概括
发展中国家的热带木材贸易政策往往导致不可持续的做法,而不是经济增长. 需要进行修订,以解决被压制的木材稀缺信号,并促进更好的森林管理.
科学领域:
- 环境科学 环境科学
- 林业林业 林业 林业 林业
- 经济学 经济学 经济学
背景情况:
- 热带木材贸易的特点是繁荣与衰退的出口模式.
- 这种模式往往归因于外部因素,如发达国家的需求和国际木材价格.
研究的目的:
- 调查热带木材贸易不可持续性的内部政策驱动的根源.
- 确定政策修订是否能促进经济持续增长和森林管理.
主要方法:
- 对热带国家关于木材特许权的政策进行分析.
- 审查与木材加工工业相关的政策.
主要成果:
- 热带木材贸易没有促进可持续的森林管理或工业化.
- 出口模式是由内部政策驱动的,这些政策掩盖了木材稀缺问题.
- 修改这些政策对于持续的经济增长至关重要.
结论:
- 热带木材贸易政策需要进行根本性修订,以防止不可持续的做法.
- 即使有政策变化,可持续产量林业也可能无法在国家一级实现.
相关概念视频
Sustainable Development
As the human population continues to grow and use resources, we must be mindful of our planet’s natural limits. Sustainable development provides a pathway to maintain and improve human life now while also ensuring that future generations will have the resources that they need. The long-term success of sustainability efforts rests on understanding the interplay between human actions and ecological systems.
Introduction to Wood
Wood, derived from trees, is a versatile and widely used construction material. Trees feature a trunk surrounded by a protective layer of dead bark. Beneath this outer layer lies the living bark, followed by the cambium, and then the sapwood which transitions into heartwood as it matures. At the center of the trunk is the pith. The age of a tree can be discerned by examining its growth rings, which are concentric bands visible in the trunk's cross-section.
The structural integrity of the wood...
The structural integrity of the wood...
Wood Products
Wood products encompass a broad range of materials crafted from wood strands, veneers, lumber, and even waste wood-like shreds, designed for both structural and nonstructural purposes. Various specialized wood products have been developed to enhance strength, durability, and versatility in building applications.
Glue-laminated wood, often referred to as glulam, combines multiple smaller pieces of dimensional lumber using adhesives to form a single, larger piece. Cross-laminated timber consists...
Glue-laminated wood, often referred to as glulam, combines multiple smaller pieces of dimensional lumber using adhesives to form a single, larger piece. Cross-laminated timber consists...
Softwoods and Hardwoods
Softwoods and hardwoods, derived from different types of trees, are distinguished by their leaf structures and cellular compositions, each serving unique purposes in construction and manufacturing. Softwoods come from cone-bearing trees with needle-like leaves and are predominantly composed of longitudinal cells called tracheids and a smaller proportion of radial cells known as rays. Due to their cellular structure, softwoods are commonly used in construction for structural frames, sheathing,...
Lumber
Lumber is derived from logs which are harvested, debarked, and processed into long pieces with a rectangular cross-section. The transformation of logs into lumber involves multiple steps, beginning with an automated saw that slices the log into slabs. These slabs are then transported via a conveyor belt to smaller saws, where they are cut into square-edged pieces of specific widths.
Initially, the surfaces of these lumber pieces are rough, and their dimensions may vary slightly from one end to...
Initially, the surfaces of these lumber pieces are rough, and their dimensions may vary slightly from one end to...
Structural Properties and Dimensions of Lumber
Wood's structural properties derive from fibers aligned along the tree's length, contributing significantly to its mechanical strength. Wood exhibits up to twenty times greater tensile strength along these fibers compared to across them, and generally shows better performance under compression than tension. The length of fibers varies, with hardwoods having fibers around one twenty-fifth inch long and softwoods ranging from one-eighth to one-third inch.
The strength characteristics of wood are...
The strength characteristics of wood are...

