Groundwater-dependent ecosystems face a greater threat of pollution. In many cases groundwater can become polluted through toxins, or even just excessive amounts of certain nutrients seeping down to the water table. This polluting of the groundwater can have many different effects on the related ecosystems in the case of an estuary in Cape Cod it was noted that an influx of new nitrogen had come from septic tank fields in the groundwater’s flow path. Increased levels of nitrogen in aquatic ecosystems can cause eutrophication which is the process of excessive introduction of nutrients causing an abundance of plant growth which can result
Plant physiology gravity or sunlight, is called a tropism. A response to a nondirectional stimulus, such as temperature or humidity, is a nastic movement. Tropisms in plants are the result of differential cell growth, in which the cells on one side of the plant elongates more than those on the other side, causing the part to bend toward the side with less growth. Among the common tropisms seen in plants is phototropism, the bending of the plant toward a source of light. Phototropism allows the plant to maximize light exposure in plants which require additional light for photosynthesis, or to minimize it