Ecology of the invading moss species Orthodontium lineare in Sweden: Spatial distribution and population structure

Ecography ◽  
1989 ◽  
Vol 12 (2) ◽  
pp. 163-172 ◽  
Author(s):  
Lars Hedenas ◽  
Tomas Herben ◽  
Hakan Rydin ◽  
Lars Soderstrom
Keyword(s):  
Population Structure ◽  
Spatial Distribution ◽  
Moss Species

scholarly journals Parasitic infection reduces dispersal of ciliate host

2010 ◽  
Vol 7 (3) ◽  
pp. 327-329 ◽  
Author(s):  
Simon Fellous ◽  
Elsa Quillery ◽  
Alison B. Duncan ◽  
Oliver Kaltz
Keyword(s):  
Population Structure ◽  
Spatial Distribution ◽  
Short Distance ◽  
Parasitic Infection ◽  
Genetic Population Structure ◽  
Paramecium Caudatum ◽  
Dispersal Capacity ◽  
Genetic Population ◽  
Social Aggregation ◽  
Aggregation Behaviour

Parasitic infection can modify host mobility and consequently their dispersal capacity. We experimentally investigated this idea using the ciliate Paramecium caudatum and its bacterial parasite Holospora undulata . We compared the short-distance dispersal of infected and uninfected populations in interconnected microcosms. Infection reduced the proportion of hosts dispersing, with levels differing among host clones. Host populations with higher densities showed lower dispersal, possibly owing to social aggregation behaviour. Parasite isolates that depleted host populations most had the lowest impact on host dispersal. Parasite-induced modification of dispersal may have consequences for the spatial distribution of disease, host and parasite genetic population structure, and coevolution.

scholarly journals Population structure and spatial distribution of porbeagles (Lamna nasus) in Irish waters

2019 ◽  
Vol 76 (6) ◽  
pp. 1581-1590 ◽  
Author(s):  
Luke W J Cameron ◽  
William K Roche ◽  
Jonathan D R Houghton ◽  
Paul J Mensink
Keyword(s):  
Population Structure ◽  
Spatial Distribution ◽  
North Atlantic ◽  
Population Decline ◽  
The North ◽  
Aggregation Site ◽  
Show Evidence ◽  
Long Term Trends ◽  
Almost All

Abstract Porbeagles throughout the North Atlantic have experienced severe population decline through overfishing, with the northeastern population listed as critically endangered. Management of this population is constrained by the paucity of data on porbeagle population structure, distribution and behaviour in this region. Here we use a long-term (47 year) Irish capture-mark-recapture dataset to investigate the population structure, spatial distribution and seasonal movements of this species. From 1970–2017, a total of 268 sharks (9 recaptures) were ID tagged, with most individuals likely being juvenile based on length at maturity estimates (mean total length = 143.9 cm, SD = 35.4). Almost all captures were recorded at three distinct locations near angling hubs along the south, west and north coasts with catches peaking in August. Long-term trends in capture date indicated a shift towards earlier capture dates in the northern site (n = 153). Our findings suggest Irish waters may act as a persistent summer aggregation site for juveniles, which show evidence for seasonal site fidelity, returning to nearby locations between years. These findings demonstrate the utility of such programmes, which can be implemented, with minimal expense by engaging with the angling sector, to elucidate the population structure and distribution of wide-ranging fish species.

The spatial distribution of illegal logging in the Anavilhanas archipelago (Central Amazonia) and logging impacts on species

2011 ◽  
Vol 39 (2) ◽  
pp. 111-121 ◽  
Author(s):  
ANDRESSA BÁRBARA SCABIN ◽  
FLÁVIA REGINA CAPELLOTTO COSTA ◽  
JOCHEN SCHÖNGART
Keyword(s):  
Growth Rate ◽  
Population Structure ◽  
Spatial Distribution ◽  
Growth Rates ◽  
Market Value ◽  
Southern Region ◽  
Illegal Logging ◽  
Negative Effects ◽  
Human Settlements ◽  
Harvesting Intensity

SUMMARYAmazonia is one of the world's leading suppliers of timber and the Amazonian timber industry is an important source of regional income, however the economic benefits of this market are associated with environmental damage, mainly when the wood is removed illegally. The Anavilhanas National Park, located in the Brazilian state of Amazonas, has been subjected to illegal logging and elaboration of control programmes requires knowledge of the distribution of timber species and the intensity of logging. This study examines the density and growth rate of the five most harvested tree species in the Park, the spatial distribution of illegal logging operations and their effects on population structure. In total, 2332 trees with diameter at breast height greater than 10 cm, as well as stumps of cut trees, were sampled, and dendrochronology was used to estimate growth rates. Some size classes of Virola surinamensis trees and species within the family Lauraceae decreased in abundance as harvesting intensity increased. Growth rates of the most abundant species of Lauraceae, Ocotea cymbarum, were high, indicating stands may recover quickly when harvesting stops. The population structure of Calophyllum brasiliense showed no negative effects due to logging, but its low growth rate and stand distribution suggest that continued exploitation may endanger these populations. Logging had no detectable negative effects on the size structure of populations of Macrolobium acaciifolium or Hevea spp., and their high growth rates suggest that they will not be threatened by current logging rates. Overall growth rates in the Anavilhanas archipelago are higher than those recorded in other black-water floodplain forest (igapó). Logging of most species (except Lauraceae spp., which have the highest market value) is concentrated in the southern region of the Park, which has more human settlements close by. There was no general relationship between harvesting intensity and geographic distance to human settlements, but there was a tendency for harvesting to be higher in sites with concentrations of trees of high market value. Potential strategies to control illegal logging activities in the Anavilhanas archipelago include encouragement of sustainable logging in Park buffer zones and stimulation of ecotourism initiatives in the southern region of the Park. Ecotourism development can provide an economic alternative to illegal logging for local communities and inhibit logging by increasing vigilance.

scholarly journals Bryophyte flora in an Amazon island: structure of communities in areas of different levels of anthropization

Rodriguésia ◽  
2021 ◽  
Vol 72 ◽  
Author(s):  
João Paulo Silva Souza ◽  
Paulo Weslem Portal Gomes ◽  
Rita de Cássia Pereira dos Santos ◽  
Ana Cláudia Caldeira Tavares-Martins
Keyword(s):  
Spatial Distribution ◽  
Community Structure ◽  
The State ◽  
Amazon Forest ◽  
High Similarity ◽  
Moss Species ◽  
Generalist Species ◽  
Structure Of Communities ◽  
First Time ◽  
Different Levels

Abstract The present study is aimed to evaluate the richness, composition and spatial distribution of bryophytes occurring in Mosqueiro Island, in the Amazon forest. Forty-one 100-m² plots in 37 flooded and 4 non-flooded environments were selected for data collection, all substrate found were considered. The results were compared with surveys in other islands from the state of Pará and were analyzed according to frequency of populations, colonized substrates, light tolerance guilds, and distribution in Brazilian biomes. Ninety-seven species were recorded, distributed in 36 genera and 17 families, being 57 (58.7%) liverwort and 40 (41.2%) moss species. The rare species stood out with 53 species (54.08%). High similarity was observed between corticolous and epixylic communities, and between the terricolous community and the bryophytes found growing on charcoal, which is an artificial substrate. In relation to light tolerance guilds, generalist species prevailed (52 species, 53.6%). As for phytogeographic distribution, there was a predominance of taxa with occurrence in the Amazon and Atlantic rainforest (35 species, 37.11%). Ceratolejeunea ceratantha is reported for the first time for the state of Pará. The level of anthropization in the island was showed mainly by high richness and occurrence of generalist species underscores and well-adapted species to stressed conditions, evidencing changes in the bryophyte community structure.

scholarly journals Surname affinity in Santiago, Chile: A network-based approach that uncovers urban segregation

PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0244372
Author(s):  
Naim Bro ◽  
Marcelo Mendoza
Keyword(s):  
Socioeconomic Status ◽  
Population Structure ◽  
Spatial Distribution ◽  
Ethnic Groups ◽  
High Socioeconomic Status ◽  
Socioeconomic Index ◽  
High Degree ◽  
The City

Based on a geocoded registry of more than four million residents of Santiago, Chile, we build two surname-based networks that reveal the city’s population structure. The first network is formed from paternal and maternal surname pairs. The second network is formed from the isonymic distances between the city’s neighborhoods. These networks uncover the city’s main ethnic groups and their spatial distribution. We match the networks to a socioeconomic index, and find that surnames of high socioeconomic status tend to cluster, be more diverse, and occupy a well-defined quarter of the city. The results are suggestive of a high degree of urban segregation in Santiago.

scholarly journals Vultures and Livestock: The Where, When, and Why of Visits to Farms

Animals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2127
Author(s):  
Marina García-Alfonso ◽  
Thijs van Overveld ◽  
Laura Gangoso ◽  
David Serrano ◽  
José A. Donázar
Keyword(s):  
Population Structure ◽  
Spatial Distribution ◽  
Breeding Season ◽  
Individual Characteristics ◽  
Food Sources ◽  
Core Areas ◽  
Vulture Conservation ◽  
Using Data ◽  
The Individual ◽  
Feeding Resources

Recent changes in European legislation have legalized the abandonment of carcasses around livestock farms, but our understanding of how vultures exploit these semi-predictable food sources is still very limited. For filling this gap, we determine the individual and ecological drivers influencing vulture visits to farms. We assessed the effects of individual characteristics of both birds and farms on the frequency of vultures’ visits to livestock facilities using data collected from 45 GPS-tagged Egyptian Vultures (Neophron percnopterus) and 318 farms (>94% of livestock) on Fuerteventura Island, Spain. Farms were more visited during the vultures’ breeding season. Farms located closer to highly predictable feeding places (i.e., vulture restaurants and garbage dumps) or with more available feeding resources were visited by more vultures, whereas those located close to roads and vultures’ breeding territories received fewer visits. Younger territorial birds visited a farm more frequently than older territorial ones, whereas older non-territorial individuals concentrated those visits on farms closer to their activity core areas compared with younger ones. Our findings indicate that visits to farms were determined by their spatial distribution in relation to the age-specific birds’ activity centers, the availability of carcasses, seasonality, and individual characteristics of vultures. These interacting factors should be considered in vulture conservation, avoiding very general solutions that ignore population structure.

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