نتایج جستجو برای: mixed and natural stands
تعداد نتایج: 16917246 فیلتر نتایج به سال:
this studyinvestigated therelations between examinees’ academic knowledge and theirperformanceonreading section of ielts and toefl (ibt) through using generalizabilitytheory. g-theory was utilized to investigate the effects of subtest, test items, participants and academic background on the reliability of ielts and toefl (ibt) score. tosamplethe subjectsofthissurvey,a placement testwasadministe...
objective: ecosystems with mixed species compared to the ones with pure compositions provide a broader range of options in the fields of biodiversity, conservation, protection and restoration. nearly all forest plantations are established as monocultures, but research has shown that there are potential advantages to be gained by using carefully designed species mixtures in place of monocultures...
the aim of this paper is eliminating cr(vi) by natural hap. hap is a inexpensive material which is used from bovine critical bone ash in order to remove heavy metal ions like cr(vi). some experiments in different ph are performed (ph=2,3,7). maximum adsorption was appeared at ph=2, dosage=0.3 gr, c0=10 mg/l. cr(vi) removal depends on ph value and initial amount of cr(vi) result of experiments w...
The natural forest and range stands of Zanjan province are located in mountainous areas. Inventorying and mapping of natural forest and range stands in mountainous areas are difficult and costly. Satellite data are suitable for this purpose. The Landsat ETM+ image data of 2002 are used for classification and mapping of natural forest stands in Zanjan province. For the purpose of data reduction ...
The natural forest and range stands of Zanjan province are located in mountainous areas. Inventorying and mapping of natural forest and range stands in mountainous areas are difficult and costly. Satellite data are suitable for this purpose. The Landsat ETM+ image data of 2002 are used for classification and mapping of natural forest stands in Zanjan province. For the purpose of data reduction ...
it is not possible to understand developments of a country’s culture and civilization without knowing his believes and myths. whether it is north or south, east or west, planes or mountains, sahara or deserts, here in iran every corner includes valuable and precious treasures which are known all over the world, and cultural – historical objects which are found here adorn all well known museums...
Forest managers need site productivity estimates for tree species growing in mixed stands. Models developed the past are generally pure stands and don’t factor effects of climate change on productivity. Therefore, index (SI) models were black spruce (Picea mariana Mill. B.S.P.) trembling aspen (Populus tremuloides Michx.) trees grown natural origin For this, 186 (93 each) sampled from 31 even-a...
Increasingly, forest managers intend to create or maintain mixed Pinus-hardwood stands. This stand assemblage may be driven by a variety of objectives but is often motivated by the desire to enhance native forest diversity and promote resilience to perturbations. Documenting the effects of natural disturbances on species composition and stand structure, and thus successional and developmental p...
Jonsson. B. 2001. Volume yield to mid-rotation in pure and mixed sown stands of Pirl~ls sylcestris and Pice& uhies in Sweden. Stztrliu Forestulir~ Suecicu 211. 19 pp. ISSN 0039-3150. ISBN 91-576-6137-5. Volume yield to mid-rotation in pure and mixed sown stands of Scots pine and Norway spruce was investigated in an experiment in central Sweden. The 43-year-old stands were situated on a 7-ha sit...
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