1. Redwood Trees: These tall trees need deeply rooted soil and access to abundant water. A pond's shallow water and muddy bottom wouldn't support their roots.

2. Deer: Deer rely on a diverse forest floor for food and shelter. A pond ecosystem wouldn't offer the necessary vegetation or protection from predators.

3. Mountain Lions: Mountain lions are apex predators in forest ecosystems, relying on a network of prey species for food. A pond would not support the large mammal population needed to sustain a mountain lion.