Safety is a basic need of people. Studies show that people who. are continually subjected to stressful situations are more. susceptible to psychosomatic illnesses. Even though it is. possible to adapt to extreme situations over the long term, they. will place a great strain on the individual.
As dendrochronologists, we are more interested in the fusiform initials. The fusiform initials produce secondary xylem and secondary phloem (the xylem and phloem produced during secondary growth). When we study wood or tree rings, we are looking at secondary xylem.As the fusiform initials divide, they produce secondary xylem towards the inside of the cell and secondary phloem towards the outside. Therefore, the vascular cambium (where we find the fusiform initials) is considered to be bifacial.s dendrochronologists, we are more interested in the fusiform initials. The fusiform initials produce secondary xylem and secondary phloem (the xylem and phloem produced during secondary growth). When we study wood or tree rings, we are looking at secondary xylem.
In the root, the xylem (stained green-blue in the photo) are arranged. in some sort of star or cross-shape. The phloem tissue are arranged in. smaller groups in between each spike of the xylem cross-shape. Around the bundle is a special layer of cells called the endodermis. This has. a key role in getting water to the xylem vessels. Inside the endodermis is a. layer of meristem cells called the pericycle. The vascular bundles are found near the outer edge in. the stem. The xylem is found towards the inside of. each vascular bundle (see the diagram), and the. phloem towards the outside. In between the xylem and the phloem vessels there is a layer of cambium. This is a layer of meristem cells which can divide to produce more phloem or xylem. The diagram to the right (top) shows a vascular bundle in close detail. The below diagram shows a transverse section of a stem, where you can see the entire outer ring