نتایج جستجو برای: limited seed dispersal and intra

تعداد نتایج: 16872138  

Journal: :Molecular ecology 2011
Emily V Moran James S Clark

The scale of seed and pollen movement in plants has a critical influence on population dynamics and interspecific interactions, as well as on their capacity to respond to environmental change through migration or local adaptation. However, dispersal can be challenging to quantify. Here, we present a Bayesian model that integrates genetic and ecological data to simultaneously estimate effective ...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه گیلان - دانشکده فنی 1392

روانگرایی در ماسه های ریزدانه اشباع در هنگام زلزله، موجب خرابی سازه های زیادی در نقاط مختلف دنیا بوده است. از عوامل موثر در این پدیده می توان به تراکم خاک، دانه بندی خاک، عمق لایه مورد نظر و تنش های موثر همه جانبه، شدت و مدت زمان زمین لرزه و درصد عبوری از الک شماره 200 (مقدار ریزدانه و جنس آن) اشاره نمود. عالباً در روشهای رایج ارزیابی وقوع روانگرایی از خصوصیات درجای خاک، همانند نتایج آزمایش های ...

2018
Addisie Geremew Melkamu G Woldemariam Alemayehu Kefalew Iris Stiers Ludwig Triest

Limited seed or pollen dispersal enhances spatial genetic relatedness between individuals (fine-scale spatial genetic structure, FSGS), which usually decreases as a function of physical distance. However, such isotropic pattern of FSGS may not always occur when spatially asymmetric processes, for instance, wind direction during dispersal, are considered in wind-pollinated and -dispersed plants....

2007
P. JORDANO

A seed shadow is the spatial distribution of all seeds dispersed from an individual plant (Janzen, 1970; Nathan and Muller-Landau, 2000; Schupp et al., 2002). The sum of seed shadows across all individuals in a population plus those seeds dispersed from other populations makes up seed rain. For vertebrate-dispersed species, seed shadows are the primary outcome of plant–frugivore interactions, y...

Journal: :PLoS ONE 2008
Paulo R. Guimarães Mauro Galetti Pedro Jordano

BACKGROUND Some neotropical, fleshy-fruited plants have fruits structurally similar to paleotropical fruits dispersed by megafauna (mammals > 10(3) kg), yet these dispersers were extinct in South America 10-15 Kyr BP. Anachronic dispersal systems are best explained by interactions with extinct animals and show impaired dispersal resulting in altered seed dispersal dynamics. METHODOLOGY/PRINCI...

Journal: :Integrative zoology 2011
Ruben Heleno Stephen Blake Patricia Jaramillo Anna Traveset Pablo Vargas Manuel Nogales

The Galápagos are considered a model oceanic archipelago, with unique flora and fauna currently threatened by alien invasive species. Seed dispersal is an important ecosystem function with consequences for plant population dynamics and vegetation structure. Hence, understanding the seed dispersal abilities of the assemblages of frugivores will inform scientists and managers of the dynamics of p...

2009
Benjamin Chi Wang Victoria L. Sork Thomas W. Gillespie Thomas B. Smith Shirley Wang

O F T H E DISSERTATION Impacts of hunting on seed dispersal in a Central African tropical forest

2008
Helene C. Muller-Landau Joseph Wright Osvaldo Calderón Richard Condit Stephen P. Hubbell

1. We investigated the relationships of seed size, dispersal mode and other species characteristics to interspecific variation in mean primary seed dispersal distances, mean annual seed production per unit basal area, and clumping of seed deposition among 41 tropical tree species on Barro Colorado Island, Panama. 2. A hierarchical Bayesian model incorporating interannual variation in seed produ...

2017
András Kelemen Béla Tóthmérész Orsolya Valkó Tamás Miglécz Balázs Deák Péter Török

Classical old-field succession studies focused on vegetation changes after the abandonment of annual croplands or on succession after the elimination of cultivated crops. Perennial-crop-mediated succession, where fields are initially covered by perennial crops, reveals alternative aspects of old-field succession theories. We tested the validity of classical theories of old-field succession for ...

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