1. fierce competition: the research in the field of biochemical wood rings involves a wide range of disciplines, attracting a large number of researchers to participate. This makes the competition in this field very fierce, and it becomes more difficult to publish high-quality SCI papers.

2. Limitation of experimental conditions: The research of biochemical wood rings usually requires complex experimental conditions and equipment, which are often only available in a few laboratories. Therefore, many researchers are limited by experimental conditions, and it is difficult to conduct high-level research.

3. High innovation requirements: SCI papers have high requirements for research and innovation, while the research in the field of biochemical wood rings is relatively mature and it is not easy to make a breakthrough. Therefore, researchers need to dig deeper and innovate on the basis of existing research in order to publish high-quality SCI papers.

4. Strict academic norms: SCI papers have strict academic norms, including the authenticity of data, the repeatability of experiments, and the accuracy of citations. These requirements are particularly important for the study of biochemical tree rings, because such research often involves complex experimental operations and data processing. Therefore, researchers need to spend more time and energy to ensure the academic standardization of papers.

5. Long review period: SCI journals usually have a long review period, especially some top journals. This is a challenge for the researchers of biochemical materials and environment, because they need to wait for the review results before they can carry out the next research work. In addition, due to fierce competition, there may be some challenges and difficulties in the review process, which will also increase the difficulty of publishing SCI papers.