Currently, urban forestry in China has been booming in both develop- ment and research with efforts by all levels of government and forestry agencies. In order to understand the structure urban forestry researchers an...
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Currently, urban forestry in China has been booming in both develop- ment and research with efforts by all levels of government and forestry agencies. In order to understand the structure urban forestry researchers and their research work, a questionnaire survey was conducted during the period from October to November 2005. 32 research institutions (unit) and 78 persons were surveyed. Results indicated that the main force of urban forestry researchers have a background of forestry education and aged between 40～49 years old. 74.3% of the researchers have already got or are doing Master or PhD degree. Majority of urban forestry researchers are working in universities with forestry component, research institutions or research teams.
In this paper,the characters of soil aggregates under different skidding modes were investigated by fractal *** results showed that the particle fraction of soil aggregates was smaller under tractor- than under animal...
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In this paper,the characters of soil aggregates under different skidding modes were investigated by fractal *** results showed that the particle fraction of soil aggregates was smaller under tractor- than under animal traction *** for different parts of skidding road,the particle fraction of air-dried soil aggregates was in the order of bottom (2.309) > middle (2.291) > upper (2.014),while that of water-stable aggregates followed the sequence of bottom (2.04) < middle (2.143) < upper (2.262).The particle fraction of aggregates was 2.215 in forest soil and 2.175 in skidding *** movement could improve soil aggregates when the cutting intensity was 15%.Tractor skidding was more favorable for soil aggregates formation.
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