نتایج جستجو برای: quercus leaves

تعداد نتایج: 85471  

Journal: :Journal of experimental botany 2002
Lawren Sack Peter J Melcher Maciej A Zwieniecki N Michele Holbrook

A comparison was made of three methods for measuring the leaf lamina hydraulic conductance (K(lamina)) for detached mature leaves of six woody temperate angiosperm species. The high-pressure method, the evaporative flux method and the vacuum pump method involve, respectively, pushing, evaporating and pulling water out of the lamina while determining the flow rate into the petiole and the water ...

Journal: :Mycologia 2012
Thomas C Harrington Doug McNew Hye Young Yun

A newly recognized, late-season leaf disease of Quercus macrocarpa (bur oak) has become increasingly severe across Iowa and in neighboring states since the 1990s. Vein necrosis and leaf death may occur over the whole crown or only on the lower branches. Symptoms typically intensify year-to-year in individual trees, and there appears to be substantial variation in susceptibility. Distinctive con...

2017
Hui Zhang Xiuqing Yang Jingyuan Wang G. Geoff Wang Mukui Yu Tonggui Wu

Plant stoichiometry in relation to the structure and function of biological systems has been investigated at multiple scales. However, few studies have focused on the roles of stoichiometry for a given species. In this study, we determined leaf N and P stoichiometry, leaf shape and plant size in three Quercus acutissima common gardens with different climatic and site conditions. In the three co...

Journal: :Tree physiology 1996
M N Angelov S J Sung R L Doong W R Harms P P Kormanik C C Black

About 95% of swamp tupelo (Nyssa sylvatica var. biflora (Walt.) Sarg.) and sweetgum (Liquidambar styraciflua L.) seedlings survived continuous root flooding for more than two years, whereas none of the swamp chestnut oak (Quercus michauxii Nutt.) and cherrybark oak (Q. falcata var. pagodifolia Ell.) seedlings survived one year of flooding. Death of oak seedlings occurred in phases associated wi...

Journal: :Agricultural and Forest Meteorology 2021

Intense spring freezing events can kill the recently produced cohort of leaves, forcing trees to expend additional carbon and nutrient stocks produce a second leaves. The future trends in frequency late frosts will affect adaptation some tree species their current habitats. Here we studied effect frost which occurred 2017 on mixed beech (Fagus sylvatica)-oak (Quercus petraea) forest located cen...

Journal: :Annals of agricultural and environmental medicine : AAEM 2006
Herminia Garcia-Mozo Carmen Galan Victoria Jato Jordina Belmonte Consuelo de la Guardia Delia Fernandez Montserrat Gutierrez M Aira Joan Roure Luis Ruiz Mar Trigo Eugenio Dominguez-Vilches

The main characteristics of the Quercus pollination season were studied in 14 different localities of the Iberian Peninsula from 1992-2004. Results show that Quercus flowering season has tended to start earlier in recent years, probably due to the increased temperatures in the pre-flowering period, detected at study sites over the second half of the 20th century. A Growing Degree Days forecasti...

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