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 Information use during movement regulates how fragmentation and loss of habitat affect body size

2018 ◽  
Author(s):  
Jasmijn Hillaert ◽  
Martijn L. Vandegehuchte ◽  
Thomas Hovestadt ◽  
Dries Bonte
Keyword(s):  
Body Size ◽  
Habitat Fragmentation ◽  
Evolutionary Dynamics ◽  
Information Use ◽  
Spatial Arrangement ◽  
Dispersal Ability ◽  
Spatially Explicit ◽  
Spatially Explicit Model ◽  
Feedback Effects ◽  
Body Sizes

AbstractAn individual's body size is central to its behavior and physiology, and tightly linked to its dispersal ability. The spatial arrangement of resources and a consumer's capacity to locate them are therefore expected to exert strong selection on consumer body size.We investigated the evolutionary impact of both the fragmentation and loss of habitat on consumer body size and its feedback effects on resource distribution, under varying levels of information use during the settlement phase of dispersal. We developed a mechanistic, individual-based, spatially explicit model, including several allometric rules for key consumer traits. Our model reveals that as resources become more fragmented and scarce, informed settlement selects for larger body sizes while random settlement promotes small sizes. Information use may thus be an overlooked explanation for the observed variation in body size responses to habitat fragmentation. Moreover, we find that resources can accumulate and aggregate if information on resource abundance is incomplete. Informed movement results in stable resource-consumer dynamics and controlled resources across space. However, habitat fragmentation and loss destabilize local dynamics and disturb resource suppression by the consumer. Considering information use during movement is thus critical to understand the eco-evolutionary dynamics underlying the functioning and structuring of consumer communities.

scholarly journals Catastrophes, connectivity, and Allee effects in the design of marine reserve networks

2019 ◽  
Author(s):  
Easton R. White ◽  
Marissa L. Baskett ◽  
Alan Hastings
Keyword(s):  
Potential Role ◽  
Oil Spills ◽  
Marine Reserve ◽  
Dispersal Ability ◽  
Spatially Explicit ◽  
Allee Effects ◽  
Spatially Explicit Model ◽  
Optimal Spacing ◽  
Optimal Reserve

AbstractCatastrophic events, like oil spills and hurricanes, occur in many marine systems. One potential role of marine reserves is buffering populations against disturbances, including the potential for disturbance-driven population collapses under Allee effects. This buffering capacity depends on reserves in a network providing rescue effects, with a potential trade-off in spacing between individual reserves to balance rescue via connectivity and independence of disturbances experienced. We use a set of population models to examine how dispersal ability and the disturbance regime interact to determine the optimal reserve spacing. We incorporate fishing in a spatially-explicit model to understand the consequences of objective choice (i.e. conservation versus fisheries yield) on the optimal reserve spacing. We show that the optimal spacing between reserves increases when accounting for catastrophes. This result is accentuated when Allee effects interact with catastrophes to increase the probability of extinction. We also show that classic tradeoffs between conservation and fishing objectives disappear in the presence of catastrophes. Specifically, we found that at intermediate levels of disturbance, it is optimal to spread out reserves in order to increase population persistence and to maximize spillover into non-reserve areas.

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.

Solo Singing Etiquette for Women in Ancient and Modern Egypt

2020 ◽  
Vol 7 (1) ◽  
pp. 41-70
Author(s):  
Enas Fares Yehia ◽  
Walaa Mohamed Abdelhakim
Keyword(s):  
Ancient Egypt ◽  
Comparative Methodology ◽  
The Subject ◽  
Similarities And Differences ◽  
Characteristic Features ◽  
Modern Egypt

Throughout the ages, people have shown great interest in music and singing of all kinds, giving these expressive forms great importance in different eras. This article aims to comprehensively overview the etiquette, customs, and characteristic rules of polite performance in the profession of female solo singing in ancient and modern Egypt from a comparative view. This is achieved by reviewing the distinctive themes of female solo singers and their contexts in both ancient and modern Egypt. The article employs a descriptive-comparative methodology to provide a detailed sequential investigation and analysis of all the data collected on the subject and the themes of female solo singers; to discern the characteristic features of female solo singing etiquette in ancient Egypt; and to identify the similarities and differences of these features in the masters and famous models of modern Egypt. One of the main findings is that the distinctive characteristics of female solo singing in ancient Egypt have been inherited in the style of oriental but not western singing, and the greatest and most widely known model of the former style is “the Oriental singing lady Umm Kulthum”.

scholarly journals Comparative Analysis of Long-Distance Transportation with the Example of Sea and Rail Transport

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1689
Author(s):  
Tomasz Neumann
Keyword(s):  
Eastern China ◽  
Time Cost ◽  
Topsis Method ◽  
Long Distance ◽  
Long Distance Transport ◽  
The Subject ◽  
Transport Analysis ◽  
Multi Criteria Analysis ◽  
The Relationship ◽  
Distance Transport

The subject of the article is a comparative long-distance transport analysis based on the relationship between central and eastern China and Poland. It provides an overview of issues related to long-haul China–Poland. The technique for order of preference by similarity to ideal solution (TOPSIS) method was proposed in the multi-criteria analysis. This method was briefly discussed, and its choice was justified. Then, the criteria adopted in the analysis were presented, i.e., time, cost, maximum number of containers, and ecology index. Multi-criteria analysis was carried out for three cases: the transport of one loading unit, 82 loading units, and 200 loading units. The geopolitical and operational situation on the transport route for the analyzed modes of transport was discussed.

Early seedling development in relation to seed mass and morph in Cakile edentula

1994 ◽  
Vol 72 (3) ◽  
pp. 402-406 ◽  
Author(s):  
Jianhua Zhang
Keyword(s):  
Surface Area ◽  
Seed Mass ◽  
Long Distance ◽  
Seed Surface ◽  
Large Seed ◽  
Cakile Edentula ◽  
Early Seedling ◽  
Seed Reserves ◽  
Early Seedling Development ◽  
Growth Of Seedlings

Cakile edentula produces dimorphic seeds from the upper and lower fruit segments. The upper seeds are well adapted to long-distance dispersal and have greater mean seed mass and surface area than those from the lower seeds. Great mean mass of the upper seeds is probably adaptive because it ensured early independent growth of seedlings and thus enhanced their chances of surviving environmental stresses. Large seed reserves also resulted in high chlorophyll content of the cotyledons. Large seed surface area resulted in large cotyledon area and cotyledon area to biomass ratio of the subsequent seedlings, but the adaptive advantage is not clear. Since increased seed surface area necessitates great protective tissues (fruit coat) that may improve the buoyant ability of seeds, large seed surface area of the upper seeds may be a result of selection for dispersal. Key words: seed mass, seed dimorphism, establishment, sand dune, selection, Cakile edentula.

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.

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