Lake Erie eutrophication, in which additional nitrogen and phosphorus enter the lake, will cause plant life to "run wild and multiply like crazy". Since there are fewer wetlands, which are like "Nature's kidneys" by filtering nutrients, as well as greater "channelization of waterways", nutrients in water can cause algal blooms to sprout as well as "low-oxygen dead zones" in a complex interaction of natural forces. As of the 2010s much of the phosphorus in the lake comes from fertilizer applied to no-till soybean and corn fields but washed into streams by heavy rains. The algal blooms result from growth of Microcystis, a
Plant defense against herbivory change their defenses in response to changes in nutrients. For example, if plants are grown in low-nitrogen conditions, then these plants will implement a defensive strategy composed of constitutive carbon-based defenses. If nutrient levels subsequently increase, by for example the addition of fertilizers, these carbon-based defenses will decrease. The growth rate hypothesis, also known as the "resource availability hypothesis", states that defense strategies are determined by the inherent growth rate of the plant, which is in turn determined by the resources available to the plant. A major assumption is that available resources are the limiting factor in determining the maximum