10 million seeds; as volatile as dust ... This is what a single orchid plant produces. How then can we explain that we need to protect this species in our latitudes to ensure its survival?
The power of expansion of life can indeed make us dizzy.
On a single fern frond, millions of spores fly away in a year. For mushrooms, it's billions. However, undergrowth is not covered with a carpet of ferns or mushrooms...
A paramecium, a tiny aquatic protozoan, can produce offspring weighing 10,000 times the Earth in a few days. The reproductive capacity of rabbits is a known example, with a single couple of rabbits responsible for the birth of 13 million rabbits within only 3 years.
So how come the Earth isn't submerged in just a few days?
Let's take the example of the Scots pine. One tree produces 38,000 seeds every year. 20% of them are not viable from the start.
In the canopy, small proportions will be eaten by birds and other squirrels (2.7%) and others will be parasitized by insects (1.3%).
Once on the ground, 2/3 will be eaten by wildlife. The remaining 20% will germinate but most of the plantlets will encounter difficulties where they grow (drought, unsuitable soil...), when they will not be eaten in their young years (rodents, herbivores). Finally, it will be necessary to win the race for light against the neighbors.
Thus, out of the 38,000 seeds from the start, only 1 or 2 will give a tree which will reach full growth.
It is indeed necessary to rely on predation, parasitism, locally different living conditions and a whole bunch of parameters and interactions to bring these figures down to something bearable for our planet.
Finally, this abundance, which could make you dizzy at first, is a necessary effort on the part of these species to ensure simple survival, and we understand then that some of them such as orchids may need a helping hand when their success rate is even lower, or their biotopes get particularly endangered.