Zhang X.,Liaoning Institute of Sand Fixation and Afforestation
Acta Geographica Sinica | Year: 2015
This article breaks down the eolian sand movement into two parts from a geographic perspective for the first time, the inner core and the outer extension. The fluid start and the impact start of saltation are the two entities that constitute the inner core, and all transportation performance after the sand particle start can be defined as the outer extension. Drawing upon this innovative idea, this article carries out discussion on the root of how divergences arise between the two systems of theories, the eolian sand physics and the eolian sand geography. The results reveal that whether one is able to distinguish the different properties of the two entities of the inner core and whether one is able to understand the interaction mechanism correctly of the two entities lead to the formation of the cores of the two theoretical systems and are the root of many divergences. This article deepens the understanding towards the connotation of eolian sand movement and theoretically breaks through the long term leading core idea in the sand movement scholastic circle presented by Bagnold whose theory on the two types of sand particle start appreciates one and depreciates the other. ©, 2015, Science Press. All right reserved.
Han H.,Liaoning Institute of Sand Fixation and Afforestation |
Zhang X.-L.,Liaoning Institute of Sand Fixation and Afforestation |
Dang H.-Z.,Chinese Academy of Forestry |
Xu G.-J.,Liaoning Institute of Sand Fixation and Afforestation |
And 2 more authors.
Forest Research | Year: 2015
The precise determination of transpirational water-consumption is of great significance of the judgement of stand water balance. The present proper density ofPinus sylvestris var. mongolica plantation was calculated by means of water balance based on 5 years' observation of the precipitation, the canopy interception, the forest evapotranspiration, the soil water content and the sap flow velocity(SFV) which was measured by thermal dissipation probe(TDP) during the growing season. The sap flow observation of P. sylvestris var. mongolica in Zhanggutai started in early April and ended in late October, the monthly average SFV during the growing season from April to October were 2.58, 4.78, 5.19, 5.01, 4.84, 4.30 and 1.93 cm·per hour respectively, the highest SFV appeared in June, higher SFV appeared in July, August, May and September successively and lower SFV appeared in April and October. Through calculating, the proper density of P. sylvestris var. mongolica in 14, 16, 18, 20 cm diameter class were 688, 531, 422 and 344 plants per hectare. Over-high density was the common problem existed in pure stands in the same diameter class. © 2015, Chinese Academy of Forestry. All right reserved.