نتایج جستجو برای: seed bank

تعداد نتایج: 138455  

2013
Alistair G. Auffret Louise Tränk Alistair Auffret

The success or failure of many organisms to respond to the challenges of habitat destruction and a warming climate lies in the ability of plant species to disperse between isolated habitats or to migrate to new ranges. European semi-natural grasslands represent one of the world’s most species-rich habitats at small scales, but agricultural intensification during the 20th century has meant that ...

2013
Alejandro A. Royo Todd E. Ristau

and deterministic processes regulate spatio-temporal variation in seed bank diversity" (2012). USDA Forest Service / UNL Faculty Publications. Paper 231. Abstract Question: Seed banks often serve as reservoirs of taxonomic and genetic diversity that buffer plant populations and influence post-disturbance vegetation trajectories; yet evaluating their importance requires understanding how their c...

آذرنیوند, حسین, عرفانزاده, رضا , غضنفریان, فاطمه,

This study aimed to investigate the effect of canopy trees and shrubs: Pistacia atlantica, Amygdalus scoparia, Amygdalus eburnean on the species diversity and richness of soil seed bank. Ten individuals of each species were selected and one quadrate was established in and outside of crown canopy of each species. In each plot, soil samples were collected from 0-5 and 5-10 cm depths. GLM was appl...

Journal: :Environmental entomology 2008
Jim M Story Lincoln Smith Janelle G Corn Linda J White

Five insect biological control agents that attack flower heads of spotted knapweed, Centaurea stoebe L. subsp. micranthos (Gugler) Hayek, became established in western Montana between 1973 and 1992. In a controlled field experiment in 2006, seed-head insects reduced spotted knapweed seed production per seed head by 84.4%. The seed production at two sites in western Montana where these biologica...

A.H Jalali

In order to evaluate the impact of crop residues (zero, 25 and 50%) and nitrogen (zero, 125 and 250 kg ha) on weed seed bank and potato yield, two-years research was conducted as a split plot arranged in randomized complete block design in Rozveh Agriculture Research Station, Freidan-Esfahan. Numbers of weed species in seed bank, aboveground, and both seed bank and aboveground were 1, 2 and...

اشرف زاده, محرم, عرفانزاده, رضا,

This study aimed to investigate the effect of canopy cover of individual woody patches on soil seed bank characteristics viz. density, richness and the similarity between soil seed bank and above ground vegetation. The study was conducted in Mazayjan, Zarindasht, south of Fars province in 2013. Therefore, 40 4m2 plots beneath and outside of Ziziphus spina-christi (dominant woody species) were e...

Journal: :American journal of botany 2012
Upekala C Wijayratne David A Pyke

PREMISE OF THE STUDY Seed longevity and persistence in soil seed banks may be especially important for population persistence in ecosystems where opportunities for seedling establishment and disturbance are unpredictable. The fire regime, an important driver of population dynamics in sagebrush steppe ecosystems, has been altered by exotic annual grass invasion. Soil seed banks may play an activ...

2017
Lukas Heinrich Johannes Muller Aur'elien Tellier Daniel Zivkovi'c

Population genetics models typically consider a fixed population size and a unique selection coefficient. However, population dynamics inherently generate noise in numbers of individuals and selection acts on various components of the individuals’ fitness. In plant species with seed banks, the size of both the aboveand below-ground compartments present noise depending on seed production and the...

2014
M. Jiang X. P. Shen W. Gao M. X. Shen Q. G. Dai

We studied the heterogeneity of soil weed seed-bank in a rice-wheat rotation system after long-term application of different organic or non-organic fertilizers, and the effects of major nutrients on the characteristics of the weed seed-bank. The soil was sampled in the Taihu area after a 31-year long-term fertilization experiment. Weed seeds were identified and counted in the surface soil of 12...

2000
Zerihun Woldu Mohammed Saleem

The species composition of grazing lands can be influenced by livestock and grazing pressure. A study on manure seed bank was conducted in Ghinchi highland Research Site in Ethiopia between 1995 and 1997. The data on species composition and life-form of the plants germinating in pots receiving air dried manure were compared with species composition of experimental plots in natural grassland sub...

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