نتایج جستجو برای: seed bank

تعداد نتایج: 138455  

Journal: :مرتع و آبخیزداری 0
پریا کمالی دانشجوی کارشناسی ارشد رشتة مرتع داری، دانشکدة منابع طبیعی دانشگاه تربیت مدرس رضا عرفانزاده استادیار گروه مرتع داری دانشکدة منابع طبیعی دانشگاه تربیت مدرس حسن قلیچ نیا استادیار پژوهشی مرکز تحقیقات کشاورزی و منابع طبیعی ساری

this study aimed to investigate the effect of animal grazing on soil seed bank characteristics in the northern slopes of alborz. for this purpose, soil seed bank characteristics were compared between grazed and ungrazed areas. therefore, four transects perpendicular to the sides of exclosure inside and outside of it were established. then soil samples were collected within 28 plots inside and 2...

2014
Miaojun Ma Zhen Ma Guozhen Du

BACKGROUND Although the effect of water level on germination in soil seed banks has been documented in many ecosystems, the mechanism is not fully understood, and to date no empirical studies on this subject exist. Further, no work has been done on the effect of water level on seed banks of drying and saline-alkaline wetlands in alpine areas on the Tibetan Plateau. METHODOLOGY We examined the...

2008
S. Aboling J. Kigel

The relationship between the soil seed bank at the onset of the growing season and the structure of the ensuing vegetation under grazing was investigated in an eastern Mediterranean grassland. Species responses to two contrasting cattle grazing regimes were studied through plant trait analyses. Traits included plant size, phenology, seed size and germination fraction. Changes in species composi...

1999
Charles B. Halpern Shelley A. Evans Sarah Nielson

During early stand development, coniferous forests of the coastal Pacific Northwest commonly pass through a period of dense shade and intense competition during which the abundance and diversity of understory plants decline dramatically. In young, managed forests, silvicultural thinning has been proposed to enhance the structural and floristic diversity of the understory. Although germination o...

2006
X. Zhan L. Li W. Cheng

The landscapes of Inner Mongolia are widely known for the vast Stipa krylovii steppes. However, overgrazing and other improper land uses have extensively degraded the Stipa krylovii steppe ecosystem in recent decades. Knowledge about the soil seed banks and the remaining vegetation in these damaged ecosystems is crucial for guiding the restoration efforts. Using a germination method, this study...

2013
Phil Stewart ALLEN Susan E. MEYER Julie BECKSTEAD

Allen P.S., Meyer S.E., Beckstead J. (2013): A predictive model for soil seed bank outcomes in the Pyrenophora semeniperda–Bromus tectorum pathosystem. Plant Protect. Sci., 49 (Special Issue): S21–S24. Pyrenophora semeniperda is abundant in soil seed banks of Bromus tectorum, where it kills a fraction of seeds throughout the year. The pathogen engages in a race with host seeds for endosperm res...

Journal: :journal of agricultural science and technology 2011
o. esmailzadeh s. m. hosseini m. tabari

we assessed the size and composition of the soil seed bank and above-ground vegetation in 52 relevés representing a range of habitats within an old- growth, temperate deciduous forest at hyrcanian region, northern iran. we identified 63 taxa in the seed bank, with an average density of 4202 seeds/spores per m2 by seedling emergence method. hypericum androsaemum, cardamine impatiens, and rub...

2014
Jochen Blath Adri'an Gonz'alez Casanova Noemi Kurt Maite Wilke-Berenguer

We identify a new natural coalescent structure, the seed-bank coalescent, which describes the gene genealogy of populations under the influence of a strong seedbank effect, where ‘dormant forms’ of individuals (such as seeds or spores) may jump a significant number of generations before joining the ‘active’ population. Mathematically, our seed-bank coalescent appears as scaling limit in a Wrigh...

2003
BRYAN L. FOSTER DAVID TILMAN

1 We present results from a long-term sowing experiment conducted in nutrient-poor savanna grassland in eastern Minnesota. We examine the effects of a one-time seed addition of 23 grassland species on plant community dynamics and structure over eight growing seasons. 2 Our goals were to: (i) test the importance of seed availability in regulating plant colonization dynamics and species richness;...

اسدی, حامد, اسماعیل زاده, امید, سخاوت, صالح,

  This study was investigated the above-ground vegetation and soil seed bank flora in three site of Albizia julibrissin Durazz. In Hyrcanian Lowland Forests (including Haloomsar, Anjilisra forests and Sisangan Box tree (Buxus hyrcanus Pojark) reserve). Aboveground vegetation was sampled by 68 plots of 400 m2 during late June and seed bank flora was studied by seedling emergence method. The resu...

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