金月芽期刊網

和“seedling”相關的論文

  • 成熟的種子到哪里去了?——評述“Seed Fates:Seed predation,Seed Dispersal and Seedling Establishment”一書 相關:《Seed Fates: Seed
  • 每年,森林內有難以計數的種子和果實成熟,但這些成熟的種子和果實到哪里去了呢?這一問題是長期以來困擾人們認識森林更新和演替變化的一個關鍵問題,也是目前食果動物與種子擴散研究領域中共同關注的焦點問題。最近,由Forget PM,Lambert J,Hulme PE和Vander Wall SB(2004)共同主編的“.Seed Fates:Seed Predation,Seed Dispersal and Seedling Establishment”一書(以下稱Seed fate book)似乎為解決這一問題提供了部分答案。
  • Development of cork oak (Quercus suber L.) seedlings in response to tree shelters and mulching in northwestern Tunisia 相關:Quercus suber L
  • The need for reforestation in cork oak (Quercus suber L.) areas is challenged by difficulties. Principal among these is herbivory of young plants, vegetative competition, and slow growth rates of cork oak seedlings. We evaluated the early development of cork oak seedlings treated using tree shelters and mulching in northwestern Tunisia. We tested three tree shelter treatments (non-vented, vented, and control) to shield seedlings from animal damage and five mulch types to control competing vegetation (Italian Stone Pine, Lentisk, combination of Italian Stone Pine and Lentisk (organic mulches), gravel (inorganic mulch) and no mulch). At the end of the two-year experiment, sheltered seedlings were 89-99% taller than unshelteredseedlings and had higher numbers and lengths of shoot growth flushes. In contrast, both stem diameter growth and dry weight biomass (from samples extracted after two years) were significantly reduced inside tree shelters. Root-to-shoot ratio was not significantly different in sheltered vs. unsheltered seedlings, suggesting that tree shelters do not adversely affect this parameter. Mulching alone did not favour growth, but could be beneficial when combined with tree shelters. The combination of vented tree shelters and gravel mulch was the most effective treatment for promoting diameter, height and stem volume growth.
  • Effects of soil moisture and light intensity on ecophysiological characteristics of Amorpha fruticosa seedlings 相關:Amorpha fruticosa ecophysiological
  • We investigated the combined effects of soil moisture and light intensity on the growth, development and ecophysiological characteristics of one-year old Amorpha fruticosa seedlings. Soil moisture and light intensity influenced the ecophysiological characteristics of Amorpha fruticosa seedlings. Soil moisture resulted in the decreases of growth rate, individual size, net photosynthetic rate, transpiration rate, leaf water loss rate (WLR), and biomass accumulation of plant parts, and led to increased leaf water saturation deficit (WSD). Under water stress, more photosynthetic products were allocated to root growth. With decreasing light intensity, net photosynthetic rate, transpiration rate, chla/b, water saturation deficit, water use efficiency, water loss rate and biomass accumulation declined, while Chla, Chlb, Chla+b and carotenoids (Car) increased and more photosynthetic products were allocated to stem and leaf growth. Maximum growth vigor, net photosynthetic rate and total biomass accumulation in Amorpha fruticosa seedlings was recorded at 75 80% soil water-holding capacity and 100% light density in greenhouse environments.
  • Phytoremediation Characteristics of Pb and Cd Contaminated Soils by Ginkgo Seedling 相關:GINKGO SEEDLING HEAVY
  • In this article,we investigated effects of lead and cadmium on the biomass of ginkgo seedlings, and roles of the seedlings in accumulation characteristics of the heavy metals and remediation of the soil contaminated by Cd2+ or Pb2+ as well as their combination.The results showed that both Cd2+ and Pb2+ significantly or very significantly reduced biomass increment of ginkgo seedlings,with Pb2+ more adverse than Cd2+.The Cd2+-Pb2+ compound pollution further reduced biomass increment of ginkgo seedlings.The mass fractions and enrichment coefficient of Pb2+ and Cd2+ in ginkgo seedlings were in an order of root>stem>leaf,which was in favor of transportation Pb2+ and Cd2+ from root to stem and leave.The Cd2+-Pb2+ compound pollution promoted ginkgo seedling absorption to Cd2+ and Pb2+.The capacity of the upward transport of Pb2+ was greater than that of Cd2+,which suggested an obvious dose-effect and synergistic effect.Cd2+ and Pb2+ accumulations in ginkgo seedlings were relatively large.The accumulation in roots was higher than that in stems and leaves.The ability of the absorption,transportation and accumulation of ginkgo seedlings to Pb2+ was relatively greater under Cd2+-Pb2+ compound pollution.The phytoremediation efficiency of Cd2+ and Pb2+ was relatively high.
  • Effects of Different Nitrogen Sources on Transformation and Availability of Inorganic Phosphorus in Root-Soil Interface of Pinus thunbergii Seedlings 相關:AMMONIUM NITRATE root-soil
  • The calcareous fluvo-aquic soil was collected and a microcosm study was carried out with root-mat and frozenslicing method in laboratory. The pH in the root-soil interface with the control treatment was just slightly lower than in the bulk soil.However,the addition of NH4- -N significantly decreased the pH value in the root-soil interface and the addition of No3 -N slightly increased the pH value in the root-soil interface.The magnitude of pH changes in the root-soil interface depended upon the concentrations of the nitrogen sources added.The contents of Ca2-P,Fe-P and Al-P in the root-soil interface were much lower after treated with NH4 -N and slightly higher after treated with No3 -N compared with control treatment.After treated with 100,200 and 400 mg·kg-1NH4+ -N,the deficiency rates of Ca2-P in the area 0-1 mm from the root plane were 37.1%,45.9%and 57.7%,respectively,the deficiency rates of Fe-P were 23.4%,29.1%and 38.2%,respectively,and the deficiency rates of Al-P were 25.1%,28.0%and 33.2%,respectively. Compared with the control the deficiency rates of Ca8-P in NH4+ -N and No3-N treatments decreased and increased,respectively,but the differences were not obvious.The contents of Ca10 -P and O-P in the root-soil interface did not significantly change after treated with NH4+ -N or No3 -N,suggesting that Ca10- P and O-P were remarkably difficult to be mobilized even at the presence of high concentration of NH4+ -N.The lowered pH in the root-soil interface induced by the addition of the NH4 -N promoted the transformation of phosphates in the root-soil interface,enhanced the mobilization and bioavailability of phosphates,and thereby remarkably increased the absorption of phosphorus by roots.
  • My Father’s Eyes——天地父子情 相關:父子情 My Father
  • 父親之愛相較于母親的細致與嘮叨,往往顯得隱忍、含蓄。所以,我們常說嚴父慈母、父愛如山。對于兒女而言,很多人常常是長大成年甚至為人父母后才真正理解父愛的厚重與不易。但無論如何,有父愛就是幸福的,那是一種如鋼似鐵的精神支柱與寄托。然而,不是所有人都能幸運地享受到父愛。譬如英國搖滾布魯斯歌手Eric Clapton,他一生未與父親謀面,中年又嘗喪子之痛,這種無父愛眷顧、親情又無處安放的痛苦全都寄托在歌曲《父親的眼睛》(My Father’s Eyes)里。
  • Effects of environmental factors on seedling growth and anthocyanin content in Betula ‘Royal Frost’ leaves 相關:BETULA 'Royal Frost’
  • Determining the influences of environmental factors on seedling growth and leaf color may improve our understanding of the chromogenic mechanisms in leaves and the biosynthesis of anthocyanin. To determine the optimum conditions for Betula 'Royal Frost' seedling cultivation,we assessed seedling growth and anthocyanin content under natural conditions. The temperature had a significant influence on height but not on radial growth.Between June and September, the anthocyanin content was significantly positively correlated with light intensity and air moisture and significantly negatively correlated with temperature. In single-factor experiments to determine the variation in anthocyanin content in the greenhouse, anthocyanin content increased with increasing soil water content and at first increased, then decreased with increasing pH of the irrigation water and temperature, but decreased with increasing light intensity. K2SO4 can increase the anthocyanin content. So to maintain leaf color, seedlings should be cultivated with\200 lmol m-2 s-1 light intensity at 20 _C and soil moisture content between 60 and 90%, and the irrigation water should be neutral or alkaline. Additionally,spraying with K2SO4 can be beneficial.