Tạp chí Khoa học Lâm nghiệp số 1-2019

Từ khóa: Đa dạng cây thuốc, thực vật có hoa, Vườn Quốc gia Phia Oắc – Phia Đén

There are 2 classes, 143 families, 465 genera, 741 medicinal species of Magnoliophyta are distributed in the Phia Oac – Phia Den National Park. Magnoliopsida comprises 119 families, 391 genera, 621 species (83.81% medicinal flowering plants); Liliopsida comprises 24 families, 74 genera, 120 species (16.19% total medicinal flowering plants). The family comprises the maximum number of medicinal flowering species is Asteraceae (56 species, 7.56% total medicinal flowering plants). The genus Ficus comprises 15 species (2.02% total medicinal flowering plants). 63 species are recorded in Vietnam Red Data Book (part 2. Plants. 2007); 3 species in critically endangered situation (CR), 21 species in endangered situation (EN) and 39 species in vulnerable situation (VU).

Keywords: Diversity of medicinal plant, flowering plants, Phia Oac – Phia Den National Park

Từ khóa: Thực vật bị đe dọa, Thực vật ở Vườn Quốc gia Phia Oắc – Phia Đén

The study is an outcome of the surveys conducted to assess the status of threatened species in the Phia Oac – Phia Den National Park, Cao Bang province. 78 species belonging to 60 genera and 34 families were identified. Out of these, 61 species have been listed in the Red Data Book of Viet Nam (2007), 20 species in the Government Decree 32/2006/NĐ-CP (2006) and 16 species listed in the IUCN Red List (2015). The number of useful plant species found in Phia Oac – Phia Den National Park is also categorized as follows: 32 medicinal plant species, 15 timber yielding species, 10 ornamental species and 3 species for vegetable.

Keywords: Threatened species, Plants of Phia Oac – Phia Den National Park

Từ khóa: Cây Tơm trơng, kiểu thảm, vùng phân bố

Urceola minutiflora or Tom trong Atao Nenso is a woody vine species of the family Apocynaceae. This medicinal plant is the main ingredient of Amakong folk remedies used to enhance strength and improve male sexual health. The survey showed that the distribution area of Urceola minutiflora includes Gia Lai (Krong Pa), Dak Lak (Ea H’leo district and Yok Don National Park) and Lam Dong (Duc Trong) province in the Central Highland. The Urceola minutiflora grows at the altitude of 200 to 900 m but clusters at 300 to 500 m above sea level on sandstone soil or sandy clay. According to the classification of Thai Van Trung (1975), distribution of Urceola minutiflora was in three types: (1) V: Tropical semi – drought broad – leaved sparse forest; with 2 extra subformation is dried – sparse forests on sandy soils and clays mixed sand (V. Mia. 2) and its degenerated population was grass and shrubs (V. Mia.4.2); (2) Tropical semi – deciduous closed forest (II.Mia); (3) Artificial forest of Eucalyptus (Eucalyptus microcorys).

Keywords: Urceola minutiflora (Pierre) D.J.Middleton, Vegetation type, Distribution area

Từ khóa: Bạch đàn lai UP, in vitro, mô sẹo, phôi soma, tái sinh

Leaf and stem of 15 days tissue culture shoots were used as explants to establish a regeneration protocol for Eucalyptus hybrid between E. urophylla and E. pellita (UP hybrid). The explants were cultured on modified MS medium (MS medium reduced half total nitrogen) supplemented with 3.0 mg/l 6 – benzylaminopurine (BAP), 0.5 mg/l naphthalene acetic acid (NAA), 2% sucrose, 100 ml/l coconut water and 2.4 g/l phytagel, the ratio of callus induction was 88.3% and 81.7% with the stem and in the leaf materials, respectively. Callus was cultured in MS medium (reduced half total nitrogen) supplemented with 0.5 mg/l BAP, 0.2 mg/l NAA, 2% sucrose, 15mg/l riboflavin, 100 ml/l coconut water and 2 g/l phytage, showed a high frequency of adventitious buds formation (69.3%). Regenerated shoots were rooted in ½ MS medium supplemented with 2.0 mg/l indole – 3 – butyric acid (IBA), 1.0 mg/l NAA, 1.5% sucrose and 7g/l Agar. Plantlets were then successfully transplanted to the greenhouse with 90% survival. Generally, Eucalyptus hybrid between E. urophylla and E. pellitaregeneration protocol via somatic embryogenesis induction could be used for genetic transformation.

Keywords: UP hybrid, in vitro, callus, somatic embryo, regeneration

Từ khóa: Bạch đàn lai UP, chuyển gen, chiều dài sợi gỗ, gen EcHB1

The gene EcHB1, is isolated from E. grandis, encoding for increasing the wood fiber length was transferred into superior clones of E. urophylla ´ E. pellita (UP hybrid) via Agrobacterium tumefaciens. Use A. tumefaciens concentration of OD₆₀₀ = 0.5 to transform the EcHB1 gene in the suspension solution with 100 µM Acetosyringone into UP hybrid for 10 mins. After 72 hours of co – culture, the transgenic stem and leaf segments were regenerated on MS* selective medium supplemented with 0.5 mg/l BAP, 0.2 mg/l NAA, 400 mg/l Cefotaxim and 150 mg/l Kanamycin. After three selections on the regenerative medium, transgenic UP hybrid shoots were transplanted on selective rooting medium supplemented with 50 g/l Kanamycin. Results of the analysis of nursery plants by PCR method confirmed the presence of the EcHB1 gene in the UP hybrid tree.

Keywords: UP hybrid, transgenic, wood fiber length, EcHB1 gene,

Từ khóa: Kon Hà Nừng, sinh khối trên mặt đất, rừng thứ sinh lá rộng thường nhanh

Accurate estimates of aboveground biomass to monitoring carbon budget in forest ecosystems are very important. Carbon budget is estimated as 50% of biomass stock. This study used allometric models to estimate aboveground biomass of secondary evergreen broadleaf forests in Kon Ha Nung, Gia Lai. The result shown that the allometric equation AGB = 0,0755*D_1,3^2,57 (R = 0,995) had least error and was selected to estimate aboveground biomass. Annual increment of biomass of forests from permanent sample plots varies from 0.25 to 8.3 ton/ha/year with an average of 5.8 ± 2.3 ton/ha/year. Results from 6 experiment sample plots shown that increment of abovegrond biomass varies from 12.6 in low impacted forests to 14.8 ton/ha/year in restored forests. In which, the rate of living biomass account of from 40.6 to 52.3% and bimass of litterfall account from 47.7 to 59.4%.

Keywords: Kon Ha Nung, Aboveground biomass, secondary evergreen broadleaf forests

Từ khóa: Đặc điểm lâm học, Mạy châu, rừng tự nhiên phục hồi, Sơn La

Carya tonkinensis Lecomte is a indigenous, large – sized, multi – purposes, narrowly distributed tree species. The research was conducted in rehabilitated natural forests where Carya tonkinensis Lecomte distributed in Son La city, Son La province. The results showed that Carya tonkinensis Lecomte is the dominant tree species in this secondary ecosystem with the important value (IV% index) of 8.45 – 10.9 and the average density of 20 trees/ha. The frequency distribution in diameter (n/D_1.3) and height (n/H_vn) were mainly in the left – handed shape. Seedling of Carya tonkinensis Lecomte could regenrated from seed bank or by copicing with species composition index ranging from 0.70 – 0.94 and density from 166 – 332 trees/ha. Proportion of promising Carya tonkinensis Lecomte seedling (> 1 m in height) ranged from 79.16% to 81.25%. The rate of regenerated trees of medium and good quality accounts for a high proportion, ranging from 88.4% to 89.43%. The distribution of Carya tonkinensis Lecomte seedling among the site was quite equal.

Keywords: Silvicultural Characteristics, Carya tonkinensis Lecomte, natural rehabilitation forest, Son La province

Từ khóa: Keo tai tượng, Keo lá tràm, keo lai, xử lý thực bì để trồng rừng, Quảng Ninh

Vegetation treatment before planting forest is one of the important technical measures, if vegetation treatment is unreasonable, it will reduce productivity and quality of forests, reduce soil fertility and affect long – term and sustainable business. Within the scope of this study, three experimental vegetation treatment formulas were applied for Acacia mangium, Acacia auriculiformis and Acacia hybrids, including: 1/ Comprehensive clearance and even organic materials spread on the area; 2/ Comprehensive clearance and collect organic materials into beds along contour lines; 3/ Selective clearance in strips (1 m – wide un – cut strips, 2 m – wide cutting strips). After 2 years of planting, the growth ability of A. mangium was significantly different with different vegetation treatment formulas, namely higher growth with comprehensive clearance treatments, diameter at breast height (D1,3) was from 6.35 – 6.97 cm, total height (H_vn) from 6.54 to 7.12 m; meanwhile, in the selective clearance treatment formula, the mentioned values ​​were only 6.09 cm and 6.30 m respectively. After 2 years of planting, the growth of Acacia auriculiformis with various treatment formulas was not significantly different, the diameter ranges from 5.03 – 5.52 cm, the height ranges from 6.02 – 6.32 m. Similarly, after 2 years of planting, Acacia hybrid growth with treatment formulas did not differs much, diameter (D_1.3) from 6.81 – 7.16 cm, height (H_vn) from 7.12 – 7.72 m. Therefore, with the current status of poor natural forests, the height of vegetation below 7 m, to plant Acacia mangium, it is necessary to to apply comprehensive vegetation clearance and even organic materials spread on the area or collect organic materials into beds along contour lines (no burning), for afforestation of Acacia auriculiformis and acacia hybrid, all three methods of vegetation treatment can be applied, but selective clearance in strips should be used because of greater benefits it brings.

Keywords: Acacia mangium, Acacia auriculiformis, Acacia hybrids, vegetation treatment before planting forest, Quang Ninh province

Từ khóa: Keo tai tượng, Keo lá tràm, keo lai, mật độ trồng, Quảng Ninh

Density of plantation is an important silviculture treatment for intensive forest planting, that contributes improves productivity and quality of plantation, especially intensive plantation of Acacia hybrids, Acacia mangium, and A. auriculiformis for the large timber production purposes. In this study, four different density levels were used include: i/ 1,660 trees/ha (2 ´ 3m); ii/ 1,110 trees/ha (3 ´ 3 m); iii/ 830 trees/ha (3 ´ 4 m); iv/ 625 trees/ha (4 ´ 4 m). After 2 years, the growth of Acacia hybrids in four density levels are significant difference in both of Diameter at Breast Height (DBH) and Height (H): The highest average DBH reached 8.25 cm with the density of 625 trees/ha, DBH gradually decreasing when density increasing and the smallest DBH is 7.08 cm with density of 1,660 trees/ha; the highest average Height reached 7.96 m with the density of 1660 trees/ha, average Height gradually decreasing when density decreasing and the smallest Height is 7.37 m with density of 625 trees/ha. The growth of Acacia mangium of four density levels are significant difference in both of average Diameter at Breast Height (DBH) and average Height (H): The highest average DBH reached 7.27 cm with the density of 625 trees/ha, DBH gradually decreasing when density increasing and the smallest average DBH is 6.39 cm with density of 1,660 trees/ha; the highest average Height reached 6.14 m with the density of 1660 trees/ha, Height gradually decreasing when density decreasing and smallest average Height is 5.99 m with density of 625 trees/ha. The growth of A. auriculiformis of four density levels are significant difference about average Diameter at Breast Height (DBH): The highest average DBH reached 6.86 cm with the density of 625 trees/ha, DBH gradually decreasing when density increasing and the smallest average DBH is 5.25 cm with density of 1,660 trees/ha; Height are not significant different with the average Height from 6.37 – 6.96 m. However, average height also tends to increase from low density to high density. That results just an initial results in the period new forest closure canopy, further investigation is required in the next 1 – 2 years for more accurate conclusions.

Keywords: Acacia mangium, Acacia auriculiformis, Acacia hybrid, planting density, Quang Ninh province

Từ khóa: Bời lời đỏ, carbon, sinh khối, seemingly unrelated regression (SUR)

Machilus odoratissimus Nees is a species of multi – purposes, hight economic value and environmental protection. In plantation business, it demands modeling system that predicts accurately aboveground biomass and its components; At the same time, the developed models support to compute carbon accumulation of forest trees for program of reducing emissions from deforestation and forest degradation. Twenty – two 300 m² plots within the full range of 1 – 7 ages in the Central Highlands were measured. A total of 22 averaged – diameter trees were destructively sampled to obtain a dataset of the dry biomass/carbon of the stem (Bst/Cst), bark (Bba/Cba), branches (Bbr/Cbr), leaves (Ble/Cle), and total aboveground biomass/carbon (AGB/AGC). The study compared two methods: developing independent equations was weighted nonlinear regression fit by maximum likelihood and building simultaneous modeling system was weighted nonlinear fit by seemingly unrelated regression (SUR). As a result, the modeling system devloped simultaneously using SUR produced higher reliability than the models established independently. The selected forms of modeling systems for estimating tree aboveground biomass/carbon and its components were AGB = Bst + Bba+ Bbr + Ble = a₁×(D²H)^b1 + a₂×(D²H)^b2 + a₃×D^b3 + a₄×(D²H)^b4 and AGC = Cst + Cba+ Cbr + Cle = a₁×(D²H)^b1 + a₂×(D²H)^b2 + a₃×D^b3 + a₄×(D²H)^b4.

Keywords: Machilus odoratissimus, biomass, carbon, seemingly unrelated regression (SUR)

Từ khóa: Google earth engine, rừng ngập mặn, tần số độ che phủ tán, tần số độ ngập triều, tần số độ xanh

Due to anthropogenis disturbances and climate change, accurate and contemporary maps of mangrove forests are needed to management, protection and establish plans for sustainable management. In this study, a classification algorithm was developed using the biophysical characteristics of mangrove forests in Viet Nam. Specifically, mangrove forests distribution maps were mapped by: (1) Greeness frequency; (2) Canopy frequency; (3) Inundation frequency from time series Landsat 8 OLI and some other datas: elevation, slop… The annual mean Normalized Difference Vegetation Index (NDVI) was found to be a key variable in determining the classification thresholds of Greeness frequency, Canopy frequency, Inundation frequency to determined areas mangrove forests distribution. In addition, the intergration of Sentinel 1 VH band and modified Normalized Difference Water Index (mNDWI) shows great potential in identifying yearlong tidal and fresth water bodies, which can not distribute of mangrove forests. Mangrove forests distribution maps were mapped at 30 m spatial resolution have accuracy greater than 93% when validated with ground reference data. This study has demonstrated the potential of using time series Landsat 8 OLI and Sentinel – 1 imagery in Google earth engine cloud computing platform to identify and map mangrove forests along the coastal zones in Viet Nam.

Keywords: GEE, mangrove forests, canopy frequency, inundation frequency, greeness frequency

Từ khóa: Mô hình trồng Trôm, Trôm, Sterculia foetida L., Nam Trrung bộ, hiệu quả kinh tế

Research in economic efficiency assessment from some Trom (Sterculia foetida L.) plantation experiment models in the dry zone at South of Central Viet Nam was a sub – content in a whole batch research topic “Research in breed selection, plantation technical and harvesting Sterculia foetida L. latex in the dry zone at South of Central Viet Nam” from 2013 to 2018. The data was collected from Sterculia foetida L. plantation experiment models in smallholders on Tuy Phong district, Binh Thuan province, and Ninh Phuoc, Thuan Nam district, Ninh Thuan province. The result on diameter growth has the range from 1,48 cm/year in MH7 to 2.98 cm/year in MH4. For height growth has the range from 0,25 m/year in MH7 to 1 m/year in MH3. For canopy’s diameter growth has the range from 0.21 m/year (MH7) to 0.72 m/year in MH3 and MH5. Survival rate was high from 74.9% in MH7 to 98% in MH4. Economic efficiency assessment from Trom (Sterculia foetida L.) plantation experiment models up to 10 – year – old show: the intensive Trom (Sterculia foetida L.) plantation experiment model (MH4) has the highest efficiency with economic indicators show NPV ≈ 153 million VND/year,
IRR ≈ 40%, BCR ≈ 2 times and labor efficiency got 463.000 VND/day. In agricultural trees (corn, bean) intercropping with Trom (Sterculia foetida L.) in the first 2 – year model, the density was 833 trees/hectare (MH5) also show the high economic efficiency with some indicators such as NPV ≈ 96.7 – 99.8 million VND/year, IRR ≈ 43 – 53%, BCR ≈ 1.8 times and labor efficiency got 463.000 VND/day. The plantation experiment model with the density 2.500 trees/hectare (MH1) was less economic efficiency model with labor efficiency got only 269.000 VND/day and the revenue also dropped rapidly, at the 10th year the revenue will get only 20 million / hectare/year.

Keywords: Trom plantation experiment models, Trom, Sterculia foetida L., South of Central Viet Nam, economic efficiency

Từ khóa: Luồng, Tre ngọt, Vầu đắng

The bonded characteristics, physical and chemical properties of Luong, Sweet Bamboo and Bitter Melon have been studied to assess the ability of materials to produce pressed bamboo. The results showed that all 3 bamboo species are big bamboo species with high roundness. Volumetric volume from 0.586 g/cm³ ~ 0.613 g/cm³; static bending strength from 138.90 N/mm² ~ 158.88 N/mm²; pH of 3 bamboo species from 5.3 ~ 5.62 is mild acidic bamboo species, high cellulose content is approximately 40%, which is the element of increasing the mechanical strength and natural durability of bamboo, lignin content. Approximately 25% high contributes to good heat – resistant bamboo and increases the hardness of bamboo. All 3 species of bamboo are suitable as raw materials for the production of pressed bamboo.

Keywords: Luong, Sweet bamboo, Indosasa angustata

Từ khóa: Bời lời vàng, tính chất vật lý, tính chất cơ học, sử dụng gỗ

Litsea pierrei Lecomte is a large tree species growing fast, adapting to many different ecological regions in Vietnam. Soft wood, smooth and straight grain, Wood diffuse – porous, 5 – 8 Vessels per square millimeter with mean tangential diameter of 148 µm; ray width 1 to 3 cells. Small wood shrinkage (total shrinkage in tangential direstion 7.6%, in radial direction 4.9% and volume of 13.7%). Litsea pierrei wood has low mechanical strength (compression parallel to grain: 38.8 MPa, tension parallel to the grain: 112.4 MPa, static bending: 69.6 MPa, impact strength: 37.5 kJ / m², cleavage parallel to grain: 16.5 N / mm, modulus of elastic: 5.2 GPa). With structural features, physical and mechanical properties mention above, Litsea pierrei wood has the ability to be less warped, cracked during drying process, easy to process, suitable for veneer, blockboards and wooden furniture. Wood is not suitable for use in construction and transportation needs a high load.

Keywords: Litsea pierrei Lecomte, wood physical properties, wood machenical properties, wood utilization