نتایج جستجو برای: seedling death
تعداد نتایج: 288147 فیلتر نتایج به سال:
Levy, Louise S.Y.; Deal, Robert L.; Tappeiner, John C. 2010. The density and distribution of Sitka spruce and western hemlock seedling banks in partially harvested stands in southeast Alaska. Res. Pap. PNW-RP-585. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 20 p. This study’s objective was to document and describe the current seedling bank o...
Promoting the seed regeneration potential of secondary forests undergoing gap disturbances is an important approach for achieving forest restoration and sustainable management. Seedling recruitment from seed banks strongly determines the seed regeneration potential, but the process is poorly understood in the gaps of secondary forests. The objectives of the present study were to evaluate the ef...
A choice test revealed that Hessian fly, Mayetiola destructor (Say) (Diptera: Cecidomyiidae), adults deposited approximately 3 times more eggs on wheat (Triticum spp.), seedlings than on barley (Hordeum spp.) or rice, Oryza sativa L., seedlings. On a barley seedling, 49.4% of eggs were deposited on either the abaxial leaf surface or the coleoptile and first leaf sheath (C&FLS), where newly hatc...
The regeneration ecology of sugar maple (Acer saccharum Marsh.) has been impacted by acid rain leaching of base cations from the soils throughout much of its range. We tracked the survival and causes of death for a natural cohort of sugar maple seedlings across 22 sites in the Hubbard Brook Valley in New Hampshire, USA, where soil acidification has been documented. Survival over 7 years average...
Seed development culminates in programmed cell death (PCD) and hardening of organs enclosing the embryo (e.g., pericarp, seed coat) providing essentially a physical shield for protection during storage in the soil. We examined the proposal that dead organs enclosing embryos are unique entities that store and release upon hydration active proteins that might increase seed persistence in soil, ge...
Wild Cardon cactus seeds were inoculated with Azospirillum brasilense strains Cd and Sp-245 to improve seed germination and seedling growth parameters. Differential germination responses were related to the bacterial strain. A. brasilense Cd (the type strain for the species A. brasilense) significantly decreased seed germination. A. brasilense Sp245 (a known beneficial bacteria for cereal plant...
To understand how temperate coexisting tree species respond to water deficit, the seedlings of two coexisting species, Phellodendron amurense Rupr. And Fraxinus mandshurica Rupr., were transplanted into plastic flowerpots. Three water deficit treatments were used, W1 (60-90% field moisture capacity), W2 (40-60% field moisture capacity), and naturally occurring precipitation (CK), with the aim o...
Poor seed germination and early seedling growth associated with urea-induced soil ammonia volatilization are major constraints in the adoption of dry direct-seeded rice. To directly examine soil ammonia volatilization and its damage to seed germination and early seedling growth of dry direct-seeded rice when urea is applied at seeding, two Petri-dish incubation experiments and a field experimen...
KOSTEL-HUGHES, F., T. P. YOUNG, AND J. D. WEHR. (Louis Calder Center—Biological Field Station and Department of Biological Sciences, Fordham University, P.O. Box 887, Armonk, NY 10504). Effects of leaf litter depth on the emergence and seedling growth of deciduous forest tree species in relation to seed size. J. Torrey Bot. Soc. 132: 50–61. 2005.—Leaf litter has a major impact on soil microenvi...
BACKGROUND AND AIMS Artemisia halodendron is a native sub-shrub that occurs mainly in moving and semi-fixed sandy lands in Inner Mongolia, China. Information on the spatial patterns of wind-dispersed seed deposition and seedling recruitment of A. halodendron inhabiting moving sandy lands is very limited. The aim of this study was to examine wind-dispersed seed deposition patterns and post-dispe...
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