Why is it important for scientists who study ecosystems to study more than the organisms that live there?

The ecosystem is the biology community and its interaction with its physical environment in a particular area.

The scientist who want to study the ecosystem, they must study all the organism living there and the physical environment they are living in. They must study the characteristics of the organism with respect to characteristics of the environmental factors, the organism interact with. So, in order to understand an ecosystem completely, the scientist must study the abiotic factors with the organism  living there. studying organism alone would provide the characteristics of the community, not the ecosystem.

answer: tributaries flow into rivers.

wetland is a biome that develops when the water gets accumulated in a land exhibiting a huge depression. these form either seasonally or permanently. the water in the wetland comes from rivers, lakes, ocean, flood, rain or other sources. the wetlands includes mangroves, marshes and peatland.

tributaries flow into the rivers develops a wetland because such water will get deposited in the depression and will restrict the original flow of tributary water. hence, water with low drainage current combines with the river water.