نتایج جستجو برای: ground metrics of seedling size ie

تعداد نتایج: 21204036  

پایان نامه :وزارت علوم، تحقیقات و فناوری - پژوهشگاه دانشهای بنیادی (مرکز تحقیقات فیزیک نظری و - پژوهشکده علوم نانو 1392

among the low–dimensional allotropes of carbon, nanotubes and graphene have attracted very much attention from nano–science and nanotechnology specialists. they have been proposed as building blocks in nanometer device engineering. however, these structures are not defect–free. in this thesis, we focused on defective carbon nanotubes and graphene, and studied the effect of couple of very common...

Journal: :American journal of botany 2007
Christopher Baraloto Pierre-Michel Forget

To investigate the existence of coordinated sets of seedling traits adapted to contrasting establishment conditions, we examined evolutionary convergence in seedling traits for 299 French Guianan woody plant species and the stress response in a shadehouse of species representing seed size gradients within five major cotyledon morphology types. The French Guianan woody plant community has larger...

Journal: :Tree physiology 2015
Eung-Jun Park Wi-Young Lee Leonid V Kurepin Ruichuan Zhang Loeke Janzen Richard P Pharis

In an even-aged pine forest trees can vary considerably in stem size. We examined the basis for this anomaly using a retrospective approach. Twelve open-pollinated families of Pinus densiflora Sieb. et Zucc. were deliberately chosen for their variation in stem volumes at age 32 years. Seedlings obtained from these families were grown to age 6 months under optimal nursery conditions. Endogenous ...

Journal: :Annals of botany 2012
Pieter De Frenne Bente J Graae Jörg Brunet Anna Shevtsova An De Schrijver Olivier Chabrerie Sara A O Cousins Guillaume Decocq Martin Diekmann Martin Hermy Thilo Heinken Annette Kolb Christer Nilsson Sharon Stanton Kris Verheyen

BACKGROUND AND AIMS The response of forest herb regeneration from seed to temperature variations across latitudes was experimentally assessed in order to forecast the likely response of understorey community dynamics to climate warming. METHODS Seeds of two characteristic forest plants (Anemone nemorosa and Milium effusum) were collected in natural populations along a latitudinal gradient fro...

Journal: :Annals of botany 2013
Carolina Quintero M Deane Bowers

BACKGROUND AND AIMS The lack of studies assessing the simultaneous expression of tolerance and resistance traits during seedling development and overall seedling defences as compared with adult plants, in general, constitutes a significant research need that can greatly improve our understanding of overall investment in defences during plant ontogeny. METHODS Using two seedling and two juveni...

Detecting, predicting and quantifying the trends of landscape pattern change in the forests of Gharasu watershed area are necessary so as to assess the crises or prevent them. To this aim, the land use maps belonging to the years 1987, 2002 and 2018 were classified through the maximum likelihood method, and the forest area changes were estimated. Then, through the Geomod model and the forest ch...

Journal: :Remote Sensing 2017
Jennifer N. Hird Alessandro Montaghi Gregory J. McDermid Jahan Kariyeva Brian J. Moorman Scott E. Nielsen Anne C. S. McIntosh

Photogrammetric point clouds (PPCs) provide a source of three-dimensional (3-D) remote sensing data that is well-suited to use over small areas that are within the scope of observation by unmanned aerial vehicles (UAVs). We compared PPC-based structural metrics to traditional ground surveys conducted by field personnel in order to assess the capacity of PPC data to contribute to vegetation-recl...

2018
Vitalis W. Temu Christos Galanopoulos Maru K. Kering Laban K. Rutto

Effects of transplanted seedling density and species on sward structure of native warm-season grass (NWSG) stands were compared in a randomized complete block design. About 6-week-old NWSG (big bluestem (BB, Andropogon gerardii Vitman), eastern gamagrass (GG, Tripsacum dactyloides L.), indiangrass [IG, Sorghastrum nutans (L.) Nash] and switchgrass (SG, Panicum virgatum) seedlings were transplan...

Journal: :Journal of environmental sciences 2007
Qiu-yan Li Wen-zhi Zhao Hai-yan Fang

This study addresses the adaptation of Nitraria sphaerocarpa to blown sand at the edge of a desert oasis with regard to the aspects of soil seed banks, seedlings, and population. Horizontally, the total number of seeds per unit area decreased from the shrub canopy center to intershrub areas, and most seeds were found under shrub canopies. Vertically, the highest proportion of seeds was found at...

Journal: :Theoretical population biology 1999
S A Geritz E van der Meijden J A Metz

We present a model for the evolutionary dynamics of seed size when there is a trade-off between seed size and seed number, and seedlings from large seeds are better competitors and have a higher precompetitive survival than seedlings from small seeds. We find that strong competitive asymmetry, high resource levels, and intermediate harshness of the precompetitive environment favor coexistence o...

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