PubAg

Main content area

You searched for: Journal Acta oecologica Remove constraint Journal: Acta oecologica Publication Year 2011 Remove constraint Publication Year: 2011 Source 2011 v.37 no.5 Remove constraint Source: 2011 v.37 no.5
Start Over

Search

15  Search Results

1 - 15 of 15
Number of results to display per page

Search Results

1. Are the long-term effects of mesobrowsers on woodland dynamics substitutive or additive to those of elephants?

Author:
O’Kane, Christopher A.J.; Duffy, Kevin J.; Page, Bruce R.; Macdonald, David W.
Source:
Acta oecologica 2011 v.37 no.5 pp. 393-398
ISSN:
1146-609X
Subject:
Elephantidae; diet; ecosystems; habitats; keystone species; long term effects; meta-analysis; savannas; trees; woody plants
Abstract:
... The large spectrum of existing literature on browser-woodland dynamics, both from savanna and temperate biomes, converges towards concluding that all browsers importantly impact woody plants. In this context a crucial question in the current debate about reintroducing elephant culling, is whether the long-term effects of elephants and mesobrowsers are similar. If the two groups impact the same woo ...
DOI:
10.1016/j.actao.2011.05.005

2. Drivers of aquatic macrophyte community structure in a Neotropical riverine lake

Author:
Sousa, Wilson T.Z.; Thomaz, Sidinei M.; Murphy, Kevin J.
Source:
Acta oecologica 2011 v.37 no.5 pp. 462-475
ISSN:
1146-609X
Subject:
Eichhornia azurea; community structure; environmental factors; floodplains; hydrology; lakes; leaves; macrophytes; oxygen; phosphorus; rivers; space and time; species diversity; summer; tropics; vegetation; Brazil
Abstract:
... We explored the hypothesis that flood events and connectivity interact with local factors (biotic and abiotic) to drive changes in aquatic vegetation in a typical backwater lake connected to the River Paraná, Brazil. Over three years, we conducted quarterly surveys to analyse macrophyte composition and abundance, and environmental variables. In total 34 macrophyte species were recorded, with stron ...
DOI:
10.1016/j.actao.2011.05.015

3. Flower size and longevity influence florivory in the large-flowered shrub Cistus ladanifer

Author:
Teixido, Alberto L.; Méndez, Marcos; Valladares, Fernando
Source:
Acta oecologica 2011 v.37 no.5 pp. 418-421
ISSN:
1146-609X
Subject:
Coleoptera; longevity; animals; corolla; shrubs; pollinators; Cistus ladanifer; Formicidae; pollen
Abstract:
... Plants with larger and longer-lived flowers receive more pollinator visits and increase reproductive success, though may also suffer more from antagonistic interactions with animals. Florivores can reduce fruit and seed production, so selection on flower size, floral longevity and/or number of flowers may thus be determined by the relative effects of both pollinators and florivores. In this study ...
DOI:
10.1016/j.actao.2011.05.007

4. Food webs of a sandy beach macroinvertebrate community using stable isotopes analysis

Author:
Colombini, Isabella; Brilli, Mauro; Fallaci, Mario; Gagnarli, Elena; Chelazzi, Lorenzo
Source:
Acta oecologica 2011 v.37 no.5 pp. 422-432
ISSN:
1146-609X
Subject:
biomass; carbon; cluster analysis; diet; food webs; macroinvertebrates; models; pitfall traps; stable isotopes; vegetation
Abstract:
... The study examines the food webs of macroinvertebrates along a gradient from the sandy shore to a dune slack in the retrodune. The study was conducted at the Maremma Regional Park in an area subjected to beach progradation. Transects with pitfall traps were set perpendicular to the sea to capture macroinvertebrates, whereas vegetation biomass was evaluated using quadrats. Marine allochthonous mate ...
DOI:
10.1016/j.actao.2011.05.010

5. Geographic variation of floral traits in Nicotiana glauca: Relationships with biotic and abiotic factors

Author:
Nattero, Julieta; Sérsic, Alicia N.; Cocucci, Andrea A.
Source:
Acta oecologica 2011 v.37 no.5 pp. 503-511
ISSN:
1146-609X
Subject:
Nicotiana glauca; altitude; climatic factors; corolla; evolution; flowering; geographical variation; hummingbirds; morphometry; phenotypic variation; pollinators
Abstract:
... Geographic pattern of phenotypic variation can appear in a clinal or a mosaic fashion and can evidence adaptive or non-adaptive variation. To shed light on the mechanisms underlying this variation, we studied the relationships between geographic variation of floral traits and both biotic and abiotic factors of the hummingbird-pollinated plant, Nicotiana glauca, across its natural range. We obtaine ...
DOI:
10.1016/j.actao.2011.07.001

6. Hard traits of three Bromus species in their source area explain their current invasive success

Author:
Fenesi, Annamária; Rédei, Tamás; Botta-Dukát, Zoltán
Source:
Acta oecologica 2011 v.37 no.5 pp. 441-448
ISSN:
1146-609X
Subject:
Bromus sterilis; Bromus tectorum; Robinia pseudoacacia; colonizing ability; habitats; nitrogen; phenology; phenotypic plasticity; surveys; understory; Central European region; Hungary; North America
Abstract:
... We address two highly essential question using three Eurasian Bromus species with different invasion success in North America as model organisms: (1) why some species become invasive and others do not, and (2) which traits can confer pre-adaptation for species to become invasive elsewhere. While the morphology and phenology of the chosen bromes (Bromus tectorum, Bromus sterilis and Bromus squarros ...
DOI:
10.1016/j.actao.2011.05.012

7. Hotspots of species richness, threat and endemism for terrestrial vertebrates in SW Europe

Author:
Pascual, López-López; Luigi, Maiorano; Alessandra, Falcucci; Emilio, Barba; Luigi, Boitani
Source:
Acta oecologica 2011 v.37 no.5 pp. 399-412
ISSN:
1146-609X
Subject:
amphibians; birds; breeding; conservation areas; cumulative distribution; ecosystems; humans; models; planning; reptiles; reserve networks; species diversity; Iberian Peninsula; Portugal; Spain
Abstract:
... The Mediterranean basin, and the Iberian Peninsula in particular, represent an outstanding “hotspot” of biological diversity with a long history of integration between natural ecosystems and human activities. Using deductive distribution models, and considering both Spain and Portugal, we downscaled traditional range maps for terrestrial vertebrates (amphibians, breeding birds, mammals and reptile ...
DOI:
10.1016/j.actao.2011.05.004

8. Leaf trait variation of a dominant neotropical savanna tree across rainfall and fertility gradients

Author:
Baruch, Zdravko
Source:
Acta oecologica 2011 v.37 no.5 pp. 455-461
ISSN:
1146-609X
Subject:
leaf area; leaves; multivariate analysis; nutrient resorption (physiology); photosynthesis; rain; savannas; soil fertility; trees; water use efficiency; wet season
Abstract:
... The evergreen tree Curatella americana dominates the woody stratum in Venezuelan savannas, along substantial rainfall and soil fertility gradients. This work determines intra-specific variation of leaf traits in Curatella which may account for its extended ecological range. Six Curatella populations, from sites spanning a 1800 mm rainfall and a 5-fold soil fertility range, were selected. Specific ...
DOI:
10.1016/j.actao.2011.05.014

9. Limitation of distribution of two rare ferns in fragmented landscape

Author:
Tájek, Přemysl; Bucharová, Anna; Münzbergová, Zuzana
Source:
Acta oecologica 2011 v.37 no.5 pp. 495-502
ISSN:
1146-609X
Subject:
rocks; microhabitats; Asplenium; ferns and fern allies; Spermatophytina; biogeography
Abstract:
... Species distribution in the landscape is limited either by 1. diaspore production, dispersal and establishment abilities or 2. by availability of suitable habitats; 3. or by a combination of both factors. The relative importance of these factors is species-dependent and has mainly been studied for seed plants. We studied the importance of habitat and dispersal limitation for distribution of two ra ...
DOI:
10.1016/j.actao.2011.06.009

10. Population growth of Nassella trichotoma in grasslands in New Zealand slower today than in the past

Author:
Lamoureaux, Shona L.; Bourdôt, Graeme W.; Saville, David J.
Source:
Acta oecologica 2011 v.37 no.5 pp. 484-494
ISSN:
1146-609X
Subject:
death; viability; inflorescences; plant growth; flowering; probability; pastures; seedlings; sowing; models; extinction; Nassella trichotoma; population growth; field experimentation; buried seeds; carrying capacity; weeds; grasslands; New Zealand
Abstract:
... Nassella trichotoma established in modified tussock-grasslands in New Zealand from about 1860. Management programmes since 1946 have reduced populations to levels no longer impacting pastoral production. Optimising future management requires knowledge of the trajectory of population growth and its regulating demographic processes. To that end, four long-term field experiments were conducted. Net r ...
DOI:
10.1016/j.actao.2011.06.008

11. Sex allocation and functional bias of quaternary and quinary flowers on same inflorescence in the hermaphrodite Ruta graveolens

Author:
Tang, Jing-Yu; Ren, Ming-Xun
Source:
Acta oecologica 2011 v.37 no.5 pp. 449-454
ISSN:
1146-609X
Subject:
viability; pollination; corolla; sex allocation; phenology; pollen; stigma; biomass; Ruta graveolens; seed set
Abstract:
... Intra-inflorescence variation in floral traits is important to understand the pollination function of an inflorescence and the real reproductive outputs of a plant. Ruta graveolens (Rutaceae) produce both quaternary (four petals and eight stamens) and quinary (five petals and ten stamens) flowers on the same cymes, while their pollination roles and the effects on the reproductive success remained ...
DOI:
10.1016/j.actao.2011.05.013

12. Sex ratio and spatial distribution of male and female Antennaria dioica (Asteraceae) plants

Author:
Varga, Sandra; Kytöviita, Minna-Maarit
Source:
Acta oecologica 2011 v.37 no.5 pp. 433-440
ISSN:
1146-609X
Subject:
Antennaria dioica; flowering; inflorescences; males; mycorrhizal fungi; reproduction; roots; sex ratio; sexual dimorphism; shoots; vesicular arbuscular mycorrhizae; Finland
Abstract:
... Sex ratio, sex spatial distribution and sexual dimorphism in reproduction and arbuscular mycorrhizal colonisation were investigated in the dioecious clonal plant Antennaria dioica (Asteraceae). Plants were monitored for five consecutive years in six study plots in Oulanka, northern Finland. Sex ratio, spatial distribution of sexes, flowering frequency, number of floral shoots and the number and we ...
DOI:
10.1016/j.actao.2011.05.011

13. Solutions for functional response experiments

Author:
Okuyama, Toshinori; Ruyle, Robert L.
Source:
Acta oecologica 2011 v.37 no.5 pp. 512-516
ISSN:
1146-609X
Subject:
ecological processes and phenomena; models; predator-prey relationships; predators
Abstract:
... Functional response is an important factor in ecological processes. Many empirical studies have characterized functional responses based on model selection procedures. However, relatively few models have been considered in such studies. This may be partly because methods for characterizing general functional response models are not well known. In this study, we present the derivation of explicit a ...
DOI:
10.1016/j.actao.2011.07.002

14. The role of native flower visitors in pollinating Opuntia ficus-indica (L.) Mill., naturalized in Sicily

Author:
Lo Verde, Gabriella; La Mantia, Tommaso
Source:
Acta oecologica 2011 v.37 no.5 pp. 413-417
ISSN:
1146-609X
Subject:
Apoidea; Opuntia ficus-indica; cactus pears; flowers; fruit set; fruits; indigenous species; insect pollination; orchards; paper; pulp; seeds; Sicily
Abstract:
... The role of insects in pollination and consequently in fruit set and quality was assessed in two commercial orchards of the cactus pear, Opuntia ficus-indica (L.) Mill., in Agrigento Province, Sicily. In 1997, insects visiting flowers were sampled during May–June (the first bloom) and July (the second bloom, induced by the “scozzolatura” practise). More than 50 insect species belonging to 10 ...
DOI:
10.1016/j.actao.2011.05.006

15. What drives seasonal fluctuations of body condition in a semelparous income breeder octopus?

Author:
Quetglas, Antoni; Ordines, Francesc; Valls, Maria
Source:
Acta oecologica 2011 v.37 no.5 pp. 476-483
ISSN:
1146-609X
Subject:
Eledone cirrhosa; aquatic invertebrates; body condition; body weight; environmental factors; females; food availability; food intake; foods; income; life history; maturity stage; molting; primary productivity; reproduction; rivers; seasonal variation; temperature
Abstract:
... The vast majority of modern cephalopods is single-season breeders, or semelparous in the strict sense, that die soon after the reproduction takes place. Individual body condition in these marine invertebrates is expected to be highly affected by reproduction because: 1) the gonad weight of females, which represents <1% of body weight when immature, increases up to 20–50% during maturation; and 2) ...
DOI:
10.1016/j.actao.2011.06.002