Population dynamics of the marsupial Micoureus demerarae in small fragments of Atlantic Coastal Forest in Brazil

2001 ◽  
Vol 17 (3) ◽  
pp. 339-352 ◽  
Author(s):  
TIAGO BOSISO QUENTAL ◽  
FERNANDO ANTONIO DOS SANTOS FERNANDEZ ◽  
ANDRÉ TAVARES CORRÊA DIAS ◽  
FLÁVIA SOUZA ROCHA
Keyword(s):  
Population Dynamics ◽  
Reproductive Activity ◽  
Small Population ◽  
Southeastern Brazil ◽  
Coastal Forest ◽  
Short Term ◽  
Atlantic Coastal Forest ◽  
Population Sizes ◽  
Time Required ◽  
Atlantic Coastal

Patterns of population fluctuation, reproductive activity and age structure were studied in populations of the marsupial Micoureus demerarae occupying two small (7.0 and 8.8 ha) fragments of Atlantic Coastal Forest in southeastern Brazil, from 1995 to 1998. Males, but not females, were observed to move between populations. Estimated sizes of the populations in each fragment were very small, usually below 20 individuals. Breeding usually occurred from September to April. Population peaks came mostly by the end of this season, the delay reflecting the time required for the young to become trappable. In August 1997, the area was hit by a fire severely affecting the smaller fragment. Populations were synchronous before the fire, although they became asynchronous after it, possibly in the short term only. Small population sizes, synchrony and presumable male-biased migration are all likely to make the set of populations more vulnerable to extinction than expected for a metapopulation.

Begonia fimbritepala (Begoniaceae), a new species endemic to the Atlantic Coastal Forest in the state of Rio de Janeiro, Brazil

Phytotaxa ◽  
2020 ◽  
Vol 439 (1) ◽  
pp. 102-106
Author(s):  
ELIANE DE LIMA JACQUES
Keyword(s):  
New Species ◽  
Endemic Species ◽  
Rio De Janeiro ◽  
The State ◽  
Coastal Forest ◽  
Adaxial Surface ◽  
Atlantic Coastal Forest ◽  
Male Flowers ◽  
Atlantic Coastal ◽  
A New Species

Begonia fimbritepala (Begoniaceae) a new endemic species to the Atlantic Coastal Forest of Brazil is described and illustrated. This species resembles B. olsoniae in occupying the same habitat (rocky slopes and outcrops), and in the shape of the leaf blades and size of male flowers. It differs by glabrous leaves on the adaxial surface, villous abaxial veins with simple trichomes (vs. hispid on both surfaces, squamulose on abaxial veins with fimbriate scales) and tepals with ciliate margins (vs entire to slightly crenulate).

scholarly journals Microbial population dynamics are dominated by stochastic forces in a low biomass subseafloor habitat

2021 ◽  
Author(s):  
Rika E. Anderson ◽  
Elaina D. Graham ◽  
Julie A. Huber ◽  
Benjamin J. Tully
Keyword(s):  
Population Dynamics ◽  
Allele Frequency ◽  
Global Scale ◽  
Small Population ◽  
Microbial Evolution ◽  
Microbial Populations ◽  
Small Scale ◽  
Crustal Fluids ◽  
Population Sizes ◽  
Stochastic Forces

AbstractThe subseafloor is a vast global habitat that supports microorganisms that have a global scale impact on geochemical cycles. Much of the subseafloor contains endemic microbial populations that consist of small populations under growth-limited conditions. For small population sizes, the impacts of stochastic evolutionary events can have large impacts on intraspecific population dynamics and allele frequencies. These conditions are fundamentally different than those experienced by most microorganisms in surface environments, and it is unknown how small population sizes and growth-limiting conditions influence evolution and population structure. Using a two-year, high-resolution environmental time-series, we examine the dynamics of 10 microbial populations from cold, oxic crustal fluids collected from the subseafloor site North Pond, located near the mid-Atlantic ridge. The 10 microbial populations were divided into groups with distinct patterns of population dynamics based on abundance, nucleotide diversity, and changes in allele frequency. Results reveal rapid allele frequency shifts linked to different types of population interactions, including sweeps, dispersal, and clonal expansion. Dispersal plays an important role in structuring the most abundant populations in the crustal fluids. Microbial populations in the subseafloor of North Pond are highly dynamic and evolution is governed largely by the stochastic forces of dispersal and drift.ImportanceThe cold, oxic subseafloor is an understudied habitat that is difficult to access, yet important to global biogeochemical cycles and starkly different compared microbial habitats on the surface of the Earth. Our understanding of microbial evolution and population dynamics has been largely molded by studies of microbes living in surface habitats that can host 10-1,000 times more microbial biomass than has been observed in the subsurface. This study provides an opportunity to observe evolution in action within a low biomass, growth-limited environment and reveals that while microbial populations in the subseafloor can be influenced by changes in selection pressure and small-scale gene sweeps, the stochastic forces of genetic drift and dispersal have an important impact on the evolution of microbial populations. Much of the microbial life on the planet exists under growth-limited conditions and the subseafloor provides a natural laboratory to explore these fundamental biological questions.

Begonia itaipeensis (Begoniaceae), a new species endemic to Atlantic Coastal Forest in the state of Rio de Janeiro, Brazil

Phytotaxa ◽  
2019 ◽  
Vol 425 (1) ◽  
pp. 57-62
Author(s):  
ELIANE DE LIMA JACQUES
Keyword(s):  
New Species ◽  
Endemic Species ◽  
Rio De Janeiro ◽  
The State ◽  
Coastal Forest ◽  
Narrow Endemic ◽  
Atlantic Coastal Forest ◽  
Atlantic Coastal ◽  
A New Species

Begonia itaipeensis (Begoniaceae), a new narrow endemic species from the Brazilian Atlantic Coastal Forest is described and illustrated. This species resembles B. friburgensis Brade but is readily distinguished from that species by its rupicolous habit, leaves with long petioles, and transversely ovate leaf blades.

Begonia microinduta (Begoniaceae) a new species from the Atlantic Coastal Forest in the state of São Paulo, Brazil

Phytotaxa ◽  
2021 ◽  
Vol 497 (1) ◽  
pp. 49-53
Author(s):  
MARCELO DIAS MIRANDA
Keyword(s):  
New Species ◽  
Leaf Surface ◽  
Dorsal Surface ◽  
The State ◽  
Coastal Forest ◽  
Atlantic Coastal Forest ◽  
Floral Bracts ◽  
Atlantic Coastal ◽  
Upper Third ◽  
A New Species

Begonia microinduta, a new species of  Begonia sect. Pritzelia from the Atlantic Coastal Forest of Brazil is described and illustrated with detailed field photographs. This species is similar to B. windischii and B. lorenzii by having three tepals on pistillate flowers, staminate flowers with pilose dorsal surface, short peduncled inflorescences, very short inflorescence ramification and persistent floral bracts. It differs from B. windischii in its petiole indumentum, which is covered with short microscopic trichomes throughout (vs. sparsely pilose in the upper third with villous trichomes, with a trichome necklace at the base of the petiole and in the apex) and differs from B. lorenzii by having microscopic (vs. villous) trichomes, glabrous (vs. pubescent) adaxial leaf surface and glabrous (vs. pubescent) fruits.

Sign in / Sign up

Export Citation Format

Share Document