Pine wood nematode disease is the most dangerous and devastating disease in the global forest ecosystem, known as "pine cancer and SARS in the plant world", with the rapid development of the world, the risk of pine wood nematode disease with pine and its products or packaging materials is increasing, pine wood nematode is an important quarantine pest at home and abroad.
If the wooden packaging encountered in the inspection of imported goods contains pine material, it may carry pine wood nematodes, a quarantine pest that is very harmful. Effective identification of wood packaging containing pine materials is of great significance for maintaining national biosecurity.
To identify wood packaging containing pine material, the first step is to master the relevant wood basics. Let's take a step-by-step look at the structure of wood and the difference between softwood and hardwood.
1 Botanical classification.
According to the seven main levels of biological classification (kingdom, phylum, class, order, family, genus, species), Pinus belongs to the gymnosperm phylum of the plant kingdom, and poplar belongs to the angiosperm phylum of the plant kingdom.
Gymnosperms is a phylum in the kingdom Planta, with bare ovules and uncoated seeds. The species of modern gymnosperms belong to 5 classes (Ginkgo biloba, cycads, yew, pine, and ma, and ma, and there are nearly 800 species in 71 genera and 9 orders.
Angiosperms are the highest and largest taxa in the plant kingdom, and their seeds are coated with pericarp. It is divided into dicots and monocots, with about 300,450 families and 250,000 species.
2. Growth rings (growth rings).
The layer of wooden rings formed by trees during a growth cycle is called a growth ring. For trees in temperate and cold zones, the growth ring only appears once a year, so the growth ring is also called the growth ring;For trees in the tropics, growth rings can occur several times a year, so they are generally not called growth rings, only growth rings.
3 tube holes. Catheters: The conduction tissue unique to most hardwoods, but not in coniferous wood.
Tube hole: the cross-section of the catheter unit, called the catheter groove in the longitudinal section, and the presence or absence of the tube hole is the main marker for identifying coniferous and broad-leaved wood.
4. Axial parenchyma.
Axial parenchyma structure: On the cross-section of the wood, it can be seen that some of the wood is slightly lighter than the surrounding area, more obvious after wetting with water, and can form various forms of tissue. The definition and distribution type of parenchyma are important criteria for identifying hardwood.
5 wood rays. Wood rays: light-colored lines arranged radially from the center of the pith to the outside of the wood cross-section. It is one of the important characteristics to identify hardwood.
6. Color gloss, texture, odor, hardness.
Conifers generally have a lighter color, a regular structure, a pine resin smell, less density, and a soft material.
Hardwood generally has a darker color and complex structure and pattern, different types have different odors, higher density, and hard material.
Pinus wood packaging.
Pinus wood packaging features:
Macroscopic characteristics: distinct growth rings, straight texture;It has a pine scent;The wood is softer.
Microscopic features: no tube pores, no or no obvious axial parenchyma, wood rays are not easy to identify.
High strength, strong corrosion resistance, small expansion and contraction deformation, strong and durable, wide applicability, higher than the same specification of poplar wood packaging.
Hardwood wood packaging (poplar as an example).
Hardwood wood packaging features:
Macroscopic characteristics: the growth rings are not obvious, and the texture is complex;No pine scent;The wood is harder.
Microscopic characteristics: there are tube pores, there are more developed axial parenchyma structures, and the wood rays are obvious and the thickness is different.
Representative tree species of hardwood are poplar, elm, willow, birch, etc. In China, it is more common to use poplar as a wood packaging in hardwood.
Tianjin Customs.
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