Final answer:
Human infrastructure impacts spongy lakes by altering flow regimes, water chemistry, sedimentation, riparian vegetation, and contributing to the introduction of non-native species, which significantly change their aquatic environments and ecosystems.
Step-by-step explanation:
The impact of human infrastructure on spongy lakes involves a complex and sometimes contradictory suite of effects. These impacts include flow regime changes that can either increase or decrease the natural variability, water abstraction, increased sedimentation as well as sediment reduction, changes in water chemistry, drastic modifications to river channels, loss of connectivity between upstream and downstream waters, the construction of impoundments, and the removal or alteration of riparian vegetation. All of these can profoundly affect aquatic environments and their ecosystems.
Human activities linked to these changes tend to increase with human population density and affluence, which is also related to a rise in the introduction of non-native species. Such introductions often thrive in modified habitats, creating further ecological disturbances. It's important to note that while these impacts are globally significant, they are felt more acutely in developed regions. Conversely, in less developed areas, the natural environment still plays a key role in shaping species distribution and richness.
The construction and operation of reservoirs and dams for instance, alter the natural habitat by changing water temperatures, chemistry, flow patterns, and silt loads, leading to significant ecological and physical changes both upstream and downstream of the infrastructure.