Silviculture Honor

Vocational Activities

Requirements

1. Have the Trees Honor (EN 006).

   Answer: You must first complete the Trees Honor (code EN-006) — a mandatory prerequisite that teaches you to identify species, the parts of the tree (root, trunk, crown), and its ecological importance. Present the Trees badge to the instructor before starting Silviculture. — The Trees Honor (EN-006) is from the Nature Study area and provides the botanical foundation that Silviculture applies in forest management; the prerequisite system of the SAD Adventist manual ensures pedagogical progression — those who master identification can measure, classify, and manage a forest with greater rigor.

2. What is silviculture?

   Answer: Silviculture is the science and practice of cultivating, managing, and conserving forests for the sustainable production of wood, fiber, fruit, and environmental services. It studies planting, regeneration, thinning, harvesting, and protection of trees, integrating ecology, economics, and forest management techniques. — Silviculture comes from the Latin silva (forest) + cultura (cultivation); in Brazil it is regulated by the Forest Code (Law 12.651/2012), and the sector accounts for 1% of GDP and around 4 million direct and indirect jobs, according to IBÁ (the Brazilian Tree Industry) in its 2023 Statistical Yearbook.

3. Learn the proper use of the following forestry instruments and practice using them on trees in a forest. Record the information and the common name of each tree.
   • Diameter tape - measure the DBH (diameter at breast height) of trees [or measure the CBH (circumference at breast height) of trees and calculate the diameter]
   • Hypsometer or clinometer — measure the height of trees

   Answer: DBH is the international standard (1.30 m) because it eliminates deformations at the base and allows inventories to be compared; the Suunto clinometer and the Vertex hypsometer are the most used in the field. The relationship CBH = π × DBH was standardized by IUFRO in the early 20th century to harmonize forest inventories.

4. Know what an increment borer is and what it is used for. Know how a tree's age is determined by counting the number of growth rings. Why is this technique not recommended for trees from tropical regions?

   Answer: 1) What an increment borer is: it is a hollow drill that removes a thin cylinder of wood from the trunk without felling the tree. 2) What it is used for: extracting a sample of the wood to count the growth rings and estimate the tree's age (it also serves to study the growth rate). 3) How age determination by counting rings works: each growth ring corresponds to one year (the light part forms in spring/summer and the dark part in autumn/winter); counting the rings from the center to the bark gives the approximate age. 4) Why it is not recommended in tropical regions: because there are no well-marked seasons there (a climate without defined winter/summer), so the rings are irregular, poorly defined, or even absent, making accurate reading difficult or impossible. — The method is dendrochronology, created by A.E. Douglass in the USA in 1901; in tropical trees (without seasonal dormancy) growth is continuous and the rings are diffuse — Brazilian researchers use carbon isotopes and wood density as alternatives, according to LAQUA-USP in Piracicaba.

5. Use the information collected in requirement 3 to determine the volume in cm3 of the forest trees you measured.

   Answer: Use the data from requirement 3 (DBH and height of each measured tree) and apply the trunk volume formula: V = (π × DBH² / 4) × H × f, where DBH is the diameter at breast height, H is the total height, and f is the form factor (approx. 0.5 for conifers/pine and 0.7 for broadleaf trees). Keep the units consistent (DBH and H in cm) to obtain the volume in cm³. Calculate it for each measured tree and record the results. — The form factor corrects the estimate because the trunk is not a perfect cylinder (it tapers toward the top); the value 0.5 derives from the conical shape and 0.7 from the paraboloid of broadleaf trees. Inventories by the Brazilian Forest Service use this formula as the national standard for estimating the commercial standing volume of trees.

6. Calculate the basal area of a tree from the measurement of the diameter (DBH) or the circumference (CBH). Know what basal area per hectare is and which instruments can be used to estimate it.

   Answer: Basal area of a tree = π × (DBH/2)², or from the circumference: BA = CBH²/(4π). It is the cross-sectional area of the trunk measured at 1.30 m from the ground (breast height). Basal area per hectare is the sum of the basal areas of all the trees in 1 hectare (m²/ha), an indicator of the forest's density/stocking. Instruments to estimate it: a diameter tape or caliper (for DBH), a measuring tape (for CBH) and, for the per-hectare estimate, the Bitterlich prism or the Bitterlich relascope, which counts the trees 'included' in a fixed angular sweep from a point. — The Bitterlich method (1948) revolutionized forest inventory: it dispenses with fixed plots and gives basal area directly — each tree that appears larger than the prism's angle counts as 1 m²/ha. In Brazil it is a standard technique used by IBÁ and Embrapa Florestas in inventories of eucalyptus and native species.

7. Study five tree species important for silviculture in your area and give the following information about each:
   • Common name and scientific name
   • Distribution range of the tree
   • Height and diameter of the tree at adulthood
   • Common use and importance of the tree
   • Habitat of the tree and altitude

   Answer: Five Brazilian species: eucalyptus (Eucalyptus grandis, planted throughout the South/Southeast, 30-50 m, paper/pulp); pine (Pinus elliottii, South, 25 m, timber); golden trumpet tree (Handroanthus chrysotrichus, Atlantic Forest, 25 m, ornamental); jequitibá (Cariniana legalis, Atlantic Forest, 50 m); cedar (Cedrela fissilis, widespread, 30 m). — Eucalyptus and pine dominate the Brazilian paper/pulp sector (98% of commercial planting); the golden trumpet tree has been the national symbol tree since 1978; the pink jequitibá is the giant of the Atlantic Forest (with individuals up to 60 m and 3,000 years old); cedar is on the Red List as Endangered according to ICMBio.

8. List the benefits of the forest for the environment, water quality, air quality, wildlife, and recreation.

   Answer: The forest sequesters CO₂, regulates the climate, and protects the soil (environment); it filters and infiltrates water into the water table; it releases oxygen and removes pollutants from the air; it shelters fauna by providing food and refuge (animals); and it offers trails, camping, birdwatching, and ecotourism (recreation). — Each hectare of tropical forest sequesters about 7 tons of CO₂/year and produces 8 tons of O₂; the Atlantic Forest recharges aquifers that supply 70% of the Brazilian population, according to the SOS Mata Atlântica Foundation; trails in federal conservation units generated R$7.8 billion in tourism in 2023.

9. List the uses of the wood produced in the forests of your area and name at least two species that are important for each use.

   Answer: Construction: peroba (Aspidosperma) and massaranduba (Manilkara). Furniture: cedar (Cedrela) and ipê (Handroanthus). Pulp/paper: eucalyptus (Eucalyptus) and pine (Pinus). Energy (firewood/charcoal): eucalyptus and bracatinga (Mimosa scabrella). Crating/packaging: pine and Pinus taeda; poles: treated eucalyptus and Pinus. — Brazil is the world's largest producer of eucalyptus pulp (about 40% of the global market, according to IBÁ 2023); the pink peroba is on the Atlantic Forest Red List as Endangered, requiring certified management (FSC) for legal extraction — being central to quality civil construction.

10. Find out and discuss the following:
    • How are forests managed to reduce damage from insects and diseases?
    • What factors influence fire behavior?
    • Considering that fires produce both benefits and destruction, what treatments can reduce the severity of fires?

    Answer: Pest management: monitoring, resistant species, biological control. Fire is influenced by dry fuel, wind, humidity, slope, and temperature. Treatments: firebreaks (strips without vegetation), controlled burning, crown thinning, and low pruning to reduce the continuity of the combustible material. — Cemaden and Ibama maintain the Queimadas/INPE monitoring system; prescribed burning reduces accumulated fuel and has been a standard technique in Cerrado conservation units since 2014; wide firebreaks (~6-8 m) prevent spread by embers and crown fire, being effective against large-scale fires in forest fields.

11. Do one of the following in a forest regeneration area:
    • Visit a forest tree seedling nursery
    • Plant forest tree seedlings or forest seeds

    Answer: You visit a forest nursery (note the cultivated species, propagation techniques by seed or cutting, substrate, and time until planting) or plant seedlings/seeds in a regeneration area — dig a 30x30x30 cm hole, plant the seedling with its root ball, water it, and protect it with a stake during its first year of life. — Forest nurseries use a substrate of pine bark and slow-release fertilizer; IBÁ recommends seedlings in 280 cm³ tubes for Eucalyptus; the Ministry of the Environment coordinates the Pact for Restoration program, which has already restored more than 1 million hectares of Atlantic Forest since 2009 in the country.

12. Explore the biblical texts in Genesis 1-3 and Revelation 22 that speak of the tree of life. Discuss the role of trees in God's perfect environment and our responsibility to care for our environment.

    Answer: In Genesis 2:9 the tree of life is at the center of Eden, and God gives Adam the mission to tend and keep it (Gen 2:15). Revelation 22:2 shows the tree of life restored in the New Jerusalem with leaves for the healing of the nations. Caring for nature today reflects the stewardship entrusted by God. — Ellen White connects Eden and the New Jerusalem in "Thoughts from the Mount of Blessing" (p.17), showing that the tree of life represents eternity in communion with God; the Adventist Church maintains the Adventist Development and Relief Agency (ADRA) with reforestation programs in Africa and Latin America.