Scientists have noted a decline in the number of all mushroom species dating back to the early 1900s. in addition, annual crops of edible mushrooms in france and germany have declined since 1950. one hypothesis explaining the decline is that edible fungi are being overharvested. global warming and air pollution have also been considered as part of the problem. what evidence to exclude overharvesting as the cause of the overall decline?

overharvesting is the act of harvesting the produce in large quantities and at a faster rate that surpasses the rate of growth of the plant (edible fungi in this case). now the hypothesis that overharvesting of edible fungi are leading to their decline in germany and france can be checked by considering the following points:

1. how fast the fungi grow in farms and in their environment? this will give insight on the affect of other environmental factors that may affect it.

2. how the harvesting of fungi is done, does it degrade the quality of soil or affect the growth of younger generations of fungi? this will directly check for the effects of harvesting methods on the population of fungi.

3. is there any biotic factor, like disease or presence of predators that are responsible for the decline of fungi numbers? this will become the alternate hypothesis to look for.

4. are other species of non-edible fungi getting affected? this will directly counter the overharvesting hypothesis.