scholarly journals Seed-Dispersal Ability of the Invasive Perennial Vines Vincetoxicum nigrum and Vincetoxicum rossicum

2018 ◽  
Vol 11 (1) ◽  
pp. 10-19 ◽  
Author(s):  
Antonio DiTommaso ◽  
Courtney A. Stokes ◽  
Stéphane Cordeau ◽  
Lindsey R. Milbrath ◽  
Thomas H. Whitlow
Keyword(s):  
Wind Speed ◽  
Cropping Systems ◽  
Seed Mass ◽  
Dispersal Ability ◽  
Settling Rate ◽  
Long Distance Dispersal ◽  
Long Distance ◽  
Vincetoxicum Rossicum ◽  
Release Height ◽  
Source Populations

AbstractBlack swallowwort [Vincetoxicum nigrum (L.) Moench] and pale swallowwort [Vincetoxicum rossicum (Kleopow) Barb.] are perennial vines of European origin that invade natural areas and perennial cropping systems in the northeastern United States and southeastern Canada. Both species reproduce via wind-dispersed seeds in the form of achenes with comas, but little is known about the extent of dispersal of these seeds. We studied the relationship of seed release height (0.75 m, 2 m), wind speed at the time of release, seed mass, and settling rate on distance traveled. Vincetoxicum nigrum and V. rossicum seeds traveled up to 72.1 and 79.6 m, respectively. Seeds of both species released from 2 m traveled greater distances than seeds released from 0.75 m, which fell within 20 m of the release point. Release height was the most important factor influencing long-distance dispersal events. Wind speed also strongly interacted with release height for long-distance dispersal of V. nigrum. Vincetoxicum nigrum seed mass was greater and settling rates faster than for V. rossicum. Increasing seed mass generally increased settling rate, which in turn decreased distance traveled, except in V. rossicum, for which longer distance–dispersing seeds had a faster settling rate. Our findings suggest that management efforts focus on reducing the presence of these two vines, especially if there is potential for them to climb up taller vegetation such as trees. Seeds released from these greater heights are more likely to travel far from source populations and initiate new populations. Preventing seed production in small, nonclimbing patches will also help suppress the expansion of these two vines, as seeds can still disperse up to 20 m away from parent plants.

An unexpected new record of the Mediterranean orchid, Ophrys bertolonii (Orchidaceae) in Central Europe

Biologia ◽  
2011 ◽  
Vol 66 (5) ◽  
Author(s):  
Attila Molnár V ◽  
András Máté ◽  
Gábor Sramkó
Keyword(s):  
Central Europe ◽  
New Record ◽  
Dispersal Ability ◽  
Long Distance Dispersal ◽  
Long Distance ◽  
Permanent Establishment ◽  
Adriatic Coast ◽  
Northward Expansion ◽  
Mediterranean Plant

AbstractOne flowering specimen of Ophrys bertolonii (s. str.) — a plant with a Circum-Adriatic distribution and hitherto unknown in other regions — was found on 7th May 2010 in the vicinity of Kunadacs (Central Hungary; N 47°00′ E 19°17′). The nearest known populations of this Mediterranean plant inhabit the Adriatic coast (ca. 450 km away) in Croatia, therefore this new occurrence represents a significant long distance dispersal event. The circumstances of the occurrence argue against introduction, but we can not decide now whether this new appearance is temporary or permanent. The permanent establishment of this strictly entomophilous plant requires the presence of its specific pollinator in the close neighbourhood of the habitat. However, no pollination was observed on the three flowers of the plant until 9th May, and one day later the stem had disappeared most likely due to grazing. Whatever the long-term fate of the plant is, this discovery represents a significant long distance (jump) dispersal event, and testifies to the dispersal ability of Ophrys species. Additionally, the appearance of a mature Adriatic plant in Central Europe fits well into the currently observed, climate change driven northward expansion of European orchids, therefore this finding most likely reflects a growing Mediterranean-like climatic influence in the region.

An Attempt to Predict Which Amazonian Tree Species May be Threatened by Logging Activities

1994 ◽  
Vol 21 (2) ◽  
pp. 152-162 ◽  
Author(s):  
Adriana M. Z. Martini ◽  
Nelson de A. Rosa ◽  
Christopher Uhl
Keyword(s):  
Forest Regeneration ◽  
Future Generations ◽  
Dispersal Ability ◽  
Timber Species ◽  
Long Distance Dispersal ◽  
Long Distance ◽  
Logging Impacts ◽  
Ecological Parameters ◽  
Negative Impacts ◽  
First World

The impacts of logging on Amazonian ecosystems has been the focus of considerable attention both within and outside of Amazonia. However, the impacts of logging on individual timber species has not been at all adequately investigated. Logging affects timber species by: (1) removing mature individuals that are important sources of seeds; (2) damaging seedlings and saplings (i.e future generations of canopy adults); and (3) creating conditions that favour fire by opening the canopy and leaving slash as fuel on the forest floor.In this study we summarize information on the ecological characteristics of 305 timber species in Brazilian Amazonia. We identify seven ecological parameters that are useful in evaluating a species' ability to resist the negative impacts of logging. These characteristics are: (1) effective long-distance dispersal ability; (2) abundance of saplings in forest regeneration; (3) rapid growth; (4) ability to resprout; (5) capacity to withstand fire; (6) broad geographic distribution; and (7) high density of adults. We hypothesize thai species with characteristics opposed to these parameters and subjected to intense logging pressure will have difficulty in maintaining their populations in logging regions.We use a simple scoring system to rank species with regard to their hypothesized ability to withstand logging impacts. Among the species that are potentially susceptible to logging impacts are Euxylophora paraensis (‘Pau Amarelo’) and Swietenia macrophylla (American Mahogany). The sawn lumber from these two species goes principally to European and North American buyers, revealing a direct link between First World consumption and possible biodiversity impoverishment in the Brazilian rain-forest. These two species, and others that might experience population reductions as a result of logging, merit special study.

scholarly journals Monodominance in tropical forests: modelling reveals emerging clusters and phase transitions

2016 ◽  
Vol 13 (117) ◽  
pp. 20160123 ◽  
Author(s):  
Martin Kazmierczak ◽  
Pia Backmann ◽  
José M. Fedriani ◽  
Rico Fischer ◽  
Alexander K. Hartmann ◽  
...  
Keyword(s):  
Phase Transitions ◽  
Tropical Forests ◽  
Seed Mass ◽  
Species Traits ◽  
Dispersal Ability ◽  
Spatially Explicit ◽  
Long Distance ◽  
Spatially Explicit Model ◽  
The Subject ◽  
Characteristic Features

Tropical forests are highly diverse ecosystems, but within such forests there can be large patches dominated by a single tree species. The myriad presumed mechanisms that lead to the emergence of such monodominant areas is currently the subject of intensive research. We used the most generic of these mechanisms, large seed mass and low dispersal ability of the monodominant species, in a spatially explicit model. The model represents seven identical species with long-distance dispersal of small seeds, competing with one potentially monodominant species with short-distance dispersal of large seeds. Monodominant patches emerged and persisted only for a narrow range of species traits; these results have the characteristic features of phase transitions. Additional mechanisms may explain monodominance in different ecological contexts, but our results suggest that percolation-like phenomena and phase transitions might be pervasive in this type of system.

scholarly journals Genotypes of Rhizophora Propagules From a Non-mangrove Beach Provide Evidence of Recent Long-Distance Dispersal

2021 ◽  
Vol 2 ◽  
Author(s):  
Magdalene N. Ngeve ◽  
Nico Koedam ◽  
Ludwig Triest
Keyword(s):  
Genetic Research ◽  
Relative Difference ◽  
Source Population ◽  
Long Distance Dispersal ◽  
Long Distance ◽  
Propagule Dispersal ◽  
Adult Trees ◽  
Southern Cameroon ◽  
Source Populations ◽  
Dispersal Events

Dispersal plays a crucial role in the connectivity of established mangrove populations and in species range dynamics. As species ranges shift in response to climate change, range expansions can occur from incremental short-distance dispersal events and from stochastic long-distance dispersal events. Most population genetic research dealt with historically accumulated events though evidence of actual propagule dispersal allows to estimate genotypic features and origin of founders. In this study, we aim to disentangle a contemporary dispersal event. Using microsatellite markers, we genotyped 60 Rhizophora racemosa drift propagules obtained on a bare unforested coastal area in southern Cameroon, estimated their relationship to 109 adult trees from most proximate sites (which were 3–85 km away), and assessed their relative difference with 873 trees of major mangrove areas (> 300 km) along the Cameroonian coastline. Proximate mangrove populations were considered as potential source populations in assignment tests. However, drift propagules could not be assigned to any of the Cameroonian mangrove sites and were genetically isolated from Cameroonian populations. Drift propagules showed higher levels of genetic diversity and private alleles giving a higher relatedness to each other than to any putative source population. Chloroplast sequences were used to confirm the identity of drift propagules as R. racemosa. We postulate that a complex interaction of ocean currents, estuarine geomorphology, and tidal patterns explain drift propagule dispersal to an area. Most likely the investigated cohort of propagules originated from more southern mangrove areas of the West African range beyond the Cameroonian border. This study unraveled the allelic, genetic, and genotypic features of stranded propagules following a stochastic long-distance dispersal. Transboundary dispersal of these propagules highlights the need for intergovernmental efforts in the management of biodiversity.

scholarly journals How do wind speed, release height, seed morphology interact to determine seed dispersal trajectory of Calligonum (Polygonaceae) species Wind speed, release height, seed morphology determine seed dispersal trajectory

2018 ◽  
Author(s):  
Quanlai Zhou ◽  
Zhimin Liu ◽  
Zhiming Xin ◽  
Jianqiang Qian ◽  
Yongcui Wang ◽  
...  
Keyword(s):  
Wind Speed ◽  
Seed Dispersal ◽  
Explanatory Power ◽  
Seed Mass ◽  
Seed Morphology ◽  
Dispersal Distance ◽  
Wind Loading ◽  
Dispersal Capacity ◽  
High Dispersal ◽  
Release Height

AbstractHow seed dispersal trajectory shifts with abiotic and biotic factors and what is the relationship between seed dispersal distance and dispersal trajectory are remain unclear. We used wind tunnel and video camera to track the seed dispersal trajectory of 7 Calligonum species with different appendages under the different wind speeds and the release heights. Dispersal trajectories and distances were determined by video analysis and spatial coordinate transformation. Based on perspective principle, 4 modes of trajectories were determined. Wind speed, seed mass and release height were the key factors determining seed dispersal trajectory modes. Release height and wind speed tended to have the strongest explanatory power on seeds with bristles and wings, respectively. Different trajectory modes lead to different dispersal distance, while the same dispersal distance can be the result of different trajectory modes. The proportion of species’ trajectory modes formed its trajectory spectrum. Wind speed tends to have strong influence on light and low-wind-loading seeds, release height tends to have that on heavy and high-wind-loading seeds. Species with high proportion of horizontal projectile and projectile have high dispersal capacity, vice versa. Therefore, trajectory spectrum of a species reveals its primary dispersal strategies and evolutionary consequences.

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