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How does spring mixing in deep lakes lead to rapid plankton growth?

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Common wildebeest — population ecology A herd of common wildebeest (*Connochaetes taurinus*) migrating across a dusty savanna in Africa. The animal is a keystone species (i.e., a species with a disproportionately large effect on its biological community) in plains and acacia savanna ecosystems from southeastern Africa to central Kenya.

In the context of population ecology, spring mixing—often referred to as vertical mixing or overturn—is a critical process that facilitates rapid plankton growth in deep, temperate lakes.12

During the winter, deep lakes often become thermally stratified or covered by ice, which limits the circulation of water and nutrients. Throughout this period, organic matter decomposes at the lake bottom, causing essential nutrients like phosphorus and nitrogen to accumulate in the deeper, colder layers (hypolimnion) where they are inaccessible to photosynthetic organisms at the surface.234

When the surface ice melts and the water temperature reaches a uniform density in the spring, wind action causes the lake to circulate completely. This overturn brings nutrient-rich water from the depths up to the surface layer (epilimnion). As daylight hours lengthen and solar intensity increases, the combination of these newly available nutrients and adequate sunlight triggers a rapid increase in phytoplankton reproduction, resulting in a spring bloom.1256