نتایج جستجو برای: pine cones
تعداد نتایج: 28479 فیلتر نتایج به سال:
The ignition and combustion of forest floor duff are poorly understood yet have been linked to soil heating and overstory tree mortality in many temperate coniferous forests. Research to date has focused on the characteristics of duff that facilitate ignition and spread, including fuel moisture, mineral content, and depth. Field observations suggest that the presence of pine cones on and within...
In this study, the yields and composition of essential oils obtained from the cones of Pinaceae family species natively grown in Turkey were investigated. Essential oils were obtained by hydrodistillation. Oil yields were 0.13-0.48 mL/100 g in pine cones, 0.42-0.59 mL/100g in fir, 0.36 mL/100g in spruce and 0.37 mL/100g in cedar. While alpha-pinene (47.1-14.8%) was the main constituent of P. sl...
Sand pine (I-‘inu.r c/trrr.srr) scrub is adapted to, and regenerated by, periodic stantl-rcplnccment wildfire, which consumch the understory and kills the overstay. The heat of the fire opens the serotinous cones of’ Ocala sand pine (P. c~/nu.srr var. c/tr~c.sc/), releasing quantities of seed that reestablish the overstory, while the understory regenerates by sproutin, (1 or from soil-stored se...
Human-caused disruptions to seed-dispersal mutualisms increase the extinction risk for both plant and animal species. Large-seeded plants can be particularly vulnerable due to highly specialized dispersal systems and no compensatory regeneration mechanisms. Whitebark pine (Pinus albicaulis), a keystone subalpine species, obligately depends upon the Clark's Nutcracker (Nucifraga columbiana) for ...
In Quebec, the law requires forestry companies to look after the regeneration of the forests they exploit. The natural cycle of jack pine (Pinus banksiana Lamb.) is related to fire, which allows opening of the cones and dispersal of the seeds. But after harvesting, the exploited sectors are normally replanted. It has been shown that the current methods of seedling production and planting cause ...
Abstract The aim of the research was to identify influence environmental factors inherent in alluvial and displaced sands study region on growth Jack pine prospects for its cultivation. We found that success seedlings sandy soils depends a set factors, which include presence or absence, rhizosphere sand, humus impurities genetic horizons zonal soils, silty loamy layers, soil density composition...
Low organic matter content and alkaline pH of calcareous soils in arid and semi-arid regions are the main reasons for the low nutrient availabilities for plants in these soils. One way to improve the chemical properties and fertility of calcareous soils is the application of organic substances such as biochar produced from pyrolysis of organic wastes. However, biochars have an almost predominan...
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