Eutrophication of lakes. Some lakes also demonstrate the reverse process (meiotrophication), becoming less nutrient rich with time. The main difference between natural and anthropogenic eutrophication is that the natural process is very slow, occurring on geological time scales. Eutrophication is a common phenomenon in coastal waters. In contrast to freshwater systems, nitrogen is more commonly the key limiting nutrient of marine waters; thus, nitrogen levels have greater importance to understanding eutrophication problems in salt water. Estuaries tend to be naturally eutrophic because land-derived nutrients are concentrated where run-off enters a confined channel. Upwelling in coastal systems also promotes increased productivity by
Glossary of plant morphology important information about its ecology: that is, how it has adapted to its environment. Each habit indicates a different adaptive strategy. Habit is also associated with the development of the plant. As such, it may change as the plant grows and is more properly called its growth habit. In addition to shape, habit indicates plant structure; for instance, whether the plant is herbaceous or woody. Each plant commences its growth as a herbaceous plant. Plants that remain herbaceous are shorter and seasonal, dying back at the end of their growth season. Woody plants (such as trees, shrubs and woody vines