Grubesic ◽  
Wei Kang
Keyword(s):  
Markov Chain ◽  
Policy Development ◽  
Temporal Dynamics ◽  
Local Level ◽  
Public Health Problem ◽  
The United States ◽  
Alcohol Outlet ◽  
Alcohol Outlets ◽  
Spatial And Temporal Dynamics ◽  
Outlet Density

Alcohol-related violence remains a serious social and public health problem in the United States. A large corpus of work suggests a positive statistical relationship between alcohol outlet density and violence. However, questions remain as to how neighborhood violence evolves in response to varying access to alcohol outlets. This paper introduces an approach for analyzing the spatial and temporal dynamics of violence and its association with alcohol outlets by embedding the evolution of assault events and outlet density within a spatially heterogeneous Markov chain framework. This framework enables the exploration of spatiotemporal dynamics of alcohol outlets and violence and controls for potentially confounding impacts and spatial heterogeneity. Using a case study at the block group level in Seattle, Washington, the results of this paper suggest that violence is spatially heterogeneous at the local level and locations with sparsely distributed alcohol outlets are less likely to see an increase in violence when compared to areas with higher densities of outlets. Further, the modeling approach helps identify locations that might “tip” into more violent conditions if more outlets were allowed to operate. This paper concludes with a brief discussion of how the methods and results can help improve the management, licensing, and policy development for alcohol outlets in a community.

scholarly journals Predicting Customer Churn and Retention Rates in Nigeria’s Mobile Telecommunication Industry Using Markov Chain Modelling

2015 ◽  
Vol 3 (1) ◽  
pp. 67-80 ◽  
Author(s):  
Sulaimon Olanrewaju Adebiyi ◽  
Emmanuel Olateju Oyatoye ◽  
Joseph Nnamdi Mojekwu
Keyword(s):  
Markov Chain ◽  
Retention Rate ◽  
Secondary Data ◽  
Developed Countries ◽  
Service Industries ◽  
Retention Rates ◽  
Telecommunication Industry ◽  
Mobile Telecommunication ◽  
Customer Churn ◽  
Markov Chain Modelling

AbstractThe telecommunication industry is one of the service industries that is most affected by the problem of subscribers’ churn. Although several techniques have been used to predict customer churn in developed countries, many of those studies used secondary data which are not readily available in Nigeria for researchers. This study investigates how Markov chains help in modelling and predicting the customer churn and retention rate in the Nigerian mobile telecommunication industry. The data generated through the survey were input in the Windows-based Quantitative System for Business (WinQSB) for analysis. The results reveal that in the study area MTN has the highest retention rate (86.11%), followed by GLO (70.51%), Airtel (67%), and Etisalat (67.5%). This result has implications for telecom firms’ strategies for competitive advantage in particular and survival in general.

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