Paragraph on human impacts on marshes

Since the humans started settling and performing agriculture, they started to have a big impact on the marshes. People started to drain the marshes when they came to a situation to be able to perform that. This was done for multiple reasons:

- the marshes had lots of insects that were transmitting diseases, so the humans wanted to remove the danger;

- a typical marsh is in a lowland region, it is shallow, and has relatively flat floor, so humans saw an opportunity to use that land for agriculture;

- because of the shape of the floor of the marshes, the humans also saw a potential in them as places for inhabiting, were building was going to be easy because of the flat surface.

In the modern time, the marshes are also heavily impacted by pollution from multiple sources caused by the humans, and that damages their ecosystems and even totally destroys them.

step 1 ammonium can be absorbed by plants, but some is converted into nitrates which are better for plants to absorb. this is called nitrification. 2. step 2 the deer eats the plants and uses the nitrogen-containing proteins for cell growth. 3. step 3 bacteria in the soil conduct nitrogen fixation to convert nitrogen gas from the atmosphere into ammonium. 4. step 4 some of the nitrates are absorbed back into plants, but denitrification breaks down the nitrates into nitrogen gas released back into the atmosphere. 5. step 5 nitrogen is found in the urine, which gets broken down into ammonium through the process of ammonification. 6. step 6 plants absorb the ammonium and begin assimilation, the process to add the nitrogen to protein.