INTRODUCTION
Forests play a vital role in human life by providing essential products and supporting ecological balance However, in recent years, forest resources in Vietnam have declined in both quantity and quality due to over-exploitation, land conversion, urbanization, and inadequate management Historically, Vietnam's total forest area was approximately 14.3 million hectares in 1945, covering 43% of the land, with high-quality primary forests By 1990, this had decreased significantly to 9.3 million hectares with only 28.4% forest cover, and forest quality had deteriorated Thanks to reforestation and conservation efforts, the forest area increased to 13.95 million hectares in 2010, including 10.4 million hectares of primary forests and 3.08 million hectares of plantations, raising the cover to 39.5% However, the overall forest quality remained poor, and the ecological benefits, such as carbon sequestration, were minimal, with most forests consisting of fast-growing, low-value trees that are insufficient for sustainable production needs.
Located in northern Vietnam, Phu Tho province is bordered by Tuyen Quang and Yen Bai to the north, Son La and Hoa Binh to the west, Hanoi to the south, and Ha Giang and Vinh Phuc to the east Covering an area of approximately 353,295 hectares, the province includes 64,097 hectares of natural forest and 121,703 hectares of plantation, with a forest cover of 50.6% Despite the extensive forestry land, forest quality remains low, primarily consisting of small timber species Therefore, sustainable development of forest tree species is a critical challenge for Phu Tho, requiring effective strategies to improve forest quality and productivity.
With over 40 years of research and experimentation on native species for afforestation across various regions, planters have achieved significant success along with certain limitations A key achievement is the selection of 50 to 52 native species for large-scale timber production, as well as for smaller timber and non-timber forest products, according to Decision No 16/2005 of MARD Additionally, 28 species, including 11 large timber species, have been systematically studied to optimize afforestation efforts and ensure sustainable forest management.
A total of 50 species were planted for timber production, with nearly 22 large timber species cultivated across a thousand hectares; however, only 18 species were successfully established The main challenges included the diverse selection of tree species and a lack of focus on key species, with decisions often based on experience rather than scientific research To address these issues, a systematic approach focusing on a few prioritized species is essential Although many native species have been included in the reforestation list introduced by MARD, most lack comprehensive studies on their biological characteristics, limiting their effective utilization.
Lithocarpus fissus is known as native and useful species which has wide distribution
Lithocarpus fissus boasts large, sturdy wood suitable for building houses, crafting household items, and manufacturing agricultural tools Its fast growth, high resistance, and excellent natural regeneration make it a valuable species for sustainable forest development Therefore, Lithocarpus fissus has strong potential to enhance forest resources and contribute to the country's economic growth (Nguyen, 1999).
Despite numerous studies on Lithocarpus fissus, there has been no research focusing on its biological characteristics in Doan Hung district, Phu Tho province Therefore, the student selected the topic "Some Biological Characteristics of Lithocarpus fissus for Large Timber Production in Doan Hung District, Phu Tho Province" for their graduation thesis This study aims to fill the research gap by examining key biological features of Lithocarpus fissus specific to this region, contributing valuable insights for sustainable timber cultivation.
LITERATURE REVIEW
Over the world
Lithocarpus fissuss, a large timber tree belonging to the Fagaceae family, is also known by several scientific names including Quercus fissa Champ ex Benth, Pasania fissa (Champ ex Benth.) Oerst, and Castanopsis fissa (Champ ex Benth.) Rehd & Wils This species is notable for its significant timber value and botanical diversity, making it a key species for forestry and ecological studies.
Fagaceae is traditionally considered part of Cupuliferae, as noted by Bentham and Hooker (1862–1883), who did not recognize it as an independent family However, many researchers, including Milchior (1964), Menisky (1984), Takhtajan A.L (1987), and Soepadmo (1972), consider Fagaceae as an independent family comprising 7–9 genera, divided into 2–5 subfamilies In 1996, Takhtajan A.L proposed a classification similar to Kupriantova (1962), excluding the genus Nothofagus from Fagaceae.
In 2008, some botanists arranged Nothofagus genus into Nothofagaceae family (Judd, 2008)
Huang Chengjiu et al (1999) describe Lithocarpus fissuss species as follows:
The trees feature bud scales, shoot apexes, and young leaf blades that are yellowish-brown, puberulent, and covered with small, rust-colored, lamellate, slightly adnate, waxy scalelike trichomes Branchlets are prominent, angular, and display a red-purple coloration Leaves are spirally arranged, varying in size from 15–25 × 5–9 cm, with a yellowish-brown to gray color, thickly papery texture, and an oblong to obovate-elliptic shape The leaf base is cuneate, with undulate and crenate margins from the base to the middle, and an apex that is acute, acuminate, or rounded; the midvein is raised on the adaxial side, with 20–28 secondary veins on each side of the midvein The infructescence measures 8–18 cm, featuring a glabrous rachis The cupule is 1–1.5 cm in diameter, irregularly 2- or 3 (or 4)-valved with often curled valves, covered with dark reddish-brown, mealy, waxy scalelike trichomes, and has a slightly cuspidate apex with a wall thickness of 0.5–1 mm The scalelike bracts are triangular to squarish, imbricate when young, but generally fused into ring ribs with age The nut is globose to elliptic, measuring 1.3–1.8 × 1.1–1.6 cm, with a brown-red tomentose apex, and a basal scar that is 4–7 mm in diameter.
The Fagaceae family comprises approximately 900 species worldwide, primarily distributed across the temperate zones of the Northern Hemisphere, as well as subtropical and tropical regions Asia, particularly Vietnam, is the most extensive and diverse distribution area for Fagaceae species, highlighting the family's significant ecological and botanical importance in this region.
216 species The Africa and the Mediterranean are two places that contain the least species of
Lithocarpus fissuss species, as described by Paul C F Tam and D A Griffiths (1993), is found at high elevations ranging from 700m to 1700m This species thrives in evergreen forests with moist, deep, and heavy loam soils that have a pH between 4.5 and 5.0 It can tolerate temperatures as low as -5°C and typically grows in areas receiving annual precipitation between 1000mm and 2000mm These conditions make Lithocarpus fissuss ideal for cultivation in mountainous regions with suitable soil and climate.
Lithocarpus fissus primarily grows in ridge areas with thick soil layers, thriving in well-drained environments Young trees are shade-tolerant and can adapt to low light conditions, while mature trees require full sunlight for optimal growth They exhibit rapid regeneration through bud growth and can grow quickly, reaching heights of up to 22 meters and diameters of 300 cm at 23 years old in secondary forests In plantation settings, their diameter can reach about 15 cm after 15 years Growth slows significantly after 30 years of age Lithocarpus fissus begins seed production at 7–8 years old, yielding approximately 50 kg of seeds annually during peak periods The seeds can be processed within 24 hours at appropriate temperatures, ensuring efficient propagation and sustainable forestry practices.
80 o C They will germinate after 4 weeks.
In Vietnam
Research on Lithocarpus fissus in Vietnam remains limited, primarily focusing on its biological characteristics, distribution, and planting techniques Key areas of study include seed selection and propagation methods, which are essential for effective cultivation and conservation efforts Future research should aim to deepen understanding of its ecological role and develop improved propagation strategies for sustainable growth.
According to Chan LM, Huyen LT (2000), the scientific name of this species is
Castanopsis cerebrina belongs to the Fagaceae family, which comprises approximately seven genera with over 600 species worldwide In Vietnam, there are five genera with around 120 species of Fagaceae However, the scientifically recognized name for this species is Lithocarpus fissuss, which is the most commonly used scientific name in research and identification.
Hoang et al (2004) describe the morphological characteristics of Lithocarpus fissuss species as follows:
“Trees up to 25 m high, up to 90 cm diameter Trunk straight, young branches covered with dense reddish brown, simple and stellate hairs Leaves distichous, obovate, 12–20 by 4 –
This plant features an 8 cm base cuneate leaf with an acutely and regularly serrate margin that extends for three-quarters of its length towards the apex The leaf tapers into an acuminate tip and exhibits a striking coloration: green on the upper surface and reddish-brown tomentose beneath, which becomes nearly glabrous when mature Its pinnate venation includes 10–20 pairs of lateral veins that curve at the margins and are prominently visible on the lower leaf surface.
Petiole 1 – 2 cm long, slightly tomentose Male catkins 4 – 9 cm long, in branched panicles, usually terminal Perianth puberulous Anthers small, filament slender Pistillode small, styles
3, divergent Female inflorescences 5 – 11 cm long Cupule cup-shaped, 1.8 – 2.5 cm long,
1.6 – 2.2 cm diam., enclosing about 1/2 the seed, densely hairy inside, slightly tomentose outside, scales acute, flat, arranged into many irregular bands, pedicel 4 – 5 mm long, solitary
Nut narrowly conical, 2 – 2.5 by 1.4 –1.8 cm, tomentose, apex sometimes 3-angled”
Lithocarpus fissus is a light-demanding tree species naturally found in Southeast Yunnan, China, Indochina, northern Thailand, and Louang Namtha Province in Laos It also grows abundantly across multiple Vietnamese provinces, including Ha Tinh, Nghe An, Thanh Hoa, Yen Bai, Tuyen Quang, Quang Ninh, Ha Bac, and Ha Tay These trees typically thrive on low hills or forest edges at altitudes below 400 meters, showcasing good natural regeneration and high germination rates both in the wild and in nurseries The flowering period for Lithocarpus fissus occurs from February to April and again in October, making it a notable species for forest ecology and reforestation efforts.
November Their fruiting times are March to June, October to December.
Reviews of the studies
Lithocarpus fissuss is a species with limited global research, primarily focused on its classification, morphological features, and biological traits Despite the limited studies, existing research highlights its significant economic value Therefore, promoting the widespread cultivation of Lithocarpus fissuss is recommended to harness its potential benefits across different countries.
Research on Lithocarpus fissuss in Vietnam has primarily focused on its classification, morphological features, and distribution However, there is limited information regarding its biological characteristics, such as species composition and distribution based on tree height Therefore, studying these aspects is essential for understanding the species better The topic “Some biological characteristics of a species of Lithocarpus fissus for large timber production in Doan Hung district, Phu Tho province” addresses this knowledge gap and holds significant importance for sustainable timber utilization.
Natural and socio – economic conditions of the study area
Doan Hung is a rural district located in Phu Tho province in the Northeast region of Vietnam Covering an area of 302.4 square kilometers, it encompasses 27 communes and one town According to data from the district's electronic communication website, Doan Hung is a significant administrative region with diverse local communities.
Doan Hung, as noted by the Central Northern Center of Forest Sciences, features a diverse topography characterized by deep gorges and dense streams Its landscape is notably varied, with two main topographical types that shape the region's natural environment.
Distributed centrally within the district, the low mountain type features a relatively flat topography with gentle slopes The area maintains an average elevation of approximately 350 meters above sea level, with an average slope of only 20 degrees This terrain is characterized by its low elevation and less steep landscape, making it distinct within the region's geographical features.
The primarily distributed hills in the district feature separated or connected formations with an average slope of 15°, making them ideal for planting industrial facilities, fruit trees, and long-term crops Small valleys between these hills provide suitable conditions for rice cultivation and short-term tree farming, maximizing land use potential in this topography.
In general, both types of topography are suitable for afforestation and planning long – term industrial trees
The study area features a straightforward geological background dominated by sedimentary and metamorphic rocks, primarily forming Oxisols on mica schist, clay schist, and Gnai The weathered soil layer is notably thick, exceeding two meters, indicating intense weathering processes Additionally, the region exhibits intermediate soil types and converging slopes, contributing to its diverse and dynamic terrain.
The soil is compositionally rich, ranging from clay to silt, with high porosity that enhances its permeability and water retention capabilities Its pH level varies between 3.9 and 5.4, indicating slightly acidic conditions, while the organic matter content is relatively high, promoting healthy plant growth.
Doan Hung district in Phu Tho province features a tropical monsoon climate, predominantly characterized by two distinct seasons each year The region experiences a long, dry winter, followed by a hot, humid summer with heavy rainfall These climatic patterns significantly influence the local weather conditions, agriculture, and daily life in the area.
The annual average temperature in this region is 23.1°C, with the dry season occurring from November to April and December being the coldest month The hot season spans from May to October, with an average temperature of 28°C and peak temperatures reaching up to 41°C.
The region experiences an average annual precipitation of 1,878 mm, with the highest rainfall occurring in August, which averages 322 mm, followed by July and September January records the lowest monthly rainfall, averaging just 31 mm Humidity levels are typically high, with an annual average of 85%, peaking in March at 92% and decreasing to a minimum of 77% in December.
The northeast monsoon occurs from October to March, bringing breezes that often lead to drizzling rains and cooler temperatures In contrast, the southeast monsoon happens from April to September, characterized by warm breezes that carry abundant moisture, resulting in heavy rainfall Understanding the seasonal patterns of these monsoons is essential for anticipating weather changes and planning accordingly.
The climate of Doan Hung district is generally suitable for cultivating Lithocarpus fissus, offering favorable conditions for growth However, the area's topography and annual rainfall patterns expose it to cyclones and hailstorms, which can adversely affect the health and development of these plants.
Doan Hung district has two rivers: Lo river and Chay river Besides, the study area has dense canal and stream systems which are favorable for transportation and irrigation
In recent years, Doan Hung District has actively invested in exploiting natural water resources through irrigation works and reservoirs to support agricultural and forestry needs However, the limited natural forest area and the monoculture plantation forests result in unstable stream flows, unable to reliably meet water demands Consequently, multiple drought years have caused significant damage to forestry production, highlighting the need for diversified forest management and improved water resource development.
Doan Hung district, situated at the heart of northern forestry, lies between the northwest and northeast forestry regions, boasting a rich biodiversity with 780 plant species across 477 genera and 120 families The area is home to numerous valuable timber species, including Erythrophloeum fordii, Dipterocarpus retusus, Amoors gigantea, Ormosia, and M faveolata, as well as various Fagaceae family members and bamboo species Additionally, the district hosts diverse herbal plants, such as Gynochthodes officinalis and Homalomena occulta, highlighting its vital role in northern biodiversity and forestry resources.
Arecaceae presented like Elaeis guineensis, Calamus armarus Lour
Due to exploitation and the traditional practice of shifting cultivation, many remaining forests are degraded secondary forests resulting from prior cultivation and subsequent restoration This ongoing habitat loss threatens numerous rare native species, putting them at significant risk of extinction.
Thanks to the dedicated efforts of authorities and research agencies, Doan Hung District has successfully reforested and rehabilitated large areas through regeneration, afforestation, and conservation initiatives Today, the district is home to protected forest stands classified as IIIa1, IIIa2, IIa, and IIb, ensuring the preservation of its vital forest ecosystems and promoting ecological sustainability.
GOAL, OBJECTIVES, AND METHODS OF THE STUDY
Goal
To provide some biological and ecological characteristics of a species of Lithocarpus fissus as the basic for large timber production in Doan Hung district, Phu Tho province.
Specific objectives
- To determine the biological and ecological characteristics of a species of Lithocarpus fissus
- To compare the different plantation models in study area
- To propose some suggestions to develop the species for large timber production
Methodology
3.3.1.1 Method for morphological characteristics study
The morphological characteristics of a species of Lithocarpus fissus are described directly through the representative objectives The results are then compared to the data sources
3.3.1.2 Species composition and regeneration study method
In the primary forest with a concentrated distribution of Lithocarpus fissus, three representative plots were established, each measuring 2,500 m² (50 m x 50 m), selected based on site conditions, slope orientation, slope gradient, and Lithocarpus fissus density Within these plots, comprehensive data collection was conducted to analyze the species' distribution and ecological characteristics.
For mature trees with a diameter at breast height (D1.3) greater than 6 cm, the survey involves identifying species names and measuring key growth indicators such as D1.3 in centimeters, total height (Ht) in meters, crown diameter (D cr) in meters, and under canopy height (H b) in meters Forest density and tree quality—classified as good, average, or bad—are also assessed Diameter measurements are obtained using a tape measure, while height data are collected using the Blume-Leiss tool.
To assess regenerated trees with a diameter at breast height (D1.3) less than 6 cm, five 5 m x 5 m sub-plots are established within each sample plot—four at the corners and one at the center Key data collected include species identification, tree density, total height measured with a tape measure, and qualitative assessment of tree health (good, average, bad) Additionally, the origin of the regenerated trees—whether from seed or bud—are documented to evaluate regeneration sources.
For the plantation forest, set up three plots (each plot has an area of 1000 m 2 – 40 m x
25 m) for mix plantation and the same for single species plantation Repeat all of measuring steps as primary forest
The mean annual increment (MAI):
According to West (2009), MAI is average rate of production (of wood, biomass, basal area, etc.) to any particular age of a stand
Figure 1: The plot sample of the primary forest
Figure 2: The plot sample of the plantation forest
Y(t): yield at time t t: the age of species at a measuring time
The coefficient of variation was calculated using Forkman‟s method (2009) γ γ: coefficient of variation
: Standard deviation à: mean of investigated factor
N%: the percentage of trees based on quality level n: number of trees based on quality level
N: total number of investigated trees
N: density of species per one hectare n: number of trees in the plot (for mature trees) or the sub – plot for (regeneration trees)
Splot: the area of plot or the total area of all sub – plots in the plot (m 2 )
The composition proportion of tree species is calculated by method of Vu (1984) IV% =
IV%: the composition proportion (important value) of the species
N%: density of tree in the plot
G%: % by total basal area of such species in the forest community
According to Thai (1978), species with an Importance Value (IV) greater than 5% are considered significant ecological species within a community To be part of the species composition, a species must have an Importance Value higher than the community’s average A dominant group is identified when it consists of fewer than 10 species, collectively accounting for at least 40% of the importance value, and these species define the community's main structure.
Ki: the species composition coefficient of a species of i
Ni: the number of a species of i
N: the total number of investigated trees
RESULTS AND DISCUSSION
Some biological characteristics of a species of Lithocarpus fissus
The investigated results in Doan Hung district, Phu Tho province illustrates some morphological characteristics of study species as follows:
Lithocarpus fissus is medium – sized timber species; the length varies around 17
– 23 m; the diameter can reach to 80 cm
Their stumps have small buttress Their trunk is straight; young branches are covered with black – brown hairs The bark has light gray color; 3 – 5 mm thick
Flower unisexual, monoecious Male catkins 4 – 8 cm long Female inflorescences 5 – 10 cm long Anthers small, filament slender
Picture 3.1: Trunk of Lithocarpus fissus species
Picture 3.2: Flower of Lithocarpus fissus (source: http://www.fpcn.net/)
Leaves simple, oblanceolate, and alternate
The leaf blade measures 12–18 cm in length and 4–8 cm in width, featuring serrated margins on three-quarters of its length towards the top for an intricate edge Its apex is acuminate, tapering to a sharp point, while the base is cuneate, forming a wedge-shaped attachment The petiole is 1.5–2 cm long and covered with dense tomentose hairs, providing a fuzzy texture Notably, the upper surface of the leaf is vibrant green, contrasting sharply with the underside, which is densely covered with dark brown hairs, creating a striking visual difference between the two sides.
Cupule is cup – shaped; 1.7 – 1.8 cm in diameter, embracing 1/2 – 2/3 the seed; hairy inside; tomentose outside There are some unevenly distributed scales in the cupule The nut is conical – shaped; 2.5 –
3 cm long; 1.5 – 1.8 cm in diameter; easy to be detached from cupule
The community structure refers to the silvicultural characteristics of a forest stand, including species composition, forest structure, and the distribution of trees based on diameter or height These factors are essential for assessing the bio-ecological stability of the forest ecosystem Understanding community structure provides insights into the stand's diversity, health, and resilience, forming the foundation for effective forest management and conservation strategies.
Picture 3.4: Cupule and seed of Lithocarpus fissus species (source: the Central Northern
The study conducted by the Center of Forest Sciences focused on assessing the species composition and forest structure, as illustrated by Picture 3.3 showing the leaf of Lithocarpus fissus species These findings provide valuable insights for developing suitable solutions to enhance forest productivity and promote sustainable forest development.
Species composition is a key indicator of forest health, reflecting the contribution of each plant species to the overall community It provides insights into forest sustainability, stability, and biodiversity Higher species diversity indicates a resilient and balanced ecosystem capable of withstanding adverse environmental conditions The complexity of species composition correlates with increased forest sustainability This study measured species participation using the IV% (Important Value) method, with all species percentages totaling 100% Species with higher IV% values are more ecologically significant within the community The findings for natural forests containing Lithocarpus fissus are detailed in Tables 3.1 and 3.2.
Table 3.1: The species composition of the mature trees in Doan Hung district, Phu Tho province
Number of trees per plot ̅̅̅̅̅
Table 3.2: The species composition’s formula of the mature trees in the study area
Plot Species composition Total number of species
Plot 1 58.05 Lf + 7.25 Ef + 6.65 Lc + 5.95 Gs + 22.1 Os (20 species) 24
Plot 2 28.0 Lf + 19.6 Ob + 10.8 Gs + 9.2 Ef + 8.7 Ld + 6.8 Sp4
Plot 3 18.7 Lf + 12.9 Ob + 9.2 Qp + 9.2 Ef + 8.0 Gc + 6.1 Sl + 5.3 Ed +
Lithocarpus fissus (Lf), Lithocarpus corneus (Lc), and Lithocarpus ducampii (Ld) are key species contributing to forest biodiversity Gironniera subaequalis (Gs) and Elaeocarpus dubius (Ed) play important roles in maintaining ecological balance, while Garcinia cambogia (Gc) is notable for its economic and medicinal significance Erythrophloeum fordii (Ef) and Ormosia balansae (Ob) are valuable timber species, whereas Quercus platycalyx (Qp) supports diverse wildlife habitats Symplocos laurina (Sl) enriches understory vegetation, and other species (Os) collectively contribute to the forest ecosystem's resilience and diversity, emphasizing the importance of conserving these native trees for sustainable forest management.
The study reveals that the natural forests in the area are secondary forests regenerating after exploitation, with species diversity ranging from 14 to 26 species Lithocarpus fissus exhibits a high importance value (IV%) across three plots, registering 58.05%, 28.0%, and 18.7%, indicating its dominance in the ecosystem Key species contributing to the forest composition in Doan Hung district, Phu Tho province, include Lithocarpus fissus, Gironniera subaequalis, Erythrophloeum fordii, Lithocarpus corneus, Garcinia cambogia, Quercus platycalyx, Ormosia balansae, Symplocos laurina, Elaeocarpus dubius, and Lithocarpus ducampii, highlighting the area's rich biodiversity and ongoing forest restoration efforts.
4.1.2.2 The plant's distribution of stand based on the tree’s height
Table 3.3: The distribution of the plants based on the trees' height
Figure 3.1: The distribution of the plants based on the tree’s height
The study categorizes forest height into three layers: A1 (above 20 m), A2 (10–20 m), and A3 (below 10 m) In Plot 1, the average total height ranged from 7.7 m to 14.6 m, with no trees recorded in the A1 layer, while the A2 and A3 layers contained 396 and 272 trees per hectare, respectively Plot 2 showed a total height variation from 7.7 m to 21.6 m, with the A2 layer hosting the highest density of 516 trees, compared to 32 trees in A1 and 176 in A3 For Plot 3, the mean height ranged from 8.2 m to 21.9 m, with the A2 layer having the highest number of trees at 404, followed by 68 in A1 and 160 in A3.
Figure 3.2: The distribution of Lithocarpus fissus species based on the tree’s height
Lithocarpus fissus exhibits similar distribution patterns across different plots, with notable variations in vertical layering In Plot 1, most trees (66) occur in the A2 layer, while fewer are in the A1 and A3 layers (0 and 23 trees, respectively) Conversely, Plot 2 shows a higher concentration of Lithocarpus fissus in the A2 layer (41 trees), with fewer in A1 and A3 layers (3 and 5 trees) Plot 3 displays a different trend, with the highest number of trees in the A1 layer (8 trees) and minimal presence in A2 and A3 layers (2 and 1 trees) The total height of Lithocarpus fissus varies across plots, with mean heights ranging from 8.2 to 14.1 meters in Plot 1, 9.0 to 21 meters in Plot 2, and 8 to 22.5 meters in Plot 3, indicating variability in tree growth within the study area.
4.1.3.1 The density of natural regeneration
Natural regeneration density, measured as the number of regeneration trees per hectare, is a crucial indicator of a site's regeneration capacity and self-sown ability Evaluating regeneration density alongside species composition helps determine the appropriate silvicultural techniques, such as additional planting and enrichment, to promote healthy forest development.
Plot 1Plot 2Plot 3 planting, cutting down bushes, sowing can be applied to achieve the forestry business purpose The results of naturally regenerated trees‟ density in Doan Hung district, Phu Tho province were presented in table 3.4
Table 3.4: The density of naturally regenerated trees
Lithocarpus fissus ’s density (trees/ha)
The study results reveal that the regenerated tree densities in the area ranged from 21,280 to 26,000 trees per hectare, indicating a healthy and valuable reforestation effort Lithocarpus fissus also showed notable density variations across the three plots, with numbers ranging from 4,400 to 8,960 trees per hectare, highlighting its successful regeneration in the area.
4.1.3.2 The species composition of naturally regenerated trees in the study area:
The species composition of naturally regenerated trees reflects the stand's natural regeneration capacity, seed dispersal abilities, and germination success It not only highlights the forest's biodiversity but also indicates its economic value, serving as a foundation for recommending effective silvicultural practices to improve forest productivity and quality Additionally, analyzing species composition enables targeted management, such as removing unnecessary regenerated trees and promoting the growth of purposeful regenerations to enhance the maturity and overall health of the forest stand.
Table 3.5: The species composition index of naturally regenerated trees
Table 3.5 reveals that Doan Hung district in Phu Tho province hosts a highly diverse range of naturally regenerated species, totaling approximately 19 to 22 species Only plant species with a Ki index of 0.5 or higher are included in the species composition, with the finalized data summarized in Table 3.6.
Table 3.6: The species composition formula of the naturally regenerated trees in the study area
No Plot Forest status Species composition
3.35Co + 2.07Lf + 0.94Am + 0.71Gs + 0.71Ob +
Note: Lf – Lithocarpus fissus, Co – Cinnamomum obtusifolium, Ob – Ormosia balansae, Am – Alphonsea monogyna, Gs – Gironniera subaequalis, Os – Other species
The results presented in table 3.6 reveal that out of 19 to 22 species identified in the study area, only 3 to 5 species contributed significantly to the overall species composition Naturally regenerated trees predominantly appeared in the restoration forests, indicating successful natural regeneration processes after forest exploitation The key species involved in the composition of these regenerated trees played a crucial role in the forest rehabilitation efforts.
Lithocarpus fissu, Cinnamomum obtusifolium, Ormosia balansae, Alphonsea monogyna, and Gironniera subaequalis
4.1.3.3 The quality and the origin of the naturally regenerated trees
Table 3.7: The quality and the origin of the naturally regenerated trees in the study area
The results of table 3.7 could illustrate several reviews about the quality and the origin of the regenerated trees
In the study area, naturally regenerated trees originating from seed dominated all three plots, accounting for 98.1%, 97.8%, and 94.7% respectively, indicating a high prevalence of seed-based regeneration Conversely, the proportion of naturally regenerated trees from bud origin was minimal and not statistically significant across the plots, fluctuating between 1.9% and 5.3%.
Lithocarpus fissus, the results remained the same as that of plots The number of Lithocarpus fissus coming from seed in three plots was massively high, accounting for 95.5%, 95.5% and
96.4% of the total, correspondingly By contrast, the percentages of this species having origin from the bud in three plots were seriously flat, at 4.5%, 4.5%, and 3.5%, appropriately
Assessing the plantation models in Doan Hung district, Phu Tho province
This study analyzed data from two plantation models in Doan Hung district, Phu Tho province: a 15-year-old single-species plantation and a 10-year-old mixed plantation The findings, detailed in Tables 3.9 and 3.10, provide insights into the growth performance and ecological benefits of both plantation types.
Table 3.9: The growth of Lithocarpus fissus in 10 – year - old mixed plantation model
Table 3.9 shows that the growth of Lithocarpus fissus was not significantly different from Lithocarpus ducampii, with both species exhibiting a mean annual height increment of 1.6 meters Although Lithocarpus ducampii achieved slightly higher results in total height, bole height, diameter at breast height (DBH), density, and overall quality, the quality percentage for both species was predominantly good, exceeding 90% The coefficient of variation for DBH and total height was 30.9% and 17.7% for Lithocarpus fissus, respectively, while Lithocarpus ducampii demonstrated slightly lower variability in these indicators.
The coefficient of variation for both species was below 1, indicating low variability in DBH and total height measurements The results show that 27.8% and 14% are significant values, but overall, both species exhibit similar growth patterns This suggests there is no dominant species in the mixed plantation, demonstrating its stability and balanced composition.
Table 3.10: The growth of Lithocarpus fissus in 15 – year - old single species plantation model
The single species plantation model for Lithocarpus fissus demonstrates that the trees have almost reached maturity for large timber production, with impressive average measurements including a crown diameter of 6.7 meters, bole height of 9.7 meters, diameter at breast height (DBH) of 21.2 cm, and total height of 17.2 meters The low variance in DBH and total height indicates consistent growth, reflected in small coefficients of variation, underscoring the species' reliable development for timber harvesting.
Lithocarpus fissus demonstrated a high quality rating, with 96.2% classified as good, 3.8% as average, and none categorized as bad However, the plantation model exhibited a low density, reaching only just over half of the initial number of planted trees This reduction was primarily caused by disease outbreaks and nutrient competition, which significantly impacted tree survival and growth.
The mean annual increment (MAI) of Lithocarpus fissus is higher in mixed plantation models compared to single-species plantations Specifically, the MAI of diameter at breast height (DBH) is 1.5 in mixed plantations versus 1.4 in single-species plantations, and the MAI of total height is 1.6 compared to 1.1 These results indicate that mixed plantation systems enhance growth rates and overall wood productivity for Lithocarpus fissus. -Boost your forestry insights with precise MAI comparisons of Lithocarpus fissus—see how mixed plantations outperform singles! [Learn more](https://pollinations.ai/redirect/claude)
Lithocarpus fissus between two models are nearly the same, including around 95% of good quality trees while the average and bad quality trees were lower than 5%.
DISCUSSION
Review of the mature trees
- The morphological characteristics of a species of Lithocarpus fissus which were described in this study are not different comparing with those of other studies
Lithocarpus fissus is a promising species with significant potential for cultivation under a single-species plantation model, owing to its high IV% in species composition Additionally, it can be effectively integrated into mixed plantations alongside other main species, enhancing biodiversity and forest productivity This versatility makes Lithocarpus fissus a valuable candidate for sustainable forest management and plantation development.
The forest in this area was most stable in the A2 layer, which contained the highest number of trees across all plots Notably, Lithocarpus fissus trees predominantly populated this layer, indicating their significant presence within the mature forest structure.
A 1 layer and A 2 layer, which indicates that this species had ecological dominant in the community However, the number of Lithocarpus fissus trees occurring in the A3 layer of plot
3 was very low because the percentage of plants in other layer were very high lead to the lack of nutrient space for this species.
Reviews of the naturally regenerated trees
In Doan Hung district, Phu Tho province, the density of naturally regenerated trees is notably high, with Lithocarpus fissus accounting for approximately one-third of the total regenerated species This indicates the impressive natural regeneration capacity of Lithocarpus fissus, suggesting that strategic combination of natural regeneration and silvicultural techniques can facilitate rapid forest restoration and sustainable forest management.
The main species that took part in species composition were Lithocarpus fissus, Ormosia balansae, Alphonsea monogyna, and Gironniera subaequalis Lithocarpus fissus and
Cinnamomum obtusifolium was identified as the dominant species with the highest Ki index across all three plots, indicating its significant role in the regeneration process Supporting these dominant regenerated trees with appropriate management practices can provide them with adequate space and conditions for healthy growth Promoting the regeneration of key species like Cinnamomum obtusifolium is essential for maintaining forest biodiversity and ensuring sustainable forest development.
The study area’s species origin, including Lithocarpus fissus, is predominantly from seed, comprising approximately 95% of the total trees, highlighting the importance of optimizing site conditions for successful sowing and sapling growth Additionally, understanding the factors influencing seed germination is crucial for effective forest management The high percentage of high-quality trees, including Lithocarpus fissus, across the three plots indicates strong natural regeneration capacity, suggesting that with positive influences, these trees can grow sustainably and maintain ecological stability.
Regenerated trees, including Lithocarpus fisuss, showed a decline as their height increased in the study area, with significant decreases observed in the 1–2 m and >2 m height ranges This trend indicates intense competition for nutrients and space between regenerated trees and bushes, highlighting the need to support the growth of regenerated trees to ensure successful forest regeneration and ecosystem balance.
Review of the plantation models
Mixed plantations offer significant advantages over single-species plantations due to their higher MAI index, leading to increased productivity and timber yield They also enhance disease resistance, protecting diverse Lithocarpus fissus species from potential outbreaks Additionally, mixed plantations are more sustainable and resilient, providing long-term stability and ecological benefits Overall, while both plantation types are effective for large timber production, mixed-species plantations are superior in promoting ecological stability and sustainable forest management.
5.4 Proposing several viable suggestions to develop Lithocarpus fissus species
- It is advised that planters determine the area which has Lithocarpus fissus species, and they could apply some suitable silviculture techniques to support the regeneration such as:
+ Cutting down the vines, brushes and purposeless regenerated trees to increase the nutrient space for Lithocarpus fissus species
+ Cutting down the diseased trees as well as underdeveloped trees, planting the healthy trees in places where the seed could not germinate or the tree died
To effectively restore large bare lands exceeding 1,000 m², it is essential to sow key seedlings Suitable species for planting include significant trees like Lithocarpus fissus and other species such as Gironniera subaequalis, Erythrophloeum fordii, Lithocarpus corneus, Garcinia cambogia, Quercus platycalyx, Ormosia balansae, Elaeocarpus dubius, and Lithocarpus ducampii These species contribute to biodiversity and ecological stability, making them ideal choices for reforestation projects.
+ Hilling and digging around the tree stump twice a year
+ Thinning trees in the place that has the dense density to generate more nutrient space for Lithocarpus fissus species
To effectively protect the natural forests in the study area from wildfires, especially during the dry season, it is essential to enhance fire prevention measures by upgrading firefighting equipment and enforcing bans on risky activities such as campfires and smoking Implementing these strategies can significantly reduce the risk of wildfires and preserve the region's vital ecosystems.
- Protecting the mother trees as well as significantly regenerated trees from logging and destroying
- Preventing people from grazing in the natural forest in order to protect the naturally regenerated trees
- Enhancing the propaganda and advising people to take part in protecting the natural forest
For optimal growth and forest health, it is recommended to establish mixed plantations with Lithocarpus fissus rather than monoculture Mixed planting increases the mean annual increment, enhances forest stability, and reduces insect infestations Ideal companion species include those naturally occurring in the forest ecosystem, such as Lithocarpus ducampii and Erythrophloeum fordii, promoting biodiversity and sustainable forest management.
CONCLUSION AND RECOMMENDATION
Conclusion
Lithocarpus fissus is a species of medium-sized trees that typically grow 17 to 23 meters in height, with a trunk diameter reaching up to 80 cm These trees feature straight trunks with small buttresses at the base, and young branches covered in black-brown hairs The bark is light gray and 3 to 5 mm thick, providing a distinct texture They have simple, oblanceolate, and alternately arranged leaves, measuring 12 to 18 cm long and 4 to 8 cm wide, with serrated margins on three-quarters of the leaf length, an acuminate apex, and a cuneate base; the petiole is 1.5 to 2 cm long and tomentose The upper leaf surface is green, while the underside is covered with dark-brown hairs, indicating their characteristic leaf morphology Lithocarpus fissus produces unisexual, monoecious flowers, with male catkins 4 to 8 cm long and female inflorescences 5 to 10 cm long The species features small anthers and slender filaments in the flowers The cupule is cup-shaped, measuring 1.7 to 1.8 cm in diameter, partially embracing the seed with 1/2 to 2/3 coverage, and is hairy inside with a tomentose exterior, adorned with unevenly distributed scales The conical-shaped nut, 2.5 to 3 cm long and 1.5 to 1.8 cm in diameter, is easily detached from the cupule, making it a distinctive fruit of the species.
Lithocarpus fissus is a key species contributing significantly to the forest composition in Doan Hung district, Phu Tho province, with an importance value ranging from 18.7% to 58.05% This species predominantly occurs in the A1 and A2 layers of the natural forest, highlighting its vital role in maintaining the ecological structure of the region.
Lithocarpus fissus is the dominant regenerated species, with Ki index values fluctuating from 2.01 to 3.64, indicating its strong potential for seed regeneration and presenting a valuable opportunity for development strategies The naturally regenerated trees of this species exhibit high quality; however, intense competition for nutrients has limited the number of regenerated individuals taller than 1 meter.
The mixed-plantation model offers several advantages over the single-species plantation model, including higher mean annual increment, improved wood quality, and increased density This sustainable approach enhances overall forest productivity and ensures better resource utilization, making it a more effective option for forest management and timber production.
- The study has provided several viable suggestions to develop the growth of the
Lithocarpus fissus species including technical suggestions and social – economic suggestions.
Shortcomings
- The study could not cover other biological characteristics such as phenological characteristics, physio - biological and distributed features due to the lack of time
- Soil features were not mentioned in this study
- The comparison between two plantation models was only relative due to the lack of the assessment about site condition and other factors.
Flower of Lithocarpus fissus (source: http://www.fpcn.net/)
Leaves simple, oblanceolate, and alternate
The leaf blade measures 12–18 cm in length and 4–8 cm in width, featuring serrated margins on three-quarters of its length towards the top and an acuminate apex Its cuneate base provides a wedge-shaped connection, while the petiole, which is 1.5–2 cm long, is densely covered with tomentose hairs Notably, there is a striking contrast in coloration between the two sides of the leaf, with the upper surface being vibrant green and the underside covered in dense dark-brown hairs, highlighting the species' distinctive features.
Cupule is cup – shaped; 1.7 – 1.8 cm in diameter, embracing 1/2 – 2/3 the seed; hairy inside; tomentose outside There are some unevenly distributed scales in the cupule The nut is conical – shaped; 2.5 –
3 cm long; 1.5 – 1.8 cm in diameter; easy to be detached from cupule
The community structure of a forest stand encompasses key silvicultural characteristics such as species composition, forest structure, and the distribution of trees based on diameter or height These features are fundamental for assessing the bio-ecological stability of the forest ecosystem, providing insights into its health and resilience Understanding community structure is essential for effective forest management and conservation efforts.
Picture 3.4: Cupule and seed of Lithocarpus fissus species (source: the Central Northern
The study, conducted by the Center of Forest Sciences, analyzed the species composition and forest structure, exemplified by the Lithocarpus fissus leaf shown in Picture 3.3 These findings provide valuable insights that can inform suitable solutions to enhance forest productivity and promote sustainable forest development.
Species composition is a crucial indicator reflecting the contribution of each plant species in forming the plant community, helping to assess forest sustainability, stability, and biodiversity A higher species diversity indicates a more resilient and balanced forest ecosystem capable of resisting adverse environmental conditions The complexity of species composition enhances the overall sustainability and equilibrium of the forest This study quantified species contribution using the IV% (Important Value) method, with species percentages expressed to total 100%, where higher IV% values denote more influential species within the community Results from the natural forest containing Lithocarpus fissus are detailed in Tables 3.1 and 3.2.
Table 3.1: The species composition of the mature trees in Doan Hung district, Phu Tho province
Number of trees per plot ̅̅̅̅̅
Table 3.2: The species composition’s formula of the mature trees in the study area
Plot Species composition Total number of species
Plot 1 58.05 Lf + 7.25 Ef + 6.65 Lc + 5.95 Gs + 22.1 Os (20 species) 24
Plot 2 28.0 Lf + 19.6 Ob + 10.8 Gs + 9.2 Ef + 8.7 Ld + 6.8 Sp4
Plot 3 18.7 Lf + 12.9 Ob + 9.2 Qp + 9.2 Ef + 8.0 Gc + 6.1 Sl + 5.3 Ed +
The study focuses on various tree species, including Lithocarpus fissus (Lf), Lithocarpus corneus (Lc), and Lithocarpus ducampii (Ld), highlighting their ecological significance Garcinia cambogia (Gc) and Quercus platycalyx (Qp) are also examined for their contribution to forest biodiversity The presence of Gironniera subaequalis (Gs), Erythrophloeum fordii (Ef), Elaeocarpus dubius (Ed), and Ormosia balansae (Ob) underscores the diverse flora within the ecosystem Symplocos laurina (Sl) and other species (Os) further demonstrate the richness of this forest community, emphasizing the importance of these species for conservation and sustainable forestry practices.
The study reveals that the natural forests in the area are secondary forests, consisting of 14 to 26 species, which are gradually regenerating after previous exploitation Lithocarpus fissus plays a significant role in these forests, with an important value (IV%) of 58.05%, 28.0%, and 18.7% across three plots, indicating its dominance in the species composition Key species contributing to the biodiversity of Doan Hung district in Phu Tho province include Lithocarpus fissus, Gironniera subaequalis, Erythrophloeum fordii, Lithocarpus corneus, Garcinia cambogia, Quercus platycalyx, Ormosia balansae, Symplocos laurina, Elaeocarpus dubius, and Lithocarpus ducampii, highlighting the area's diverse forest composition and ongoing natural regeneration.
4.1.2.2 The plant's distribution of stand based on the tree’s height
Table 3.3: The distribution of the plants based on the trees' height
Figure 3.1: The distribution of the plants based on the tree’s height
The study categorizes forest height into three layers: A1 (above 20 m), A2 (10–20 m), and A3 (below 10 m) In plot 1, the average total height ranged from 7.7 m to 14.6 m, with no trees present in the A1 layer; A2 and A3 layers had 396 and 272 trees per hectare, respectively Plot 2's mean total height varied from 7.7 m to 21.6 m, with the highest tree density in the A2 layer at 516 trees per hectare, compared to 32 in A1 and 176 in A3 In plot 3, the average total height ranged from 8.2 m to 21.9 m, with the A2 layer containing 404 trees, while A1 and A3 layers had 68 and 160 trees per hectare, respectively.
Figure 3.2: The distribution of Lithocarpus fissus species based on the tree’s height
Lithocarpus fissus primarily populates the A2 layer, with 66 trees in Plot 1, while its presence in A1 and A3 layers is minimal, with 0 and 23 trees respectively In Plot 2, there are 41 trees in the A2 layer, with only 3 in A1 and 5 in A3, indicating a dominant distribution in the middle canopy layer Conversely, Plot 3 shows a different trend, with the highest number of trees (8) in the A1 layer, and fewer in A2 and A3 layers, with 2 and 1 trees respectively The average total height of Lithocarpus fissus varies across plots, ranging from 8.2 to 14.1 meters in Plot 1, 9.0 to 21 meters in Plot 2, and 8 to 22.5 meters in Plot 3, reflecting differences in growth patterns within each plot.
4.1.3.1 The density of natural regeneration
Natural regeneration density, measured as the number of regeneration trees per hectare, is a crucial indicator of a site's regeneration capacity and self-sown ability, influenced by various factors Evaluating this density alongside species composition helps determine the most effective silvicultural techniques, such as additional planting and enrichment, to promote healthy forest development.
In forestry management, techniques such as planting, cutting down bushes, and sowing are crucial for achieving business objectives The effectiveness of these practices was evaluated through the density of naturally regenerated trees in Doan Hung district, Phu Tho province, with the findings summarized in Table 3.4.
Table 3.4: The density of naturally regenerated trees
Lithocarpus fissus ’s density (trees/ha)
The study results, as presented in Table 3.4, reveal that the regenerated tree densities in the study area are substantial, ranging from 21,280 to 26,000 trees per hectare Notably, Lithocarpus fissus exhibited impressive densities across three plots, with figures ranging from 4,400 to 8,960 trees per hectare, highlighting the successful regeneration and dominance of this species in the area.
4.1.3.2 The species composition of naturally regenerated trees in the study area:
The species composition of naturally regenerated trees reflects the stand's natural regeneration capacity, seed dispersal ability, and germination success It highlights both the diversity of the forest community and its economic value, serving as a foundation for developing silvicultural techniques aimed at increasing productivity and enhancing forest quality Additionally, analyzing species composition allows for the improvement of mature tree populations by removing unnecessary regenerated trees and promoting the growth of purposefully regenerated ones.
Table 3.5: The species composition index of naturally regenerated trees
The findings presented in Table 3.5 indicate that Doan Hung district in Phu Tho province harbors a highly diverse range of naturally regenerated species, totaling approximately 19 to 22 species Since only plants with a Ki index of 0.5 or higher are included in the species composition, the final selection and summarization of species are detailed in Table 3.6, reflecting the most ecologically significant and resilient species within the area.
Table 3.6: The species composition formula of the naturally regenerated trees in the study area
No Plot Forest status Species composition
3.35Co + 2.07Lf + 0.94Am + 0.71Gs + 0.71Ob +
Note: Lf – Lithocarpus fissus, Co – Cinnamomum obtusifolium, Ob – Ormosia balansae, Am – Alphonsea monogyna, Gs – Gironniera subaequalis, Os – Other species
The results shown in Table 3.6 reveal that out of 19 to 22 species observed in the study area, only 3 to 5 species contributed to the overall species composition Naturally regenerated trees predominantly appeared in restoration forests that had undergone rehabilitation after exploitation The key species involved in the species composition of regenerated trees were primarily those that naturally recovered in the degraded areas, highlighting their vital role in forest regeneration and biodiversity restoration.
Lithocarpus fissu, Cinnamomum obtusifolium, Ormosia balansae, Alphonsea monogyna, and Gironniera subaequalis
4.1.3.3 The quality and the origin of the naturally regenerated trees
Table 3.7: The quality and the origin of the naturally regenerated trees in the study area
The results of table 3.7 could illustrate several reviews about the quality and the origin of the regenerated trees
In the study area, naturally regenerated trees originating from seed dominated three plots, accounting for 98.1%, 97.8%, and 94.7% respectively, highlighting the high prevalence of seed-based regeneration Conversely, naturally regenerated trees from bud were not significant across the plots, with proportions fluctuating between 1.9% and 5.3%, indicating limited contribution from vegetative regeneration methods.
Lithocarpus fissus, the results remained the same as that of plots The number of Lithocarpus fissus coming from seed in three plots was massively high, accounting for 95.5%, 95.5% and
96.4% of the total, correspondingly By contrast, the percentages of this species having origin from the bud in three plots were seriously flat, at 4.5%, 4.5%, and 3.5%, appropriately