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The Highland Central of Vietnam has a high potential for livestock development with a vast area of grazing areas include scrubs, grassland and some forest types but currently, the livestock of the Central Highland has been facing with a problem as long period of dry season as 4-6 months that make most of the plant communities stop growing. To contribute to the livestock development of the Central Highland, in this study, we focus on the ecological characteristics of the natural vegetation to gather experiences about the structure, seasonal rhythm and succession trend of each plant communities related to grazing. Therefore, in this paper, the ecological characteristics of 11 natural ecological habitats and 1 artificial habitat are descripted; natural grazing vegetation includes 5 forests, 3 scrubs and 3 grasslands belonging to 3 bio-climate types (tropical monsoon moisture, tropical monsoon dry and sub-tropical monsoon moisture) and 3 ecological canopy types (evergreen, semi-deciduous and deciduous). The seasonal rhythm of each ecosystem also affects to the food resources for the cattle, among that, the main food was found in dry grasslands and scrubs in the rainy season but in the dry season those habitats have support food not considerable, the cattle would get food from the moisture habitats in this period. The largest changes of food source ratios between rainy and dry seasons were found in Dak Lak and Gia Lai provinces, where the dry habitats are common while the changing ratios at Kon Tum and Lam Dong provinces have been not much that means two provinces would support food for the large cattle stability during the year. However, when the density of the cattle head is too high, the capacity of the habitat is lower than the requirement of the animal, especially in the dry season, the natural food sources cannot adapt for the cattle food requirement and the people must use the other sources such as planting, industrial food. The density of the cattle also effects on the ecological succession trend of each habitat. In normally, the forest would be changed to the scrubs, the scrubs would be changed to the grassland and vice versa. In the first trend, it is positive but the second trend is negative. Because of high density of cattle, the negative ecological succession within the natural vegetation related to the grazing in the Central Highland has been found at the western area of Dak Lak and Gia Lai provinces, most areas of Kon Tum and Dak Nong provinces except the habitat along the boundary of the special used forest (national park, nature reserves) and the positive succession would be found at all of the special used forest areas, Lam Dong province, Southeastern area of Dak Lak province, Central areas of Gia Lai province.

Biogeographically mapping flora of Vietnam requires the studies on the distribution of some important species groups for identifying the typical species composition of each phytochorion. The Dipterocarpaceae family contains taxa originated in tropical Asia and its subfamily of Dipterocarpoideae is proved to have Southeast Asia origin. In Vietnam, this family includes 43 species in 7 genera. In this study, Dipterocarpaceae species from 645 sites in Vietnam are assessed and compared to those in over the world. In Vietnam, this family distributes in tropical and/or slightly passing to subtropical climate but none of its species is naturally found in the Red River and the Mekong River deltas. In the world, the Dipterocarpaceae species found in Vietnam concentrated distributes in Indochina floristic region, corresponding to the originative area of South Myanmar. Statistically, there are 12 endemic species for the Indochinese floristic region and five of them are endemic for four provinces of this region related to Vietnam, respectively as follows: South China-1, North Indochina-1, South Indochina-2 and Annam-1. Additionally, some species distribute in East Asia floristic region of Holarctic Kingdom because of expanding the distribution area from the Indochinese floristic region. All genera of this family in Vietnam were originated in the Indochinese floristic region. Moreover, the floristic data and phytogeographical phylogeny diagram, based on analyses of phytogeography and DNA, would be better to use for finding out the distributional source or the forming time of species or genus, then the phylogenetic diagram.

This study is conducting an empirical examination on the determinants of firm profitability of real estate companies listed on HOSE from 2010 to 2018. The difference from previous studies would lie in the usage of explanatory variables, the quantity of sample and the period of study. Based on data of 34 companies with 306 observations, this research methodology applies descriptive statistics, correlation statistics and regression analysis. The empirical results revealed that firm size, asset turnover, liquidity have a significant impact on firm profitability, while firm growth showed no significant effect on profitability denoted by ROA and ROE.

This study is conducting an empirical examination on the determinants of firm profitability of real estate companies listed on HOSE from 2010 to 2018. The difference from previous studies would lie in the usage of explanatory variables, the quantity of sample and the period of study. Based on data of 34 companies with 306 observations, this research methodology applies descriptive statistics, correlation statistics and regression analysis. The empirical results revealed that firm size, asset turnover, liquidity have a significant impact on firm profitability, while firm growth showed no significant effect on profitability denoted by ROA and ROE.