scholarly journals Patchy Invasion of Stage-Structured Alien Species with Short-Distance and Long-Distance Dispersal

2015 ◽  
Vol 77 (8) ◽  
pp. 1583-1619 ◽  
Author(s):  
Luiz Alberto Díaz Rodrigues ◽  
Diomar Cristina Mistro ◽  
Elisa Regina Cara ◽  
Natalia Petrovskaya ◽  
Sergei Petrovskii
Keyword(s):  
Alien Species ◽  
Short Distance ◽  
Long Distance Dispersal ◽  
Long Distance

scholarly journals Measuring short distance dispersal of Alliaria petiolata and determining potential long distance dispersal mechanisms

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4477 ◽  
Author(s):  
Christopher A. Loebach ◽  
Roger C. Anderson
Keyword(s):  
Seed Dispersal ◽  
Point Source ◽  
Short Distance ◽  
Alliaria Petiolata ◽  
Point Sources ◽  
Wire Mesh ◽  
Long Distance Dispersal ◽  
Long Distance ◽  
Seed Point ◽  
Dispersal Distances

Introduction Alliaria petiolata, an herbaceous plant, has invaded woodlands in North America. Its ecology has been thoroughly studied, but an overlooked aspect of its biology is seed dispersal distances and mechanisms. We measured seed dispersal distances in the field and tested if epizoochory is a potential mechanism for long-distance seed dispersal. Methods Dispersal distances were measured by placing seed traps in a sector design around three seed point sources, which consisted of 15 second-year plants transplanted within a 0.25 m radius circle. Traps were placed at intervals ranging from 0.25–3.25 m from the point source. Traps remained in the field until a majority of seeds were dispersed. Eight probability density functions were fitted to seed trap counts via maximum likelihood. Epizoochory was tested as a potential seed dispersal mechanism for A. petiolata through a combination of field and laboratory experiments. To test if small mammals transport A. petiolata seeds in their fur, experimental blocks were placed around dense A. petiolata patches. Each block contained a mammal inclusion treatment (MIT) and control. The MIT consisted of a wood-frame (31 × 61× 31 cm) covered in wire mesh, except for the two 31 × 31 cm ends, placed over a germination tray filled with potting soil. A pan filled with bait was placed in the center of the tray. The control frame (11 × 31 × 61 cm) was placed over a germination tray and completely covered in wire mesh to exclude animal activity. Treatments were in the field for peak seed dispersal. In March, trays were moved to a greenhouse and A. petiolata seedlings were counted and then compared between treatments. To determine if A. petiolata seeds attach to raccoon (Procyon lotor) and white-tailed deer (Odocoileus virginianus) fur, wet and dry seeds were dropped onto wet and dry fur. Furs were rotated 180 degrees and the seeds that remained attached were counted. To measure seed retention, seeds were dropped on furs and rotated as before, then the furs were agitated for one hour. The seeds retained in the fur were counted. Results For the seed dispersal experiment, the 2Dt function provided the best fit and was the most biologically meaningful. It predicted that seed density rapidly declined with distance from the point source. Mean dispersal distance was 0.52 m and 95% of seeds dispersed within 1.14 m. The epizoochory field experiment showed increased mammal activity and A. petiolata seedlings in germination trays of the MIT compared to control. Laboratory studies showed 3–26% of seeds were attached and retained by raccoon and deer fur. Retention significantly increased if either seed or fur were wet (57–98%). Discussion Without animal seed vectors, most seeds fall within a short distance of the seed source; however, long distance dispersal may be accomplished by epizoochory. Our data are consistent with A. petiolata’s widespread distribution and development of dense clusters of the species in invaded areas.

Roads Accelerate the Invasion Process of Alien Species

2011 ◽  
Vol 347-353 ◽  
pp. 1483-1487
Author(s):  
Hua Chen ◽  
Jian Liu ◽  
Tong Xue ◽  
Ren Qing Wang
Keyword(s):  
Alien Species ◽  
Human Activities ◽  
Native Species ◽  
Economic Loss ◽  
Global Changes ◽  
Invasion Process ◽  
Long Distance Dispersal ◽  
Long Distance ◽  
Human Disturbances ◽  
Considerable Economic Loss

Biological invasions have been identified as one of the human-induced global changes, which not only threaten native biodiversity but also cause a considerable economic loss both globally and locally. The long distance dispersal of alien species is often facilitated by human activities and disturbances. This paper summarized lots of paper to explain how road affect the local biodiversity and accelerate the invasion process of alien species. We discuss several aspects to clarify this issue: the impacts of roads affect the alien and native species in new regions, environmental conditions near roads affect the effect of roads, the effects of roads on alien species in high altitude regions, the effects of roads on different propagation manner of alien species and at last the fast growth of road length and alien species in China. Human disturbances promote the performance and abundance of alien species in new regions, and roads as one key of human disturbances act as corridors for the flow of alien propagules and seeds into new landscapes and ultimately accelerate the invasion process of alien species.

scholarly journals Biphasic range expansions with short- and long-distance dispersal

2021 ◽  
Author(s):  
Benjamin R. Liu
Keyword(s):  
Invasive Species ◽  
Mathematical Models ◽  
Short Distance ◽  
Initial Phase ◽  
Long Distance Dispersal ◽  
Long Distance ◽  
Integrodifference Equation ◽  
Key Factor ◽  
Heavy Tailed ◽  
Dispersal Kernels

AbstractLong-distance dispersal (LDD) has long been recognized as a key factor in determining rates of spread in biological invasions. Two approaches for incorporating LDD in mathematical models of spread are mixed dispersal and heavy-tailed dispersal. In this paper, I analyze integrodifference equation (IDE) models with mixed-dispersal kernels and fat-tailed (a subset of the heavy-tailed class) dispersal kernels to study how short- and long-distance dispersal contribute to the spread of invasive species. I show that both approaches can lead to biphasic range expansions, where an invasion has two distinct phases of spread. In the initial phase of spread, the invasion is controlled by short-distance dispersal. Long-distance dispersal boosts the speed of spread during the ultimate phase, and can have significant effects even when the probability of LDD is vanishingly small. For fat-tailed kernels, I introduce a method of characterizing the “shoulder” of a dispersal kernel, which separates the peak and tail.

scholarly journals K → μ+μ− as a clean probe of short-distance physics

2021 ◽  
Vol 2021 (7) ◽  
Author(s):  
Avital Dery ◽  
Mitrajyoti Ghosh ◽  
Yuval Grossman ◽  
Stefan Schacht
Keyword(s):  
Matrix Element ◽  
Standard Model ◽  
Short Distance ◽  
Time Dependent ◽  
Final States ◽  
Interference Effects ◽  
Fundamental Theory ◽  
Long Distance ◽  
Ckm Matrix ◽  
The Standard Model

Abstract The K → μ+μ− decay is often considered to be uninformative of fundamental theory parameters since the decay is polluted by long-distance hadronic effects. We demonstrate that, using very mild assumptions and utilizing time-dependent interference effects, ℬ(KS → μ+μ−)ℓ=0 can be experimentally determined without the need to separate the ℓ = 0 and ℓ = 1 final states. This quantity is very clean theoretically and can be used to test the Standard Model. In particular, it can be used to extract the CKM matrix element combination $$ \mid {V}_{ts}{V}_{td}\sin \left(\beta +{\beta}_s\right)\mid \approx \mid {A}^2{\lambda}^5\overline{\eta}\mid $$ ∣ V ts V td sin β + β s ∣ ≈ ∣ A 2 λ 5 η ¯ ∣ with hadronic uncertainties below 1%.

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