Cascadas tróficas en ecosistemas de marismas salinas | Video HHMI BioInteractive

What is one significant ecological service provided by salt marshes?

• Producing freshwater for human consumption.

• Filtering pollutants from water.

• Generating strong ocean currents.

• Creating deep-sea habitats.

In an ecosystem, what primarily limits plant abundance under bottom-up control?

• The number of predators in the ecosystem.

• The availability of resources like water, sunlight, and soil nutrients.

• The frequency of natural disasters.

• The presence of invasive species.

Dr. Silliman's initial understanding of salt marsh plant growth was challenged by observing what?

• A lack of available soil nutrients in the marsh.

• An unusually high number of plant diseases.

• A large abundance of snails actively consuming marsh grass.

• Severe coastal erosion impacting plant habitats.

The experiment demonstrated that removing snails from the marsh led to a significant increase in plant growth. What type of ecological control does this primarily illustrate?

• Bottom-up control, as plants had more space to grow.

• Top-down control, as herbivores were removed.

• Resource limitation, due to increased nutrient availability.

• Competitive exclusion, as other species thrived.

What was the initial observation regarding the interaction between marsh grass and snails in the salt marsh?

• Snails consumed the marsh grass, leading to its decline.

• Snails helped fertilize the marsh grass, promoting growth.

• Snails had no significant impact on the marsh grass.

• Snails were a food source for the marsh grass.

What happened to the marsh grass in areas where snails were experimentally excluded?

• The marsh grass continued to die off, forming mudflats.

• The marsh grass grew significantly and became healthy.

• The population of other herbivores increased.

• The water quality in the marsh deteriorated.

Which animal was identified as a primary predator that helps regulate the snail population in the salt marsh ecosystem?

• Fish

• Birds

• Blue crabs

• Alligators

The phenomenon where predators indirectly benefit producers by controlling herbivore populations is known as a:

• Mutualistic relationship

• Commensalistic interaction

• Trophic cascade

• Competitive exclusion principle