(Originais Teachy 2023) - Question Hard of Sciences

When the leaves fall from the trees, they begin to decompose on the forest floor. This decomposition process is very important for nature, as it releases nutrients that were stored in the leaves back into the soil. Fungi and bacteria play a key role in this stage of the life cycle, acting as decomposers. An experiment was conducted in a forest area where leaves from different trees were collected. Each set of leaves was placed in a separate container and kept under suitable conditions to observe decomposition. The experiment lasted several weeks and the students regularly noted the changes that occurred. At the end of the experiment, they compared the decomposition state of each set of leaves. Based on the natural cycle, the importance of decomposition, and the described experiment, what conclusion can be drawn about the role of the fungi and bacteria observed in the decomposition of leaves in the forest?

Exotic and invasive species are those that, due to human transportation, are taken to other ecosystems and end up becoming a non-native species, which can affect local biodiversity. For example, the red swamp crayfish (Procambarus clarkii) was introduced in Brazil in the mid-20th century for food production. What is the biggest risk of this species to Brazilian biodiversity?