When you plant a garden, you need good dirt, seeds, water, and some kind of fertilizer, whether it be manure, compost, mulch, or granules you buy from your local nursery. Anyone who’s gardened for more than a few years knows that it’s good to fertilize your garden every so often because, eventually, the garden plants stop growing as well as they used to. This happens because the plants slowly consume nutrients in the soil that need to be replaced by some form of fertilizer. The same basic thing happens with cultivated crops regardless of whether they’re grown in fields or greenhouses – eventually, the soil nutrients are depleted and need to be replenished.
Unlike gardens and crops, wild plants lack human caretakers providing fertilizer. Wild plants have to scrounge for their soil nutrients wherever and however they can get them, and it is often the case that soil nutrients, especially nitrogen, phosphorus, and potassium, limit how fast forests, grasslands, etc. can grow. A paper in the journal Geophysical Research Letters shows that the availability of soil nutrients will probably limit how much human-emitted carbon dioxide (CO2) plants can absorb. This limit will prevent plants from absorbing as much CO2 as climate scientists have modeled, and so global warming will likely be worse than current projections. Full story »
